Dissertations / Theses on the topic 'Post-harvest processing of grain'

Thesis: S.B., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2014.<br>Cataloged from PDF version of thesis. "June 2014."<br>Includes bibliographical references (pages 32-33).<br>Tin sulfide (SnS) is a semiconductor material with both an indirect and direct bandgap at 1.1 eV and 1.3 eV respectively. Due to the availability of tin and sulfur, SnS is seen as a feasible alternative to the thin film CIGS and CdTe solar cells. With a direct bandgap of 1.1 eV and the ability to be produced as a thin film, the SnS solar cell should achieve high levels of efficiency of approximately 32% according to the Shockley-Queisser limit (Shockley, Queisser, 1961). However, the efficiency of most SnS systems is around 4% in low sun conditions (Hartman, 2011). To understand how to improve this efficiency, further research is being done on the grain structure and how grain growth occurs under different annealing conditions. After thermal evaporation deposition, three different conditions were varied during annealing to affect grain growth: time, temperature, and annealing atmosphere. The samples were also deposited on two different substrates, glass and molybdenum. The samples were coated with Pt/Pd and characterized using SEM imaging. The SEM images were segmented to collect grain area information from each sample. The characterization revealed that longer annealing times and higher annealing temperatures lead to faster and greater grain growth. The annealing atmosphere of the samples affected surface diffusion in that the greater the partial pressure of S2 gas present in the environment the greater the facilitation of grain growth. The key conclusion based on the experimental data was that the annealing grain growth mechanism for SnS films is secondary or abnormal grain growth. This was evidenced by the initial columnar structure, the bimodal grain area distribution, and the non-uniform grains present in the SEM images. Further research on grain boundary diffusion with respect to time and texture of the thin films is needed although they suggest secondary grain growth as well.<br>by Max L. Powers.<br>S.B.

Yield monitors have become an indispensable part of precision agriculture systemsbecause of their ability to measure the yield variability. Accurate yield monitor data availabilityis essential for the assessment of farm practices. The current technology of measuring grainyields is prone to errors that can be attributed to mass flow variations caused by the mechanismswithin a grain combine. Because of throughput variations, there are doubts regarding thecorrelation between the mass flow measurement and the actual grain volume produced at aspecific location. Another inaccuracy observed in yield monitor data can be attributed to inexactcut-widths values entered by the machine operator.To effectively address these yield monitor errors, two crop mass flow sensing deviceswere developed and used to correct yield monitor data. The two quantities associated with cropmaterial mass flow that were sensed were tension on the feeder housing drive chain and thehydraulic pressure on the threshing cylinder's variable speed drive. Both sensing approacheswere capable of detecting zero mass flow conditions better than the traditional grain mass flowsensor. The alternative sensors also operate without being adversely affected by materialtransport delays. The feeder housing-based sensor was more sensitive to variations in cropmaterial throughput than the hydraulic pressure sensor. Crop mass flow is not a surrogate forgrain mass flow because of a weak relationship (R2 andlt; 0.60) between the two quantities. The cropmass flow signal does denote the location and magnitude of material throughput variations intothe combine. This delineation was used to redistribute grain mass flow by aligning grain andcrop mass flow transitions using sensor fusion techniques. Significant improvements (?? = 0.05)in yield distribution profile were found after the correction was applied.To address the cut-width entry error, a GIS-based post-processing algorithm wasdeveloped to calculate the true harvest area for each yield monitor data point. Based on theresults of this method, a combine operator can introduce yield calculation errors of 15%. Whenthese two correction methods applied to yield monitor data, the result is yield maps withdramatically improved yield estimates and enhanced spatial accuracy.

Maize (Zea mays L.) ranks third as a food crop after wheat and rice and is characterized not only as a cereal crop but also as a vegetable. Maize used as a vegetable is known as “baby corn”. Baby corn consists of unfertilized young ears harvested 2 or 3 days after silk emergence. The present study was implemented in 2009 at Western Kentucky University Agriculture Research and Education Center (36.93 N, 86.47 E) in Bowling Green, Kentucky. The purpose of the study was to compare the effect of different schemes of harvest on baby corn (BC) yield, grain maize (GM) yield, and estimated economic return. Experimental harvest treatments were 1) no BC harvest, only GM harvest, 2) first harvest as BC, final harvest as GM, 3) first and second harvests as BC, final harvest as GM, and 4) first, second, and third harvests as BC, final harvest as GM. Average estimated BC yields (Kg/ha) for Treatments 2, 3, and 4 were 1445.1, 2681.8, and 3437.5; GM yields (Kg/ha) for Treatments 1, 2, and 3 were 12522.2, 8226.5, and 1380.9; respectively. Since few grain kernels were found after three harvests for BC (Treatment 4), no usable GM yield was produced. BC and GM yields were used for evaluating the economic returns. Results indicated that the sequence of best economic returns would be obtained by harvesting BC three times (Treatment 4), first two harvests for BC and the final for GM (Treatment 3), first harvest for BC and subsequent for GM (Treatment 2), and only for GM harvest (Treatment 1). Although the pattern for only BC harvest was the most profitable system, the human labor requirement and critical timing of harvest limited its production. In states similar to Kentucky, BC could only be grown as an additional crop or to supplant a limited amount of traditional GM hectarage.

Orientador: Marcos David Ferreira<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola<br>Made available in DSpace on 2018-08-19T15:37:33Z (GMT). No. of bitstreams: 1 Rodrigues_MicheleCarvalhodaSilva_M.pdf: 1787890 bytes, checksum: ad42d636315e1e015773f4c6f3929bd8 (MD5) Previous issue date: 2011<br>Resumo: O beneficiamento da batata lavada no Estado de São Paulo, destinada ao mercado in natura ou ao processamento, consome volume excessivo de água, provocando danos ao meio ambiente principalmente no descarte da água residual da etapa de lavagem. Tendo em vista a exigência do mercado consumidor por batata lavada, e a necessidade da redução do consumo de água utilizado para este tipo de beneficiamento, a hipótese deste trabalho é a de que é possível reduzir o consumo de água na etapa de lavagem da batata modificando os parâmetros de funcionamento dos equipamentos utilizados atualmente (vazão e rotação), mantendo a eficiência de limpeza, sem afetar a qualidade do produto. Sendo assim, o objetivo deste trabalho foi avaliar a etapa de limpeza em linhas de beneficiamento de batata lavada produzida no Estado de São Paulo, e propor modificações para redução no volume de água com manutenção da qualidade do produto e da eficiência de limpeza. Para tanto, inicialmente foi realizada a avaliação de desempenho da etapa de limpeza em unidades de beneficiamento de batata lavada no Estado de São Paulo, identificando o método de lavagem, os tipos de roletes/escovas, velocidade média do produto, e volume de água consumido. A partir do estudo de desempenho, foram propostas alterações para melhoria na etapa de limpeza com relação ao volume de água consumido e a limpeza do produto. A eficiência de limpeza, o consumo de água, e a influência do beneficiamento na qualidade da batata lavada foram avaliados e comparados nos sistemas propostos, onde foram avaliadas três rotações para as escovas, e três vazões de água na lavagem de tubérculos de dois solos com diferentes teores de argila. A qualidade do produto beneficiado foi avaliada por meio dos parâmetros: perda de massa fresca, coloração, danos físicos e firmeza. Neste trabalho foi possível verificar que o consumo de água nas unidades de beneficiamento pode ser reduzido, mantendo a eficiência de limpeza do produto, apenas com ajustes de vazão e rotação do equipamento de lavagem. Com relação à qualidade, verificou-se o incremento na perda de massa e incidência de brotamento, e redução da e firmeza da batata lavada em comparação aos tubérculos não lavados<br>Abstract: The washing for potatoes in São Paulo, for the fresh market or industry, consumes excessive amounts of water, causing damage to the environment mainly due to waste water discharge from the washing step. Considering the requirement of the consumer market for washed potatoes, and the need to reduce water consumption, the hypothesis is that it is possible to reduce water consumption on the washing of potato just modifying the configuration of the equipment currently used (flow and rotation), and maintaining the cleaning efficiency without affecting quality. Therefore, the main goal was to evaluate the cleaning step in processing lines of washed potatoes produced in the state of Sao Paulo, and propose modifications to reduce the amount of water and with maintenance of product quality and cleaning efficiency. Therefore, early, characterization of the cleaning step was made in processing and classification units of washed potatoes in the state of Sao Paulo, identifying the method of washing used, types of rollers / brushes, average speed of the product, and water volume consumed on this step. From the characterization study, changes were proposed in the cleaning step that would improve the efficiency with respect to water consumption and cleaning product. The cleaning efficiency, water consumption, and influence of improvement in the quality of washed potatoes were evaluated and compared in the proposed systems. The quality of the processed product was evaluated by the following parameters: weight loss, color, physical damage and firmness. In this study, it was possible to verify that water consumption on processing units can be reduced maintaining cleaning efficiency, only adjusting water flow and rotation of the equipment. Related to tuber quality, it was also observed an increase of mass and firmness loss, and sprouting of washed potatoes compared with unwashed tubers<br>Mestrado<br>Tecnologia Pós-Colheita<br>Mestre em Engenharia Agrícola

The objective of this dissertation is to investigate how developments in post-harvest systems may have influenced hunter-gatherer subsistence change during the Epipalaeolithic (23,970-11,990 14C yr BP cal) of Southwest Asia. The term post-harvest system, as it is used here, refers to the knowledge, technology and co-ordination of labour that are necessary to convert raw plants into edible products and/or storable yields. It is argued that post-harvest systems promote increased abundance in four ways: i) permitting a wider variety of plants or plant parts to be added to the diet ii) transforming a single plant part into several forms of food iii) producing physical or chemical changes that improve the nutrient value and iv) reducing spoilage and/or transforming seasonally available resources into to year-round staple foods. Moreover, it is argued that the development of post-harvest systems entailed more than simple increase: that it transformed hunter-gatherer productive systems. A schematic model is presented to illustrate how developments in post-harvest systems would be expected to transform hunter-gatherer production systems. The links between food processing intensification and resource selection, during periods of resource scarcity and of resource abundance, are also considered. This study is multidisciplinary, bringing together the archaeological and ethnographic records and data from food science and botany. A case study was carried out on the harvesting, processing and nutrient analyses of the mature tubers of sea club-rush Bolhoschoenus maritimus (L.) Palla. Sea club-rush was selected, from among plants recovered from Epipalaeolithic contexts, because it is widespread at early sites, its occurrence has significant archaeological time depth and no previous research of this type has been undertaken on this plant. The results of the case study show that the potential yields and nutrient values of sea club-rush tubers are comparable with those reported for other wild root foods. Like many other wild and domesticated edible roots, the tubers were found to require extensive processing to make them edible. A model is presented which suggests the technological and environmental conditions in which the intensification of sea club-rush tubers is tenable.

Mestrado em Engenharia Alimentar - Processamento de Alimentos - Instituto Superior de Agronomia<br>In this study correlations between Rocha pear quality attributes and the incidence of internal browning (IB) were performed in order to know the major factors which determine different susceptibility of the fruit. Fruits under study were previously stored in dynamic controlled atmosphere (four months) and from three geographical origins (west region). The fruit incidence of IB showed to be dependent on geographical production localization. Fruits from Mafra and Lourinhã with 28 and 43% of IB, respectively, versus Alcobaça, where no symptoms were detected (0% IB). Fruits from Alcobaça showed the highest contents of ascorbic acid (AA) (4,8 mg/100 g) and of total phenolic compounds (CFT) (111,0 mg CAE/100 g), with increases of 20% and 40%, respectively, in comparison to the others, representing these the most distinctive quality factors. It was found that fruits with more calcium content, lesser potassium content and higher antioxidant capacity are more resistant to IB. By other side, the symptoms incidence is bigger in advanced post-harvest ripeness stages and minor AA content. The effects of AA content of the fruit on IB incidence were inconclusive. However, in the fruit core tissues the presence of similar AA contents between fruits, with and without IB, along with significant differences in CFT, could suggest that phenolic compounds are involved as a stress response to internal browning disorders mechanisms. Full ripening capacity was achieved in 4 days (room temperature) regardless fruits origin. However, fruits with higher internal browning incidence showed lesser storage ability (5 C), as a fresh-cut product

Thesis (Ph. D.) -- University of Maryland, College Park, 2007.<br>Thesis research directed by: Food Science. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

Forced convective drying using a wind turbine mechanically connected to a ventilation fan was hypothesized for low cost and rapid grain drying in developing countries. The idea was tested using an expandable wind turbine blade system with variable pitch, at low wind speeds in a wind tunnel. The design was based on empirical and theoretical models embedded in a graphical user interface (GUI) created to estimate airflow-power requirements for drying ear corn. Output airflow (0.0016 - 0.0052 m3kg-1s-1) increased within the study wind speed range (2.0 - 5.5 m/s). System efficiency peak (8.6%) was observed at 3.5 m/s wind speed. Flow resistance was overcome up to 1m fill depth in 0.5 m x 0.5 m wide drying bin. Drying study at different airflow rates (no forced convection, 0.002 m3kg-1s-1 and 0.008 m3kg-1s-1) were conducted in a controlled environment at 35oC and 45% relative humidity with mean drying time; 40.3, 37.9 and 22.9 h respectively, that reduced with increasing airflow while drying the ear corn from 22% to 15% moisture content. The overall result supports the hypothesis that the wind convection system increased grain drying rates and should be further developed.

Le cacao et le café sont les produits agricoles les plus échangés dans le monde. Ils subissent de nombreuses transformations post-récolte au niveau des pays producteurs (tropicaux) avant d'être exportés. Les procédés de traitements post-récolte diffèrent d'un pays à l'autre voire d'un agriculteur à l'autre. La transformation technologique du cacao en fèves marchandes et des grains de café en café vert nécessite un processus primaire de manutention. Ces pratiques participent et influencent, en général, la qualité marchande et organoleptique des produits destinés à la transformation. Notre hypothèse de travail est que les différents procédés de transformation post-récolte appliqués sur le café et le cacao ont une influence sur la structure des communautés microbiennes. L'objectif principal était de pouvoir mesurer cet effet en réalisant l'analyse globale des communautés microbienne en utilisant un outil de biologie moléculaire, la PCR-DGGE (Amplification par PCR couplée à l'électrophorèse sur gel en gradient dénaturant). Cette technique a été associée au séquençage afin d'identifier les espèces microbiennes majoritaires. Cette étude a montré que les communautés microbiennes associées aux grains de café et aux fèves de cacao varient au cours des différentes étapes pour chaque type de traitement post-récolte appliqué.Notre approche a permis de discriminer les voies de traitements, et l'origine géographique du café Camerounais et Indonésien. Notamment, nous avons montré que l'origine géographique et l'espèce de café utilisée ont un impact sur l'écologie microbienne du café moins important par rapport à celui du procédé. L'application au cacao nous a permis de relier l'analyse globale de l'écologie microbienne (DGGE) à l'analyse des composés volatils (SPME-GC-MS) afin de discriminer les différents traitements post-récolte. Des micro-fermentations ont été réalisées avec des souches microbiennes isolées du cacao (L. fermentum, A. pasteurianus, P. kudriavzevii et P. mashurica) dans le but d‘identifier l'origine des composés volatils détectés sur le cacao fermenté. Notre étude a contribué à montrer que la fermentation combinée à une courte durée de stockage avant fermentation est le procédé qui permet d'obtenir des fèves contenant plus de composés aromatiques désirables sur le cacao. Une analyse statistique a permis de combiner les résultats des deux types d'analyses (écologie microbienne et composés aromatiques) et de créer des relations entre les espèces détectées et les composés volatils présents. Les profils aromatiques identifiés ont permis d'envisager l'utilisation des souches testées comme starters de culture pour la fermentation du cacao<br>Cocoa and coffee are the most traded agricultural commodities in the world. They undergo many post-harvest transformations in producing countries (tropical) before being exported. Post-harvest processes differ from one country to another and from one production site to another. The technological transformation of cocoa on commercial beans and of coffee to green coffee requires a primary process handling. These practices play a crucial role in global and organoleptic quality of the products that will be processed. Our work hypothesis isthat different post-harvest processing applied to coffee and cocoa have an influence on the structure of microbial communities. The main objective was to measure this effect by performing a global analysis of microbial ecology using a molecular biology tool (PCR-DGGE, PCR amplification coupled to denaturing gradient gel electrophoresis). This technique allows variations in microbial communities to be detected and the main microbial species to be identified by sequencing.Our approach permitted to discriminate treatments, and the geographical origin of Cameroonian and Indonesian coffees. Notably, we showed that geographical origin and coffee species have a minor impact on the structure of the microbial communities when compared to the type of process used (wet or dry).By applying the approach to cocoa, we could link the global analysis of microbial ecology (PCR-DGGE) to the analysis of volatile compounds (SPME-GC-MS) to discriminate the different post-harvest treatments. Micro-fermentation were carried out with strains isolated from cocoa (L. fermentum, A. pasteurianus, P. kudriavzevii and P. mashurica) in order to identify the origin of the volatile compounds detected in the fermented cocoa. This study contributed to to show that fermentation combined with a short storage duration before fermentation is the best method to obtain cocoa beans with more desirable aromatic compounds. The statistical analysis was used to combine the results of the two types of analyzes (microbial ecology and aromatic compounds) and get relations between the detected microbial species and volatile compounds. The identified aromatic profiles prompted us to consider the use of the tested microbial strains as starter culture for cocoa fermentation

Um dos grandes desafios da citricultura brasileira, como grande produtora de lima ácida \'Tahiti\', tem sido a conservação do fruto in natura com destino à exportação. A prevenção da mudança na coloração de verde para amarelo durante o armazenamento constitui o foco de grandes esforços na área de pesquisas em pós-colheita. O presente trabalho teve como objetivo: (1) avaliar a aplicação de concentrações de etileno visando determinar a concentração mínima necessária para ativar a mudança da cor na casca dos frutos; (2) avaliar o tratamento térmico por imersão em água quente, visando utilizá-lo como alternativa para retardar o amarelecimento. No capítulo 1 foram realizados dois experimentos, sendo avaliados 4 tratamentos no experimento 1: 0 &mu;L L-1, 3 &mu;L L-1 , 6 &mu;L L-1 e 12 &mu;L L-1 de etileno, armazenados por 18 dias a 22 ± 2 °C e 85 ± 5% de umidade relativa (UR), utilizando frutos beneficiados, mas não tratados com ácido giberélico (GA). Se observou baixa perda de massa fresca e uma aceleração no desverdecimento a partir do dia 10 nos tratamentos de 3, 6 e 12 &mu;L L-1 de etileno. No experimento 2 foram avaliados seis tratamentos: 0, 1, 2, 3, 6 e 12 &mu;L L-1 de etileno, armazenados por 21 dias a 25 ± 2 °C e 85 ± 5% de UR. Foram utilizados frutos beneficiados, e tratados com ácido giberélico (GA). Os resultados mostraram pouco desverdecimento segundo análise no colorímetro, sendo esse resultado mais perceptível na análise por nota de cor para concentrações de 3 &mu;L L-1 de etileno e baixa perda de massa fresca. O beneficiamento com GA e cera pode ter afetado a ação do etileno. No Capítulo 2 foi conduzido um experimento utilizando frutos colhidos diretamente do campo e avaliado o tratamento térmico por imersão em água quente e posterior armazenamento em presença ou ausência de 3 &mu;L L-1 de etileno. Foram estabelecidos 6 tratamentos: controle sem etileno, controle + 3 &mu;L L-1 de etileno, 3 minutos a 50 ± 2 °C sem etileno, 3 minutos a 50 ± 2 °C + 3 &mu;L L-1 de etileno, 5 minutos a 50 ± 2 °C sem etileno, e 5 minutos a 50 ± 2 °C + 3 &mu;L L-1 de etileno. Os frutos foram armazenados por 30 dias a 25 ± 2 °C e 90 ± 5% UR. Foi observado que o tratamento hidrotérmico por 5 minutos a 50 ± 2 °C ajudou na manutenção da cor verde na casca dos frutos, também houve redução significativa na taxa respiratória e na perda de massa fresca dos frutos. Esses resultados sugerem que o tratamento térmico auxilia na manutenção da qualidade de frutos de lima ácida \'Tahiti\', uma vez que tem efeito no retardo de processos envolvidos no amadurecimento e senescencia.<br>One of the great challenges of the Brazilian citrus industry, as a major producer of \'Tahiti\' acid lime, has been the conservation of the fruit in natura with destiny to export. Preventing the change in color from green to yellow during storage is the focus of great efforts in post-harvest research. The objective of the present work was: (1) to evaluate the application of ethylene concentrations in order to determine the minimum concentration necessary to activate the color change in the fruit peels; (2) to evaluate the heat treatment by immersion in hot water, in order to use it as an alternative to delay the yellowing. In Chapter 1, two experiments were carried out and four treatments were evaluated in experiment 1: 0 &mu;L L-1, 3 &mu;L L-1, 6 &mu;L L-1 and 12 &mu;L L-1 of ethylene, stored for 18 days at 22 ± 2 ° C and 85 ± 5% of relative humidity (RH), using fruits benefited, but not treated with gibberellic acid (GA). It was observed low fresh mass loss and an acceleration in de-greening from day 10 in the treatments of 3, 6 and 12 &mu;L L-1 of ethylene. In the experiment 2, six treatments were evaluated: 0, 1, 2, 3, 6 and 12 &mu;L L-1 of ethylene, stored for 21 days at 25 ± 2 ° C and 85 ± 5% RH. The fruit was benefited and treated with gibberellic acid (GA). The results showed little de-greening according to the colorimeter analysis, being this result more noticeable in the analysis by color rating for concentrations of 3 &mu;L L-1 of ethylene and low fresh mass loss. Processing with GA and wax may have affected the action of ethylene. In Chapter 2 an experiment was conducted using fruits harvested directly from the field and the heat treatment was evaluated by immersion in hot water and subsequent storage in the presence or absence of 3 &mu;L L-1 of ethylene. Six treatments were performed: control without ethylene, control + 3 &mu;L L-1 ethylene, 3 minutes at 50 ± 2 ° C without ethylene, 3 minutes at 50 ± 2 ° C + 3 &mu;L L-1 ethylene, 5 minutes at 50 ± 2 ° C without ethylene, and 5 minutes at 50 ± 2 ° C + 3 &mu;L L-1 ethylene. The fruits were stored for 30 days at 25 ± 2 ° C and 90 ± 5% RH. It was observed that the hydrothermal treatment for 5 minutes at 50 ± 2 ° C helped to maintain the green color in the fruits peel, also there was a significant reduction in the respiratory rate and the loss of fresh fruit mass. These results suggest that the hydrothermal treatment helps to maintain the quality of \'Tahiti\' acid lime fruits, since it has an effect on the delay of processes involved in ripening and senescence

Submitted by Samira Ramos (samira.ramos@unifenas.br) on 2018-04-23T21:22:43Z No. of bitstreams: 1 João Paulo Marques.pdf: 1012005 bytes, checksum: 71d82a764900814bb8c03c30f77accce (MD5)<br>Made available in DSpace on 2018-04-23T21:22:43Z (GMT). No. of bitstreams: 1 João Paulo Marques.pdf: 1012005 bytes, checksum: 71d82a764900814bb8c03c30f77accce (MD5) Previous issue date: 2017-08-11<br>Brazilian coffee growers are becoming more and more concerned about the production of high quality coffees, with the purpose of producing special coffees, adding value to the final product. The production of special coffees gains force in the world market pleasing the palate of different consumers. Coffee beans have their intrinsic attributes modified by local characteristics such as altitude, temperature, lightness, rainfall index and relative humidity where the crop is located. Together with the climatic conditions of the place, the method of processing the grains by dry (producing natural coffee), wet (peeled coffees), moist with fermentation (pulped coffee) and wet desmucilador demultipled), confers changes in the quality of the grains produced. The objective of this study was to evaluate the relationship between post-harvest processing and the chemical and sensorial attributes of coffee from three locations in Minas Gerais. The coffees of the different regions presented their own characteristics, which are conferred according to the type of processing to which the grains are submitted in the post-harvest period. The samples of peeled coffees from the three regions studied presented higher scores for the sensorial attributes, compared to samples of natural coffees. The chemical analysis of coffee supports, however does not replace the sensorial analysis aiming at the classification of coffee beverage quality.<br>Os cafeicultores brasileiros vêm a cada dia mais se preocupando com a produção de cafés com qualidade superior, tendo como propósito a produção de cafés especiais, agregando valor ao produto final. A produção de cafés especiais ganha força no mercado mundial agradando o paladar de diferentes consumidores. Os grãos de café têm os seus atributos intrínsecos modificados pelas características locais como altitude, temperatura, luminosidade, índice pluviométrico e umidade relativa de onde a lavoura se encontra instalada. Juntamente com as condições climáticas do local, o método de processamento dos grãos realizado por via seca (produzindo o café natural), por via úmida (cafés descascados), por via úmida com fermentação (café despolpado) e por via úmida com desmucilador (cafés desmucilados), confere variações na qualidade dos grãos produzidos. Objetivou-se com o presente estudo avaliar a relação entre o processamento de pós-colheita e os atributos químicos e sensoriais de cafés de três locais de Minas Gerais. Os cafés das diferentes regiões apresentaram características próprias, que são conferidas de acordo com o tipo de processamento a que os grãos são submetidos no período de pós-colheita. As amostras de cafés descascados das três regiões estudadas, apresentaram maiores notas para os atributos sensoriais, em relação às amostras de cafés naturais. A análise química do café apoia, entretanto não substitui a análise sensorial visando a classificação da qualidade de bebida do café.

La tomate est un des fruits les plus consommés au monde, reconnu pour ses qualités nutritionnelles, et en particulier sa forte teneur en caroténoïdes. Le changement climatique et les sècheresses qu’il engendre amènent à repenser les méthodes de production, en diminuant les intrants. Dans le cas de la tomate d’industrie, destinée à la transformation, une approche intégrée depuis le champ jusqu’à la purée est nécessaire pour définir les effets des conduites à bas intrants sur les fruits et les purées de tomate, mais aussi leur interaction avec le procédé de transformation et la variété. Nous avons montré que la diminution de l’irrigation, et dans une moindre mesure de l’azote, modifient peu les caractéristiques biochimiques du fruit, augmentent la viscosité des purées et augmentent l’efficience de l’eau des cultures. Ces données sont prometteuses pour diminuer la consommation d’eau mais soulignent aussi l’importance de maitriser le déficit en particulier en cas de canicule. Un déficit modéré, jusqu’à 70% des besoins en eau semble possible. La viscosité des purées est avant tout modifiable par le choix variétal et par le procédé de transformation. Nous avons montré que la variété et le procédé modifient la viscosité par des mécanismes différents et que la quantité, la nature et la conformation des pectines jouet un rôle majeur dans la viscosité des purées. De plus nous avons mis en évidence des phénomènes d’agglomération de particules pouvant participer à la viscosité. Enfin, nos travaux ouvrent des perspectives sur le lien entre la structure du fruit et la structure et la viscosité des purées, et sur la manière dont le déficit hydrique peut modifier ce lien<br>Tomato is one of the most consumed fruit in the world, recognized for its nutritional qualities, and in particular its high carotenoid content. Climate change and the droughts it causes are leading us to a retconsider the production methods, by reducing inputs. In the case of processing tomatoes, intended for processing, an integrated approach from the field to the puree is necessary to define the effects of low-input practices on the fruits and tomato purees, but also their interaction with the processing method and the variety. We have shown that the reduction of irrigation, and to a lesser extent of nitrogen, has little effect on the biochemical characteristics of the fruit, increases the viscosity of purees and increases the water efficiency of crops. These data are promising for reducing water consumption but also underline the importance of controlling the deficit, particularly in the case of heat waves. A moderate deficit, up to 70% of water needs seems possible. The viscosity of purees can be modified by the choice of variety and by the transformation process. We have shown that the variety and the process modify the viscosity by different mechanisms and that the quantity, the nature and the conformation of pectins play a major role in the viscosity of the purees. In addition, we observed particle agglomeration phenomena that can contribute to viscosity. Finally, our work opens perspectives on the link between the structure of the fruit and the structure and viscosity of purees, and on the way the water deficit can modify this link

Objetivou-se com este estudo avaliar a potencialidade dos revestimentos comestíveis à base de Fécula de mandioca e pectina com e sem adição de óleo de buriti para aplicação em melancia e melão minimamente processados, visando a extensão da vida de prateleira destes produtos. A qualidade do óleo de buriti adicionado aos revestimentos comestíveis foi comprovada através do parâmetros físico-químicos; densidade: 1021 kgm-3; índice de acidez: 1,59 % em ácido oleico; índice de peróxido: 6,20 meqKg-1 e viscosidade cinemática: 41,3 mm²s-1. A caracterização dos principais ácidos graxos presentes no óleo de buriti foi realizada por métodos espectroscópicos de Ressonância Magnética Nuclear de Prótons (1H-RMN) e Espectroscopia de Infravermelho com Transformada de Fourier (FTIR). O ácido oleico (78%) foi o componente majoritário na composição do óleo de buriti. Os revestimentos comestíveis foram elaborados com 3% de fécula de mandioca ou 3% de pectina, 1% de glicerol ou 1% óleo de buriti, 2,5% de gelatina, 0,5% de ácido cítrico e 0,5% ácido ascórbico, os frutos minimamente processados foram revestidos utilizando a técnica de imersão. Os frutos revestidos foram analisados em relação ao pH, sólidos solúveis totais, acidez titulável e contagem microbiana ao longo de 10 dias de armazenamento. Os pH dos frutos revestidos variaram entre 5,35-5,76 para o melão e (4,52-5,49) para a melancia ao longo do tempo de armazenamento. Os teores de sólidos solúveis totais da melancia (7,6-9,6 °Brix) e do melão (7,2-8,6 °Brix) minimamente processados se mantiveram constantes para todos os revestimentos testados. A acidez titulável da melancia e do melão variou de 0,11 à 0,20 % e de 0,06 a 0,14 % em ácido cítrico, respectivamente. Os revestimentos comestíveis apresentaram eficiente barreira para permeabilidade de vapor, sendo que película à base de fécula proporcionou menor média de perda de massa da melancia (2,32%) e o revestimento fécula/óleo para o melão (3,39%). A população microbiana aeróbica e mesófila foi crescente ao longo do período de armazenamento em todos os revestimentos e no controle em ambos os frutos. Ao final dos 10 dias de armazenamento, a melancia apresentou crescimento de bactérias cerca de 9,0 log UFCmL-1, sendo o mesmo valor na população de bolores e leveduras. Os revestimentos fécula e pectina/óleo proporcionaram menor população de bactérias, aproximadamente 7,8 log UFCmL-1. O melão apresentou maiores valores de população de bactérias em comparação com a melancia no revestimento fécula e controle; 10,1 e 9,7 log UFCmL-1, v respectivamente. A contagem de bolores e leveduras também foi maior nos revestimentos fécula e fécula/óleo, aproximadamente 9,0 log UFCmL-1. Conclui-se que o óleo de buriti neste trabalho não apresentou atividade antimicrobiana nos revestimentos comestíveis presentes nos frutos. Os revestimentos comestíveis fécula e pectina proporcionaram à melancia condições adequadas para o consumo até o oitavo dia após o processamento. Entretanto no melão, apenas o revestimento pectina e pectina/óleo garantiram estabilidade microbiológica ao consumo até o quarto dia de armazenamento.<br>The objective of this study was to evaluate the potential of cassava starch and pectin-based edible coatings with and without addition of buriti oil for application in minimally processed watermelon and melon, aiming to extend the shelf life of these products. The quality of the buriti oil added to the edible coatings was confirmed by physicochemical parameters; Density: 1021 kgm-3; Acidity index in oleic acid: 1.59%; Peroxide index: 6.20 meqKg-1 and kinematic viscosity: 41.3 mm²s-1. The characterization of the main fatty acids present in the buriti oil was performed by spectroscopic methods of Proton Nuclear Magnetic Resonance (1H-NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Oleic acid (78%) had the major percent composition in the buriti oil. The edible coatings were prepared with the concentration of 3% cassava starch or 3% pectin, 1% glycerol or 1% buriti oil, 2.5% gelatin, 0.5% citric acid and 0.5% ascorbic acid, the minimally processed fruits were coated using the immersion technique. The coated fruits were analyzed for pH, total soluble solids, titratable acidity and microbial counts over 10 days of storage. The pH of the coated fruits varied between 5.35 and 5.76 for melon and 4.52 and 5.49 for watermelon over the storage time, respectively. The total soluble solids contents of minimally processed watermelon (7.6-9.6 ° Brix) and melon (7.2-8.63 ° Brix) remained constant for all evaluated coatings. The titratable acidity of watermelon and melon ranged from 0.11 to 0.20% and from 0.06 to 0.14% in citric acid. The edible coatings presented an efficient barrier for vapor permeability, being the starch-based film provided a lower average loss of watermelon mass (2.32%) and starch/oil coating for melon (3.39%). The aerobic and mesophilic microbial population was increasing over the storage period in all coatings and control in both fruits. At the end of the 10 days of storage, the watermelon had a bacterial growth of about 9 log UFCmL-1, the same value for mold and yeast population. The starch and pectin/oil coatings provided a lower bacterial population of approximately 7.8 log UFCmL-1. The melon presented higher values of bacterial population in comparison with the watermelon in the starch and control coating; 10.15 and 9.7 log UFCmL-1, respectively. The mold and yeast counts were also higher in the starch and oil coatings, approximately 9 log UFCmL-1. It is concluded that the buriti oil in this work didn’t present antimicrobial activity in the edible coatings present in the fruits. The edible coatings starch and pectin provided the watermelon suitable conditions for consumption until the eighth day after processing. However, for the melon, only pectin and pectin/oil coating ensured microbiological stability for consumption up to the fourth day of storage.

Orientador: Fabiano Fruett<br>Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação<br>Made available in DSpace on 2018-08-23T18:28:13Z (GMT). No. of bitstreams: 1 HenaoRoa_YullHeilordt_D.pdf: 5648105 bytes, checksum: a3dd3974832587d7000df5c643e2d6d9 (MD5) Previous issue date: 2013<br>Resumo: Os frutos submetidos a grandes impactos sofrem danos irreversíveis, perdem qualidade e nem sempre podem ser aproveitados no final do processo de pós-colheita. Identificar e entender estes eventos críticos pode colaborar na redução do desperdício na produção de alimentos. Já no caso do esporte, o estudo dos impactos do equipamento esportivo levando em consideração características particulares do material pode ser uma ferramenta valiosa durante o desenvolvimento e fabricação de, por exemplo: bolas de futebol. Com o objetivo de fornecer novas ferramentas à análise e ao estudo dos impactos na agricultura e nos esportes desenvolvemos o hardware e o software de dois instrumentos os quais interagem de forma sincronizada com o método da cinemetria para análise de movimento através de câmeras. O primeiro instrumento desenvolvido é um sistema de monitoramento de variáveis biomecânicas chamado Esfera Eletrônica Sem Fio (EESF). Na agricultura, o circuito eletrônico da EESF, é encapsulado dentro de uma esfera, facilitando o monitoramento de frutas e outros produtos perecíveis mediante a aquisição de variáveis que afetam a qualidade do produto. No esporte, o circuito eletrônico pode ser encapsulado, acoplado ou embutido em equipamentos esportivos facilitando o monitoramento do atleta ou do próprio equipamento esportivo. O hardware da EESF possui um diâmetro de 63 mm, massa de 168 g, densidade de 1,1, acelerômetros triaxiais na faixa de ±200 g, comunicação sem fio no padrão ZigbeeTM, alcance de 70 m, taxa de amostragem de 438 Hz e autonomia de 45 minutos. Já o software integra duas Interfaces Gráficas de Usuário (GUI), uma para Análise em Tempo Real (RTA) e outra para Análise e Pós-Processamento (PPA), que inclui uma opção de vídeo sincronização. O segundo instrumento é uma Plataforma de Força (PF) uniaxial, de baixo custo, projetada para trabalhar tanto estática quanto dinamicamente, para uma faixa de ±2,2 kN, taxa de amostragem de até 2,4 kHz, alta Relação Sinal-ruído (SNR), alto ganho e tampo de vidro com a opção de sincronismo com vídeo por baixo da mesma. Com a EESF foram realizados testes de queda livre em laboratório, sincronizados com a PF, para comparar os valores dos impactos obtidos pelos dois instrumentos, e testes em unidades de beneficiamento de maçã e laranja para medir os impactos sofridos pelas frutas no processo de pós-colheita. A PF também foi utilizada durante os testes de repique com diferentes bolas de futebol, em sincronismo com a cinemetria, comparando os resultados obtidos com os dois sistemas e ainda caracterizando cada bola através das variáveis cinemáticas e dinâmicas. A integração de diferentes tecnologias mostrou-se uma ferramenta valiosa na análise do impacto e suas relações com o objeto em estudo. As informações colhidas de diversos instrumentos foram comparadas e cruzadas, favorecendo o entendimento da mecânica do impacto. Estes instrumentos são facilmente adaptáveis a qualquer necessidade específica dentro da análise de problemas que envolvem impacto, tendo aplicações não somente em agricultura e esporte, mas também na área médica e de materiais<br>Abstract: Fruits submitted to large impacts suffer irreversible damage, lose their quality and, most of the times, and can't be availed at the end of the post-harvest process. Identifying and understanding these critical events may help to reduce food losses. With reference to sports, studying the impacts related to sport equipments by taking into account their particular material characteristics, can be a valuable tool for the development and manufacture of improved sport items like soccer balls. Aiming to provide new tools to analyze and study agriculture and sports impacts, we developed two instruments including hardware and software, which interact synchronously with the kinematic method based on cameras motion analysis. The first instrument developed is a monitoring system of biomechanical variables system called Wireless Electronics Sphere (WES). In focus on agriculture, the WES electronic circuit is encapsulated inside a sphere, facilitating fruit and other perishable products is monitored through the acquisition of product quality variables. In other application focus on sport, the electronic circuit can be encapsulated, attached or embedded into sport equipment, facilitating monitoring the athlete or sports equipment. The WES hardware has a 63 mm diameter, 168 g weight, 1.1 density, triaxial accelerometers in the range of ±200 g wireless communication with ZigbeeTM standard, 70 m range, 438 Hz sampling rate and 45 minutes of battery autonomy. The software integrates two Graphical User Interfaces (GUI), one for Real-Time Analysis (RTA) and the other for Post-Processing Analysis (PPA), which includes a video synchronization option. The second instrument is a low cost uniaxial Force Platform (FP), designed to work both static and dynamically for a ±2.2 kN range, 2.4 kHz sampling rate, high Signal-to-Noise Ratio (SNR), high gain and glass top with video sync option. The WES was used in the laboratory freefall test and synchronized with the FP, to compare the impact values obtained by both instruments. Beside, the WES was tested in apple and orange packing houses to measure the impact suffered by the fruits in the post-harvest process. The FP was also used during the rebounding tests with different soccer balls, synchronized with the kinematics and the results obtained were compared with both systems and each ball was also characterized through the kinematic and dynamic variables. The integration of different technologies proved to be a valuable tool on impact analysis and its relations with the object under study. The information collected from different instruments was compared and crossed, promoting the understanding of the impact mechanic. These instruments are easily adaptable to any specific requirement in the analysis of problems involving impact, with applications not only in agriculture and sports, but also in medical and material areas<br>Doutorado<br>Eletrônica, Microeletrônica e Optoeletrônica<br>Doutor em Engenharia Elétrica

Este trabalho teve por finalidade avaliar os efeitos de temperatura nos metabolismos de couves-flores e rúculas inteiras e minimamente processadas e diferentes materiais de embalagem na sua qualidade. No primeiro experimento, couves-flores, seus floretes, rúculas e suas folhas foram mantidos a 1º, 5º e 11ºC e determinados suas taxas de respiração, produção de etileno e quocientes de temperatura (Q10). No segundo, os floretes foram colocados em embalagens de filmes de polietileno de baixa densidade (PEBD), poliolefínicos coextrusados (PD – 941 e Clysar) e de policloreto de vinila, PVC esticável de 12 e 20 mm, envolvendo bandejas de poliestireno expandido mantidos a 5ºC. Análises físicas, químicas, físico-químicas, microbiológicas e sensoriais foram realizadas. No terceiro, folhas de rúculas foram colocadas em embalagens de filme de polietileno de baixa densidade (PEBD), laminado de polipropileno/polietileno (PP/PE), poliolefínicos coextrusados (PD – 900 e Clysar) e de policloreto de vinila, PVC esticável de 20 mm, envolvendo bandejas de poliestireno expandido e armazenados a 5ºC. Análises físicas, químicas, físico-químicas, microbiológicas e sensoriais foram realizadas. As taxas respiratórias das couves-flores inteiras e minimamente processadas foram iguais em quaisquer das temperaturas estudadas e sempre decrescentes até o 16º dia. A 1º e a 5ºC, tiveram a mesma taxa respiratória, diferindo das mantidas a 11ºC. Na faixa de 1º a 11ºC, o Q10 foi o mesmo para floretes e couves-flores; 2,1 e 2,2, respectivamente. Comportamento distinto tiveram as rúculas inteiras e as folhas soltas, pois, a 1ºC e a 5ºC, as taxas respiratórias foram significativamente iguais. A 11ºC, a partir do 4º dia, as folhas soltas começaram a apresentar taxas de respiração superiores às das inteiras, chegando a ser o dobro nos 14º e 16º dias de armazenamento. O Q10 médio para as rúculas inteiras situou-se ao redor de 3,54 e para as folhas soltas, 5,74, na faixa de 1º a 11ºC. Não foi detectada produção de etileno. As embalagens para floretes de couves-flores tiveram pouca ou nenhuma influência em seu pH, acidez, ºBrix, luminosidade, croma, Hue e firmeza. A embalagem PD – 941 foi a melhor por manter uma atmosfera modificada próxima à da recomendada para couves-flores (2-3% O2 e CO2 < 5%) e permitir menores perdas de vitamina C e melhores notas para vários atributos sensoriais de qualidade. Todas as embalagens mantiveram níveis de coliformes totais, bolores e leveduras bem abaixo dos limites permitidos pela Legislação Brasileira. As folhas de rúculas apresentaram níveis de coliformes totais ao redor de 10 5 UFC/g de produto no 10º dia a 5ºC, tornando-as impróprias para o consumo. Nestes 10 dias, as embalagens de PEBD e PP/PE se destacaram em relação às outras por reterem melhor a vitamina C e a coloração verde das folhas, por alcançarem melhores valores para sólidos solúveis, firmeza, presença de odor estranho, qualidade geral das folhas, deterioração e murchamento. As atmosferas modificadas desenvolvidas no interior destas embalagens, 5 a 7% O2 e 10 a 15% CO2, talvez sejam as mais indicadas para a conservação de rúculas minimamente processadas a 5ºC.<br>This work aimed at evaluating the effects of temperature on the metabolism of minimally processed and intact cauliflowers and salad rockets, and of different packaging materials on the quality of cauliflower florets and loose salad rocket minimally processed leaves. In the first experiment, intact cauliflowers, florets, intact salad rockets and loose salad rocket leaves were held at 1º, 5º and 11ºC and their respiration rates, ethylene production and temperature quotients (Q10) determined. In the second experiment, the florets were packed in low density polyethylene film (PEBD), co-extruded polyolefins (PD – 941 and Clysar AFG) and in 12 and 20 mm polyvinyl chloride (PVC) overwrapping expanded polystyrene trays, and maintained at 5ºC/85-95% relative humidity for 14 days. In the third experiment, loose salad rocket leaves were held under the same conditions in bags of low density polyethylene film (PEBD), laminated polypropylene/polyethylene film (PP/PE), co-extruded polyolefins, PD – 900 and Clysar HP and in expanded polystyrene trays overwrapped with 20 mm polyvinyl chloride (PVC). In the second and third experiments, physical, chemical, physical-chemical, microbiological and sensory analyses were performed. The respiration rates of both intact and fresh-cut cauliflowers declined over the 16-day period and were significantly the same at all temperatures studied. At 1º and 5ºC the respiration rates were the same but differed from those (cauliflower and florets) at 11ºC. From 1º to 11ºC, the Q10 for the cauliflowers was 2.2 and for the florets, 2.1. In contrast, the intact and fresh-cut salad rocket respiration rates were the same at 1º and 5ºC. At 11ºC, the fresh-cut salad rocket showed higher respiration rates than the intact ones as from the 4 th day. By the end of the experiment (14 th and 16 th days) the respiration rates of the fresh-cut salad rockets were twice those of the intact salad rockets, whose Q10 was about 3.45 from 1° to 11°C as compared to 5.74 for the fresh cut product. No ethylene production was detected by any sample at any temperature. The packaging materials had little or no effect on pH, titratable acidity, soluble solids, luminosity, chroma, hue and firmness of the florets at 5ºC. PD – 941 seemed to be the best packaging for florets, maintaining the atmosphere closest to that recommended for intact cauliflower (2-3%O2, CO2 < 5%), showing the lowest vitamin C losses and the best scores for several of the quality attributes. In general, all the packaging materials kept the yeast and mold counts low and the total coliform counts far below the maximum values permitted by the Brazilian Legislation, during 14 days at 5ºC, except for fresh-cut salad rocket leaves, which presented 10 5 CFU/g total coliforms by the 10 th day, being inappropriate for consumption. For 10 day periods, PEBD and PP/PE were the best packaging materials for green color and vitamin C retention, higher soluble solids, firmness, lack of off-odors, overall quality, decay and shriveling. The modified atmosphere generated inside these packaging materials (5-7% O2, 10-15% CO2) seemed the best for maintaining the quality of fresh-cut salad rockets held at 5ºC.

Elderberry is very popular plant, that is due to its beneficial effects to human organism very reputable. The main content substances are flavonoids and anthocyanins. Fruits of this flower are available only seasonally (which is usual for most of flowers), so we have to search for alternative solution of getting them. One of these solutions is conservation. Nowadays there are lots of types of postharvest adjustment, so we have more opportunities to find an optimal concept for every one specific plant. The diploma thesis is focused on assessment of content of phenolic substances harvested in different parts of Hradec Králové. They were conservated at laboratory temperature, elevated (40řC, 60řC) and reduced (-18řC) temperature. Next part of thesis is focused on assessing of the content of anthocyanins in fruits, that had been conservated for 3 years in refrigerator. The theme was finding the best concept of postharvestal adjustment. Despite to the individual places of harvest, there were not mentionable differences found out in content of phenolic substances in fruits. Main differences in content of substances were caused by different temperature of conservating area. With the upper temperature the content of phenolic substances was lower. Storage in the fridge for 3 years did not have any influence...

Oysters are filter-feeding bivalves, which filter water for nutrients and often accumulate contaminants and human pathogens such as Vibrio parahaemolyticus and Vibrio vulnificus naturally occurring in the marine environment. These naturally occurring pathogens have been frequently isolated from raw shellfish, particularly oyster, in the United States and are recognized as the leading causes of human gastroenteritis associated with seafood consumption. Human illness caused by consumption of raw oyster contaminated with V. parahaemolyticus and Vibrio vulnificus typically results in reduced sales of oysters and a consequent significant financial burden for the producers. The United States produces more than 27 million pounds of oysters each year with a large portion of them being produced from the coastal water of the Gulf of Mexico. It is estimated that 20 million Americans eat raw shellfish and consumption of raw oyster is responsible for about 95% of all deaths associated with seafood consumption in the U.S., making raw oysters one of the most hazardous seafoods. Several post-harvest processes, including low temperature pasteurization, freezing, high pressure processing and irradiation, have been reported capable of reducing Vibrio contamination in raw oysters. However, most of them require either a significant amount of initial investment or operation costs, and oysters are often killed during processing. Cost-effective post-harvest processing for reducing V. parahaemolyticus in raw oysters without significant adverse effects on the oysters remains to be developed. This study was conducted to determine impacts of low-temperature (15, 10 and 5°C) depuration and frozen storage on reducing V. parahaemolyticus and V. vulnificus in raw oysters. Depuration of the Gulf oyster (Crassostrea virginica) with electrolyzed oxidizing (EO) water (chlorine, 30 ppm; pH 2.82; oxidation-reduction potential, 1,131mV) containing 3% NaCl was found ineffective on reducing both V. parahaemolyticus and V. vulnificus in the oysters. Reductions of V. parahaemolyticus and V. vulnificus in oyster after 48 h of EO water depuration at 22°C were limited to 0.7 and 1.4 log MPN/g, respectively. Depuration with EO water at lower temperatures did not enhance reductions of Vibrio in the oysters. Greater reductions of V. parahaemolyticus (1.2 log MPN/g) and V. vulnificus (2.0 log MPN/g) were observed when the oysters were depurated with artificial seawater (ASW) at room temperature (22°C) for 48 h. Decreasing temperature of ASW to 15°C for depuration significantly increased the reductions of V. parahaemolyticus and V. vulnificus to 2.1 and 2.9 log MPN/g, respectively, after 48 h of process. However, depuration of oyster in ASW at 10 and 5°C were found less effective than at 15°C in reducing Vibrio in the Gulf oysters. An extended depuration with ASW at 15°C for 96 h was capable of achieving 2.6 and 3.3 log MPN/g of reductions of V. parahaemolyticus and V. vulnificus, respectively, in the Gulf oysters. Study of effects of frozen storage at -10, -23 and -30°C on reducing V. parahaemolyticus in raw half-shell Pacific oyster (Crassostrea gigas) found that the population of the bacterium decreased faster in oysters stored at -10 than at -23 or -30°C. Holding half-shell Pacific oyster at -10°C for three months or at -23°C for four months was capable of achieving a greater than 3-log (MPN/g) reduction of V. parahaemolyticus in the Pacific oyster.<br>Graduation date: 2008

The Australian rice industry faces tremendous pressure for incremental increase in water use efficiency. Rainfed (RF) rice production could provide opportunities for diversifying the options for the rice industry to address the issue of water shortage. Rice varieties for RF production need to be developed to extend the rice industry to Australian wet-tropical regions. Achieving economic yields and matching grain quality to market standards are some of the challenges for RF rice production. Thirteen RF rice genotypes obtained from Australian Agricultural Technologies Limited (AAT) were evaluated during 2013 – 2015 in central and north Queensland locations as RF and supplementary/strategic irrigation (SI) crops, and were assessed for their yield potentials and grain quality performances. The results from varietal trials under RF and SI showed large genetic variation, primarily associated with grain types (GT), for yield and grain quality attributes. The long grain (LG) types recorded significantly greater (6.7 fold) yield response to SI (3.16 vs 0.47 t/ha) compared to the medium grain (MG) type varieties (1.8 fold yield in SI) (4.37 vs 2.49 t/ha). The RF yields under the drier tropical environment of Alton Downs (AD) were limited by a short growing season and low rainfall which impacted on late maturing LG type indica varieties. However, greater yield was recorded for early maturing, MG type japonica varieties. The effect of SI on grain quality was not as strong as the effects on the yields. Among the milling characteristics millout, was significantly greater for LG compared to MG type (0.58 vs 0.47) under the SI. Among the chemical characteristics, the SI rice showed greater gelatinisation and pasting temperature compared to RF rice, particularly in the second year, due to earlier planting, therefore, LG type varieties escaped low temperature stress. The effects of SI on physical, cooking and nutritional characteristics were not significantly. Given the short window of the warm, wet season (January – May) at AD, the performance of LG types was significantly favoured by SI. The LG type were generally late maturing, and therefore, flowering and grain filling coincided with cold spells, particularly for late planted crops. Hence, a RF cropping option at AD is favourable for short duration MG type varieties. In the varietal evaluations under RF production over multiple seasons of three years, RF yield was 1.38 – 1.43 t/ha. The overall yield of MG type was significantly greater compared to LG type (2.49 vs 0.47 t/ha). In the first season (planting February 2013), none of the LG type produced yield; however, in the second and third season (planted in January and November), LG type varieties produced yields of 0.12 – 0.66 t/ha. These longer term yield data for LG types clearly demonstrated that the commercial harvest of LG as a rainfed crop in central Queensland could not be a viable option. Among the MG types the higher yielding varieties were AAT-4 and AAT-19 (2.92 t/ha), followed by AAT-6 and AAT-17. In spite of the low yield, the milling ratio/millout was significantly higher in LG types compared to MG varieties. The Year (Y) x Grain type (GT) x Variety (V) interaction for milling ratio was due to the fact that the varietal effect was significant in both grain types, as LG variety AAT-12 recorded the highest millout (~0.60), whereas MG variety AAT-4 maintained lowest mill out (0.40) in the first year. Similarly, chalkiness was significantly higher for MG compared to LG (14% vs 7%) types. The grain chemical characteristic measured as alkali spreading value was significantly greater for MG compared to the LG varieties (6.01 vs 1.60 score). The amylose content differed significantly due to YxGTxV interactions suggesting greater genotype x environmental effects. Amylose content was greater in year1 followed by year2 and year3, and was generally higher for LG compared to MG. However, the highest amylose containing LG varieties AAT-15 and AAT-16 in 2013 and 2014 showed significant reduction of amylose in 2015 but the amylose content of LG AAT-18 recorded consistently higher amylose (24%) in all 3 years. The gelatinisation temperature (GeT) of LG type lines was significantly greater than that of the MG types (74.2 °C vs 70.2 °C). In summary, the yield performance of LG type at AD was low, primarily governed by a smaller planting window for late maturing rice varieties. Some of the MG type varieties, e.g., AAT-4 recorded the highest but economically marginal yield, but the MG types suffered from poor grain quality associated with the lowest millout and higher chalkiness; both of these contributed negatively to marketable yield. Hence, a RF rice crop performance under a dry tropical environment with limited rain and a short planting window can be a significant limitation for development of the RF rice industry. The AAT rice varietal evaluations in contrasting RF environments of AD (c. 593 mm rain) and wet tropical South Johnstone (SJ) (c. 876 mm rain) showed that paddy yield in the SJ was 2.4 times greater than at AD (4.66 vs 1.92 t/ha), and the yield difference between the LG and MG in the wet tropics was not significant (4.92 vs 4.36 t/ha), demonstrating the opportunity of commercial RF rice crops for both grain types. Significant effects of the growing environment were noted on grain quality parameters. Millout was consistent across the locations; however, a greater millout was recorded for LG compared to MG type (0.56 vs 0.50). Although greater chalkiness was recorded for MG compared to LG types at AD (27% vs 13%), no difference between GT for GeT was recorded at SJ. The GeT varied between 71.3 and 80.0 °C and differed due to GT x V interaction; the greatest GeT (80.2 °C) was recorded for AAT-4 at both locations. The amylose content is related to cooking and nutritional quality, but did not vary significantly due to V and locations. The effect of growing location was significant for cooking time, suggesting that grain from AD took longer to cook (42 vs 29 minutes). Nutrition characteristics, primarily the protein, nitrogen and sulphur concentrations of the grain were higher at SJ, irrespective of the GT compared to AD where the protein, nitrogen and sulphur concentration decreased in MG compared to LG varieties, showing significant L x GT interactions. Under the environment of SJ, the yield and grain quality of LG varieties were enhanced when compared to AD. The results showed that AAT RF rice varieties in SJ could produce a feasible crop, with acceptable level of milling recovery, and grain quality traits comparable to those of the commercially recommended varieties such as Topaz and Doongara in tropical Australian north Queensland.<p></p>

Gulf oysters are harvested and consumed year-round, with more than 90% consumed in a raw, unprocessed state. A chief concern of policymakers in recent years is the incidence of Vibrio vulnificus infection following raw seafood consumption. V.vulnificus refers to a halophilic bacterium naturally occurring in brackish coastal waters, which concentrates in filter-feeding oysters. Proposed FDA legislation requiring processing of all raw Gulf oysters sold during warmer summer months threatens the Gulf oyster industry, as little to no research regarding demand for post-harvest processing (PHP) has preceded the potential mandate. This research endeavors to examine the relationship between oyster consumers' fears of V.vulnificus infection and their willingness-to-pay (WTP) for processing of an oyster meal. The psychological model of Protection Motivation Theory (PMT) is employed alongside the economic framework of contingent valuation (CV) to result in an analysis of oyster processing demand with respect to threats and efficacy. A survey administered to 2,172 oyster consumers in six oyster producing states elicits projected consumption and PMT data. Principal Component Analysis is used to reduce the number of PMT variables to a smaller size, resulting in five individual principal components representing the PMT elements of source information, threat appraisal, coping appraisal, maladaptive coping, and protection motivation. Using survey data, the marginal willingness-to-pay (MWTP) for PHP per oyster meal is also calculated, and the five created PMT variables are regressed on this calculation using four separate OLS models. Results indicate significant correlation for four of the five created PMT variables. In addition, a mean MWTP for PHP of $0.31 per oyster meal is determined, contributing to the demand analysis for processing of Gulf oysters. The findings suggest a strong relationship between the fear elements and the demand for processing, and support arguments in favor of further research on specific PHP treatments and the necessity for a valid PMT survey instrument.

Farmers in Nepal lose about a third of their harvested grain due to postharvest handling and storage. This has led to food insecurity and economic losses. Despite the importance of postharvest, the grain storage system in Nepal relies on traditional storage structures like bamboo granaries. The incidence of storage pests is reported up to 100% in these structures. To minimize the storage loss, farmers use different grain protection methods including toxic chemicals. Multiple cases of pesticides-related poisoning and deaths have been caused by misuse and overuse of pesticides. To push safer, chemical-free alternatives like hermetic storage it is important to understand current pest challenges and management practices in Nepal. Adaptation of chemical-free pest management strategies like hermetic storage largely depends upon basic and applied laboratory research findings. Determining the baseline adult mortality under various hypoxia levels and subsequent insect emergence will help determine the effectiveness of a low oxygen environment in controlling <i>Sitophilus oryzae</i> (L.). This would increase our understanding of hermetic storage technology and help improve its application to both farmers and commercial users and serve as a possible substitute to traditional or chemical pest control methods. In chapter one, I report the result of the survey conducted in Nepal to understand i) current post-harvest storage practices and (ii) assessment of the best delivery approach for storage innovations. In chapter 2, I report the result from laboratory experiment conducted to understand the lethality of hypoxia at 5% oxygen level and below against <i>Sitophilus oryzae</i> (L.), which is a major storage pest reported by farmers in Nepal.

Il settore del commercio elettronico è un settore in sempre più ampio e rapido sviluppo. Le motivazioni possono essere molteplici ma sono sicuramente legate al cambiamento dello stile di vita delle persone e alla possibilità di accedere all’acquisto di beni che altrimenti sarebbe stato pressoché impossibile acquistare. La disciplina riguardante questo settore è anch’essa stata elaborata mano a mano che questo settore si è evoluto, per rispondere di volta in volta alle diverse necessità che si sono presentate. La disciplina è tutt’oggi ancora in evoluzione, soprattutto a causa del fatto che in questo settore ci sono molteplici forme contrattuali che vengono utilizzate per creare accordi commerciali dei più vari tipi, e ognuno dei quali prospetta problematiche diverse. In questo lavoro si parte dalla nascita e dallo sviluppo del commercio elettronico per analizzare l’evoluzione della disciplina associata. Dopodiché si analizza il tipo di contratto posto in essere tra la Santoni S.p.A. (noto marchio di calzature di alta gamma) e la Filoblu s.rl. (società veneta che si occupa della creazione e gestione di piattaforme e-commerce) per valutarne i punti cruciali. Dopo aver analizzato in dettaglio gli aspetti sopra citati, viene illustrata la disciplina delle denunce per difetto di conformità del bene e come queste vengono gestite dalla Santoni S.p.A., per passare poi all’analisi delle denunce per difetto di conformità degli ultimi 3 anni. Questo perché, come si noterà, questo è un campo in cui le problematiche sono controverse e gran parte della gestione viene lasciata alle ditte produttrici che si trovano di volta in volta di fronte alla scelta su come gestire il caso per rendere il cliente soddisfatto del servizio. La disciplina segue i suoi sviluppi e cerca di prevenire (per quanto possibile) situazioni sgradevoli sia per il fornitore del bene che per l’acquirente. L’entusiasmo mostrato dagli acquirenti per la comodità e la facilità dell’acquisto on-line, viene molto spesso smorzato dall’impossibilità di vedere e toccare con mano il bene oggetto della transazione, creando un senso di inquietudine legata alla qualità del bene che si sta acquistando. Per questo motivo, nel momento in cui un acquirente denuncia un difetto di conformità sul bene acquistato on-line o semplicemente la sua insoddisfazione su determinati aspetti del bene (colore, calzata, forma, ecc.), si attiva un meccanismo volto a valutare la presenza o meno di un eventuale difetto sul bene e di risolverlo nel modo più soddisfacente per l’acquirente. Dopotutto per un’azienda, gestire un negozio on-line equivale ad avere una vetrina di sé stessa attiva 24 ore su 24 e visibile a chiunque abbia un accesso al mondo di internet, e per questo motivo gestire i clienti che utilizzano questo tipo di servizio significa migliorare o peggiorare, in maniera esponenziale rispetto a quanto può avvenire in un negozio fisico, l’immagine percepita da ogni singolo acquirente. C’è però da dire che, in molti casi registrati, nonostante una perizia tecnica effettuata da operai specializzati sul prodotto venduto, la poca conoscenza dei processi di produzione dei singoli clienti, mette i venditori in situazioni difficili da gestire, in quanto il cliente non riesce a capire che quello che lui percepisce come un difetto in realtà non lo è, e che quindi non è imputabile all’azienda quello che lui crede che lo sia. Generalmente in questi casi, sempre per cercare di limitare degli inevitabili danni d’immagine, si offrono al cliente soluzioni alternative come resi gratuiti, omaggi di piccoli prodotti complementari o buoni sconto su acquisti successivi, ma sarebbe sicuramente necessaria una normativa completa e definitiva, che indichi in maniera risoluta come gestire casistiche particolari che si presentano frequentemente nella fase post-vendita. Viste le innumerevoli problematiche che si riscontrano frequentemente in questo ambito, la normativa a tutt’oggi presente non risulta essere sufficientemente soddisfacente per lo scopo a cui è stata creata. Come detto precedentemente, tutto il meccanismo che viene messo in atto all’interno di ogni azienda dopo una denuncia di difetto di conformità, si innesca per risolvere il problema ed evitare un inevitabile danno d’immagine, quindi si può concludere che, nonostante la presenza di una normativa (anche se ancora in via di sviluppo), l’arma migliore che un consumatore on-line può mettere in atto e che spaventa di più i venditori è sicuramente il danno d’immagine. Una cattiva recensione su un blog, un social network, o semplicemente un racconto di una brutta esperienza derivante da un acquisto on-line, può vanificare tutti gli sforzi fatti dal venditore per raggiungere una buona percezione del proprio marchio, e innestare un meccanismo a catena che non giova all’immagine aziendale.