Dissertations / Theses on the topic 'Quality of products'

Class of 2007 Abstract
Objectives: The purpose of this study is to assess the quality of study medications obtained without a prescription through international websites. Methods: Samples of levothyroxine, warfarin, and sildenafil were obtained through various websites and compared to U.S. standards. Each sample was physically evaluated for weight, color, shape, and external tablet markings. High performance liquid chromatography (HPLC) was performed to quantify the amount of active ingredient. Results: When physically inspected, only 3 of the 9 lots met FDA labeling requirements. Three of 60 (20 tablets from 3 lots) of the individual levothyroxine tablets were out of the USP acceptable range (90% - 110%). For warfarin, 16 of the 60 samples (20 samples from 3 lots) of the individual tablets were out of the USP acceptable range (95% - 105%). When averaged, each of the lots for both levothyroxine and warfarin were within their USP acceptable ranges. As sildenafil is not available as generic in the U.S., there is no USP standard acceptable range for comparison. All of the sildenafil samples fell within 90%- 105% of Viagra® tablets obtained from a local pharmacy. Conclusions: While there were a few samples outside of the U.S. acceptable range, the majority of samples analyzed for active ingredient were within the range published in the USP. While the outcomes of this study presented interesting findings, further evaluation in larger studies is needed to properly assess the quality of foreign medications purchased over the internet.

The food sector accounts for $1 of every $6 in the U.S. economy, with more than $700 billion in revenue every year. However, incidents of food safety and substandard quality continue to rise. Consumers are beginning to mistrust and have lower confidence in the food supply chain. Food manufacturers need to address this issue to remain profitable. One approach includes the introduction of food policy programs that allow for independent auditing and certifications such as the Safe Quality Food (SQF) certification. The SQF certification was established as a rigorous and credible benchmark for food handlers to enforce food safety and quality standards. The purpose of this qualitative case study research was to evaluate the perceived usefulness of the SQF certification to food manufacturers. Guided by the theory of diffusion of innovation, data collection for this study included 35 stakeholder semistructured interviews and a review of 5 publicly available documents for triangulation. Thematic analysis of the transcripts was performed to generate answers to the research questions. Study findings revealed that if properly implemented, the SQF certification is a credible and robust GFSI scheme that provides effective guidelines for food production. Findings also revealed 2 opportunities for improvement. Participants noted that training programs for SQF practitioners and auditors should be improved, likewise more commitment and involvement of facility management should be required. The findings may contribute to social change by providing food producers with strategies to minimize food production failures. With the perceived benefits of the SQF certification, other food producers who have not adopted this scheme can benefit from this holistic certification to enhance their food production network.

University of Central Florida College of Engineering Thesis
The quality movement has become popular among corporations big and small for one reason: empirical evidence suggests that quality and productivity (and hence profitability) are linked. Unfortunately, while many firms accept that quality and productivity go together, few actually track the gains associated with their quality improvement programs. Companies also tend to spend on quality improvement with no indication of estimation of the impact of funding on the targeted process. It would be of great value to know: (1) the impact of spending to enhance the product/process quality level, and (2) the point at which expenditures for quality improvement are not economical. This research involves modeling the quality level of a product composed of integrated components/processes and the costs associated with quality improvement. Presented in this research is a methodology for determining the point at which the target quality level is reached. This point signifies when future spending should be re-directed. The research defines this point as the "Crash Quality Point (CQP)." Cases of a single process level and double level three-stage process are modeled to conceptualize CQP. The finding from the output analysis reveal that the quality level appoaches the target level at varying points in time. Any spending beyond this point does not have an impact on the quality level compared to the period prior to the Crash Quality Point. Spending past this point is futile and these funds could be spent on othe quality improvement projects. The special case modeled also illustrates the use of this tool in the selection of processes for improvements based on the quality level of the process. This is an added advantage in scenarios where funds are limited and management is constrained to improve process quality with limited funds. Using a real world example validates the proposed CQP methodology. The results of the validation indicate that the model developed can assist managers in forecasting the budget requirements for quality spending based on the quality improvement goals. The tool also enables managers to estimate the point in time at which allocations of funds may be directed for process reengineering. The CQP method will enable quality improvement professionals to determine the economical viability and the limits in expenditures on quality improvement. It enables managers to evaluate spending alternatives and approximate when the point of diminishing return is reached.
Ph.D.;
Engineering;
Industrial Engineering Management Systems;
154 p.
xiii, 154 leaves, bound : ill., (some col.) ; 28 cm.

The purpose of this research is to learn about quality measurement practices in a wood products supply chain. According to the Supply Chain Management paradigm, companies no longer compete as individual entities, but as part of complex networks of suppliers and customers, linked together by flows of materials and information. Evidence suggests that a high degree of integration between supply chain members is essential to achieve superior market and financial performance. This study investigates the potential benefits from adopting supply chain quality management practices, focusing specifically on quality measurement. A case-study was conducted to accomplish the objectives of the research. An exemplary wood products supply chain was studied in great detail. The current state was compared with best practices, as reported in the literature. Supply chain quality metrics were used to assess current performance and a simulation model was developed to estimate the impact of changes in significant factors affecting quality, such as production volume, on the supply chainâ s quality performance. Quality measurement practices in the supply chain of study are described in detail in this dissertation. A high degree of internal integration was observed in the focal company, attributed in great part to the leadership of management, which formulates comprehensive quality planning, specifying quality measurement practices and goals. These practices provide the company with a competitive advantage, and have undoubtedly contributed to its relatively strong market share and financial performance. Significant improvements in defect rate and on-time performance at all levels in the supply chain have been achieved in great part thanks to current initiatives. There is room for improvement, however, regarding external integration; the supply chain of study could benefit from more information sharing with its external suppliers and increasing its supplier development efforts. There is also a lack of true measures of supply chain quality performance that could facilitate tracing variances back to their origin upstream the supply chain. Supply chain metrics must reflect the contribution of each supply chain member to the overall performance, and span the entire supply chain. This is the first study that looks in depth at quality measurement practices from a supply chain perspective. It is also one of very few studies of supply chain management applied to the wood products industry. Examples are presented of how a supply chain performance measurement system can be developed. Results from this research show that it is important to adopt a supply chain perspective when designing a performance measurement system, not least to avoid sub-optimization. Poor quality at any point in the supply chain eventually translates into higher prices for the final customer, is detrimental to customer dissatisfaction, and hurts profitability; with the end result of declining competitiveness of the entire system.
Ph. D.

In many business sectors today, the focus on quality as a competitive tool is being replaced by a focus on innovation. Research exploring connections between quality management, innovation, and company performance suggests that quality is 'necessary but insufficient' in today's business environment. In short, the question facing managers, particularly those in small firms, is how to adapt their quality management practices to achieve innovation performance in addition to quality performance. To answer this question, West Coast U.S. forest products manufacturers were surveyed about quality management practices and performance with respect to both quality and innovation. Quality management practices were assessed following the systems perspective articulated by the Malcolm Baldrige National Quality Award. Data envelopment analysis was used to identify companies efficiently using quality management practices to lead to quality and/or innovation performance. Survey responses from the efficient firms were then analyzed via cluster analysis to identify two categories of firms: those achieving primarily quality outcomes and those achieving both quality and innovation outcomes. Executives from two firms in each category were interviewed to provide detail on the management practices used by the companies. Interview transcripts were examined to identify similarities and differences in practices between the two categories of firms. Results suggest several specific areas of focus for firms wanting to adapt their quality management practices to achieve both quality and innovation performance. For example, firms focused on innovation proactively seek to identify and meet customers' needs whereas quality-focused firms primarily emphasize reacting to customer complaints. More specifically with respect to 'customer focus', firms focused on innovation emphasize convenience for their customers through practices such as standardizing product lines and providing product specifications on their websites. In contrast, neither quality-focused firm had a website. These firms were at their production capacity (at least prior to the recession) and viewed websites strictly as a means to attract new business rather than as a service to existing customers. Also with regards to customer focus, firms focused on innovation sought to generate new business - not just for their company, but for their customers as well. Beyond customer focus, firms focused on innovation provide employees with opportunities to help the organization implement changes. With respect to benchmarking, firms focused on innovation actively sought to measure their performance against the 'best practice' in the industry; firms focused primarily on quality performance demonstrated little if any emphasis on benchmarking. Finally, there were apparent overarching and hence cultural differences between the two categories of firms - firms focused on innovation were more proactive, strategic, and willing to take risk; in addition, these firms discussed innovation as the means to improve product quality, reduce costs, or attract new customers. By contrast, the quality-focused firms were reactive, conservative, and risk-averse; these firms discussed innovation primarily as 'technology' without reference to potential linkages to company performance.

Thesis (MSc)--Stellenbosch University, 2008.
ENGLISH ABSTRACT: The objectives of this study were threefold: (i) to investigate the effect of the replacement of pork fat with olive oil on the physico-chemical and sensory characteristics of ostrich polony; (ii) to investigate the effect of replacement of sodium tri-polyphosphate (STPP) with iota-carrageenan (CGN) on the physico-chemical and sensory characteristics of restructured cooked ostrich ham; and (iii) to investigate the effect of salt (NaCl) reduction on the physico-chemical and sensory characteristics of ostrich bacon. Five levels of olive oil were added to a polony formulation in 5% increments from 0 to 20%. Hardness, gumminess and shear force values decreased (P≤0.05) with increased levels of olive oil. The L* and b* values decreased (P≤0.05) with increased levels of olive oil producing lighter and more yellow products. Ostrich polony proved to have a favourable fatty acid profile in line with international recommended standards. A trained sensory panel found that the effect of increased levels of olive oil on had an effect (P≤0.05) on the sensory characteristics of colour; processed meat aroma and flavour; ostrich aroma; olive oil aroma; firmness and juiciness. A consumer panel found all the olive oil treatments to be acceptable. It can be concluded that olive oil can be used successfully for the production of low fat ostrich meat polony. In a restructured ostrich ham five decreasing levels of phosphate (0.7, 0.53, 0.35, 0.18 and 0%) were substituted with five increasing levels of carrageenan (0, 0.1, 0.2, 0.3 and 0.4%). The cooked yield of the restructured ostrich ham decreased significantly (P≤0.05) with decreased levels of phosphate. No tendencies in instrumental colour measurements with relation to decreased levels of phosphate were revealed. Hardness, cohesiveness and gumminess increased with decreased levels of phosphate. Ostrich ham had a favourable fatty acid profile and the latter is in line with international recommended standards. The trained sensory panel found that decreased levels of phosphate had a significant effect on the ham sensory characteristics of meat aroma and flavour; ostrich meat aroma and flavour and mealiness, but no significant effect on the spicy aroma and flavour. Three ham treatments with different levels of phosphate (0.7, 0.35 and 0%) were presented to a consumer panel. The consumer panel found the ham treatments with levels of 0.7 and 0.35% most acceptable. Carrageenan can be used to substitute phosphate at a level of 0.35% phosphate and 0.2% carrageenan in ostrich ham. Ostrich bacon was produces with five targeted salt (NaCl) levels of 3.5, 2.75, 2.0, 1.25, and 0.5%. Decreased salt levels had no significant effect on the L*, a* and b* values of the five treatments. Ostrich bacon had a favourible fatty acid profile. A trained sensory panel found that the effect of increased levels of salt had a significant effect on bacon sensory characteristics of ostrich aroma and flavour smoky bacon aroma and flavour and saltiness. A consumer panel found all the bacon treatments acceptable, with 2.75 and 2.0% being most likable. It can be concluded that, from a technical point of view, the salt content in ostrich bacon can be reduced successfully to produce ostrich bacon with low salt levels, although consumer preference for salt remains high.
AFRIKAANSE OPSOMMING: Die doelstellings van hierdie studie was drievoudig: (i) om die effek van die vervanging van varkvet met olyfolie op die fisiko-chemiese en sensoriese eienskappe van volstruispolonie te bestudeer; (ii) om die effek van die vervanging van natriumtripolifosfaat met iotakarrageenan op die fisikochemiese en sonsoriese eienskappe op die van hergestruktureerde volstruisham te bestudeer; en (iii) om die effek van sout (NaCl) vermindering op die fisiko-chemiese en sensoriese eienskappe van volstruisspek te bestudeer. Die polonie behandelings het uit vyf vlakke olyfolie bestaan wat by die polonie formulasie in 5% inkremente 0% tot 20% gevoeg is. Hardheid, taaiheid en skeurkrag het afgeneem (P≤0.05) met verhoogde vlakke van olyfolie. Die L*- en b*-waardes het afgeneem (P≤0.05) met verhoogde vlakke van olyfolie en uiteibdelik ‘n ligter en geler produk geproduseer. Die betrokke volstruispolonie behandelings het ‘n gunstige vetsuurprofiel wat in lyn is met internasionale aanbevole standaarde. ‘n Opgeleide sensoriese paneel het gevind dat die verhoogde vlakke van olyfolie ‘n betekenisvolle (P≤0.05) effek het op die kleur, geprossesseerde vleisgeur en -aroma, volstruis aroma, olyfolie aroma, fermheid en sappigheid. ‘n Verbruikerspaneel het gevind dat al vyf polonie behandelings aanvaarbaar is. Olyfolie kan dus suksesvol gebruik word in die produksie van laevet volstruispolonie. Hergestruktureerde volstruisham het bestaan uit vyf afnemende fosfaat vlakke (0.7, 0.53, 0.35, 0.18 and 0%) en vyf toenemende vlakke van karrageenan (0, 0.1, 0.2, 0.3 and 0.4%). Die opbrengs van gaar hergestruktureerde volstruisham het afgeneem (P≤0.05) met verlaagde vlakke van fosfaat. Geen betekenisvolle patroon is in instrumentele kleurmeting gevind nie. Hardheid, binding en taaiheid het toegeneem met afnemende fosfaat vlakke. Daar is bewys dat volstruisham ‘n gunstige vetsuurprofiel het wat in lyn is met internasionale aanbevole standaarde het. ‘n Opgeleide sensoriese paneel het gevind dat afnemende fosfaatvlakke ‘n betekenisvolle effek op die sensoriese eienskappe van volstruisvleis geur en aroma asook melerigheid, maar geen betekenisvolle effek op die speserygeur en -aroma gehad nie. Drie behandelings met verskillende fosfaat vlakke (0.7, 0.35 and 0%) is deur ‘n verbruikerspaneel vir aanvaaraarheid getoets. Die verbruikerspaneel het gevind dat die behandelings met 0.7 en 0.35% fosfaat aanvaarbaar was. Karrageenan kan dus gebruik word om fosfaat te vervang by ‘n vlak van 0.35% fosfaat en 0.2% karrageenan in volstruisham. Volstruisspek is geproduseet met vyf soutvlakke (NaCl), nl 3.5, 2.75, 2.0, 1.25 en 0.5%. Verlaagde soutvlakke het geen beteknisvolle effek op die L*-, a*- en b*-waardes van die vyf behandelings gehad nie. Volstruisspek het ook ‘n besonder gunstige vetsuurprofiel. ‘n Opgeleide sensoriese paneel het gevind dat die effek van verhoogde soutvlakke ‘n betekenisvolle effek het op die volgende sensoriese eienskappe: geur en aroma van volstruisvleis; geur en aroma van gerookte spek; en southeid. ‘n Verbruikerspaneel het gevind dat al die behandelings aanvaarbaar was, met die monsters met 2.75 and 2.0% sout as mees aanvaarbaar. In opsomming, die soutinhoud van volstruisspek kan uit ‘n tegniese oogpunt suksesvol verlaag word om ‘n produk met ‘n laer soutinhoud te produseer, alhoewel verbruikersvoorkeur vir sout hoog bly.

Current models of quality in the marketing discipline tend to have a producer orientation. Influences on quality outside the control of the firm, such as consumer perceptions or needs, are only addressed in a rudimentary manner. While quality is acknowledged as being determined by the consumer and akin to an attitude, ironically, literature on quality is not well grounded in relevant theory from psychology and related disciplines. This thesis presents an exploration of quality and its meaning within the context of assessing scholarly marketing articles. The objective of the study is to develop a new consumer- oriented model of quality to enhance understanding of the construct, enabling marketers to better influence consumers� assessment of quality. The academic marketplace involves articulate and experienced producers, channel members and consumers. An investigation of quality within the context of marketing�s scholarly articles therefore provides rich material for refining the quality construct. The first stage of the research addressed two research questions related to scholarly articles: RQ1: What intrinsic factors (article attributes) influence quality assessments? RQ2: What extrinsic factors (external to the article) influence quality assessments? The components of quality in scholarly articles were drawn from several sources: literature sources; journal editorial policies; key informant interviews; and analysis of the content and editorial boards of the top journals. Overall, results suggested a connection between consumers� assessments of quality and factors such as their belief structures, reference group norms, and consumption context. The empirical findings led to further investigation through literature analysis. Theories from psychology helped to explain the interplay of beliefs, attitudes and perceptions in quality assessments and suggest consumer characteristics (such as the rigidity of mental sets, or novelty seeking behaviour) that influence that interplay. On a theoretical level, the new quality model integrates theories of psychology with product-oriented aspects providing a multifaceted view of the quality construct. This is achieved by using the Theory of Planned Behaviour as the central framework, providing a robust depiction of quality assessment from a consumer perspective. Elements of quality from managerial models, such as product attributes and company image, are found to fit logically into the new structure. The new model also reveals connections with the philosophy and sociology of science and provides an enhanced understanding of the workings of academia and the dissemination of scholarly knowledge. There has previously been no comprehensive study of quality in academic articles, therefore on a practical level the model of quality supports authors in producing improved manuscripts, thus enabling faster review and dissemination of research within the discipline. Further research to refine and test the model is recommended.

Aim: The aim of this study is to examine and compare the importance of services and products in grocery store and to study the effects of services and products on customer retention. Method: This study is quantitative and data is collected by conducting a survey. Primary data is collected through questionnaires by visiting the stores in two cities of Sweden, namely Bollnäs and Gävle. In order to study the importance of service and products, importance scale is used in the questionnaire. Comparative analysis is used to analyze the data. Results & Conclusions: The results show that customers are more concerned about the quality of products rather than quality of services. Further, it is found that among all service elements, personal interaction is considered more important whereas, among products elements, quality of products has most influence on customer decisions. After the comparison of services and products, we found out that product quality influences customer retention to a greater extent. Suggestions for future research: Research always continues and could be followed up with more perception dimensions either from customers’ perspectives or from managerial perspectives. Future research can be conducted to study managerial perception of service and product quality. Furthermore, future research can be conducted to find out other factors that determine customer retention. Customers from multiple stores and larger cities can also be the theme for future researches. Contribution of the study: This study helps retail business to build strong customer base by focusing first on quality of products and then services. Further this helps firms to know how customer’s decision making is affected. Firms with limited resources can first focus on product improvement then on services.

Tendencies in product development of today make it likely that many future products will be functional equivalent and therefore hard to distinguish between for the customer. Customers will decide by highly subjective criteria which product to purchase. One task for product development in this context is to be able to capture the customer’s considerations and feelings of products and translate these emotional aspects into concrete product design.

Today a number of different methods, such as Quality Function Deployment (QFD), Semantical Environment Description (SMB), Conjoint Analysis and Kansei Engineering exist and are used in practical applications.

The purpose of this thesis is to understand and apply Kansei Engineering methodology and explore ways to integrate the methodology into an industrial product development process.

This was done by conducting a study on forklift trucks in different European countries and business areas and by exploring ways of integrating Kansei Engineering in product development processes.

The number of Kansei words collected was reduced based on the result of a pilot study using a combination of different tools. A computerized data collection method was used in combination with a modified VAS-scale in order to reduce the time for filling out the evaluation forms The results of the study in the visited Northern and Middle European companies make it evident that Kansei Engineering has to be adapted in several aspects to the circumstances in each situation. The data showed that there are differences in attitude towards reach trucks in the different European countries. These results were used in order to adapt the product requirements for each specific country. Starting at Cooper’s stage gate model Kansei Engineering was applied on a macro level, a micro level and for verifying purpose. Using QFD, Kansei Engineering helps to identify customer needs their importance and the technical responses as well as to conduct benchmarking and to connect the customer needs mathematically to the technical responses.

This study of Kansei Engineering revealed that there was no general model on the methodology available in English literature. Outgoing from a previous flowchart, a conceptual framework of Kansei Engineering was developed integrating the existing Kansei Engineering Types and future tools.

ISRN/Report code: LiU-Tek-Lic 2002:19

In drug, medical, and consumer products businesses, leaders should establish strategies that ensure production of quality products and drive profitability. Sales of defective or substandard products carry a potential risk of unintended effects on the consumer. The purpose of this single case study was to explore the strategies used by leaders to influence a culture of quality and compliance, leading to production of saleable products, and business profitability. The conceptual framework of the theory of constraints served to guide the scope and data analysis for this study. Participants included ten individuals with a minimum of 5 years of experience at the study company, based in the northeast region of the U.S., in director, manager, and technical leader roles who participated in individual, telephone-based interviews. Additional data sources for methodological triangulation included observations during a tour of the headquarters site, and analysis of policies, procedures, annual reports, and publicly available information. Data analysis included coding of the data and analysis to identify themes and patterns that identify the strategies leaders use to embed a culture of quality. The emergent themes in this study included: leadership, culture and habits, communications, and management systems and data analysis. The findings of this study may contribute to positive social change and improved business practice by providing tools and skills needed by business leaders to ensure product quality and business success. By consistently delivering quality products to the market, the organization builds a sustainable business where the community can benefit from a stable supply of jobs and the consumer from a reliable supply of products that safely meet customer needs.

Recent years there has been a large increase in the worldwide sales of cultured products containing probiotics. The obstacle in the production of fermented products incubated with probiotic strains is its effect on sensory, chemical and physical properties. This Master´s Thesis investigates how extended storage times in fermentation tank as well as buffer tank during production of probiotic yoghurts affect final product quality. Through experimental studies, maximum storage times for probiotic yoghurts were to be recommended. The study includes analyses of pH, viscosity, stability, acetic acid concentration, microbial viability and sensory evaluations.

Design of experiments (DOE) was used to construct a 3²-factorial design for the experiment where different storage times were tested. The analyses showed that:

• pH decreases with both storage time in fermentation tank and buffer tank.
• Viscosity increases with long storage times in fermentation tank, while it decreases with long storage times in buffer tanks.
• Many samples had a sandy/grainy and slimy texture which could be related to high levels of Bifidobacteria or high fermentation temperatures.
• High levels of acetic acid was found in all samples.
• All measurements data where within the specification limits, whereas no recommendation for maximum storage times during production could be given.

In the present study the effects of characteristic freezing times and storage time at -22°C on the quality of the adductor muscle of post-rigor scallops (Pecten maximus)and gilthead seabream fillets (Sparusa urata) were studied in regard to the integrity of muscle structure, myofibrillar protein denaturation and aggregation, lipid degradation, texture and sensory changes. This information would be useful for achieving optimal conditions for freezing these species and assessing their quality during frozen storage for commercial purposes. Scallop muscles and gilthead seabream fillets were frozen individually with characteristic freezing times that can be met in commercial practice of freezing seafoods. After freezing, the samples were thawed and their quality was evaluated. Fresh samples were analyzed as controls. Intermediate characteristic freezing times (i. e. 89 and 49 minutes for scallop muscles and 74 minutes for gilthead seabream fillets) caused more damage to cell structure of both species than the shorter and longer characteristic freezing times tested. Short characteristic freezing times (i. e. 19 minutes for scallop muscles, and 2 and 18 minutes for gilthead seabream fillets) reduced the thawing losses of both species compared to the longer characteristic freezing times (. e. 235 to 1000 minutes for scallop muscles, and 640 minutes for gilthead seabream fillets) tested. Freezing at short characteristic freezing times produced raw fillets similar in texture to the fresh fillets. Therefore, short characteristic freezing times (equal to or less than 19 minutes) are beneficial for freezing both species. Scallop muscles and gilthead seabream fillets were kept frozen for up to 301 and 340 days, respectively. Sampling was carried out at regular intervals on fresh and stored frozen samples. Storage time affected the integrity of infra-cellular organelles, reduced the water holding capacity, caused structural changes to myofibrillar proteins and affected the sensory attributes of both species. Frozen scallop muscles were in acceptable eating condition after a storage period of ten months, with most of the changes in bio-chemical and physical properties being pronounced after three months of storage. Based on the changes in taste scores versus storage time, it was assessed that the practical storage life of frozen gilthead seabream fillets was circa 5 to 6 months Cat+-ATPase activities for scallop muscles and a linear model that combines free fatty acids, peroxide values and protein content in centrifugal tissue fluids for gilthead seabream fillets, may be reliable methods for industry to use for assessing their quality during long term storage at -22°C.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico
The mangrove crab, Ucides cordatus is one of the most shellfish produced in Brazil, but his consumption becomes scarce during closed season. This study aimed development of freezedried products of the mangrove crab stored at ambient temperature and analyze the effect of lyophilization in relation to physicalchemical, microbiological, nutritional and sensory characteristics. Two products were developed: a "freeze-dried crab meat" and "freeze-dried crab cone". The product quality was evaluated through sensory tests, microbiological, TBARS, water activity, water holding capacity, centesimal composition, nutritional value, fatty acids content, and amino acid profile of volatile compounds. The best formulation of the "freeze-dried crab cone", acceptance by the tasters, corresponded to that contained only crab meat and dehydrated condiments. The lyophilized products were stored in two different packages (laminated polyethylene terephthalate) in the period 0 to 120 days of storage at ambient temperature. Both products did not suffer microbiological and sensory changes during this period, occurring only a slight increase in water activity and moisture. As to biochemical characteristics, freeze-dried products showed all essential amino acids in quantities greater than those recommended by FAO. In the freeze-dried products was higher concentration of fatty acids when compared to the fresh beef. The volatile compounds were detected in highest concentrations after rehydration of the product in heated water (Â 100 Â C), mainly in relation to groups of aldehydes (hexanal and pentanal) and alcohol (2-methyl-3- phenyl-propanal and 3,7-dimethyl-1,6-octadien-3-ol). In general, the total volatile compounds were lowered after 240 days of storage at ambient temperature. Therefore, with this research was observed the feasibility of developing lyophilized products ("land crab freeze-dried meat" and "freeze-dried crab cone") the basis of land crab meat can be stored at ambient temperature with sensory attributes, physicalchemical and microbiological characteristics acceptable.
O caranguejo-uÃÃ, Ucides cordatus à um dos crustÃceos mais produzido no Brasil, porÃm o seu consumo torna-se escasso no perÃodo do defeso da espÃcie. Desta forma, o objetivo deste trabalho foi o desenvolvimento de produtos liofilizados do caranguejo-uÃa armazenados à temperatura ambiente e analisar o efeito da liofilizaÃÃo em relaÃÃo Ãs caracterÃsticas fÃsicoquÃmicas, microbiolÃgicas, nutricionais e a sensoriais. Foram desenvolvidos dois produtos: a âcarne de caranguejo liofilizadaâ e âcasquinha de caranguejo liofilizadaâ. A qualidade dos produtos foi avaliada, atravÃs de anÃlises sensoriais, microbiolÃgicas, TBARS, atividade de Ãgua, capacidade de retenÃÃo de Ãgua, composiÃÃo centesimal, valor nutricional, teor de Ãcidos graxos, perfil de aminoÃcidos e dos compostos volÃteis. A formulaÃÃo da âcasquinha de caranguejo liofilizadaâ de melhor aceitaÃÃo pelos degustadores correspondeu Ãquela que continha somente carne de caranguejo e condimentos desidratados. Os produtos liofilizados foram acondicionados em dois tipos de embalagens (laminada e tereftalato de polietileno) no perÃodo de 0 a 120 dias de armazenamento à temperatura ambiente. Ambos os produtos, nÃo sofreram alteraÃÃes microbiolÃgicas e sensoriais, neste perÃodo, ocorrendo apenas um leve aumento da atividade de Ãgua e umidade. Quanto Ãs caracterÃsticas bioquÃmicas, os produtos liofilizados apresentaram todos os aminoÃcidos essenciais em quantidades superiores Ãs recomendadas pela FAO. Nos produtos liofilizados houve maior concentraÃÃo dos Ãcidos graxos quando comparados com a carne in natura. Os compostos volÃteis foram detectados em maiores concentraÃÃes apÃs a reidrataÃÃo dos produtos, em Ãgua aquecida (Â100 ÂC), principalmente, no que se refere aos grupos dos aldeÃdos (hexanal e pentanal) e alcoÃis (2- metil-3-fenil-propanal e 3,7-dimetil-1,6-octadien-3-ol). De modo geral, o total dos compostos volÃteis foi reduzido apÃs 240 dias de armazenagem à temperatura ambiente. Portanto, com essa pesquisa observou-se a viabilidade de desenvolver produtos liofilizados (âcarne de caranguejo-uÃà liofilizadaâ e uma âcasquinha de caranguejo liofilizadaâ) a base de carne de caranguejo-uÃà que podem ser estocados a em temperatura ambiente com caracterÃsticas sensÃrias, fÃsico-quimica e microbiolÃgica aceitÃveis.

Seafood products are a common consumer choice and a variety of cooking methods are used in seafood preparation. Although often cooked, products such as shrimp and salmon remain some of the most common carriers of foodborne disease. Cooking these products at elevated temperatures efficiently reduces foodborne disease causing pathogens to a safe level, but applying too much heat to seafood products can produce an overcooked, low quality food. It is necessary to investigate the cooking processes used in seafood preparation and establish appropriate consumer cooking parameters that optimize both the quality and microbial safety of the products. To achieve these goals, this study develops mathematical models for the inactivation of Salmonella sp., change in quality attributes, and the product heating profiles during the cooking process for shrimp and Atlantic salmon.

Studies were performed to monitor the product heating profile during the baking and boiling of shrimp and the baking and pan-frying of salmon. Product color, texture, moisture content, mass loss, and pressed juice were evaluated during the cooking processes as the products reached the internal temperature recommended by the FDA. Studies were also performed on the inactivation of Salmonella cocktails in homogenized and non-homogenized shrimp and salmon. To effectively predict inactivation during cooking, the Bigelow, Fermi distribution, and Weibull distribution models were applied to the homogenized data. Minimum cooking temperatures necessary to destroy Salmonella sp. in shrimp and salmon were also determined. The heating profiles of the two products were modeled using the finite difference method. Temperature data directly from the modeled heating profiles was then used in the kinetic modeling of quality change and Salmonella inactivation during cooking.

It was concluded that consumers need to judge the doneness of both shrimp and Atlantic salmon by the lightness factor (CIE L*) of the core region of both products. The core regionâ s lightness factor, which a consumer may consider as opaqueness, more accurately represented the thermal doneness than the external qualities. The FDAâ s current recommendations for a 3 log reduction for intact seafood products and homogenized seafood products were each analyzed. Results were in agreement with the recommended 68°C plus 15 seconds for homogenized products. For intact products, shrimp inactivation results were in agreement with the recommended 63°C plus 15 seconds, but intact salmon achieved only a 2 log reduction by the temperature-time combination.

It was also found that predictive models can effectively describe the survival data for two Salmonella cocktails. The Weibull distribution model, which takes into account any tailing effect in survival data, fit the survival data of Salmonella in shrimp acceptably. The Fermi distribution model, which incorporates any shouldering effect in data, was an acceptable fit for the inactivation data for salmon.

Using three-dimensional slab geometry for salmon fillets and two-dimensional frustum cone geometry for shrimp resulted in acceptable model predictions of thermal distributions for the cooking methods studied. The temperature data attained directly from the modeled heating profiles was effectively used in the predictive quality and inactivation models. Agreeable first-order kinetic models were formulated for Î L and Î C color parameters in shrimp and salmon. Other kinetic models formulated were for texture change in salmon and pressed juice in both salmon and shrimp. Using a fixed inactivation level of 3 logs and a fixed quality of 95% best quality, optimal cooking conditions were determined that both provide a high quality product and assure microbial safety. Based on the specific cooking methods in this study, the optimal boiling times for extra jumbo and colossal sized shrimp were 100 seconds and 159 seconds, respectfully. The optimal oven baking times were 233 seconds for extra jumbo shrimp and 378 seconds for colossal shrimp. For Atlantic salmon, the optimal oven baking time was 1132 seconds and the optimal pan frying time was 399 seconds.
Master of Science

Le attività condotte nella presente tesi di dottorato hanno inteso individuare strumenti, tali da consentire un più agevole sviluppo di strategie “verdi” per il controllo di microrganismi indesiderati nei prodotti alimentari. Negli ultimi due decenni, molta attenzione è stata, infatti, focalizzata sulle "strategie verdi" che utilizzando microrganismi o composti antimicrobici possono assicurare l'estensione della shelf-life ed il controllo di microrganismi sempre più pericolosi come Listeria monocytogenes. Finora, sono stati sviluppati diversi processi di screening per selezionare ceppi più efficaci ed appropriati da utilizzare come culture protettive. Lactobacillus plantarum è sicuramente la specie più versatile e diffusa e produttore di acido 3-fenil-lattico, il quale sembra essere uno dei composti bio-conservanti più efficaci ed interessanti. Tuttavia, detti programmi di screening sono piuttosto laboriosi e spesso necessitano di valutare un gran numero di ceppi, isolati da diverse matrici alimentari. Pertanto, sono necessari investimenti particolarmente costosi al fine di evitare risultati insoddisfacenti. Inoltre, fino ad oggi, la concentrazione minima inibitoria, la stabilità dei composti antimicrobici, la conoscenza del modo d'azione, nonché la relazione tra la crescita microbica e la cinetica di formazione dei composti, non sono del tutto noti. È necessario, dunque, un approccio più semplificato ed utile per la selezione di nuovi ceppi protettivi, tenendo conto che le condizioni di stress alimentare possono influenzare fortemente lo sviluppo di specifici ceppi microbici. Sarebbe, quindi, estremamente interessante accertare l'effetto di diversi ambienti d’isolamento sulla selezione di ceppi in grado di esercitare attività antimicrobiche. Tuttavia, la correlazione tra la resistenza del ceppo alle condizioni di stress e la capacità di produrre effetti antimicrobici è stata poco studiata. Pertanto, attraverso le azioni previste dal progetto di dottorato è stata preliminarmente valutata la correlazione tra i ceppi di Lb. plantarum isolati da ambienti ostili e la capacità di assicurare un'azione inibitoria contro microrganismi indesiderati, nonché la correlazione tra matrice di isolamento e la capacità di questi ceppi di produrre un composto antimicrobico specifico (acido 3-fenillactico). I risultati oltre a confermare che la capacità di produrre PLA sia un carattere ceppo-dipendente hanno evidenziato una chiara relazione tra i ceppi produttori di PLA e le caratteristiche chimico-fisiche della matrice di isolamento. In dettaglio, matrici caratterizzate da caratteristiche chimico fisiche più restrittive (alti livelli di etanolo o di zucchero e bassi valori di pH), come il vino o il miele, permettono l’isolamento di ceppi con maggiori proprietà antagonistiche rispetto ad altre matrici fermentate, come formaggi, impasti acidi o insaccati fermentati. Sulla base di tali risultati sono stati valutati gli effetti della fase di crescita e delle condizioni di coltivazione sulla formazione di acido 3-fenil-lactico (PLA) prodotto da Lb. plantarum. Infatti, l’incremento ed il miglioramento della formazione di PLA rappresenta un argomento molto attuale e cruciale per assicurare una maggiore produzione di PLA nell'industria alimentare. La formazione di PLA potrebbe essere legata a meccanismi di risposta allo stress messi in atto da Lb. plantarum. Tuttavia, non sono disponibili informazioni sulla relazione tra la risposta dello stress dei LAB e la produzione di PLA, così come sono riportate poche informazioni sulla relazione tra la fase di crescita microbica e la formazione di PLA. La comunità scientifica ritiene che la formazione di PLA sia correlata all'arresto della crescita de LAB, tuttavia, non sono state spiegate le vie metaboliche coinvolte in tale produzione in fase stazionaria. Inoltre, poche informazioni sono riportate sulla condizione ottimale di pH del metabolismo di produzione del PLA nelle specie di Lactobacillus. Anche in tal caso sono emersi risultati fortemente innovativi. In dettaglio, l’accumulo nelle prime ore della fase esponenziale evidenzia, infatti, un comportamento tipico di un metabolita primario. D’altra parte, la più alta quantità prodotta tra la fase esponenziale e la fase stazionaria, suggerisce che la produzione di PLA potrebbe assumere un ruolo importante nella risposta allo stress acido. Dal presente studio è emerso, infatti, che un pH sub-ottimale (pH 4,0), migliora la formazione di PLA da parte di uno specifico ceppo di Lb. plantarum. Infine, è stato studiato il meccanismo anti-Listeria dell'acido 3-fenil-lattico. A tal fine, l'effetto antimicrobico del PLA è stato valutato a differenti valori di pH e l’attività anti-Listeria del PLA è stata confrontata con quella espressa dall'acido lattico e dagli acidi idrossibenzoici e idrossicinnamici, meglio studiati. I risultati ottenuti hanno evidenziato che il PLA esplica una spiccata attività antimicrobica nei confronti di Listeria innocua. L’attività anti-Listeria del PLA, ha dimostrato di essere pH dipendente, evidenziando un comportamento tipico di altri acidi deboli e acidi organici. È possibile ipotizzare che la modalità di azione del PLA sia correlata alla sua forma indissociata, la quale è in grado di attraversare la membrana microbica ed esplicare un maggiore effetto antimicrobico. L' azione antimicrobica del PLA è risultata sostanzialmente diversa da quella esplicata dell’acido lattico. L’effetto nettamente differente e più efficace del PLA potrebbe essere legato alle sue proprietà anfifiliche, conferitegli dall'anello benzoico idrofobo, e al gruppo carbossilico idrofilo presenti nella sua struttura chimica. Queste sue proprietà permetterebbero un'interazione con le molecole lipidiche e le proteine della membrana citoplasmatica ed un’interazione con il materiale genomico. Dal confronto con altri composti fenolici, i risultati evidenziano che l’attività anti-Listeria del PLA, viene attuata attraverso un meccanismo specifico, alquanto diverso da quello impiegato dagli altri composti fenolici. Gli acidi idrossicinnamici e l’acido idrossibenzoico sembrano indurre un'alterazione nella permeabilità della membrana senza causarne la rottura. Mentre, il PLA, interagendo con la superficie cellulare e la membrana citoplasmatica, determina una grave rottura delle strutture cellulari. Quanto riportato contribuisce, dunque, all'arricchimento delle conoscenze scientifiche sul meccanismo anti-Listeria del PLA, ed evidenziano una maggiore efficacia del PLA rispetto agli altri acidi preservanti impiegati nel presente studio.
The purpose of this PhD research is to facilitate the development of green and successful strategies for the control of undesirable microorganisms in food products. It is well known that many stress resistant bacteria are able to contaminate food products and produce their spoilage or, worse still, be a potential source of human illness. In the last decade, illnesses resulting from food borne pathogens have been higher than in the past and have become one of the most widespread public health problems in the world. Contextually, contaminations with spoilage microorganisms remain a major threat for the industry and food-based market, so much so, that consumers are not only paying more attention to the risk of foodborne pathogens but also the safety of chemical preservatives that are used to control undesirable microorganisms. It is, therefore, essential to find a satisfactory solution and useful strategy to prevent or reduce the incidences of pathogens or spoilage microorganisms. In the last two decades, much attention has been focused on food bio preservation, a “green strategy” that can assure shelf-life extension and food safety using microorganisms or their antimicrobial compounds. Lactic acid bacteria could be considered an ideal choice for application as protective cultures in food products and, more specifically, Lactobacillus plantarum is the most versatile and widespread species. Several screening processes are developed in order to select the most appropriate effective strains to be used as protective cultures, including the production of bacteriocins, BLIS, organic acids, hydrogen peroxide as well as short chain fat acids. However, these screening programmes are labour intensive and a large number of strains isolated from different food matrices are assessed, thereby requiring more expensive investments in order to avoid unsatisfactory results. These findings call for a more simplified and useful approach when searching for new protective strains, taking into account that food stress conditions strongly influence the development of specific microbial strains. It would be extremely interesting to ascertain the effect of different environments on the selection of strains able to exert antimicrobial activities and, therefore, this research looks at the correlation between the Lb. plantarum strain isolated from hard environments and the ability to produce antimicrobial compounds. In addition, the main antimicrobial compound produced by producers Lb. plantarum strains and its mode of action was also investigated. This dissertation assesses the observations and the main significant results were reported in six chapters. Chapter 1 is an overview of the biocontrol strategies developed. More specifically, advancements in control strategies based on natural compounds and living organisms and/or their antimicrobial products (biocontrol, or bio preservation) were highlighted. These natural preservation methods are regarded as health-friendly by consumers, and are expected to have a lower impact on food nutritional and sensory properties. In addition, they may reduce the processing costs and, at the same time, extend the product shelf life period. However, until now, several issues, such as the high minimal inhibitory concentration levels, the stability of antimicrobial compounds, the knowledge of action mode, as well as the relation between microbial growth and compound formation kinetics, still remain unclear, making the individuation of a simplified screening procedure necessary. In Chapter 2 are reported the objectives of PhD research. Chapter 3 considers the relation between antimicrobial properties of Lb. plantarum strains and their source of isolation. For this purpose, a total of 110 Lb. plantarum strains were used as antagonistic strains (producers) against 33 undesirable microorganisms (indicators), including both moulds and bacteria. The antimicrobial activity exerted by cells, cell free supernatants (CFS), neutralized CFS (nCFS) or CFS added with α-chymotrypsin, proteinase K, and trypsin (pCFS) of the producer strains was evaluated by the spot-on-the-lawn and by the agar well diffusion assay. Moreover, the inhibition effects expressed by cell free supernatant (CFS) and by neutralized cell free supernatant of selected strains was evaluated in culture-broth expressed against strains belonging to Ps. fluorescens, B. thermosphacta and L. innocua. The preliminary results achieved by the evaluation of the antimicrobial effects expressed by CFS and the correspondent neutralized CFS support the hypothesis that the inhibition was due to the production of extracellular compounds having neither acid (such as lactic acid, that represent the principal extracellular metabolites produced by Lb. plantarum) nor proteinaceous nature. In addition, the results evidenced that the inhibitory effect produced by certain Lb. plantarum strains also remains at higher pH values. Therefore, the comparison between the inhibitory effects produced by CFS and lactic acid could provide more information on the antimicrobial compound. Moreover, in order to better appreciate differences between lactic acid and CFS, the most lactic acid resistant strains among the indicators should be chosen. L. innocua strains are well known for their acid stress resistance. The relative results evidenced that the inhibitory effect of CFS from Lb. plantarum H_BB1 against L. innocua was due to the synergic presence of more than one inhibitory substance. A more in depth, further investigation evidenced that in addition to lactic acid, the CFS might also possess another compound of acid nature. On the basis of this evidence, PLA in the cells free supernatant from strains (able to produce antimicrobial effects), was evaluated. The results highlighted significant differences among the assayed strains showing that PLA production is strain-dependent. In addition, for the first time, a relation between PLA-producing strains and isolation environment of the strains was highlighted. In fact, those environments characterised by harsh conditions (high ethanol levels, low pH and high sugar levels), such as wines and honey, harboured a higher number of antagonistic strains than other fermented matrices (e.g. cheese, sourdoughs or fermented sausages). This could be due to selective pressures which are more accentuated in wines and honey than in the other food matrices researched. The most important scientific enrichment produced by the activities in Chapter 1 is attributable to results highlighting that the choice of the source of isolation could be an important preliminary tool for the individuation of antagonistic strains. However, the correlation between Lb. plantarum PLA formation ability and their isolation sources would lead to opening new frontiers in understanding the PLA formation process. PLA formation seems to be linked to stress response mechanisms performed by Lb. plantarum. However, no information with regards the LAB stress response and PLA production is available in literature and little information is reported on the relation between the microbial growth phase and PLA formation. Even if the prevailing opinion in the scientific community believes that PLA formation is related to LAB growth arrest, the linkage to metabolic pathways involved in its stationary phase has not been clarified. Little information, if any, can be found on the optimal pH condition of PLA metabolic pathway in the Lactobacillus species. With this in mind, the research reported in Chapter 4 focuses on the effect of growth phase and on the PLA formation by Lb. plantarum H_BB1. Moreover, cultivation conditions that were able to assure the highest PLA levels were investigated. The production of PLA by Lb. plantarum H_BB1 was preliminarily investigated in MRS broth. The comparison between PLA behaviour and growth curves evidenced that the PLA accumulation begins immediately after the end of the lag phase and reached the highest levels between the exponential and the stationary phase. As far as I know, these results show, for the first time, that the PLA production is strictly related to the growth and to the exponential phase of Lb. plantarum. More specifically, the results obtained in the present study suggest that the PLA could assume new metabolic meanings. In fact, the accumulation from the beginning of the exponential phase highlight typical behaviour of a primary metabolite. On the other hand, the highest production rate between the exponential and stationary phase suggests that PLA production could assume a key role in the acid stress response. In fact, in the transition between exponential and stationary phase, pH showed values similar to the pKa of lactic acid. On the basis of the above reported statements, the evaluation of ecological factors on the PLA formation process appear essential. More precisely, sub-lethal pH could positively affect some metabolic pathways in Lb. plantarum. For this purpose, PLA production by Lb. plantarum was assayed in different cultural conditions (MRS acidified to pH 4.0 and to pH 3.5) and the results suggest that the metabolic pathway involved in PLA formation is tied to the energetic metabolism of growing cells. Key reactions of PLA formation, such as the regeneration of NAD+ levels, the transamination reaction (where the -ammino group is transferred to a keto acid acceptor) and the deamination reactions with NH3 and amino acceptor regeneration, found different linkages with typical metabolic activities of growing cells. The results evidenced that, in no way, could the PLA formation be related to cell growth arrest. Whereas, its formation could represent an adaptation response of growing cells to acid stress. In fact, evaluating the behaviour of ratio between PLA (g/L) and biomass (g/L) levels, the highest performances were detected when the strain was cultivated in MRS pre-acidified to pH 4.0. On the basis of the above reported results, the PLA could be considered a “primary-like metabolite” of Lb. plantarum in sub-optimal pH condition and may open new horizons to the development of an advanced optimal design for maximum PLA production. Moreover, the evidences reported in state-of-the-art Chapter 1, together with data specified in Chapters 2 and 3 suggest the opportunity to use PLA as anti-Listeria compounds. To date, antimicrobial activity of PLA, including anti-Listeria ability, was well recognized. Whereas, little information is available on the PLA anti-Listeria mechanism. Some results reported in literature suggest that the PLA mode of action could be similar to lactic acid. Nevertheless, considering the chemical structure of PLA, an action mode which is different from the lactic acid and more similar to phenolic acids could also be hypothesized. In Chapter 5, the anti-Listeria mechanism of 3-phenyllactic acid was investigated and, hence, the antimicrobial effect of PLA was evaluated to different pH. Moreover, the PLA anti-Listeria has been compared with those expressed by the lactic acid and the better studied hydroxybenzoic and hydroxycinnamic acids. Listeria innocua was chosen as the indicator to investigate the antimicrobial mechanism of PLA. Listeria innocua is regarded as a non-pathogenic indicator for the presence of Listeria monocytogenes in foods. This study has evidenced that PLA, which, for many years, has been considered an antifungal metabolite, is also able to inhibit bacteria cells. Moreover, very low concentrations were required to produce anti-Listeria activity. MIC values of about 0.47 or 0.94 mg/mL appear compatible with the maximum PLA production revealed in Lb. plantarum cultures. In fact, this PhD research (chapters 2 and 3), recognizes that Lb. plantarum strains produced up to 0.12 or 0.23 mg/mL and this production level could be increased two or even tenfold when specific cultural strategies were applied. Therefore, a resolution to the gap between PLA required to assure antimicrobial activity and the PLA levels detected in fermentation batches seems possible. This gap has long proven to be a serious obstacle when applying PLA producing bacteria as protective or as anti-Listeria cultures in food characterized by neutral or sub-acid pH. Moreover, the relation between pH values and anti-Listeria activity of PLA was clarified. A relation between MICs and pH values was found and a significant reduction in PLA anti-Listeria activity was detected at the highest pH values tested. In order to understand the PLA mode of action, the anti-Listeria effect produced by PLA at pH 5.5 was compared to the effect illustrated by lactic acid to the same pH value. Lactic acid was the best choice as its antimicrobial mechanism is well known. The results evidenced that the antimicrobial action of PLA was substantially different from LA. The different and more successful effect produced by PLA must be due to its amphiphilic properties resulting from the hydrophobic group-benzene ring and hydrophilic group-carboxy in its chemical structure. These properties would allow an interaction with the lipid and protein in cytoplasmic membrane as well as an interaction with genomic materials. Therefore, a comparison between PLA and the more studied phenolic acids (hydroxybenzoic and hydroxycinnamic) should be researched. Furthermore, to better understand the antimicrobial effect of PLA on L. innocua, further experiments were conducted using three phenolic compounds (gallic, ferulic and caffeic acid). The results generated from both an MIC and MBC survival test, highlighted that the gallic acid and PLA showed the most performing anti-Listeria activity. However, the differences between PLA and GA in death kinetic parameters suggest that PLA produces anti-Listeria activity through a specific mechanism which is somewhat different from those usually adopted by other phenolic compounds. Antimicrobial activity of phenolic acids involves several mechanisms of action such as permeability destabilization or the rupture of the cytoplasmic membrane as well as enzymes inhibition through nonspecific interaction. It is possible to hypothesize that PLA utilizes more than one of these pathways but differently from the other phenolic compounds. More exhaustive results were obtained by the evaluation of the effect of phenolic acids on surface charge and loss of cellular content. In fact, zeta potential measurements demonstrated that after phenolic acids exposure, the cells become more (P<0.05) negatively charged when exposed to PLA. While in the presence of other phenolic compounds (GA, CA, FE) no variation in charge was detected. This fact may open new horizons to the understanding of the PLA anti-Listeria mechanism. It is possible to surmise that the PLA anti-Listeria action is also associated with the affinity with cell surface and the interaction PLA-cell surface could contribute to the damage of cellular structures. The rupture of cellular structures was also supported by the results of the cellular content loss. The results could help to explain the differences in the anti-Listeria mechanism of phenolic compounds. Hydroxybenzoic and hydroxycinnamic acid seem to induce an alteration in membrane permeability without causing its rupture. Whereas, PLA having the main targets in cellular surface and in cytoplasmic membrane, leads to a severe rupture of the cellular structures. All these evidences contribute to the enrichment of scientific knowledge in the anti-Listeria mechanism of PLA and highlighted that PLA effectiveness is superior to that expressed by other preservative acids. Finally, in Chapter 6 are reported the general conclusions of PhD research.

This research activity aimed at investigating cow and goat milk and cheese quality, organic beef quality in mountain areas. Experimental trials were set-up to evaluate the chemical, technological, and nutritional characteristics of products obtained in organic and conventional farms located in the Veneto region. From the first study on the quality of milk from organic and conventional farms in mountain areas the milk was found to be substantially similar for chemical composition and technological properties despite two production systems were used. The fatty acid profile, instead was viewed favorably from a nutritional point of view for milk obtained form organic farming. Based on the trial carried out on cheese made from organic and conventional milk the differences in fatty acid profiles were confirmed, once again in favor of organic cheeses. It is possible to use some of the fatty acid profile parameters (saturated, mono-unsaturated, poly-unsaturated fatty acids, and ratio for some fatty acids of nutritional interest), to distinguish cheese based on the production system used and period of production. Special interest is paid for poly-unsaturated fatty acids, n3 and CLA fatty acids, which are found in cheeses produced in summer from organic milk. Organic cheese is more yellow and brighter in colour than conventional cheese because it is richer in a-tocopherols. From the sensory analysis no distinctive characteristics resulted for organic cheeses, so it is not possible to distinguish them from conventional ones through taste trials. In the third study, the investigation carried out on organic dairy goat farms in the Veneto region has shown great variability in feed management in farms. Regarding the fatty acid profile for goat milk, the study has revealed better results when grazing was possible; particularly high concentrations of CLA were found in farms where grazing was allowed in the summertime. In the fourth study, organic calf farming results in leaner animals, with lower cholesterol content, compared to conventionally farmed calves. The quantity of haeminic iron in organic meat almost doubles that found in conventional meat, which causes organic meat to be darker. This aspect is viewed negatively form a commercial point of view: darker meat is not appreciated by consumers who expect it to be slightly pink in colour (“white meat”). Overall, with this thesis it was possible to affirm that organic-farming mountain livestock could be exemplified as the method to use for increase the value of productions and sustainable farming.
Questa attività di ricerca ha avuto come obiettivo quello di investigare la qualità del latte bovino e caprino, di formaggi e di carne di vitello ottenuto da allevamenti biologici in zona montana. Sono state impostate quattro prove sperimentali che hanno valutato le caratteristiche chimiche, tecnologiche e nutrizionali di prodotti ottenuti da allevamenti biologici e convenzionali localizzati nella Regione Veneto. Il primo studio sulla qualità del latte ottenuto da allevamenti biologici e convenzionali di vacche da latte in zona montana ha evidenziato una sostanziale similitudine nella composizione chimica e nelle caratteristiche tecnologiche del latte ottenuto con i due diversi sistemi di produzione. Il profilo acidico del grasso del latte, invece, è risultato più favorevole dal punto di vista nutrizionale nel latte ottenuto da allevamenti biologici. Nel secondo studio sui formaggi ottenuti con latte biologico e convenzionale sono state confermate le differenze relative al profilo acidico, risultato ancora una volta più favorevole nei formaggi biologici. E’ stato possibile utilizzare alcuni parametri del profilo acidico per poter discriminare formaggi ottenuti con sistemi di produzione diversi e in mesi diversi. In particolare la quantità di acidi grassi polinsaturi, il contenuto di acidi grassi della serie n3 e i CLA, sono risultati più elevati nei formaggi estivi di produzione biologica. L’elevato contenuto di a-tocoferolo rilevato nel formaggio biologico ha portato a una colorazione brillante e più gialla rispetto ai formaggi convenzionali. Dall’analisi sensoriale non sono emerse particolari caratteristiche del formaggio ottenuto con latte biologico che quindi non è possibile discriminare rispetto ai convenzionali con prove di degustazione. Nel terzo studio, l’indagine riguardante le aziende biologiche di capre da latte presenti nella Regione Veneto, ha evidenziato una grande variabilità nella gestione alimentare delle aziende. Il lavoro ha rilevato concentrazioni elevate di CLA nelle aziende che hanno effettuato pascolo per tutti i mesi estivi. Nel quarto studio la carne di vitello ottenuta con metodo biologico è risultata più magra e con un più basso contenuto di colesterolo rispetto alla carne di vitello convenzionale. Il quantitativo di ferro eminico nella carne biologica è risultato quasi il doppio rispetto alla carne convenzionale causando una colorazione più rossa della carne biologica. Questo aspetto può penalizzare la commerciabilità del prodotto in quanto una colorazione rossa della carne di vitello non è apprezzata dal consumatore che desidera una carne rosata (carne “bianca”). Nel complesso questa attività di ricerca ha permesso di affermare che la zootecnia biologica in montagna si può proporre come metodo per la valorizzazione di alcune produzioni e la sostenibilità degli allevamenti.

2 pp.
Originally published: 2001
An onsite sewage treatment system or "septic system" is effective way to safely recycle household wastewater back into the natural environment. The key to effective treatment is proper design, system installation, responsible operation, and periodic maintenance. This article provides information about how to improve septic system performance by taking simple steps at home.

Five soymilk quality-related characteristics were investigated as affected by different grinding, heating, extraction methods and varieties. The five characteristics are (1) protein and solid recovery, (2) trypsin inhibitor activity, (3) antioxidant compounds and antioxidant capacity, (4) soy odor, and (5) isoflavone content and profile. The two varieties were Prosoy and black soybeans. The results show that significant differences existed among the three grinding methods (ambient grinding, cold grinding, and hot grinding). Ambient grinding gave the best protein and solid recoveries. Hot grinding showed the best results for the other four parameters. Cold grinding gave the poorest performance, with the exception of the odor profile. The three heating methods (traditional stove cooking, one-phase UHT, two-phase UHT) also resulted in significant differences in the chemical compounds and properties of the soymilk. In many cases, the effects of heating methods were closely related to grinding methods and varieties. Our results clearly demonstrated that a UHT processor equipped with a vacuum chamber was a very efficient way to reduce or eliminate some undesirable soy odors, especially in conjunction with hot grinding. Our results also demonstrated that many complex reactions occurred during thermal treatment. Because of different seed characteristics, the two different varieties behaved differently during processing. For both varieties, extraction with okara washing water from last batch (Method #2) gave the highest solid and protein recoveries.

The aim of this study was to determine the quality of slaughtered ostrich meat and to evaluate the ostrich slaughter process, to determine whether ostrich meat are contaminated by the in-house slaughtering practices and if prevalence of microorganisms increase with the succession of the slaughter process. Furthermore, the presence of specific foodborne pathogens and spoilage organisms was explored by means of molecular and conventional methods to determine whether ostrich meat is a source of these microorganisms. Data obtained from this study provides some baseline information that could be used in future studies on system contamination and the extent of downstream processing steps in the production of ostrich meat. Antimicrobial resistance has become a growing area of concern in both human and veterinary medicine, it is therefore necessary that another aim of this study was to determine the antibiotic resistant pattern of Staphylococcus aureus in ostrich meat in order to establish whether Staphylococcus aureus strains isolated from ostrich meat samples show resistance to antibiotics

Contemporary quality issues in product design are moving from materialistic to emotional user fulfillment; comprehensive research is needed to examine quality product feelings. This research is directed toward a deeper understanding of user and customer quality feelings for different product types, including services. The quality feelings concept includes dimensions of product quality, especially functionality, ergonomics and aesthetics. The first objective of this thesis is to identify, prioritize and synthesize quality feelings into product attributes in product development applications. The second objective is to explore, test and propose methodological approaches for designing quality feelings into products. Several methods from psychology, ergonomics, statistics and probabilistic methods and heuristics were applied to achieve the objectives. From a methodological viewpoint, Likert scales, free elicitation technique and Just About Right scales were applied for data collection. Multiple Regression, Factor Analysis, Correspondence Analysis, Genetic algorithms, Partial Least Squares (PLS) and Rough Sets (RS) were applied for data analyses. For ergonomic product evaluations, direct observations, 3D workload simulations, time and frequency analyses were conducted. Five product applications are included in this thesis: operator driver cabin design of reach trucks, steering wheel design trigger switch design in right-angled nutrunners, bed-making systemsproducts and waiting room environments. Heuristic methods were found effective when there is a high number of product attributes that interact to provide quality feelings. RS results are consistent with PLS attribute predictions. When the number of product attributes is large in comparison to the number of observations, PLS extracts informative results for quality feelings. The RS method is effective in identifying interactions among design attributes. Quality feelings are associated with both tangible (tactile characteristics) and intangible (quick and easy to use) product characteristics. Words such as safety, functionality, ergonomics, comfort, reliability, supportiveness, usability, feedback, pleasantness, attractiveness, durability and distinctiveness describe quality feelings from tangible products and services. Based on product type, the quality dimensions represented by these words possess different interactions and dependencies. In work environments, products act as prostheses between workers for social interaction, which need to be considered as important quality feelings dimensions.
QC 20111017

Nuclear Magnetic Resonance was used to investigate selected fruit with internal defects and at different stages of ripening. This was motivated by the need for an industrial NMR sensor of fruit and vegetable quality capable of operating at typical industrial conveyor speeds. Such a sensor requires the development of NMR protocols capable of determining fruit and vegetable quality in a single-shot manner. It also requires knowledge of which combination of NMR parameters is most sensitive to the quality factor of interest. In this thesis we therefore address this issue by exploring the off-line relationship between NMR parameters and fruit quality. We mainly focus on three areas: the detection of mealiness in apples, the single-shot measurement of Brix, and a single-shot measurement of oil in avocado. One dimensional techniques, measuring transverse relaxation times, were used as starting point. The correlation between mealiness and one dimensional was not observed at low fields. Therefore two-dimensional approaches were taken. The first of these was correlation spectroscopy, which showed that the of the water associated with the cell wall in mealy apples is much longer that that of fresh apples. This in principle could be used to classify apples. The differences between fresh and mealy apples observed with the second two-dimensional protocol, could ~ot be used to classify apples. However, when the technique was applied to avocado, it became clear that the difference between the diffusion coefficients of water and oil could be exploited for an on-line application. A fast pulse sequence was developed and the off-line measurements showed a good correlation between oil content and the echo ratio. A similar protocol was developed for the on-line measurement of Brix value in apple and strawberry.

Assessment of freshness and quality of meat and fish is a major activity of both food regulatory agencies and the food industry. Various methods are used for measuring fish and meat quality, each with its particular advantages and limitations. However, methods based on monitoring the products of proteolysis have received relatively little attention. The objective of the present study was to identify specific protein and peptide products of proteolysis as indicators of freshness and quality during chilled storage of fresh fish and meat.
Samples of meat and fish were subjected to chilled storage; at intervals of 0, 2, 4, 8, 12 and 16 days, samples were subjected to protein and peptide extraction, and separation of individual sarcoplasmic and myofibrillar proteins by SDS and native electrophoresis. These extracted proteins along with acid soluble nitrogen (ASN) were separated by RP-HPLC, fractions were collected and identified by electrospray ionization mass spectrometry (ESI-MS).
RP-HPLC separated at least thirty fractions from the ASN extract of fresh fish. ESI-MS revealed the presence of at least twenty-five polypeptides with molecular weights (MW) ranging from 2 to 32 kDa. The relative area % of the polypeptides with MW 32.8 kDa and 42.8 kDa decreased during the storage while polypeptides of MW of 10.9 kDa and 16.7 kDa increased during storage. Changes in polypeptides of MW 12, 34.2 and 42.8 kDa was also observed. The sarcoplasmic protein extracted from ground and whole meat contained at least 12 polypeptides with MW ranging from 11 to 42 kDa. The relative area % of polypeptide of MW of 35.7 kDa decreased during storage. The results suggest that changes in proteins and polypeptides of MW 10.9, 12, 16.7, 32.8, 34.2 and 42.88 kDa in fish and 35.7 kDa in meat could serve as indicators of spoilage.

Objective: The World Health Organization (WHO) requested the Research Institute for Industrial Pharmacy, at the North-West University, Potchefstroom, South Africa, to develop monographs for anti-tuberculosis products for The International Pharmacopoeia (IntPh). These included monographs for rifampicin capsules; rifampicin tablets; isoniazid and ethambutol hydrochloride tablets; rifampicin and isoniazid tablets; rifampicin, isoniazid and pyrazinamide tablets; and rifampicin, isoniazid, pyrazinamide and ethambutol hydrochloride tablets. Background: Tuberculosis (TB), caused by Mycobacterium tuberculosis, is an airborne disease that mainly affects the lungs. TB is currently causing a global health emergency and is among the principal killers of HIV infected people. First line anti-tuberculosis medicines include the active pharmaceutical ingredients (APIs) rifampicin, isoniazid, pyrazinamide, ethambutol and streptomycin. The WHO recommends the use of fixed dose combination products (FDCs) for the treatment of TB and multi-drug resistant TB. In the development of monographs, it is important to consider the safety, efficacy, and in particular the quality requirements for FDC products, which comprise stability, assay and identification testing, as well as the determination of degradation products / related substances. Comprehensive guidelines on FDCs, as published by the WHO, were applied in this study. Chemical and physical compatibility of APIs in an FDC, the degradability of each API under conditions of stress when in combination with other APIs, as well as API-excipient incompatibility, are important considerations for FDCs and their specifications. The reaction between isoniazid and rifampicin to form 3-(isonicotinoylhydrazinomethyl) rifamycin (commonly known as the isonicotinyl hydrazone, or rif-iso hydrazone) is particularly important, as this could result in a loss of therapeutic activity of rifampicin, that could lead to reduced bioavailability, poor patient compliance and subsequently failure to cure TB. Experimental procedure: Methods were developed for identity, assay and related substances testing. Although not requested by the WHO, it was decided to develop a dissolution test for isoniazid and ethambutol hydrochloride tablets, for which the WHO had supplied a number of different brands of products. The aims were to compare the dissolution profiles being generated during this study with those presented in the relevant WHO draft guideline (Chapter 4), and to establish whether the recommended dissolution conditions and specifications were appropriate for control of these FDC products. General requirements set for HPLC assay methods were: one method for more than one API, easily available columns, the use of an isocratic profile, stability-indicating methods, and the possibility of determining related substances using the same assay method(s). HPLC methods from available literature were identified, screened and the best alternatives selected for further development. Method development and validation were initially performed on the 4FDC tablets, then adjusted for lower API combinations and eventually for Rifampicin tablets and capsules. The assay method for determining rifampicin was also used for testing rifampicin degradation products. An infrared spectroscopic method was developed as identity test for Rifampicin tablets and capsules. As an alternative for identifying rifampicin in Rifampicin tablets and capsules a colour -, a TLC - and an HPLC test (based on correlating retention times of Rifampicin in the sample and standard solutions from the assay test results) were developed. For the FDC products, two identity tests (HPLC and TLC) were developed. Results and discussion: 4FDC products were successfully analysed by employing two methods, i.e. one for analysing ethambutol hydrochloride, isoniazid and pyrazinamide, and a second for analysing rifampicin and its related substances. Ethambutol hydrochloride does not absorb UV light; however, it forms a complex with cupric ions, with maximum absorption at 270 nm. By including Cu(II) acetate in the mobile phase, ethambutol hydrochloride was successfully quantified by UV detection. For the assay of FDC products not containing ethambutol hydrochloride, Cu(II) acetate was omitted from the mobile phase. The validation outcomes confirmed the suitability of these methods. The mobile phase of the TLC test for the identification of APIs in FDC products, consisted of methano1:strong ammonia solution (100:1.5). The TLC plate could be inspected under W light (254 nm) after exposing it to iodine vapours. In the absence of W light (254 nm), the pyrazinamide spot was only vaguely visible when inspected in daylight after iodine exposure. The spot-intensity of isoniazid, pyrazinamide and ethambutol hydrochloride is concentration dependent and can be used for semi-quantitative determination of these APIs in anti-tuberculosis FDCs. The dissolution study was conducted according to the conditions as set out in a draft WHO guideline for products containing BCS (Biopharmaceutics Classification System) defined, highly soluble APIs. The study and acceptance criterion were accepted by the WHO and included in the monograph for isoniazid and ethambutol hydrochloride tablets. Disintegration has been included as an alternative to dissolution, with the acceptance criterion based on a correlation between the dissolution profiles and disintegration times, as had been determined for products being supplied by the WHO. Conclusion: The monographs were compiled according to the format, as required by the WHO, and submitted to the WHO. The monographs were distributed for review within the WHO advisory channels and discussed at WHO consultation and expert committee meetings. Feed-back was considered and the monographs updated accordingly. The monographs were approved for The International Pharmacopoeia during a meeting of the 4oth WHO Expert Committee on Specifications for Pharmaceutical Preparations. The monographs have been posted on the WHO website and are to be included in the fourth edition of The International Pharmacopoeia.
Thesis (Ph.D. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2007.

There has been an upsurge in the use of Complementary and Alternate Medicines (CAMs) in both developed and developing countries. Although herbal medicines have been in use for many centuries, their quality, safety and efficacy are still of major concern. Many countries are in the process of integrating CAMs into conventional health care systems based on the knowledge and use of traditional medicines. The quality control (QC) of herbal products usually presents a formidable analytical challenge in view of the complexity of the constituents in plant material and the commercial non-availability of appropriate qualified reference standards. Sceletium, a genus belonging to the family Aizoaceae, has been reported to contain psychoactive alkaloids, specifically mesembrine, mesembrenone, mesembrenol and some other related alkaloids. Sceletium is marketed as dried plant powder and as phyto-pharmaceutical dosage forms. Sceletium products and plant material marketed through health shops and on the internet are associated with unjustified claims of specific therapeutic efficacy and may be of dubious quality. Validated analytical methods to estimate Sceletium alkaloids have not previously been reported in the scientific literature and the available methods have focused only on qualitative estimation. Furthermore, since appropriate markers were not commercially available for use as reference standards, a primary objective of this study was to isolate relevant compounds, qualify them as reference standards which could be applied to develop appropriate validated qualitative and quantitative analytical methods for fingerprinting and assay of Sceletium plant material and dosage forms. The alkaloidal markers mesembrine, mesembrenone and ∆⁷ mesembrenone were isolated by solvent extraction and chromatography from dried plant material. Mesembranol and epimesembranol were synthesised by hydrogenation of the isolated mesembrine using the catalyst platinum (IV) oxide and then further purified by semi-preparative column chromatography. All compounds were subjected to analysis by ¹H, ¹³C, 2-D nuclear magnetic resonance and liquid chromatography-tandem mass spectroscopy. Mesembrine was converted to hydrochloride crystals and mesembranol was isolated as crystals from the hydrogenation reaction mass. These compounds were analysed and characterised by X-ray crystallography. A relatively simple HPLC method for the separation and quantitative analysis of five relevant alkaloidal components in Sceletium was developed and validated. The method was applied to determine the alkaloids in plant material and dosage forms containing Sceletium. An LCMS method developed during the study provided accurate identification of the five relevant Sceletium alkaloids. The method was applied for the quantitative analysis and QC of Sceletium plant material and its dosage forms. This LCMS method was found to efficiently ionize the relevant alkaloidal markers in order to facilitate their detection, identification and quantification in Sceletium plant material as well as for the assay and QC of dosage forms containing Sceletium. The chemotaxonomy of some Sceletium species and commercially available Sceletium dosage forms were successfully studied by the LCMS method. The HPLC and LCMS methods were also used to monitor the bio-conversion of some of the alkaloids while processing the plant material as per traditional method of fermentation. Additionally a high resolution CZE method was developed for the separation of several Sceletium alkaloids in relatively short analysis times. This analytical method was used successfully to fingerprint the alkaloids and quantify mesembrine in Sceletium and its products. Sceletium species grown under varying conditions at different locations, when analyzed, showed major differences in their composition of alkaloids and an enormous difference was found to exist between the various species with respect to the presence and content of alkaloids. Sceletium and its products marketed through health shops and the internet may thus have problems with respect to the quality and related therapeutic efficacy. The QC of Sceletium presents a formidable challenge as Sceletium plants and products contain a complex mixture of compounds. The work presented herein contributes to a growing body of scientific knowledge to improve the QC standards of herbal medicines and also to provide vital information regarding the selection of plant species and information on the specific alkaloidal constituents to the cultivators of Sceletium and the manufacturers of its products.

A non destructive approach for the determination of quality and safety parameters of agri-food products was developed. The main objective is the elaboration of reliable methods that could improve the efficiency, the quality and the safety of different processes in the food supply chain. The focus is put on these main topics: quality aspects (harvesting, variety identification), process control (harvesting and drying) and safety aspects (food contaminants). Different spectroscopic techniques are involved (Near Infrared spectroscopy, Ultra Violet and Visible spectroscopy, Fluorescence spectroscopy). Special attention is given to the mathematical and statistical treatment of data: predictive models are elaborated applying on raw data chemometric treatment. For every dataset, different pre-treatments are tested and performances are compared. Multivariate analysis is applied to obtain chemometric model from raw data, that will describe analyzed parameters and processes. Selected models are tested in a following working step aiming to verify the feasibility of the method on unknown samples.

The main objective of this thesis was to have a deeper knowledge about the influence of feeding strategies with several natural plants extracts on pig performance and meat quality in different phases of pig production. To achieve this objective, a set of 4 studies were performed (chapter 2-6). The first study evaluated the effect of dietary supplementation with a mixture of algae plus polyphenols (AM) in lactating sow on maternal and piglets performance and sows reproductive data until the subsequent farrowing. This study showed that integration of AM in sow diet decreased the fat mobilization during lactation. Moreover, dietary AM inclusion in lactating sows positively affected body weight and average daily gain in piglets at 21 days. Moreover, sows that received AM had more total number of piglets born at the subsequent farrowing. Regarding the effects of plant extracts on meat and product quality, two different studies were performed. In the second study of the thesis, the impact of dietary integration with vitamin E and verbascoside (AOX) in pigs, on carcass characteristics, meat quality, shelf life of pork under modified atmosphere packaging (MAP) was evaluated. This study demonstrated the positive effects of plant extracts as antioxidant. Particularly, highlighted that dietary AOX positively affected carcass dressing percentage and pork oxidative and colour stability. Moreover, sensory analysis revealed that, at 15 days under MAP, meat from AOX was comparable with fresh meat in appearance and aroma. In the same way, the third study showed that vitamin E and verbascoside (AOX) also affected the quality of derived product like smoked cured ham. Results relieved infact that the AOX dietary inclusion affected the seasoning losses and influenced the consumers' preference of smoked cured ham, without affecting other quality parameters. Finally, the fourth experimental trial examined the impact of 3 % hydrolysable tannins (HT) from chestnut extract and two levels of polyunsaturated fatty acid (PUFA) in the diets on growth performance, carcass traits, meat quality and boar taint compounds in entire males. Results showed that dietary HT reduced the feed efficiency but not feed intake and the pigs final weight. These results show that performance, carcass composition and meat quality traits are not affected by dietary 3% chestnut extract supplementation in entire male. The boar taints compounds like androstenone, skatole and indole tended to be lower in HT group. The cytochrome mRNA expression in the liver and colon mucosa was not affected by the diet. No evident relationship between dietary PUFA level and boar taint compound levels was observed. Overall, these results contribute to improve the knowledge regarding beneficial effects of plant extracts. The inclusion of bioactive components contained in natural extracts can be considered an innovative approach to improve pig wellbeing and pork quality without negative effects on animal production.

Dissertation presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Marketing Intelligence
The growing concern with the environment over the past years reflects into changes in consumer behavior and an increased willingness to buy products that are benign for the planet. This study investigates the behavior of consumers when choosing between a product that is perceived to be green and more sustainable and another product that is perceived to offer superior quality (e.g. premium), in order to better understand consumer behavior. For the development of this research, two separate experimental studies were conducted. The first was a pilot study based on respondents’ habits to choose which green product between organic, from fair trade and from local production would be used in the main study. After choosing the organic category, a second study was performed to explore the effects that environmental values, product quality, price and pride (as an emotion) have on consumer’s perception and what influence would they have in consumer purchase satisfaction when choosing between an organic and a premium olive oil. The findings of this study is aligned with previous literature as it reinforces consumers’ interests in the environment and their health. For instance, findings demonstrate that the ones who buy organic products show a considerably increased environmental concern than those who buy premium products, that purchase satisfaction is moderated by environmental values and that organic products are perceived to be healthier than premium ones. Furthermore, our results demonstrate that price and quality would not influence the perception of an organic product, whereas perception would be strongly affected by consumers’ feeling of pride. More specifically, this research evidences that pride mediates consumer satisfaction depending on the product chosen (organic or premium) and that consumers feel prouder when consuming an organic than a premium product regardless of its quality, which brings meaningful value to marketers as it helps them understand customer needs by studying their sustainable beliefs, values, attitudes and behaviors.

碩士
國立勤益科技大學
工業工程與管理系
105
To quickly and accurately enter the markets in the era of globalization. Every manufacture need to know the regulatory standards. Professional service is the key factor in the certification industry. For the purpose to strengthen the advantage of products in the markets. This study is for the certification industry. We establish four scopes. The first is the service quality of certification industry. The second is the knowledge of products of certification industry. The third is the value of products of certification industry. The fourth is the satisfaction of certification industry. We use the method of Structure equation modeling and Amos to analysis the questionnaire. We hope to get the points and give the reference suggestion to the certification industry. The conclusion of this research, we find the effect of following scope. Service quality has a positive effect with the knowledge of products and the value of products. The knowledge of products has a positive effect with the value of products. The value of products has a positive effect with satisfaction.

碩士
元培醫事科技大學
食品科學系碩士班
104
This study we sampled 209 delicatessen products that contain poultry form Taiwan , analyzed their microbial indicators (Coliforms, Escherichia coli, Salmonella)and food pathogen (Staphylococcus aureus, Campylobacter), the results showed that the passing rate and the number of detection were 71.8%、95.2%、98.1%、96.7%、100% and 59、10、4、7、0, respectively. The same time we conduct pathogen bacteria drug resistance analyzed, the results showed Salmonella for chloramphenicol drug resistance lowest, antibacterial range for 44-50mm；S. aureus for penicillin drug resistance lowest, antibacterial range for 33-37mm；E. coli for chloramphenicol and tetracycline drug resistance lowest, antibacterial range both for 44-50mm.The test results for epidemiology as reference. We analysis GHP(good hygiene practice) sanitization management according sampled observed, the results showed the due to lack of ingredients preparation, under cooking and not really perform washing hand、replacing uniform、wearing masks and gloves before work. Suggesting to the producers of such products to health management for GHP strengthen advocacy. The objectives of this study were to investigate the hygienic quality and potential hazard of histamine in the bonito. Seventy samples including 40 bonito samples and 30 bonito related products, 40 bonito samples including 20 Euthynnus affinis and 20 Katsuwonus pelamis, 30 bonito related products including 11 bonito sauce , 11 dried bonito and 8 bonito extract powder, subjected to determine the occurrence of histamine-forming bacteria and the residue of histamine. The results showed that bonito had an average pH of 5.77, salt content of 8.46%, water content of 68.18%, water activity of 0.98, total volatile basic nitrogen of 20.7 mg/100g, aerobic plate count of 3.48 log CFU/g, total coliform of 299.12 MPN/g, and Escherichia coli detection of negative. Nine biogenic amines analysis were detected, except spermidine and tyramine, average contents of biogenic amines, putrescine 0.61 ppm、cadaverine 0.94 ppm, histamine 20.95 ppm, 2-phenylethylamine 1.73 ppm, spermine 2.51 ppm, tryptamine 4.63 ppm and agmatine 6.10 ppm, histamine level in almost samples was less than the allowable limit of U.S. Food and Drug Administration for bonito and/or product (5 mg/100g of histamine), but 7 Euthynnus affinis higher than the standard, it will have risk of histamine poisoning if ate they. Furthermore, 11 histamine-forming bacterium isolated from bonito samples, after analysis the bacterium capable of producing 59.55 ppm of histamine in trypticase soy broth supplemented with 1% L-histidine (TSBH). Bonito related products analysis including biogenic amines contents and preservatives analysis, nine of biogenic amines contents analyzed, to divide preservatives into acid preservatives and ester preservatives, 5 acid preservatives standard analyzed and 7 ester preservatives standard analyzed. The result about biogenic amines, spermidine 0.01ppm, tyrosine 0.80 ppm, putrescine 0.05 ppm, cadaverine 0.09 ppm, histamine 4.40 ppm, 2-phenylethylamine 0.13 ppm, spermine 1.49 ppm and tryptamine 0.05 ppm, agmatine not detected. Preservatives were detected sorbic acid in one bonito related products.

Defence date: 19 January 1998
Examining board: Prof. Pierre Pestieau, CREPP, University of Liège ; Prof. Alessandro Petretto, University of Florence ; Prof. Louis Phlips, EUI and University of Florence, Supervisor ; Prof. Robert Waldmann, EUI and IGIER, Milan
PDF of thesis uploaded from the Library digitised archive of EUI PhD theses completed between 2013 and 2017

博士
國立臺灣科技大學
工業管理系
92
Due to the highly competitive consumer market of today, consumers take account of their rights more serious than before. Hence, product warranty plays an important role in promoting their products to the market for the manufacturers. However, because variations may exist in production process or the production system might be deteriorate, the items of imperfect quality to be produced are inevitable. In case these imperfect items are released to the consumers, it will result in additional costs to the manufacturer. Moreover, these costs will increase as the quantity of defects increases. In order to reduce the total warranty cost, quality control methods are employed in this paper. We propose EOQ/EPQ models by considering the ordering and production system respectively. 1. For an ordering system, when some products manufactured or received are not of perfect quality, the production inspection is the most common remedy to be adopted to ensure the outgoing product quality. Most of the cases, the inspection time is usually assumed and simplified to be negligible. Unfortunately, this assumption may not be valid in practice. Under these circumstances, we propose an EOQ model with backordering, which incorporate the screen inspection and items are inspected at a certain rate. The objective here is to obtain the optimal lot size and the optimal level of backorders so that the total profit per item is maximized. 2. For a production system, it may be stable but with variation or will be deteriorate with time (or the quantity of items produced). However, the item of imperfect quality is inevitable. In this paper, we focus on the policy that avoiding the items of imperfect quality being released. First, when variation exists in the production system, we consider the situation that shortages are allowed and the system will produce a certain proportion of defective. Under these circumstances, the screen inspection is employed and the reworkable items are reworked at a certain rate. The objective here is to obtain the optimal lot size, the optimal level of backorders, and the optimal rework time such that the total cost per item is minimized. Secondly, for the deteriorate system, lot-sizing control, last-K inspection policy and reworking the items of imperfect quality are employed here to reduce the items of imperfect quality produced for the products sold with warranty. The objective is to fine the optimal lot size and the optimal quantity of inspection such that the total cost per item is minimized.

碩士
國立臺北大學
企業管理學系
100
Cosmeceutical products are the skin care products positioned between cosmetics and pharmaceuticals by the defined mechanisms, simple and pure ingredients as well as higher concentration of actives. The product benefits are also tested and demonstrated through scientific validation. In addition, as adjuvant therapeutic products for curative surgery, cosmeceutical products are usually with professional indication and consultation, thus the consumer confidence and reliability will be higher than general products. This research adopted questionnaires targeting to explore how the product attributes, perceived risks affect consumer’s perception on quality in regard of cosmeceutical skin care products. The results concluded that, for cosmeceutical products, the perceived quality has negative significant effect on perceived risk while the product attributes have significant effect both on perceived quality and perceived risk. In descriptive statistic results, it showed that it is still female the main consumer for cosmeceutical products with main age range between 31~40, close to 80% of the subjects have no kids and the main residence located in north and south part of Taiwan. Meanwhile, the AVONA analysis demonstrates that particular dimensions under three variables of different ages, with kids or not and residence were found to be significant different. In addition, the main channel for purchasing cosmeceutical products centralized to mass chain stores as well as professional ones such clinic and drug stores. The result shows that purchase frequency and amount only have significant effect on certain dimension while the channels significantly related to all variables. The correlation and regression analysis also shows the product attributes, perceived quality and perceived risk of consumers purchasing in different channels have significant differences.

碩士
國立中興大學
光電工程研究所
105
In recent years, quality control of agricultural products is one of the most important issues for public. However, modern quality inspection methods are mostly manual control. These kinds of methods are not only complicated and also time-consuming therefore are unable to generate detection results comprehensively and efficiently. Moreover, some destructive methods will destroy the experimental samples hence may cause it never be eaten or sell. Hyperspectral imaging is an advance technique which is capable of collect object information from the visible light spectrum to infrared light spectrum. The reflectance spectrum of the test target in a hyperspectral data can be modelled as an n dimensional vector. The divergence between different spectral vectors are applying to recognize the compositions on different target’s surface. Currently, this method is widely used in agriculture products for quality inspection. We take two researching subjects in this studies. In order to build a detection models for Fusarium wilt on Phalaenopsis and pesticide residues on fruit’s surface, a hyperspectral databases is generated form different statues samples. We applied band selection (BS) processing base on band prioritization (BP) and band de-correlation (BD) to extract the significant bands and eliminate the redundant bands. Then, two algorithms were used, constrain energy minimization (CEM), and support vector machine (SVM), to detect the defect on agriculture products. The analyzing result shows that hyperspectral techniques in agriculture products quality inspection is feasible.

Ho Wing Yee.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.
Includes bibliographical references (leaves 110-123).
Abstracts in English and Chinese.
Chapter 1 --- Introduction
Chapter 1.1 --- Bioconversion --- p.1
Chapter 1.2 --- Functional foods & quality improvement in fermentation Edible mushroom --- p.2
Chapter 1.3 --- Substrates --- p.4
Chapter 1.4 --- Edible mushroom --- p.6
Chapter 1.5 --- Nutritional value of food and feed --- p.9
Chapter 1.6 --- Protein digestibility --- p.16
Chapter 1.7 --- Problem caused by fungal contamination --- p.17
Chapter 1.8 --- Antioxidant --- p.18
Chapter 1.9 --- Research objectives --- p.20
Tables and figures --- p.21
Chapter 2 --- Materials and Methods
Chapter 2.1 --- Materials --- p.32
Chapter 2.2 --- Sample preparation --- p.33
Chapter 2.3 --- Fungal growth measurement --- p.34
Chapter 2.4 --- Proximate compositions --- p.34
Chapter 2.4.1 --- Moisture determination --- p.34
Chapter 2.4.2 --- Ash determination --- p.35
Chapter 2.4.3 --- Crude lipid determination --- p.35
Chapter 2.4.4 --- Dietary fiber determination --- p.36
Chapter 2.4.5 --- Crude protein determination --- p.38
Chapter 2.4.6 --- Carbohydrate determination --- p.38
Chapter 2.4.7 --- Glucose determination --- p.39
Chapter 2.4.8 --- Chitin determination --- p.40
Chapter 2.4.9 --- Phytic acid determination --- p.41
Chapter 2.5 --- In vitro protein digestibility --- p.42
Chapter 2.6 --- Aflatoxin determination --- p.43
Chapter 2.7 --- Antioxidant ability --- p.45
Chapter 2.7.1 --- Ferric reducing antioxidant powder (FRAP) assay --- p.45
Chapter 2.7.2 --- Trolox equivalent antioxidant capacity (TEAC) assay --- p.46
Chapter 2.8 --- Statistical analysis --- p.47
Table --- p.48
Chapter 3 --- Results
Chapter 3.1 --- Mycelia growth --- p.49
Chapter 3.1.1 --- Growth diameter --- p.49
Chapter 3.1.2 --- Chitin content --- p.50
Chapter 3.2 --- Weigh loss in sample preparation --- p.51
Chapter 3.3 --- Proximate composition --- p.52
Chapter 3.3.1 --- Moisture --- p.52
Chapter 3.3.2 --- Ash --- p.52
Chapter 3.3.3 --- Crude lipid --- p.53
Chapter 3.3.4 --- Dietary fiber --- p.54
Chapter 3.3.5 --- Crude protein --- p.55
Chapter 3.3.6 --- Carbohydrate content --- p.56
Chapter 3.3.7 --- Glucose content --- p.56
Chapter 3.3.8 --- Phytic acid --- p.56
Chapter 3.4 --- In vitro protein digestibility (IVPD) --- p.57
Chapter 3.5 --- Aflatoxin --- p.53
Chapter 3.6 --- Antioxidant ability --- p.58
Chapter 3.6.1 --- Ferric reducing antioxidant powder (FRAP) assay --- p.58
Chapter 3.6.2 --- Trolox equivalent antioxidant capacity (TEAC) assay --- p.60
Tables and figures --- p.62
Chapter 4 --- Dissusions
Chapter 4.1 --- Mycelia growth --- p.89
Chapter 4.2 --- Weigh loss in sample preparation --- p.90
Chapter 4.3 --- Proximate composition --- p.90
Chapter 4.3.1 --- Moisture --- p.90
Chapter 4.3.2 --- Ash --- p.91
Chapter 4.3.3 --- Crude lipid --- p.92
Chapter 4.3.4 --- Dietary fiber --- p.93
Chapter 4.3.5 --- Crude protein --- p.96
Chapter 4.3.6 --- Glucose concentration --- p.98
Chapter 4.3.7 --- Phytic acid --- p.99
Chapter 4.4 --- In vitro protein digestibility (IVPD) --- p.101
Chapter 4.5 --- Aflatoxin --- p.102
Chapter 4.6 --- Antioxidant activity --- p.103
Chapter 4.7 --- Bioconversion ability --- p.105
Chapter 4.8 --- Best substrate --- p.105
Chapter 4.9 --- Functional foods --- p.106
Chapter 4.10 --- Limitation of the methodology and future development --- p.107
Table --- p.108
Chapter 5 --- Conclusion --- p.109
References

碩士
國立勤益科技大學
資訊管理系
106
“Bedding” is a significant factor which can influence our sleeping quality. Since bedding is the goods used for speeding every day and a good mattress can properly adjust and support the stress of every part of the body, the primary functions of the mattress should emphasize heat preservation, moisture absorption, moisture release, comfort, support, and durability. A comfortable mattress can help our muscles properly extend and fully rest to effect relaxation. Thus, both mattress quality and selection are extremely important. Therefore, this study is targeted at the quality requirements of mattress products, interviewing 182 customers for their quality requirements of mattress products. Two dimensional quality model (Kano) is employed to collect customers’ voices from the curved panels, focusing on the requirements of the key customers. Next, the Analytic Network Process (ANP) is applied to calculate the weights of the voices of customers (VOC), in order to figure out the ranking of the key customers’ requirements and the management connotation. Finally, QFD was used to obtain the final technical demand ranking. The first five items were the independent tube spring design, the mattress protection design, the ergonomic design, the mattress material design, and the mattress padding coolness design. This study explores its design strategies and implications. By means of this study’s results, it is hoped that the mattress manufacturers can gain some help in their development and design, so that not only can customers’ voices be considered in the stage of design but also their requirements can be fully met.

碩士
真理大學
管理科學研究所
92
This research mainly aims to investigate the influences of product category characteristics on consumers’ perceived quality of the private label brand. Additionally, we also examine the moderating effects of the product involvement on the relationship between the product information and perceived quality of the private label brand. The subjects who shopped in the merchandise store or hypermarket were asked to participate in the study. After questionnaire survey, we collected 527 responses, and 400 of them were effective. This study investigates the manner in which product category characteristics influenced consumers’ perceptions of the private label quality by regression analysis. In the results, we find that perceptions of the private label quality are driven by the complexity, the quality variance, average interpurchase time, and price level of the product category. By using regression analysis, this study also investigates the moderating effects of the product involvement on the relationship between the product information and perceived quality of the private label brand. We find that product information has positive influences on the perceived quality of the private brand products. Amount of product information and product involvement have no interactive effects on perceived quality of the private brand products.

碩士
國立成功大學
工業與資訊管理學系碩博士班
97
Recently, many enterprises are constrained by international regulations to be responsible for the recycle and reuse of their products. Besides, the production costs of enterprises are increased largely due to the strong fluctuation on the price of petroleum and raw material. Consequently, some scholars propose the concept of closed-loop supply chain to collect the used-products for remanufacturing. Under this environment, how to price the remanufacturing products becomes a key to whether the manufacturers make profit or not. By literature review, we have found that most models assume the quality of remanufacturing product is as good as the new one. This assumption is unrealistic and different from the real situation. Moreover, most scholars propose the pricing model on a single quality level of remanufacturing products (Guide et al., 2003c). This kind of model can not meet the different demand types. Based on Guide’s model, we develop a new model that sets different quality levels of remanufacturing product and forms different models to find out the optimal product mix of the remanufacturing products and used-products. In addition, this model also incorporates the capacity constraint. In this research, we use the Genetic algorithm to solve the model. In addition to Genetic algorithm, we also solve the model by Sequential Quadratic Programming and Interior point algorithm. As for the numerical result with the capacity constraint, we have found that capacity will affect the optimal product mix. This model also provides decision maker to find optimal product mix of maximum profit under known capacity constraint.

Dissertação de Mestrado em Biotecnologia Farmacêutica apresentada à Faculdade de Farmácia
O presente trabalho foi baseado no desenvolvimento de um método analítico utilizando a abordagem de Analytical Quality by Design (AQbD). Esta abordagem é utilizada quando existe a necessidade de se obter um conhecimento completo do método e, ao mesmo tempo, controlar os possíveis fatores que podem influenciar os resultados no trabalho de rotina. O método analítico escolhido foi o Next Generation Impactor (NGI) que tem a capacidade de avaliar a distribuição aerodinâmica do tamanho de partícula de um aerossol. Este método foi escolhido com o objetivo de melhorar a sua robustez e, ao mesmo tempo, criar um fluxo de trabalho representativo das etapas essenciais no seu desenvolvimento.A parte experimental começou após a realização de uma análise de risco do método geral de NGI usando uma ferramenta chamada “Failure Mode and Effect Analysis”. Com todas as possíveis variáveis críticas identificadas, foi desenvolvido um método de NGI e foram definidas as condições ótimas para cada variável.As variáveis testadas foram: o número de cápsulas utilizadas em cada teste, tempo e tipo de agitação de cada componente, influência do revestimento e presença de perdas através do interstage. Ao longo de todos os testes, verificou-se que o balanço de massa esteve sempre dentro dos critérios definidos pela Food and Drug Administration exceto no teste realizado sem revestimento. As variáveis que tiveram influência considerável nos resultados obtidos estão relacionadas com a aplicação da solução de revestimento e com o tempo de agitação durante a recuperação. Testes adicionais foram realizados para avaliar a estabilidade de padrões e amostras.No final do trabalho, concluiu-se que a abordagem AQbD no desenvolvimento do NGI foi muito útil, uma vez que permitiu avaliar quais as variáveis críticas do método com maior impacto nos resultados obtidos.
The present work was based on the development of an analytical method using the approach of Analytical Quality by Design (AQbD). This approach is used when there is a need to reach a full knowledge of the method and, at the same time, to control the possible factors that can influence the results during routine work. The analytical method chosen was the Next Generation Impactor (NGI) that has the capacity of evaluating the aerodynamic particle size distribution (aPSD) of an inhalation product. This method was chosen in order to improve its robustness and, at the same time, to create a workflow representative of the essential steps on its development.The experimental part began after the accomplishment of a risk analysis of the general NGI method using a tool called “Failure Mode and Effect Analysis”. With all the possible critical variables identified, an NGI method was developed and the optimal settings for each variable were defined. The variables tested were: number of capsules discharged per test, time and type of agitation of each component, influence of coating and presence of interstage losses. Among all the tests, it was verified that the mass balance was always within the range recommended by Food and Drug Administration except on the test performed without coating. The variables that had a considerable influence on the results obtained were related with the application of the coating solution and with the time of agitation used during recovery step. Additional tests were performed to evaluate the stability of standards and sample solutions.At the end of the work, it was concluded that the AQbD approach was very useful on the NGI development since it allowed to evaluate which are the method variables with higher impact on the results obtained.

博士
淡江大學
管理科學研究所博士班
97
For the manufacturers and service industry, they not only need to produce or supply customers the products meet with the specification, but also have to satisfy them by enhancing process capability through regulation and improvement. Process capability indices(PCIs) are used as a means of measuring process potential and performance. The better process capability, the higher level of product quality it is, and the conforming rate. Until now, the literatures of quality performance mostly assumed the quality characteristics of product with the Normal distribution. However, the lifetime of products generally may possess an exponential, Weibull or gamma distribution and so on. Under a exponential distribution, this study constructs a maximum likelihood estimator (MLE) and an uniformly minimum variance unbiased estimator (UMVUE) of the lifetime performance index. Then the MLE and UMVUE of the lifetime performance index are utilized to develop the new hypothesis testing procedure. To more reasonably and accurately utilize the lifetime performance index in assessing the lifetime performance of products, this study constructs a new hypothesis testing procedure. This thesis mainly focuses on some topics. There are three topics included in this study. In Chapter 2, under the exponential distribution, this study constructs MLE and UMVUE of the lifetime performance index based on the type II right censored sample. Then, the MLE and UMVUE of the lifetime performance index are utilized to develop the new hypothesis testing procedure. In Chapter 3, we extend Chapter 2’s idea to construct the UMVUE of the lifetime performance index based on the upper record values. Then the UMVUE of the lifetime performance index is utilized to develop the new hypothesis testing procedure. In addition, the Weibull distribution includes the exponential distribution as the special case. Hence, under the Weibull distribution, this study constructs the UMVUE of the lifetime performance index based on the upper record values. Then the UMVUE of the lifetime performance index is utilized to develop the new hypothesis testing procedure. Moreover, a practical example is illustrated to employ the testing procedure to determine whether the process is capable. Finally, the concluding remarks and future research directions are made in Chapter 4.