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Huang, Huidong. "Developing Saturated Fat-reduced Processed Cheese Products." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1431089024.
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Combes, Christian Daniel. "Analysis of proteolytic breakdown products in Emmentaler cheese and in a related model /." [S.l.] : [s.n.], 2000. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13571.
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Huang, Min-Hsin. "Price competition between store brands and national brands determinants of price elasticities for cheese products /." Columbus, Ohio : Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1083621040.
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Thesis (Ph. D.)--Ohio State University, 2003.Title from first page of PDF file. Document formatted into pages; contains xiv, 169 p.; also includes graphics (some col). Includes abstract and vita. Advisor: David E. Hahn, Dept. of Agricultural, Environmental & Development Economics. Includes bibliographical references (p. 164-169).
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Karathanassi, Vassiliki. "Exploring elements of the cheese purchase decision process through application of purchasing involvement methodology : the case of cheese products in Athens, Greece." Thesis, Imperial College London, 1995. http://hdl.handle.net/10044/1/8785.
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Fairbrother, Paul. "The fermentation of cheese whey by Lactobacillus helveticus." Thesis, University of South Wales, 1991. https://pure.southwales.ac.uk/en/studentthesis/the-fermentation-of-cheese-whey-by-lactobacilius-helvecticus(32b72e44-3d2a-4fcb-85d4-9b34263bd05e).html.
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The lactic acid fermentation of cheese whey permeate by Lactobacillus helveticus was studied. Precipitate formation during autoclaving of whey permeate was examined. Precipitation was found to be pH and temperature dependent. Qualitative analysis suggested that the precipitate was a calcium-phosphate complex. Solubilisation was achieved both by acidification and use of the sequestering agent EDTA. Optimisation of L. helveticus growth in whey permeate was carried out using factorial design, as opposed to a traditional univariate approach. Using this technique, the variation of specific growth rate with pH, temperature and stiirer speed was assessed. Cell growth and lactic acid formation in whey permeate containing various supplements, were investigated. Yeast extract was the most effective nitrogen/growth factor supplement. Maximum lactic acid production was achieved in permeate containing yeast extract (0.75% w/v), Tween 80 (0.1% v/v) and sodium acetate (0.05% w/v). Optimisation of lactic acid production in supplemented whey permeate was performed using factorial design. Optimum conditions for both acid formation and cell growth were pH 5.9, temperature 42°C and stirrer speed 200 rpm. Fourier transform infrared spectroscopy was applied to the on line and off line quantitative analysis of lactose and lactic acid during the fermentation process. This technique enabled substrate and product levels to be assessed quickly and simply, with no sample pre-treatment. Continuous culture of L. helveticus in MRS medium and supplemented whey permeate was carried out. Substrate conversion and lactic acid productivity decreased with increasing dilution rate. Maximum productivity corresponded to a dilution rate of 0.3 h" 1, whereas minimum residual substrate occured at a dilution rate of 0.1 h' 1 . Translation of the fermentation process from bench scale (11) to pilot scale (161) appeared to be successful. Completion times, productivity and lactose utilisation compared favourably with bench scale results.
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Rahman, Ruksana. "Study of radiolytic products from gamma irradiated lipids." Thesis, London South Bank University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245134.
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Ocampo-Garcia, Jorge Ricardo. "Cottage Cheese from Ultrafiltered Skimmilk by Direct Acidification." DigitalCommons@USU, 1987. https://digitalcommons.usu.edu/etd/5344.
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Pasteurized skimmilk at 4°C was acidified to pH 5.8 with 85.5% phosphoric acid (136g H3Po4;100 kg skimmilk), then warmed to 54°C and ultrafiltered to a protein concentration 9.1 ± 0.2%. The retentate was heated to 76.5°C for 16 s then cooled to 2°C. Phosphoric acid (85.5%) was added at a rate of 3.41g per kg retentate. The acidified retentate was slowly warmed to 29.5 °C (3°C/5 min) when the pH was checked. The pH at this point was no lower than 5.4. Heating was continued until a temperature of 32.2°C was reached. Glucono delta lactone was added to the retentate (17.6 g/kg retentate) and left undisturbed for approximately 80 min. The curd was cut at pH 4.7 with 0.64 cm curd knives and allowed 10 min for syneresis. Permeate obtained from the same lot of milk was acidified to pH 4.8 (66 g H3Po4;100 kg permeate), then added to the curd at 32.2°C (three parts permeate to four parts retentate) and used as a cooking vehicle. The curd was cooked to 59°C in 90 min. The curd was held at 59°C for 10 min, drained and washed once with ice water. Cream dressing containing 12.5% fat and 3% salt was used at the rate of two parts curd to one part dressing.
Control cottage cheese was produced by a direct acid method from the same skimmilk used to produce ultrafiltered curd.
Use of ultrafiltered skimmilk retentate for cottage cheese making resulted in 2.24% more curd (corrected to 20% solids) and 2.24% more curd per kg original milk protein than the control. However, satisfactory firmness in UF curd required slightly more than 20% solids in the final product. Sensory evaluations indicated that creamed cottage cheese was not significantly different (p
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Mandrinos, Symeon. "Internationalisation processes of FMCG products : a study of Protected Designation of Origin (PDO) products : the case of feta cheese in Greece." Thesis, University of Essex, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603324.
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This thesis explores the internationalisation process of firms in the context of Protected Designation of Origin. The study shows the impact of firm's specific internal, industry and country's specific external factors on the exporting process and the export development of small, medium and large enterprises. In particular, this investigation sheds more light on internationalization theories through a context specific lens as it explains the internationalisation process of PDO firms , and the way it fits with the -existing internationalisation model in the literature that has not previously addressed. The current and upcoming significance for European Union external trade policies and strategies have increased the importance of this study. That is, with regard to enterprises ' main concern for international expansion in both European and Third countries proximity level. Methodologically, this thesis is framed on realism paradigm through interpretative qualitative case study approach. Throughout this approach a semi-structure in-depth interview exploration demonstrates how key respondents conceive PDO firms international expansion as an enacted practice. These participants shape the output that it has experienced. This is subject to wide range of causal influences, and is equivalent to the analysis of management and organisational actions, as enhances to bring out different complexities. From analysis and testing structure, insights unearthed via thirty one (31) responses of expert practitioners in the field. Therefore, solutions demonstrate the hidden factors that influence PDO firms' export process. The findings exhibit that managerial, organisational, product, strategy" corporate finance, customer, competition, home and host specific factors dynamically affect Greek PDO firms export orientation. In addition, the aforementioned factors appear that purposely correspond to openness for export experience.
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Knopp, Thomas Karl. "Lipoprotein removal from cheese whey by cross-flow microfiltration." Connect to resource, 1992. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1202145220.
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Feliz, Perez Danis Jesus. "Accelerated ripening by enzyme modified application in swiss cheese." The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1187104055.
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Smith, Anita Mohler. "Objective judgement of cheese varieties by multivariate analysis of HPLC profiles." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26535.
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An objective analytical method was developed to characterize the taste profiles of five cheese varieties. Nonvolatile water extracts of Cheddar, Edam, Gouda, Swiss, and Parmesan cheeses were analyzed by high performance liquid chromatography (HPLC) with a reversed phase column. The HPLC operating conditions were determined with Mapping Super-Simplex followed by Centroid Mapping Optimization. A ternary gradient elution system was used with an Adsorbosphere C8 column to resolve a maximum number of components. The optimum solvent volume ratio was 96.8 : 1.2 : 2.0 for trifluoroacetic acid (0.1%), acetonitrile, and methanol, with a flow rate of 1.0 mL/min. Over 50.3 min this ratio was changed to 56.3 : 30.3 : 13.4.
Multivariate statistical analyses including principal component and discriminant analyses were applied to 55 peak areas from 106 cheese chromatograms. Principal component analysis reduced the dimensionality of the "data from 55 to 17 principal components, which are-combinations of the original variables, with a 26% loss of explained sample variation. Discriminant analysis on data from a single HPLC column was able to correctly classify cheeses by variety at a greater than 90% success rate. This grouping rate dropped to 64% when data from all four HPLC columns was combined, implicating large between column variations. A semi-trained sensory panel correctly classified cheeses by variety at a 63% rate. This objective method provides a lasting fingerprint of cheese products.Land and Food Systems, Faculty of
Graduate
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Mostafa, Imeni Seyed. "Techno-Economic Assessment of Anaerobic co-digestions of livestock manure with agro-industrial by-products." Doctoral thesis, Universitat de Vic - Universitat Central de Catalunya, 2019. http://hdl.handle.net/10803/667824.
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L’aplicació al sol d’una quantitat excessiva de dejeccions ramaderes, pot tenir un impacte ambiental notable sobretot en sòls i aigües subterrànies. Les dejeccions ramaderes com a residus biodegradables es poden tractar i reciclar per obtenir recursos (compost o biogàs) i per tant la producció d’energia renovable i productes fertilitzants. En general, els residus biodegradables reben una especial atenció a la legislació europea (Revised Framework Directive 2008/98 / CE) i, per tant, és necessari desenvolupar instal·lacions adequades per tractar i reciclar aquest tipus de residus i assegurar el funcionament correcte i eficaç d'aquestes instal·lacions de tractament i gestió.
La digestió anaeròbia dels fems i purins és una pràctica habitual; no obstant, el baix potencial de producció de biogàs pot dificultar la rendibilitat dels sistemes de digestió anaeròbia en explotacions ramaderes de petita i mitjana producció. Així doncs, perquè aquesta tecnologia sigui més atractiva per als agricultors, es podria aconseguir un increment de la producció de biogàs co-digerint els fems animals amb un co-substrat abundant i accessible, com ara subproductes agrícoles com la palla de blat (en forma crua o pre-tractats) i derivats de la indústria làctia com el sèrum de formatge.
A més de l'augment de la producció de biogàs i conseqüentment de la producció energètica, afavoreix la viabilitat econòmica de les tecnologies i plantes de digestió anaeròbia a explotacions ramaderes petites i mitjanes. No obstant això, hi ha poca informació disponible en la literatura científica sobre la viabilitat tecno-econòmica de l'aplicació d'aquestes plantes en explotacions ramaderes petites i mitjanes.
Per tant, en aquesta tesi es va dur a terme una avaluació tecnoeconòmica de la co-digestió anaeròbia de fems de bestiar i palla de blat (en forma crua i pretratada) i amb sèrum de llet.
L'avaluació tecnològica es va realitzar a escala de laboratori mitjançant reactors discontinus i semicontinguts. Amb les dades obtingudes, es va desenvolupar un model econòmic per investigar la rendibilitat de les plantes de co-digestió anaeròbia en explotacions ramaderes petites i mitjanes; també es va realitzar un anàlisis de sensibilitat per investigar l’efecte de paràmetres importants (per exemple, el preu de l'electricitat) sobre el rendiment econòmic global del sistema.
Els resultats obtinguts a partir de l’avaluació tecnoeconòmica van mostrar que per a una granja de 250 caps de bestiar adult, els ingressos generats en un procés de digestió anaeròbia no són capaços de compensar la inversió inicial necessària. No obstant això, la co-digestió de fems amb palla crua o briquetada ha mostrat uns rendiments econòmics positius (valors actuals nets> 0, taxa interna de retorn> 9% i retorn de la inversió en 11 anys), així com la co-digestió de fems amb un 30% de sèrum de llet amb resultats econòmics també positius (valors actuals nets> 0, taxa interna de retorn> 11% i retorn de la inversió en 9 anys). Pels agricultors disposats a aplicar la digestió anaeròbia, el preu de venda de l'electricitat i el preu de la palla són els paràmetres clau per determinar la rendibilitat del sistema.
A més a més, s'han provat i avaluat els tractaments previs per augmentar la producció de biogàs de palla des d'una perspectiva tècnica i econòmica. Els pre-tractaments alcalins i de microones-alcalins amb palla van mostrar els millors resultats amb un augment de la producció de biogàs del 156% i del 92% respectivament en comparació amb la palla crua.Deposition of excess amount of livestock waste when they are not properly treated has a notable environmental impacts specially on soil and undergrounds water. Livestock waste as a biodegradable waste can be treated and recycle to finally obtain compost or biogas which means green energy and fertilizer/soil-amendment products. In general biodegradable waste receives especial attention in the European Legislation (Revised Framework Directive 2008/98/CE) and therefore, is necessary to develop suitable facilities to treat these types of waste and assure the correct and efficient operation of such treatment and management facilities. Anaerobic digestion of dairy cattle manure is a common practice; however, the low biogas yield of manure can hamper the profitability of anaerobic digestion systems in small to medium dairy cattle farms. To make this technology more attractive to farmers, an increase in biogas yield per cubic meter of reactor could be achieved by co-digesting animal manure with an abundant and easy accessible co-substrate such as agricultural by-products like wheat straw (in its raw form or pre-treated) and dairy industry by-products like cheese whey. In addition of increase in biogas production which can be translated to production of more energy, economic feasibility of implementation of anaerobic digestion plants in the farms is a must. However, there is scarce information provided in scientific literature about economic feasibility of implementation of such plants in small to medium cattle farms. Thus, in this thesis a techno-economic assessment of anaerobic co-digestion of animal manure and wheat straw (in the raw form and pretreated) or cheese whey was carried out. The technological assessment was carried out at lab scale using batch and semi-continuous reactors. With the data obtained, an economic model was developed in order to investigate the profitability of anaerobic co-digestion plants in small to medium dairy cattle farms, sensitivity analyses were carried out to investigate important parameters (e.g. electricity price) on the overall economic performance of the system. The results obtained from the techno-economic assessment showed that for a farm of 250 adult cattle heads the revenues generated in an anaerobic mono-digestion process are not able to offset the initial required investment. However, the co-digestion of manure with raw or briquetted straw showed positive economic performance and positive returns (Net Present values > 0, Internal Rate of Return > 9 % and a Return of the investment in 11 years) as well as the co-digestion of manure with 30% of cheese whey which showed positive returns (Net Present values > 0, Internal Rate of Return > 11% and a Return of the investment in 9 years). For farmers willing to implement anaerobic digestion, Electricity selling price, and the price of the straw are the key parameters to determine the profitability of the system. Moreover, pre-treatments to increase the straw biogas production have been assessed and evaluated from a technic and economic perspective. Alkali and microwave-alkali straw pre-treatments showed the best results with an increase in biogas production of 156 % and 92 % compared to raw straw.
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Lejonklev, Johan. "Possibilities to Vary the Functional Properties of Yellow Cheese by Using Different Vegetable Fats." Thesis, University of Kalmar, University of Kalmar, University of Kalmar, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hik:diva-1073.
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Prabhakar, Veena. "Rapid Analysis of Spores and Swiss Cheese Bacterial Cultures by Infrared Microspectroscopy." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1258402626.
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Haileselassie, Seble Sereke Berhan. "Production of enzyme-modified cheese and bioactive peptides by Lactobacillus and commercial enzymes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ50782.pdf.
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Avsar, Yahya Kemal. "Production of white-brined cheese by the direct recombination system using retentate powder." Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246046.
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Shrestha, Subash. "Ensuring Microbial Safety in Food Product/Process Development: Alternative Processing of Meat Products and Pathogen Survival in Low-Salt Cheddar Cheese." DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1163.
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Most outbreaks of foodborne illness in the United States occur as a result of improper food-handling and preparation practices in homes or food establishments. Some food-safety recommendations that are difficult to incorporate into handling and cooking procedures have contributed to a gap between food-safety knowledge and the actual behavior. The first part (Chapter 3, 4) of this study sought to ensure microbial safety by establishing alternative processing of meat products that can be easily practiced by food-operators and consumers. In Chapter 3, a novel method was developed to thaw frozen chicken-breast by submersion in hot water at 60 °C, an appropriate temperature setting for foodservice hot-holding equipment. This method is rapid (compared to either refrigerator or cold-water thawing that also uses a significant amount of water), safe, and the final cooked-product sensory-quality was not different from refrigerator-thawed and cooked product (microwave thawing results in localized overheating). Chapter 4 developed marinade-cooking (91 °C) and holding (60 °C) procedures for hamburger-patties. Frozen patties were partially grilled and finished cooking in marinade. The moderate temperature of marinade cooking overcomes the chances of thick-patties being surface-overcooked while innermost portions remain undercooked as seen in high-temperature cooking methods (grilling and pan-frying). Consumers liked the marinade-finished cooked and held patties (up to 4 h) equally or more (holding-time dependent) compared to patties grilled and held in a hot-steam cabinet.
Reducing salt in perishable foods including cheese is microbial-safety concern especially in their distribution and storage. The second part (Chapter 5, 6) of this study sought to evaluate microbial safety of low-salt hard-type cheese. Aged Cheddar cheeses were inoculated with either Listeria monocytogenes (3.5 log CFU/g) or Salmonella spp. (4.0 log CFU/g) and their survival or growth was monitored at 4, 10, and 21°C for up to 90, 90, and 30 d, respectively. Low-salt (0.7% NaCl) Cheddar formulated at pH 5.1 or 5.7 exhibited no-growth or gradual reduction in L. monocytogenes and Salmonella counts. The results suggest that low-salt Cheddar is as safe as its full-salt counterparts (1.8% NaCl) and that salt may only be a minor food-safety hurdle regarding the post-aging contamination and growth of L. monocytogenes and Salmonella.
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Schumann, Kerstin Monika. "Modulation of NF-kB signaling by measles Virus P gene products." Diss., Ludwig-Maximilians-Universität München, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-178535.
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Sun, Han. "Stereochemistry of Challenging Natural Products Studied by NMR-based Methods." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2012. http://hdl.handle.net/11858/00-1735-0000-000D-FD1A-F.
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Chala, Bilhate [Verfasser]. "Valorizing by-products from primary coffee processing through anaerobic fermentation / Bilhate Chala." Düren : Shaker, 2020. http://d-nb.info/1220610232/34.
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Trichia, Eirini. "Dairy products and cardio-metabolic health : aspects from nutritional, molecular and genetic epidemiology." Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/290034.
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There is accumulating evidence on differences in the link between types of dairy products and cardio-metabolic health, but inconsistent findings limit the field. In my PhD project, I undertook an epidemiological investigation comprising inter-related but distinct themes evaluating aspects of nutritional, molecular and genetic epidemiology to advance scientific understanding. I undertook research to describe dairy consumption patterns over time by evaluating nationally-representative data of the United Kingdom National Diet and Nutrition Survey. I observed significant time trends for specific dairy types and groups, which were different among different groups of people e.g. adults younger than 65 years or elderly people. Using data from the large Fenland (n~12,000) and EPIC Norfolk (n~25,000) studies, I investigated associations of total and types of dairy consumption with markers of metabolic risk and adiposity as potential pathways to cardio-metabolic disease. The analyses showed differential associations of dairy types and groups mainly with markers of adiposity and lipidaemia. I explored the potential of objective markers to assess dairy consumption, by examining metabolomics profiles and blood fatty acids to identify a set of biomarkers predicting dairy consumption and prospective associations of the identified biomarkers with type 2 diabetes risk. I was able to develop and validate metabolite scores reflecting consumption of some dairy products and observed inverse associations between some of these scores and type 2 diabetes incidence. I analysed genetic determinants of dairy consumption, using a genome-wide association study in the UK Biobank (n~500,000) and identified single nucleotide polymorphisms predicting milk, cheese and total dairy consumption. Overall, this PhD work contributed towards (1) a more precise description of dairy consumption patterns in the UK, (2) hypothesis formulation for potential biological pathways linking to cardio-metabolic disease, (3) discovery of metabolite scores as potential dairy biomarkers and (4) hypothesis formulation for potential genetic predictors of dairy consumption.
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Kammerer, Judith [Verfasser]. "Selective Polyphenol Recovery from By-Products of Plant Foodstuff Processing by Adsorption and Ion Exchange Technology / Judith Kammerer." Aachen : Shaker, 2011. http://d-nb.info/1071529005/34.
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Grove, Tina Moler. "Use of Antimycotics, Modified Atmospheres, and Packaging to Affect Mold Spoilage in Dairy Products." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/26512.
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The effects of natamycin, oxygen scavengers and a 25% CO₂:75% N₂ modified atmosphere on the growth of Penicillium roqueforti in shredded cheddar and mozzarella cheese stored at 10°C for 0, 60, 120, or 180 day was studied. Microbiological and sensory testing was assessed on 0, 7, 14 and 21 days after opening. Carbon dioxide decreased (P<0.05) as O₂ (P>0.05) and N₂ (P>0.05) increased throughout storage. Cheddar and mozzarella cheeses were stored for 180 and 60 days, respectively without significant (P> 0.05) increases in yeast and mold populations. Fungal populations increased significantly (P< 0.05) after packages were opened. Differences in yeast and mold (YM) counts during storage and once the packages were opened were independent of natamycin application and presence, O₂ scavengers and inoculated Penicillium roqueforti for both types of cheeses.
Growth of Penicillium roqueforti, Aspergillus niger, Geotrichum candidum and Neosartorya fischeri were evaluated in atmospheres of 0:30:70, 0.5:29.5:70, 1:29:70, 2:28:70, and 5:25:70, O₂:CO₂:N₂ over a 5-day period. Spores were cultured on antibiotic-supplemented potato dextrose agar (pH 5.6, aw 0.95) and incubated at 25°C. All four molds germinated and grew at 0.5:29.5:70. Extent of mycelia growth diameter (mm) increased significantly (P<0.05) as oxygen concentration increased from 0.5% to 5%. All growth was inhibited at 0:30:70, but germination and growth occurred once cultures were exposed to 20.9% atmospheric O₂, indicating that a modified atmosphere containing no residual O₂ is fungistatic.
Yeast and mold growth was seen in ultra-pasteurized (UP) extended shelf-life fluid milk stored at (7.2°C). Ten half-pint, pint, quart and half gallon filled cartons were randomly selected from all UP products available. Samples, pulled at random on day 0, 15, 30, 45, and 60, were plated on Yeast and Mold Petrifilm™. Forty-seven percent of the UP products stored for 45 days tested positive for mold. Fungal growth was apparent down the side and along the bottom of the 5th panel. Contamination was traced to the presence of yeast and mold spores in paperboard cartons. Pinholes were present in the polyethylene coating and wicking occurred at the unskived 5th panel. Fungi of similar origin and fatty acid profile were isolated from UP milk products and the paperboard cartons.Ph. D.
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Ratao, Isabel Maria Carneiro. "Microbiological and chemical characterization of traditional cheese made from milk produced by the Algarvian goat breed." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/6794.
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This study was concerned with a chemical and microbiological characterisation of cheese made using milk from Algarvian goat breed. Seasonal variation of the microbiota and the gross chemical composition of the raw and boiled milk and cheese during the lactation period were studied. The cardoon microbiota and the variation of microbiota during ripening were studied also. The lactic acid bacteria (LAB) were isolated, identified to genus level and their technological properties such as bacteriocin production, acidifying capacity, proteolysis and lipolysis were studied. The results showed that boiling milk does not represent a cause of variation in its gross composition and almost all the gross components of the milk and cheese register no variation during the studied period, except for fat, which increased until the middle of the lactation period and decreased after that. In cardoon, the microorganisms that are able to produce spores are the most important, thus analysis of yeasts and moulds was carried out which allowed the arrangement of the tested samples into three groups. Most of the identified moulds from the cardoon samples are from the genus Aspergillus. During the study period, differences in the microbiota of the raw milk were not observed, with Lactococcus and Lactobacillus being the prevalent groups. All the tested microorganisms increased approximately by two orders of magnitude from milk to cheese. Lactobacillus was the predominant group during the maturation period. Total coliforms tended to diminish in the early stages of ripening. Isolates from Lactobacillus and Pediococcus genera showed fast acidification capacity, which could be an indicator of good potential for their use as starter bacteria. Some Lactobacillus produced bacteriocin which can contribute to the removal of other bacteria. Aerococcus, Leuconostoc and Lactobacillus presented high proteolytic activity, which mean they could be used as adjunct cultures to improve proteolysis. Only one isolate (Pediococcus) showed lipolytic activity. In conclusion, by their technological characteristics some isolates could be selected as starter cultures, however, further research of their pathogenesis is necessary before using them in pilot plant production.
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Gummalla, Sanjay. "Tryptophan Catabolism by Lactobacillus spp. : Biochemistry and Implications on Flavor Development in Reduced-Fat Cheddar Cheese." DigitalCommons@USU, 1998. https://digitalcommons.usu.edu/etd/5454.
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Amino acids derived from the degradation of casein in cheese serve as precursors for the generation of key flavor compounds. Microbial degradation of tryptophan (Trp) is thought to promote formation of aromatic compounds that impart putrid fecal or unclean flavors in cheese, but pathways for their production have not been established. This study investigated tryptophan catabolism by Lactobacillus casei LC301 and LC202 and Lactobacillus helveticus CNRZ32 and LH212 cheese flavor adjuncts in carbohydrate starvation (pH 6.5, 30 or 37°C, no sugar) and cheese-like conditions (pH 5.2, 4% NaCl, 15°C, no sugar). Enzyme assays of cell-free extracts revealed both species of Lactobacillus catabolized tryptophan to indole lactic acid via indole pyruvic acid through transamination followed by dehydrogenation. Micellar electrokinetic capillary chromatography of culture supernatants showed these enzymes also catalyzed the reverse reactions, i.e., conversion of indole lactic acid to tryptophan. Tryptophan decarboxylase activity was detected in Lactobacillus cell-free extracts, but tryptamine was not detected in culture supernatants. Analysis of culture supernatants showed that tryptophan metabolism in Lactobacillus casei did not differ between the two conditions of incubation as it did in Lactobacillus helveticus LH212 and CNRZ32. Lactobacillus helveticus LH212, for example, did not catabolize Trp in carbohydrate starvation but did in cheese-like conditions. While cells of L. helveticus CNRZ32 did not catabolize Trp in either condition, they catabolized indole pyruvic acid to only Trp in carbohydrate starvation and to both Trp and indole lactic acid in cheese-like conditions. Micellar electrokinetic capillary chromatography of culture supernatants incubated under either starvation or cheese-like conditions showed Lactobacillus casei strains produced more indole lactic acid, and Lactobacillus helveticus strains favored tryptophan anabolic reactions. Based on the results obtained in this study, a putative pathway for the catabolism of tryptophan by lactobacilli in cheese is proposed.
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Gummalla, Sanjay. "Aromatic Amino Acid Catabolism by Lactobacillus spp.: Biochemistry and Contribution to Cheese Flavor Development." DigitalCommons@USU, 2002. https://digitalcommons.usu.edu/etd/5484.
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Amino acids derived from the degradation of casein in cheese serve as precursors for the generation of desirable and undesirable flavor compounds. Microbial degradation of aromatic amino acids is associated with the formation of aroma compounds that impart putrid-fecal, barny-utensil, and floral off-flavors in cheese, but pathways for their production had not been established. This study investigated Tyr and Phe catabolism by Lactobacillus casei and Lactobacillus helveticus cheese flavor adjuncts under simulated Cheddar cheese-ripening conditions (pH 5.2, 4% NaCl, 15°C, no sugar). Enzyme assays of cell-free extracts and micellar electrokinetic capillary chromatography of supernatants indicated that L. casei and L. helveticus strains catabolize Tyr and Phe by successive transamination and dehydrogenation reactions. Major products of Tyr and Phe catabolism included off-flavor compounds formed by chemical degradation of the α-keto acids, produced by transamination, and aromatic α-hydroxy acids derived from α-keto acids by α-hydroxy acid dehydrogenases. Action of Lacrococcus lactis aminotransferase enzymes on Trp, Tyr, and Phe also leads to the formation of α-keto acids, but unlike lactobacilli, the former bacteria do not express dehydrogenase activity under cheese-like conditions (pH 5.2, 4% NaCl, 15°C, no sugar). Since aromatic α-keto acids may degrade spontaneously into undesirable flavor compounds, α-hydroxy acid dehydrogenases may be useful in controlling off-flavor development via diversion of chemically labile α-keto acids to more stable a-hydroxy acids. To test this hypothesis, we investigated the effect of D-hydroxyisocaproate dehydrogenase overexpression by a L. casei adjunct on chemical and sensory properties of reduced-fat Cheddar cheese made with and without addition of 20 mM α-ketoglutarate. The D-hydroxyisocaproic acid dehydrogenase gene (D-HicDH) was cloned into a high copy number vector pTRKH2 and transformed into L. casei ATCC334. Reduced-fat Cheddar cheeses were made with Lactococcus lactis starter only, starter + L. casei ATCC334 with pTRKH2, and starter + L. casei ATCC334 with pTRKH2: D-HicDH, and then volatile analysis was performed by gas chromatography and mass spectrometry. Statistical analysis of volatile data after 3 mo of ripening at 7°C showed profiles of ketones, aldehydes, alcohols, esters, sulfur compounds, and benzaldehyde were significantly altered by culture treatments and α-ketoglutarate addition, and these treatments also affected sensory flavor attributes of experimental cheeses. Results also indicated overexpression of D-hydroxyisocaproic acid dehydrogenase can divert labile α-keto acids into more stable compounds, but the overall effect seemed to diminish both beneficial and detrimental flavor notes.
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Young, Michael J. "Characterization of Volatile and Metabolite Compounds Produced by Lactococcus lactis in Low-Fat and Full-Fat Cheddar Cheese Extract." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/1029.
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This study was conducted to compare and contrast potential aroma compounds in the headspace and small molecule metabolites produced as a result of starter culture metabolism in a full-fat and low-fat cheddar cheese model system. Past studies have indicated differences in the headspace flavor compound profiles between full-fat and low-fat Cheddar cheeses with no indication as to what compounds were produced as a result of starter culture metabolism.
Starter cultures were incubated in a Cheddar cheese extract environment that was made up of the water-soluble portion of Cheddar cheese with environmental conditions mimicking full-fat and low-fat Cheddar cheese by altering the levels of salt and milk fat globular membrane in the system. Incubation times were up to 14 days at 30°C and samples were taken at days 0, 1, 7, and 14. Headspace analysis was accomplished using solid phase micro-extraction coupled with GC-MS and small metabolites were monitored using metabolomic methods coupled with GC-MS.
Results indicate that the starter culture was responsible for an increase in the concentration of propan-2-one, heptan-2-one, 3-methylbutanal, heptanal, benzaldehyde, 2-ethylhexanal, and dimethyl trisulfide in both the full-fat and low-fat medias when compared to their respective controls. While heptanal was present at a higher concentration in the full-fat treatments compared to the low-fat treatments and 2- ethylhexan-1-ol and isothiocyanato cyclohexane were present at higher concentrations in the low-fat treatments compared to the full-fat treatments.
Principal component analysis for the headspace compounds showed a clear separation of the treatments with heptanal, p-cymene, nonan-2-one, and undecan-2-one contributing the most to the variation between the full-fat and low-fat samples, while 3- methylbutanal, heptan-2-one, benzaldehyde, 2-ethylhexan-1-ol, 2,6-dimethylheptan-4-ol, and 3-methylbutanol contributed the most to the variation between the controls and treatments.
The metabolomics data for both the bacteria and Cheddar cheese extract did not provide a clear separation between the full-fat and low-fat samples.
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Kostadinovik, Velickovska Sanja [Verfasser], and Peter [Akademischer Betreuer] Winterhalter. "Polyphenolic and volatile profile of Macedonian wines and by-products / Sanja Kostadinovik Velickovska ; Betreuer: Peter Winterhalter." Braunschweig : Technische Universität Braunschweig, 2012. http://d-nb.info/1175823600/34.
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Liao, Ge [Verfasser], and Shu-Ming [Akademischer Betreuer] Li. "Increasing structural diversity of natural products by enzymatic or nonenzymatic reactions / Ge Liao ; Betreuer: Shu-Ming Li." Marburg : Philipps-Universität Marburg, 2020. http://d-nb.info/1218685905/34.
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Barra, Lena [Verfasser]. "Studies on the Biosynthesis and Structure Elucidation of Terpene Natural Products by Isotopic Labeling Experiments / Lena Barra." Bonn : Universitäts- und Landesbibliothek Bonn, 2019. http://d-nb.info/1177881667/34.
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Ferreira, Andreza Angélica. "Biodiversity of lactic acid bacteria and preserving by freeze and spray drying of Lactobacillus plantarum from Marajó cheese." Universidade Federal de Viçosa, 2016. http://www.locus.ufv.br/handle/123456789/9912.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
No norte do Brasil, na região Amazônica se destaca a produção de um queijo artesanal na Ilha de Marajó, Pará Brasil. Este queijo é definido como um queijo não maturado obtido pela fermentação natural do leite de búfala pela sua microbiota autóctone e posterior fusão de sua massa. As bactérias láticas (BAL) oriundas de queijos artesanais contribuem para propriedades sensoriais originais nesses queijos, caracterizando os produtos como únicos e específicos de cada região e preservam uma produção tradicional de importância cultural, econômica e social. Sendo assim, o conhecimento da diversidade de BAL é fundamental para a caracterização deste tipo de queijo. Neste contexto, o objetivo desta tese foi isolar e identificar a diversidade de BAL envolvidas no processamento do Queijo Marajó, bem como avaliar os efeitos da liofilização e da secagem por atomização na preservação de BAL. A caracterização preliminar de cocos e bacilos Gram positivos e catalase negativo permitiu a identificação de 149 isolados de BAL obtidas a partir de amostras de leite de búfala cru, massa fermentada e utensílios envolvidos no processamento do queijo Marajó e 97 cocos de BAL oriundas de amostras do queijo Marajó. Por meio do sequenciamento do gene 16S rDNA oito espécies foram identificadas: Weissella confusa, Streptococcus infantarius, Lactococcus lactis, Leuconostoc pseudomesenteroides, Weissella paramesenteroides, Pediococcus pentosaceus, Pediococcus acidilactici, Lactobacillus brevis e o gênero Enterococcus. A Rep-PCR foi capaz de identificar diferentes perfis genéticos demonstrando uma grande diversidade entre os isolados avaliados. Dentre os isolados, as espécies Lactobacilus plantarum e Lactobacillus paraplantarum também foram identificadas oriundas do queijo Marajó. E uma cepa de L. plantarum foi selecionada para estudos de preservação em processos liofilização e secagem por atomização. As células de L. plantarum submetida à secagem por atomização mantiveram-se aproximadamente em 10 9 UFC∙g -1 , enquanto que as amostras submetidas à liofilização reduziram a viabilidade para 10 7 UFC∙g -1 durante 60 dias de estocagem a 4 °C e 20 °C. Os efeitos da secagem por atomização na viabilidade das células de L. plantarum foram menores que a liofilização. As características fenotípicas apresentadas pelas BAL, neste estudo, permitem direcionar futuras pesquisas para preservação das cepas de BAL envolvidas na produção do Queijo Marajó, bem como desenvolver culturas starter/adjuntas com um elevado número de células viáveis para aplicação industrial por meio da secagem por atomização a um de baixo custo.
Northern Brazil, in the Amazon region stands out in the production of an artisanal cheese on the Marajó Island (Pará, Brazil). It is defined as a fresh cheese obtained through natural coagulation of raw buffalo milk by the autochthonous microbiota and subsequent curd fusion. LAB from artisanal cheeses contribute to original sensory properties in these cheeses, characterizing unique and specific products of each region, preserving a tradition of cultural, economic and social importance. Thus, the knowledge of LAB diversity is fundamental to the characterization of this type of cheese. In this context, the aim of this thesis was to isolate and to identify the LAB biodiversity involved in the production of Marajó cheese and to evaluate the effects of freeze drying and spray drying in the preservation of LAB. Preliminary characterization as Gram positive cocci and/or bacilli and as negative catalase plus identification by using 16S rDNA sequence analysis and Rep-PCR were undertaken for 149 LAB isolates obtained from samples of raw buffalo milk, curd and utensils involved in Marajó Cheese making and 97 LAB cocci from Marajó Cheese. Eight species have been identified as follows: Weissella confusa, Streptococcus infantarius, Lactococcus lactis, Leuconostoc pseudomesenteroides, Weissella paramesenteroides, Pediococcus pentosaceus, Pediococcus acidilactici, Lactobacillus brevis and the Enterococcus genus. The Rep-PCR was able to identify different genetic profile showing a high diversity among the evaluated isolates. Among the isolates, the species Lactobacillus plantarum and Lactobacillus paraplantarum were also identified coming from Marajó cheese. And a strain of L. plantarum was selected for preservation of freeze drying and spray drying.The cells of L. plantarum subject to spray drying process at approximately 10 9 CFU.g -1 , while the freeze dried samples showed 10 7 CFU.g -1 after 60 days of storage at 4°C and 20 °C. The spray drying was less damaging than freeze drying for L. plantarum cells. The phenotypic characteristics showed by LAB isolated in this study allow of directing further investigations to preserve LAB strains involved in production of Marajó cheese in order to produce starter and adjunct cultures by spray drying with a high number of viable cells to be used for industrial application through a cost-effective method.
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Jou, Kuen-Da. "Integrated analysis and pattern recognition of Swiss cheese aroma by SPME/GC, SPME/GC/MS and electronic noses /." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487946776020555.
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Broome, Malcolm Charles, and mikewood@deakin edu au. "Aspects of milk protein catabolism by lactobacilli." Deakin University. School of Sciences, 1988. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20050902.120502.
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Lactobacillus plantarum and subspecies of Lactobacillus casei were isolated from good quality mature Cheddar cheese and characterized with respect to metabolic functions that would allow their use in cheesemaking. In this way microbiological control of the maturation process with particular emphasis on protein catabolism was achieved. The lactobacilli isolated were selected for low growth rates (and acid production) in milk, and low proteinase activity to allow for their addition in high numbers to cheesemilk together with the normal starter flora (group N streptococci). The growth and acid production of the starter bacteria were unaffected by the presence of the lactobacilli during cheese manufacture and it was found that the added lactobacilli were able to grow and function under the conditions prevalent in Cheddar cheese during maturation. It was also demonstrated that the lactobacilli could be grown in an artificial medium to high numbers under controlled conditions and could be harvested for the preparation of cell concentrates, a necessary characteristic for commercialization. The lactobacilli also metabolized citrate, a potential problem in cheese maturation associated with C02 production but this did not adversely affect the maturation process under the conditions used.
Compared to the group N streptococci the non-starter lactobacilli possessed a proteinase system that had a higher temperature optimum and was less affected by heat and sodium chloride. They also possessed a more active peptidase system although both the lactobacilli and the starter organisms possessed a similar range of peptidases.
Non-starter lactobacilli were added to normal cheese and cheese made with proteinase negative starter. The added organisms did not adversely affect manufacturing parameters and did not metabolize citrate or lead to the formation of biogenic amines. However protein catabolism rates, particularly with respect to peptide degradation,
were increased, as was flavour development and intensity. It was observed that the body and texture of the cheeses was unaffected by the treatment. By controlling both the starter and non-starter microflora in the cheeses a practical system for favourably influencing cheese maturation was possible.
The investigation has demonstrated that carefully selected and characterized non-starter lactobacilli can be incorporated into Cheddar cheese manufacture in order to influence flavour development during maturation. Moreover the organisms can be added to the vat stage of manufacture without causing problems to the manufacturing process. This approach is a simple cost effective means of improving the cost of Cheddar cheese production and provides an unique opportunity to improve and control quality of all Cheddar cheese produced.
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AHMAD, MUHAMMAD [Verfasser], Joachim [Akademischer Betreuer] Ulrich, and Heike [Akademischer Betreuer] Lorenz. "Separation of complex feed streams of products by layer melt crystallization / Muhammad Ahmad ; Joachim Ulrich, Heike Lorenz." Halle, 2016. http://d-nb.info/1116952335/34.
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Thiyam, Usha [Verfasser]. "Antioxidative compounds of rapeseed oil by-products for stabilization of rapeseed bulk oil and emulsions / Usha Thiyam." Aachen : Shaker, 2005. http://d-nb.info/1186576243/34.
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Flügel, Ralf [Verfasser]. "Quality and Authenticity Control of Fruit Products by Isolation and Characterisation of Cell Wall Polysaccharides / Ralf Flügel." Aachen : Shaker, 2005. http://d-nb.info/1186588160/34.
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Hahn, Christian [Verfasser]. "Textural properties of fresh cheese as affected by post-processing: particle cluster formation, characterization, and size reduction / Christian Hahn." München : Verlag Dr. Hut, 2014. http://d-nb.info/1060587610/34.
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Rasmussen, Taylor. "Texture Profile Analysis and Melting in Relation to Proteolysis as Influenced by Aging Temperature and Cultures in Cheddar Cheese." DigitalCommons@USU, 2007. https://digitalcommons.usu.edu/etd/5543.
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Changes in cheese physical properties during aging are related to proteolysis by coagulant type, culture enzymes, and non-starter lactic acid bacteria (NSLAB). Storage temperature also affects aging rate. Cultures are important for flavor development , but less is understood about their role in melting and textural properties.
Our objective was to make Cheddar cheese using different cultures, to age it at 6 and 13°C, and measure physical and proteolytic properties over 12 mo to determine whether changes in texture and melting correlated with the extent of proteolysis that occurred during aging.
Cheese was manufactured using Lactococcus lactis starter culture either alone or combined with one or both of Lac Lc. Lactis or Lactobacillus helveticus adjunct cultures . Three replicates of cheese were made using 1500 lb of milk. Cheese composition was 35.5 ± 1.0% moisture, 52.5 ± 2.5% FDB, 1.65 ± 0.05% salt, and pH 5.2 ± 0.1. All cheeses were initially stored at 6°C, then half moved to l3°C after 21 d.
Texture profile analysis was performed using 25% and 60% compression and melting measured using a Meltmeter at 65°C. The data were analyzed based on culture and temperature over 12-mo storage time. The overall hardness decreased, while the cohesiveness decreased for all treatments. Extent of melting was significantly correlated with hardness (r = 0.62), cohesiveness (r = 0.40), and inversely with adhesiveness (r = 0.24). Correlations with adhesiveness and cohesiveness were not linear.
Proteins were extracted from cheese at 1 wk, 1, 2, 4, 6, 9, and 12 mo of aging using 500 mM sodium citrate solution containing 1% sodium chloride. Purified extracts were then applied to a high-performance liquid chromatography CS reverse phase column and large hydrophobic peptides and protein peaks monitored at 214 nm. Melting was inversely correlated with the amount of intact ɑs1-caserienm remaining in the cheese (r = -0.54) and directly correlated with what was thought to be ɑs1-casein (f 24 - 199) (r = 0.56).
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Fromm, Matthias [Verfasser]. "Development of strategies for the recovery of valuable compounds from by-products of apple juice production / Matthias Fromm." Aachen : Shaker, 2014. http://d-nb.info/1049378539/34.
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Mohdali, Adel Abdelrazek Abdelazim [Verfasser], and Iryna [Akademischer Betreuer] Smetanska. "Evaluation of some food processing by-products as sources for natural antioxidants / Adel Abdelrazek Abdelazim Mohdali. Betreuer: Iryna Smetanska." Berlin : Technische Universität Berlin, 2010. http://d-nb.info/1064813488/34.
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Sun, Han Verfasser], Christian [Akademischer Betreuer] [Griesinger, and Philipp [Akademischer Betreuer] Vana. "Stereochemistry of Challenging Natural Products Studied by NMR-based Methods / Han Sun. Gutachter: Christian Griesinger ; Philipp Vana. Betreuer: Christian Griesinger." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://d-nb.info/1044172827/34.
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Lekkas, Panagiotis. "The Microbial Ecology Of Listeria Monocytogenes As Impacted By Three Environments: A Cheese Microbial Community; A Farm Environment; And A Soil Microbial Community." ScholarWorks @ UVM, 2016. http://scholarworks.uvm.edu/graddis/463.
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This dissertation examined the microbial ecology of Listeria monocytogenes in three distinctly different environments: a cheese microbial community; a farm environment; and a soil microbial community.
The aim of the first study was to investigate the effects of L. monocytogenes on the composition of the surface microflora on washed rind soft cheese. Two trials with washed rind cheeses that were inoculated with 100cfu cm⁻² of a L. monocytogenes six strain cocktail were conducted. The first trial had to be terminated early (day 28) as contamination of Pseudomonas spp. from the initial brine did not produce the expected characteristics of the cheese during the aging period. For the second trial, cheese samples were aged in the lab for 60 days according to the cheesemakers specifications. Surface cheese rind samples were collected from both control and inoculated cheeses every 7 days. Cheese rind samples were analyzed through the standard BAM method for enumeration of L. monocytogenes and through amplification of the V4 region of 16S rRNA and ITS regions for identification of the surface rind bacterial and fungal communities, respectively. Our data showed that Pseudomonas spp. significantly changed the composition of the microorganisms found on the surface of the rind while L. monocytogenes had little effect. In addition, although the concentration of L. monocytogenes increased to levels of 10⁶ cfu cm⁻² based on the enumeration data, the genetic data was not able to identify it in the flora due to the fact that other genera were found at much higher concentrations, which is a limitation of molecular methods used for identification of pathogens in foods.
For the second study the presence and incidence of L. monocytogenes on farms that either produce raw milk cheese or supply the milk for raw milk cheese production was investigated. Five farms were visited and in total 266 samples were collected from barn, environmental, and milk sites. L. monocytogenes prevalence was found to be at 6% from all the farms tested with 10 isolates found in the barn samples, 5 from environmental sites and 1 from milking equipment. Samples were identified to the genus level through a modified BAM method and speciated though multiplex PCR. Included in the pathogenic isolates was a DUP-1042B L. monocytogenes strain that has been implicated in major outbreaks, which emphasizes the adaptability and persistence of highly pathogenic stains in food manufacturing environments. Results from this study continue to support the fact that contaminated silage can be an important reservoir of the pathogen in a dairy farm setting. From our data and field observations we identified that drinking water sources for the animals is also an important reservoir of L. monocytogenes in farm environments. More importantly this study has shown the importance of continuous monitoring of environmental sites for the presence of the pathogen, particularly in silage.
Lastly manure amended soils in the northeastern U.S. were tested for the presence and survival of rifampicin resistant Escherichia coli (rE. coli), generic E. coli (gE. coli) and Listeria spp.. Both gE.coli and rE.coli samples were processed using either direct enumeration, MPN or bag enrichment methods. Samples were taken from both tilled and surface dairy solid manure-amended plots. Listeria samples were processed using a modified BAM method. Listeria presence was constant throughout the study. In contrast, rE. coli and gE. coli levels declined with time. The main conclusions of this study were that soil type, location and physical characteristics have a significant role in the survival of bacterial populations of rE. coli, gE. coli and Listeria spp. in soil. Dairy solids application does not seem to have a long term effect on the natural microbial population of soils. Tilling of soils results in increased survival of the bacterial population due to the fact that it increases soil pore size and facilitates moisture entry, which in turn has been shown to increase bacterial survival rates. Data from this research will assist in the creation of preventative measures that lead to the elimination of pathogen reservoirs. It will be further used to verify that a 120 day interval following manure application should be sufficient to ensure food safety of edible crops subsequently planted on these soils.
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Moiseeva, Elena S. "Manufacture, Shelf Stability, and Acceptability of Aseptically Packaged, Unripened Soft Cheese Produced by Post-Ultra-High Temperature Acidulant Injection of Ultrafiltered Milk Concentrate." DigitalCommons@USU, 1996. https://digitalcommons.usu.edu/etd/5430.
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This study investigated the manufacturing procedures and texture attributes of direct acid set of an unripened, shelf-stable cheese variety produced by the combined technologies of ultrafiltration and ultra-high temperature processing. Product evaluation included physical and chemical properties such as gel strength, syneresis, pH, moisture, protein, and fat. Whole milk was concentrated by ultrafiltration to 30, 35, and 40% total solids. Milk retentate was ultra-high temperature-processed by preheating to 65 or 77°C, sterilized at 141°C for 4 s by direct steam injection, flash cooled to approximately 62 or 72°C, homogenized in two stages at either 13.8/2.1 or 27.6/4.1 MPa, cooled to 38°C, and aseptically packaged. iv sterilized sodium chloride was aseptically added and dissolved in the ultra-filtrated and ultra-high temperature processed retentate to produce .5% final concentration. Autoclaved solutions of citric and lactic acids, or glucono-delta-lactone were added aseptically to the salted retentate to form a soft gel by lowering the pH range from 4.3 to 4.6. The coagulated retentates were stored at room temperature for 6 months. The effects of total solids, homogenization pressures, preheat temperatures, acidulants, and storage time on selected physicochemical properties of the acid gels were determined.
Taste panels evaluated selected soft cheese characteristics after 6 months' storage. No statistically significant effect of the total milk solids level on gel firmness was observed. High homogenization pressure and the interaction of high preheat temperature and homogenization pressure produced significantly firmer gel and caused less syneresis. Acidulant types influenced significantly gel strength, syneresis, appearance, and texture. Soft cheeses prepared with citric acid were firmer than those acidified with lactic acid or gluconodelta-lactone. Lactic acid samples produced more syneresis than citric acid cheese samples. Cheese samples prepared with glucono-delta-lactone had the smoothest and least grainy texture, shiny appearance, little or no wheying-off, and a gel strength intermediate between the two other acidulants.
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Wirth, Benjamin [Verfasser], Peter [Akademischer Betreuer] Neubauer, Peter [Gutachter] Neubauer, Michael [Gutachter] Nelles, and Jan [Gutachter] Mumme. "Anaerobic treatment of liquid by-products from hydrothermal carbonization of biomass / Benjamin Wirth ; Gutachter: Peter Neubauer, Michael Nelles, Jan Mumme ; Betreuer: Peter Neubauer." Berlin : Technische Universität Berlin, 2021. http://d-nb.info/122950494X/34.
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Assi, Zeina [Verfasser]. "Structural and chemical investigations of the thermal behavior of B-H based materials (NaBH4 and NH3BH3) and their oxidation metaborate by-products / Zeina Assi." Hannover : Technische Informationsbibliothek (TIB), 2016. http://d-nb.info/1122030576/34.
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Schäfer, Johannes [Verfasser]. "Fresh cheese made from concentrated milk: Tailoring the calcium content of milk retentates by means of microfiltration to modulate the bitter taste / Johannes Schäfer." München : Verlag Dr. Hut, 2019. http://d-nb.info/1198542764/34.
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Valente, Rui Lopes. "Desenvolvimento de novos produtos tendo por base o queijo de ovelha curado : avaliação da sua estabilidade e aceitação pelo consumidor." Master's thesis, Universidade Técnica de Lisboa. Faculdade de Medicina Veterinária, 2013. http://hdl.handle.net/10400.5/5372.
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Dissertação de Mestrado em Segurança AlimentarEste trabalho teve como objectivo o desenvolvimento de novos queijos partindo do seu processo de produção tradicional com introdução de ingredientes, designadamente, presunto, chouriço ou orégãos e estabelecendo-se o seu período de validade. Produziram-se os novos queijos a partir de um lote de 50 Litros de leite de ovelha crú, coalhado com flor de cardo (Cynara cardunculus), efectuando-se o seu corte até obter um grão com dimensão de bago de arroz. Após esgotamento do soro efectuou-se a divisão da coalhada dessorada em 3 sub-lotes. Um a um, em tempos diferentes foi-se colocando os sub-lotes sobre a francela para mistura da massa de coalho com os diferentes ingredientes (Chouriço, presunto ou orégãos) efectuando-se o encinchamento em multimoldes e transporte para a cura. Após um período de cura total de 28 dias iniciou-se a caracterização analítica e inquérito de opinião. A caracterização dos novos produtos consistiu numa avaliação microbiológica, química e sensorial. Estabeleceu-se um período de armazenamento a uma temperatura inferior a 100C durante 45 dias, considerando-se 3 períodos (T0, T28 e T45) de análise laboratorial e sensorial. Nos diferentes períodos analíticos recolheu-se aleatoriamente 3 amostras de cada sub-lote para análise laboratorial e 16 amostras para avaliação sensorial. Na avaliação química, caracterizaram-se os novos produtos quanto à composição centesimal, valor energético, teor de cloretos e do índice de peróxidos durante os três períodos analíticos estabelecidos. Na avaliação microbiológica consideraram indicadores quanto à higiene (Escherichia coli e Staphylococcus aureus) e quanto à segurança (Salmonella spp. e Listeria monocytogenes). Para a análise sensorial realizaram-se três sessões durante os três períodos estabelecidos (T0, T28, T45; 15 pessoas com idades superiores a 18 anos) onde se avaliou a aceitabilidade dos queijos, considerando o aspecto geral, cor da pasta, textura, aroma e sabor. Concluiu-se que os queijos são estáveis química e microbiologicamente ao longo do período de armazenamento em estudo. Obteve-se uma apreciação sensorial global acima de 4 para os diferentes atributos considerados. O prazo de validade estabelecido para a comercialização destes novos queijos foi de 45 dias.
ABSTRACT - This study aimed to develop new cheeses starting from its tradicional process and introducing ingredients, namely, ham, chorizo or oregano and settling shelf life of these new products. these new cheeses were manufactured from a batch of 50 liters of raw sheep milk, curdled with thistle flower (Cynara cardunculus), cutting the clot until obtaining a grain size equal to rice. After taking out the serum were created three sub-lots. One by one, at different times the ingredients were mixed (sausage, ham or oregano) with the clot and then filled the molds and transported it to ripening. After a total ripening period of 28 days we have started the analytical protocol and consumer opinion survey. The characterization of new products consisted of a microbiological, chemical and sensory evaluation. There has been established a shelf life of 45 days, with three periods of laboratory analysis (T0, T28 and T45) and simultaneous sensory analysis. Throughout the analytical period we have picked randomly three samples of each sub-lot for laboratory analysis and sixteen samples for sensory evaluation. Therefore, during the chemical evaluation we have characterized the new cheeses about centesimal compound, energetic value and peroxide index throughout the three established analytical periods. About microbiological analysis we have considered a hygienic indicators (Escherichia coli and Staphylococcus aureus) and safety indicators (Salmonella spp. and Listeria monocytogenes). For sensory analysis were held three sessions during established periods (T0, T28 and T45), consisting of 15 people aged over 18 years old) which evaluated the acceptability of new cheeses, considering the general appearance, color, texture, aroma and flavor. The new cheeses were chemical and microbiologically stable over the storage period under study. The limit of shelf life for the new cheeses was established for 45 days.
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Dohlen, Sophia [Verfasser]. "Assessment of a novel active packaging material to improve the resource efficiency of food production by increasing the safety and shelf life of perishable products / Sophia Dohlen." Bonn : Universitäts- und Landesbibliothek Bonn, 2016. http://d-nb.info/112459079X/34.
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Struck, Susanne [Verfasser], Harald [Akademischer Betreuer] Rohm, Harald [Gutachter] Rohm, and Thomas [Gutachter] Becker. "Interactions of wheat macromolecules and fibres from fruit processing by-products using model systems and the application example muffin / Susanne Struck ; Gutachter: Harald Rohm, Thomas Becker ; Betreuer: Harald Rohm." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://d-nb.info/1160875529/34.
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Šuranská, Hana. "Izolace, identifikace a charakterizace mikroflóry vína a vybraných potravin." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-233385.
Full textAbstract:
Proposed dissertation thesis deals with wine and artisanal cheeses microbiology. The first part is focused on identification of yeasts isolated from grapes and musts during production of white and red wines. The grape varieties were grown under the integrated and organic farming on Moravian vineyard. Yeasts were identified by ITS-PCR-RFLP method (amplifying internal transcribed spacer ITS: ITS1, ITS2 and 5.8S rDNA) and unknown species were subjected to partial sequencing of ITS rDNA region. In total, 524 isolates were divided into 14 different species belonging to six genus were identified from. The first stages of fermentation process were characterised by predominance of non-saccharomyces species especially H. uvarum. Due to increased ethanol concentration strains of S. cerevisiae prevailed in the later phases of the process. Further, partial aim of this study was to isolate and to apply selected autochthonous S. cerevisiae strains as starter culture during controlled industrial wine fermentation process. Genus Saccharomyces was distinguished from other non-saccharomyces species by ITS-PCR-RFLP. Further, in order to distinguish Saccharomyces genus at the species and the strain level, several molecular methods were applied including PCR-fingerprinting (rep- and RAPD-PCR), species-specific primers (multiplex and touchdown PCR), LSU-DGGE and interdelta PCR. Species-specific primers enabled us to distinguish some species of the Saccharomyces sensu stricto complex. Furthermore, interdelta PCR seems to be useful tool for S. cerevisiae strains identification. Among 120 isolated autochthonous strains belonging to Saccharomyces genus, 45 different strains were identified. Based on its sufficient technological properties (osmo- and ethanol tolerance, low H2S production etc.), S. cerevisiae 1-09 strain isolated from grape berries coming from moravian vineyard was chosen. Strain S. cerevisiae 1-09 was tested in small amount of must and after that also during industrial fermentation of red and white wine production. Based on the results of chemical and sensorial analysis, the strain seems to be suitable for application as the starter culture for winemaking process. The final part of this thesis is focused on quantification and identification of the yeasts isolated from artisanal cheeses and their by-products coming from Western Balkan Countries. Isolated species were identified by ITS-PCR-RFLP, partial sequencing and by physiological tests. Among the 20 yeast species found, D. hansenii, C. zeylanoides and Y. lipolytica were found to be predominant. Moreover, we developed culture-independent, semi-quantitative technique based on construction of ITS-clone library from metagenomic DNA to investigate complex fungal communities associated with artisanal cheeses and their by-products. Novel technique is based on direct extraction of total DNA from the sample. This was compared with culture-dependent ITS-PCR-RFLP and culture-independent LSU-DGGE methods. The results highlighted the discrepancies among these methods. Finally, the divergences among applied methods were confirmed by correlation analysis and by indices of general biodiversity and dominance of species. ITS-clone library approach combines the advantages of cultivation-based analysis and LSU-DGGE with semi-quantification of fungal species without the requirement of their cultivation. This study might open new perspectives in direct and complex analysis of yeasts and moulds in food matrices.