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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The nature of the chemical groupings responsible for the colour of the products of the Maillard reaction

O'Reilly, R. January 1982 (has links)
No description available.
2

The effect of castration and slaughter age on the aroma of cooked lamb

Sutherland, Michelle M. January 1996 (has links)
No description available.
3

Evaluation of the beef marbling insurance theory

Drey, Lindsey January 1900 (has links)
Master of Science / Department of Animal Sciences and Industry / Travis G. O'Quinn / The objectives of this study were to evaluate the extent marbling compensates for reduced beef palatability at elevated degrees of doneness and to determine the relationship of residual moisture and fat in cooked steaks to beef palatability, specifically beef juiciness. Paired strip loins (IMPS # 180) were collected to equally represent five quality treatments [Prime, Top Choice (modest and moderate marbling), Low Choice, Select, and Select Enhanced (110% of raw weight)]. Steaks were grouped into sets of three consecutively cut steaks and randomly assigned a degree of doneness (DOD): very-rare (VR; 55°C), rare (R; 60°C), medium-rare (MR; 63°C), medium (M; 71°C), well-done (WD; 77°C), or very well-done (VWD; 82°C). Samples were subjected to consumer and trained sensory evaluation, Warner-Braztler shear force (WBSF), slice shear force (SSF), pressed juice percentage (PJP) evaluation, and raw and cooked proximate analysis. There were no (P > 0.05) interactions for consumer sensory ratings, indicating increased DOD had the same negative impact regardless of marbling level. There was a quality treatment × DOD interaction (P < 0.05) for percentage of steaks rated acceptable by consumers for juiciness. Increased marbling extended the point in which steaks became unacceptable for juiciness. Similarly, there was a quality treatment × DOD interaction (P < 0.05) for trained juiciness ratings. When cooked to MR and lower, Prime was only rated 8 to 18% higher (P < 0.05) than Select for trained juiciness ratings but was rated 38 to 123% higher (P < 0.05) than Select when cooked to M and higher. Besides cook loss, combined cooked moisture and fat percentage was more highly associated (P < 0.01) to consumer juiciness (r = 0.69) and trained initial (r = 0.84) and sustained (r = 0.85) juiciness ratings than all other objective evaluations. For regression analysis, cooked moisture and fat percentages, alone, were poor indicators of consumer and trained juiciness ratings. However, when combined, the regression equations explained 45, 74, and 69% of the variation in consumer, trained initial, and trained sustained juiciness ratings, respectively. These results indicate that increased marbling levels only offer “insurance” for juiciness of steaks that are cooked at high degrees of doneness, but not for other palatability traits. Additionally, cooked residual moisture and fat percentages when combined are a good indicator of sensory juiciness ratings.
4

Use of Natural Antioxidants to Control Oxidative Rancidity in Cooked Meats

Vasavada, Mihir 01 May 2006 (has links)
The research in this dissertation focused on determining antioxidant effects of various natural antioxidants in cooked meat systems. Milk mineral (MM), spices, and raisin paste were used in cooked meat systems to verify their potential antioxidant properties. The MM study determined the antioxidant activity of 1.5% MM added to uncured cooked beef meatballs, and possible additive effects of MM in combination with 20-ppm or 40-ppm sodium nitrate in cooked beef sausages . There was no additive inhibition of lipid oxidation in samples containing 20-ppm or 40-ppm sodium nitrite plus 1.5% MM. Cooked meat yield was not different between control meatballs and those containing MM. As expected, treatments containing nitrite had higher redness (a*) values than samples without nitrite. The MM at 1.5% was a very effective antioxidant as compared to controls. The Garam Masala (GM) study determined the antioxidant effects and sensory attributes of the individual spices in an Indian spice blend GM in cooked ground beef, and possible additive antioxidant effects between Type I and Type II antioxidants. All spices had antioxidant effects on cooked ground beef, compared to controls without spices, with cloves being the most effective. All spices at their lowest effective recommended level effectively lowered the perception of rancid odor and rancid flavor in cooked ground beef as compared to control samples. As expected, most spices also imparted distinctive flavors to the cooked ground beef. Type II antioxidants (iron binding phosphate compounds) were more effective than individual Type I antioxidants (spices and butylated hydroxytoluene; BHT) in cooked ground beef. There was a positive additive antioxidant effect seen with rosemary + MM and rosemary + sodium tripolyphosphate (STPP) treatments as compared to individual rosemary treatment. There was no additive antioxidant effect observed for other combinations of spices with phosphate antioxidants. The raisin study was done to determine the antioxidant activity of raisin paste added to cooked ground beef, pork, and chicken. Thiobarbituric acid (TBA) values were measured using the distillation method, on the distillates, to avoid interference from sugar in the raisins. Beef, pork, and chicken flavor intensity, rancid flavor intensity, and raisin flavor intensity were evaluated by a trained sensory panel (n = 6). Addition of 2% raisin paste effectively inhibited rancid flavor development for 14 days after cooking in cooked ground beef, pork, and chicken. Sugar added at levels equivalent to that contributed by the raisins inhibited rancidity, probably due to antioxidant effects of Maillard browning products, suggesting that the antioxidant effect of raisins was due to their sugar content.
5

PROMOTING HEALTHY, HOME-COOKED MEALS: FORMATIVE RESEARCH FOR A SOCIAL MARKETING PROGRAM TARGETING LOW-INCOME MOTHERS

Najor, Jean M 01 January 2014 (has links)
The purpose of this study is to gain a deeper understanding of the dynamic of perceived benefits and barriers associated with cooking meals at home. The findings will be used to design a social marketing campaign promoting healthy home-cooked meals. Participants included 64 SNAP-eligible mothers throughout the state of Kentucky aged 21-49 years with young children. Eight focus groups were conducted in four metro and four non-metro counties. A mixed methods approach was used to examine behaviors such as where families purchase foods, the types of foods purchased, family cooking skills and habits, and family time management. Results from this study show women regularly incorporate home-cooked meals into their lives. Three major themes evolved from analysis: learning more about preparing healthy, home-cooked family meals; the important relationship of families and cooking, and the dread of kitchen cleanup following a meal. Data from the written survey provided information regarding eating and cooking patterns in a week, important meal characteristics, relative confidence in cooking skills, and Internet and social media use.
6

Evaluation of microbial dynamics on low-sodium cooked bologna under different packaging conditions

2014 September 1900 (has links)
The purpose of this study was to assess the growth of spoilage and pathogenic bacteria on low sodium concentration sliced cooked bologna under refrigerated storage conditions. In study 1, the effect of three different sodium concentrations (1%, 2% and 3%) and two packaging conditions (aerobic and vacuum) on growth of a cocktail of inoculated spoilage bacteria such Lactobacillus curvatus, Leuconostoc mesenteroides, Brochothrix thermosphacta and Pseudomonas fluorescens were investigated by using culture-dependent and culture-independent techniques. In general, reducing the sodium concentration from 2% (the current industry standard) to 1% NaCl in the cooked bologna system did not have a significant effect on microbial growth. The utilization of Ion Torrent high-throughput sequencing in this study allowed the description of the total microbial community present on sliced cooked bologna. Taxonomic analysis revealed the microbial community belongs to the phyla Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. Finally, in this study, in situ meat redox measurement values were collected over time using platinum electrodes placed on top of, and in between bologna slices. While the redox values obtained were, in general, consistent with increasing bacterial cell numbers, issues of reproducibility and consistency were evident. The second study focused on the impact that the addition of a bacteriocin, Micocin X®, to the meat blend would have on growth of spoilage bacteria and in particular, Listeria monocytogenes, in vacuum-packaged cooked bologna formulated with 1% and 3% NaCl. In general, results demonstrated Micocin X® had a significant effect on the growth of Pseudomonas fluorescens and Listeria monocytogenes; however, no substantial effect was assessed in the control of lactic acid bacteria or Brochothrix thermosphacta.
7

Make or buy analysis for cooked sausage products

Ausloos, Peter January 1900 (has links)
Master of Agribusiness / Department of Agricultural Economics / Allen M. Featherstone / Johnsonville Sausage is a privately held company based in Sheboygan Falls, WI. The company has a growing cooked sausage business and is evaluating options to expand capacity. Investing in either of two existing facilities or outsourcing production to a co-manufacturer is being considered in this make versus buy analysis. Intense competition in the category and uncertain raw material markets are considerations in the evaluation. Data used for the analyses were obtained from Johnsonville sources. Assumptions for the “make” analyses were based on existing data where applicable such as labor and utilities, and in other cases assumptions were made based on company knowledge of the process. Johnsonville engineers worked closely with equipment vendors to develop the building and equipment investment plan. Data for the “buy” alternative were received from a prequalified co-packer with advanced manufacturing technology. A Net Present Value (NPV) model is developed for each alternative and used to determine financial viability of each. The models consider varying investment requirements, freight rates and cost of goods for each alternative. Sensitivity analyses are performed to address key variables such as raw material prices and sales volume. The paper concludes that investment in Sheboygan is a viable option; however, the investment poses risk if raw material prices rise and or volume declines from expected projections. Therefore, the recommendation is to outsource production and initiate the Sheboygan project when the co-packed volume reaches 15 million pounds.
8

Avaliação dos atributos de qualidade de presunto cozido "cook-in" adicionado de fibra solúvel, do tipo frutooligossacarídeo de cadeia curta (ScFOS) / Evaluation of quality attributes of "cook-in" cooked ham added soluble fibers, of short-chain fructooligosaccharides (ScFOS)

Abreu, Larissa Weissheimer de, 1981- 12 January 2011 (has links)
Orientadores: Pedro Eduardo de Felício, Expedito Facco Silveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T05:51:04Z (GMT). No. of bitstreams: 1 Abreu_LarissaWeissheimerde_M.pdf: 3531090 bytes, checksum: 653a23f59bd2bc7c449fe6c68f12bea6 (MD5) Previous issue date: 2011 / Resumo: O presente trabalho de pesquisa consistiu na avaliação dos efeitos da adição de fibra solúvel, do tipo frutooligossacarídeo de cadeia curta, sobre os atributos de qualidade, física, físico-químicas microbiológicas e sensoriais de presunto cozido cook-in. Os presuntos cozidos foram processados no frigorífico Marba, em São Bernardo do Campo ¿ São Paulo. Elaborou-se uma formulação padrão de presunto cozido (¿cook in¿) para 170% de rendimento sobre o peso da matéria prima, e a partir desta balancearam-se as formulações adicionadas de fibra solúvel, do tipo frutooligossacarídeo de cadeia curta (ScFOS) marca NutraFlora®. Realizaram-se quatro tratamentos, F0 ¿ padrão ou controle sem adição de fibra, F3 ¿ adição de 3% de fibra solúvel, F6 ¿ adição de 6% de fibra solúvel, F9 ¿ adição de 9% de fibra solúvel. Os produtos assim obtidos foram avaliados (em cinco pontos - aos 7, 20, 41, 62 e 93 dias) ao longo da estocagem refrigerada a 2±2ºC, quanto ao valor de pH, atividade de água (Aa), composição centesimal, teores de nitrito e nitrato, cor, força de cisalhamento, fatiabilidade, qualidade microbiológica e parâmetros sensoriais através de uma equipe treinada. Aos 45 dias de estocagem refrigerada, realizou-se um teste laboratorial de ordenação por preferência com consumidores, avaliando-se os atributos de cor, odor, sabor e firmeza (textura). Os resultados das determinações físicas, físico-químicas e sensoriais foram submetidos à análise de variância (ANOVA) para se avaliar o efeito dos tratamentos e tempo de estocagem, sendo a diferença entre as médias determinada pelo teste de Tukey com um intervalo de confiança de 95%. Para a avaliação sensorial de ordenação por preferência de consumidores foram utilizados os testes de Friedman e de Fisher. Os produtos apresentaram uma tendência no incremento dos valores de pH em função do tempo de estocagem. O aumento do teor de fibra solúvel adicionado resultou uma redução significativa (p<0,05) na atividade de água dos produtos. Para os parâmetros de cor avaliados, observou-se que a adição de níveis crescentes de fibra solúvel promoveu a diminuição dos valores de luminosidade (L*) e aumento no teor de vermelho (a*). Os maiores valores do teor de amarelo (b*) ao longo do período de estocagem foram observados no tratamento F0 ¿ sem adição de fibras. Os tratamentos F0 e F9 apresentaram nos primeiros 40 dias de estocagem, uma queda acentuada nos valores obtidos dos parâmetros C* (Chroma) e h (hue), enquanto os tratamentos F3 e F6 demonstraram a tendência de estabilidade ao longo da estocagem. Os resultados das avaliações microbiológicas indicaram que a adição de fibra solúvel não afetou a estabilidade microbiológica dos presuntos cozidos, uma vez que as contagens de micro-organismos deteriorantes e patogênicos mantiveram-se dentro dos limites estabelecidos pela legislação vigente ao longo do período de estocagem. A avaliação sensorial com equipe treinada evidenciou para os tratamentos contendo fibra solúvel, maior intensidade da cor rósea característica tanto na superfície das peças inteiras como nas fatias do produto. Por outro lado, para os atributos descoloração, exsudação, coesividade, sabor e odor, a equipe treinada não reportou influência da adição da fibra solúvel. A avaliação realizada com consumidores revelou preferência pelos tratamentos F3 e F6 para todos os atributos avaliados, entretanto o tratamento F9 foi o menos preferido em relação ao sabor e firmeza, evidenciando que a adição até o nível de 6% de fibra solúvel melhora a aceitação das características sensoriais avaliadas neste estudo do presunto cozido / Abstract: The present research aims the evaluation of the effects of addition of soluble fiber of short chain fructooligosaccharides (ScFOS - NutraFlora ®) over the physical, physical-chemical, microbiological and sensorial quality attributes of cook-in cooked ham. The processing of cooked hams was conducted at Marba industry, Sao Bernardo do Campo - São Paulo, Brazil. There was elaborated a standard formula of cook-in cooked ham, for 170% yield over weight of raw material, from which were balanced other formulas with soluble fiber addition:F0, F3, F6 e F9; standard (without fiber addition, 3%, 6% and 9% of fiber addition, respectively). The hams were evaluated through refrigerated storage at 2 ± 2 º C at five points (7, 20, 41, 62 and 93 days) for pH, water activity (Aw) values, centesimal composition, contents of nitrite and nitrate, colour, shear force, sliceability measurement, microbiological and sensory parameters using a trained judges. At the 45th day of storage there was processed a ranking preference test with regular consumers, assessing colour, characteristic odor, characteristic taste and firmness (texture) attributes. Physical measurements, physical-chemical and sensory results were analyzed for variance (ANOVA) to survey soluble fiber addition effects over considered parameters. The difference between means was ascertained through Tukey test at 95 % of confidence. For the ranking test there were used Friedman and Fisher tests. The hams exhibited a tendency of increasing pH values according to storage. The increasing content of soluble fiber (NutraFlora ®) added resulted in a significant reduction (p <0.05) water activity of products. For colour parameters, the rising of soluble fiber resulted in reduction of luminosity (L*) and addition of redness (a*) values. The highest yellowness (b*) values during the storage were observed at F0 treatment - without the fiber addition. The treatments F0 and F9 had at the first 40 days of storage, a sharp drop for C * (chroma) and h (hue) values while F3 and F6 treatments remained stable during that period. Microbiological evaluations pointed that the addition of soluble fiber did not affected the microbiological stability of cooked hams as the spoilage and pathogenic microorganisms counts remained within Brazilian official limits throughout the storage period. Sensory evaluation with trained judges pointed that the characteristic pink colour of whole ham and slices had higher intensity in the samples with soluble fiber addition. On the other hand, attributes of discoloration, exudation, cohesiveness, taste and odor, had no influence over the different treatments. The assessment carried out with consumers submitted comments similar to those obtained with the trained judges. The ranking preference test revealed higher preference for F3 and F6 for all the considered traits, meanwhile F9 was the least preferred regarding characteristic taste and firmness, pointed that the addition as high as 6% of soluble fiber NutraFlora ® increase the cooked ham acceptance / Mestrado / Tecnologia de Alimentos / Mestre em Tecnologia de Alimentos
9

Establishing Threshold Levels of Nitrite Causing Pinking of Cooked Meat

Heaton, Kevin M. 01 May 1998 (has links)
Sporadic problems with pink color defect, or pinking, has occurred in cooked meat products for decades. Pink color can be due to the presence of undenatured myoglobin, denatured globin hemochromes, or nitrosylhemochrome. This research documented the level of added nitrite that produced nitrosylhemochrome in processed meat rolls from fabricated beef round, pork shoulder, turkey breast, and chicken breast. For each meat type, preliminary studies were conducted to narrow the range at which added nitrite caused pinking. Subsequently, the nitrite levels were increased incrementally by 1-ppm, and pink color was measured by trained panelists and by a Hunter color meter. Nitrosylhemochrome content was determined by acetone extraction. Panel and instrumental measurements identified pink color in beef samples formulated with 14-ppm nitrite; nitrosohemochrome extracts detected pigment at 12- ppm. Nitrite levels that caused pinking in pork shoulder were much lower than in beef. Panelists identified pink color at 4-ppm nitrite, and Hunter color meter values showed increased redness at 6-ppm. Pigment extraction detected nitrosylhemochrome at 4- ppm added nitrite. The trained panel and Hunter color meter detected pink color in turkey breast at 2-ppm added nitrite; nitrosohemochrome extraction detected pink pigment at 3-ppm added nitrite. In chicken breast, pink color was detected visually and instrumentally at 1-ppm added nitrite. Pigment extraction detected nitrosylhemochrome at 2-ppm added nitrite. Lower levels of nitrite (1-3-ppm) caused pinking in light-colored meats (turkey and chicken breast, meats with total pigment between 19-ppm and 27-ppm). Higher levels of nitrite (5-14-ppm) caused pink color defect in dark pigmented meat (beef round and pork shoulder, meats with total pigment levels between 56-ppm and 147-ppm). Regression analysis was used to relate total pigment and the minimum level of nitrite causing pinking. The minimum nitrite level causing pinking was the lowest level of nitrite at which the trained panel, acetone extraction, and instrumental results detected pink color or nitrosyl pigment. The formula obtained from the model was as follows: Y = 0.092X + 0.53, where "Y" is the minimum level of added nitrite to cause pinking and "X" is the total pigment of the meat. This formula can be used to estimate the level of nitrite that can be expected to cause pinking in a wide range of pigmented meats.
10

Characterization of Pigments Responsible for Red or Pink Discoloration in Cooked Pork

Ghorpade, Viswasrao M. 01 May 1992 (has links)
The pigments responsible for pink or red discoloration in cooked vacuum-packaged meat products {bratwurst (pork and beef), ground pork, and pork roasts} were investigated. In bratwurst, this study attempted to characterize the red pigment that appears upon refrigerated storage, and to determine the effect of pH, cooking and storage temperature, and sodium lactate on incidence of red discoloration. Myoglobin was identified in the exudate of samples with red discoloration. Myoglobin levels of cooked products were significantly lower in samples of low initial pH (5.5) or cooked to higher than normal internal temperature (74°C). Red discoloration was associated with microbial growth. Frozen samples had no red discoloration after 4 weeks storage. Microbial plate count and incidence of red discoloration were lower in samples of lower pH (5.5 vs 5.8 or 6.2), samples cooked to higher internal temperature (74° vs 68°C), and samples containing 3% sodium lactate. Further, the effects of microbial growth in raw materials (ground pork) on cooked pork color were investigated. In two trials with sow meat held aerobically at 2°C for 3 weeks, microbial load reached spoilage levels (107 cfu/g), pH increased to 6.46, and samples cooked to 71°C had red exudate, shown by absorption spectroscopy to contain myoglobin and cytochrome c. Samples cooked to 82°C received high panel ratings for red color, due to red, flocculent precipitate in exudate, but samples containing undenatured myoglobin levels received low panel ratings. In sow meat held frozen or vacuum packaged at 2°C, pH after 3 weeks was 6.03 and 6.18, and plate counts were 104 and 107, respectively, but exudates after cooking were much less red. In five trials with fresh U. S. #1 pork legs, plate counts also reached 107 cfu/g by 3 weeks storage, and pH increased from 5.99 to 6.37, but cooked samples were not red. Higher myoglobin levels in sow meat probably accounted for the red color and the high level of undenatured myoglobin remaining after cooking of high pH, spoiled samples. Finally, pink or red discoloration was investigated in the cooked U. S. #1 pork roasts. Myoglobin was the pigment responsible for pink color in pork roasts cooked to 65°C. Roasts cooked to 82°C had gray internal color after cooking, but developed pink internal color after refrigerated storage. Reflectance spectra of pink slices from roasts, cooked to 82°C, then stored for 12 days at 2°C, were charactetistic of denatured globin hemochromes or related non-nitrosyl hemochromes.

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