The relationship among consumer acceptability, descriptive sensory attributes, and shelf-life was determined for 2 % milk pasteurized at 77, 79, 82, or 85?aC. Pasteurization temperature had no effect (p>0.05) on shelf-life. Consumers preferred (p<0.05) 79?aC over other treatments on day 0; however, six days post-pasteurization 79?aC milk was only preferred (p<0.05) over 77?aC. Consumers were grouped into eight clusters based on product liking for both day 0 and 6 evaluations. The largest cluster liked all pasteurization treatments, and 79?aC was highly acceptable to all consumers that liked milk. Similar sensory descriptors indicated the end of shelf-life for all pasteurization treatments even though treatments could be differentiated by descriptors on day 0. This research reveals that altering pasteurization temperature from 79?aC may cause a decrease in consumer acceptability to some consumers. Altering pasteurization temperature does not affect shelf-life or sensory descriptors and volatile compound profiles at the end of shelf-life.

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No description available.

No description available.

The use of Pulsed Energy (Flashbasttm) Technology (PET) to extend the shelf life of fresh fish fillets was studied. Unskinned fillets from fresh sea trout (Cynoscion regalis) and hybrid striped bass (Morone chrysops x ~ saxatilis) were treated with 7.45 Joules/cm² of PET, stored individually in sterile polyethylene bags, and kept in ice for 21 days at 3°C. Sensory data showed no significant differences (pâ ¤ 0.05) in the appearance, odor, texture, or taste of cooked samples from treated and control fillets, regardless of species. Raw sea trout fillets developed "alien" odors upon treatment which disappeared within the first week of storage and were not detected in cooked samples. These off-odors were significant (pâ ¤ 0.05) in the freshwater species only during the first three days post-treatment. Microbiological analyses revealed that PET reduced bacteria growing on the flesh surface and skin at significantly higher (pâ ¤ 0.05) rates than those in the flesh. Total coliforms were the most susceptible bacteria to PET. / Ph. D.

An enzyme-linked immunosorbent assay (ELISA) using polyclonal antibodies has been developed for the detection of the fluorescing group of Pseudomonas. The assay was used as a rapid test (6h) for predicting the shelf-life of pasteurized fluid milk. Milk samples were held at 7°C and tested weekly until determined to be unacceptable by daily sensory evaluation. Sterile milk samples were inoculated with target concentrations of 0 (control), 100, and 1000 cells/ml of Pseudomonas fluorescens on day 0. Samples were tested before and after preliminary incubations. Preliminary incubations conducted include milk alone and milk with broth (1:1) for 18h at 21°C. ELISA and plate counts were performed before and after preliminary incubation to determine the number of pseudomonads present and the relationship between ELISA and plate counts. These numbers were correlated to the shelf-life of each sample, as determined by sensory evaluation. Samples undergoing a preliminary incubation with only milk gave the best correlation to shelf-life (R=0.86). / Master of Science

The effects of packaging treatments, post harvest cooling delay and storage duration on color, texture, ascorbic acid content, weight loss and glucosinolate retention in crown-cut heads of broccoli were studied. Oxygen and CO2 levels inside shrink wrap packages were also monitored. Shrink wrap packaging had a significant positive effect on hue angle (p<0.05). Packaging and post harvest cooling delay had no effect on hue difference and total color difference. While post harvest cooling delay had no effect on texture, crown-cut heads of broccoli stored in shrink wrap packaging retained firmness significantly better than ice packaged heads of broccoli (p<0.05). Ascorbic acid was retained better in broccoli held in shrink wrap packages and cooling delay had a significant negative influence on ascorbic acid content (p<0.05). Packaging and post harvest cooling delay had a significant positive effect on weight loss (p<0.05). Broccoli stored in shrink wrap film lost about 3.7% of original weight while ice packaging resulted in about 17.4% weight loss (p<0.05). No consistent trends were observed in the levels of O2 and CO2 inside shrink wrap packages. An important glucosinolate, glucoraphanin was retained significantly better in shrink wrapped heads (p<0.05). Between two cultivars, shelf life of cv.Gypsy was better than cv.Everest with respect to color, ascorbic acid retention and weight loss. But cv.Everest retained texture (firmness) better after 35 days of storage. Overall results indicate that shrink wrap packaging and shorter post harvest cooling delays protect quality of broccoli. / Master of Science

The purpose of this project was to evaluate the antioxidant activity in vitro and its effects at the oxidative stability of mechanically deboned poultry meat (MDPM) of five natural extracts. It was studied: the yerba mate (Ilex paraguariensis), the marcela (Achyrocline satureioides), a mixture of yerba mate (50%) and marcela (50%), green tea (Camellia sinensis) and propolis without alcohol. The synthetic antioxidant BHA (Butylated Hydroxianisole) was used as a positive control and the meat treated with no antioxidant was used as negative control. Natural extracts were evaluated in vitro for quantification of phenolic and flavonols total content, for antioxidant activity, by DPPH radicalscavenging, Phosphomolybdenum complex and Reducing Power assay methods. All antioxidants were mixed separately in different and equal portions of mechanically deboned poultry meat, as follow: 0.50% of yerba mate, marcela and the mixture, 0.05% of green tea, 0.10% of própolis without alcohol and 0.02% of BHA. Samples of MDPM were packed and storage at 0 to +4ºC for 10 days. The samples were evaluated each two days and the pH, TBARS and peroxide index were measured, as well as the Total Mesophilic Aerobic counts, Total Coliforms, E. coli, Lactic Bacteria, Clostridium perfringens, Salmonella spp and Staphylococcus aureus. Surface and internal colour ( L*, a*, b*) were measured and pictures of each treatment were done. Green tea extract showed the higher (p<0.05) phenolics contents and the higher (p<0.05) antioxidant activity in vitro compared to the other extracts. Yerba mate extract showed the higher (p<0.05) flavonols content. Propolis without alcohol extract showed the lowest (p<0.05) phenolics, flavonols and antioxidant activity in vitro. Marcela had the best oxidative inhibitory effect at the MDPM, with the lowest TBARS values. Propolis extract showed the best performance for the meat colour stability. Natural antioxidant addition do not interfere at MDPM pH and peroxide values. Salmonella spp was not detected in any of the samples evaluated and the results found to Staphylococcus aureus were in agreement with the Brazilian Mechanically Deboned Meat Legislation. The mixture of extracts showed the lowest (p<0.05) media for Total Mesophilic Aerobic counts. Propolis extract showed the lowest media count for Total Coliforms, E. coli and Clostridium perfringens. Yerba mate extract showed the lowest media count for Lactic Bacteria. The use of natural antioxidants should provide benefits in relation to the MDPM lipid oxidation and the microbiological growth inhibition. More researchs are necessary, looking for a better understanding about the action mechanisms of these extracts. / Este trabalho teve como objetivo avaliar cinco extratos naturais em relação a sua atividade antioxidante in vitro e na Carne Mecanicamente Separada (CMS) de frango. Foram estudadas a erva mate (Ilex paraguariensis), a marcela (Achyrocline satureioides), uma mistura de erva mate (50%) com marcela (50%), o chá verde (Camellia sinensis) e o própolis sem álcool. O antioxidante sintético BHA foi utilizado como controle positivo e o tratamento sem adição de antioxidante como controle negativo. Nos extratos naturais foram identificados o conteúdo total de fenólicos, flavonóides e a atividade antioxidante pelos métodos do DPPH, Fosfomolibdênio e do Poder de Redução. Todos os extratos foram aplicados separadamente em porções distintas e iguais de Carne Mecanicamente Separada (CMS) de frango, sendo os percentuais de aplicação de 0,50% de erva mate, marcela e da mistura, 0,05% de chá verde, 0,10% do própolis sem álcool e 0,02% de BHA. A CMS de frango foi mantida sob refrigeração de 0 a +4ºC durante 10 dias. As amostras foram avaliadas a cada dois dias, em relação ao pH, índice de TBARS, índice de peróxido, em relação a contagem média de Aeróbios Mesófilos Totais, Coliformes Totais, E. coli, Bactérias lácticas, Clostridium perfringens, Salmonella spp e Staphylococcus aureus. A cor objetiva (L*, a*, b*) foi medida na superfície e na parte interna da CMS de frango assim como o registro em foto de cada tratamento. O extrato de chá verde apresentou o maior (p<0,05) conteúdo de fenólicos e a maior (p<0,05) atividade antioxidante in vitro em relação aos demais extratos. O extrato de erva mate apresentou o maior (p<0,05) conteúdo de flavonóides. O extrato de própolis sem álcool apresentou os menores (p<0,05) conteúdos de fenólicos, de flavonóides e a menor atividade antioxidante in vitro. O extrato de marcela teve o melhor efeito na inibição da oxidação lipídica da CMS de frango, apresentando os menores valores médios de TBARS. O extrato de própolis sem álcool manteve por mais tempo a estabilidade da cor da carne. A adição dos antioxidantes naturais não interferiu no pH e nem no índice de peróxido da CMS de frango. Não foi detectada a presença de Salmonella spp e os resultados de Staphylococcus aureus ficaram dentro dos padrões estabelecidos pela Legislação. O tratamento com a mistura de extratos de erva mate e de marcela apresentou a menor (p<0,05) contagem média de Aeróbios Mesófilos Totais em relação aos demais tratamentos. O extrato de própolis sem álcool apresentou a menor contagem média de Coliformes totais, E. coli e Clostridium perfringens. O extrato de erva mate apresentou a menor contagem média de Bactérias lácticas. O uso de antioxidantes naturais pode trazer benefícios em relação a inibição da população microbiana da CMS de frango. Mais estudos são necessários visando um melhor entendimento dos mecanismos de ação desses extratos na carne mecanicamente separada (CMS) de frango.

Fler svenskar vill konsumera mer inhemskt producerad fisk. Scandinavian Aquasystems odlar och försöker introducera fisken tilapia på svenska marknaden. Tilapia är en fisk som precis börjat göra intåg i Europa men är stor runtomkring resten av världen. En smakprofil som berättar hur länge produkten är sensoriskt tjänlig kan vara av hjälp. Denna undersökning syftade till att skapa en sensorisk smakprofil för fisken tilapia och till att se hur smakprofilen förändrades vid lagring i vakuumförpackning. För att skapa smakprofilen användes metoden QDA. Resultatet gav många egenskapsord var av vissa kunde klassificeras som färskhetsrelaterade och vissa som förskämningsrelaterade. Det kunde även konstateras att färsk, odlad tilapia har en antydan av saftigare och mer mjäll textur. Vid lagring finns en möjlighet att tilapia får en intensivare smak av dy och metall, samt en intensivare doft av dy. / A large amount of Swedes has a desire to consume more nationally produced fish. Scandinavian Aquasystems produces and tries to introduce tilapia into the Swedish market. As a fish, tilapia has just begun making ways into Europe but is already a big commodity around the rest of the world. In addition, a sensory profile which tells how long the product remains sensorially suitable could be of help. This study aimed to create a sensory profile and to study its inherent effects of vacuum packaging over time. In creating the sensory profile, a QDA method was used. The study resulted in a variance of different attributes which of some could be categorized as either fresh related or spoilage related. It was found that fresh, farmed tilapia carried an indication of having a juicier and more tender texture. With storage there is chance of tilapia getting a more intense flavor of mud and metal, as well as a more intense odor of mud.

Para o desenvolvimento de um novo produto, busca-se atender a necessidade da indústria, do mercado e do consumidor, nos parâmetros qualidade, conveniência e com valor nutritivo que remeta à boa saúde. Com o objetivo de desenvolver o coproduto Quenelle de tilápia iniciou-se a etapa criativa de elaboração e a seguir, estabeleceu-se o processo do estudo de vida útil, a fim de definir a validade do produto, com base nos parâmetros físico-químico, microbiológico e sensorial. Na primeira etapa, 11 formulações foram testadas e a partir da avaliação destas, outras 4 formulações foram desenvolvidas e avaliadas através de análise sensorial de preferência por ordenação, resultando na formulação eleita composta dos seguintes ingredientes: Minced, gordura vegetal, cebola desidratada, proteína isolada de soja, tempero Hondashi, salsa desidratada, urucum e sal. O teste de vida útil foi realizado no período de 120 dias, sendo as análises físico-químicas, microbiológicas e sensoriais realizadas a cada 30 dias. O produto Quenelle contém, em média, 69,63 g/100g de umidade, 2,46 g/100g de cinza, 8,51 g/100g de lipídeos,15,18 g/100g de proteína e 4,23 g/100g de carboidrato, apresentando valor de TBARS de 1,12 mg malonaldeído/kg e pH de 6,5. Quanto às análises microbiológicas os valores foram os seguintes: para psicrotróficos 3,24 log UFC/g; coliformes termotolerantes, <3,0 NMP/g; coliformes totais, 3,6 NMP/g; Staphylococcus aureus, <10 NMP/g e ausência de Salmonella em 25/g. O produto foi embalado em dois tipos de embalagem, pouche de polietileno com zíper (QA) e embalagem de polietileno complementada com caixa de cartão parafinado (QB). A rotulagem, para a porção de 40g de Quenelle, mostrou os seguintes valores: 59 kcal, 2,1g de carboidrato, 5,64g de proteína, 2,84g de gorduras totais, 1,53g de gordura monoinsaturada, 0,64g de poliinsaturada, 0,04g de ômega 3 e 0,56g de ômega 6, 1,06g de gordura saturada, 0,39 de gordura trans, 0,63 mg de ferro, 271 mg de sódio, 10 UI de vitamina A, 3,03 mcg de retinol. A análise sensorial foi realizada através de um teste de avaliação de atributos, aparência (úmida, homogênea, impressão global), aroma (característico de peixe, característico do produto), textura (maciez, suculência, elasticidade), gosto (sal) e sabor (característico de peixe, condimento, off flavor de barro, off flavor de geladeira). Os valores médios dos atributos avaliados de Quenelles de tilápia em diferentes embalagens (QA e QB), durante o armazenamento, não apresentaram diferença significativa (p>0,05), bem como a interação tratamento versus provador. Quando se avaliou as médias dos atributos sensoriais nos dias de armazenamento e para as diferentes embalagens, pôde-se notar que houve diferença significativa (p<0,05) para todos os atributos, com exceção da maciez. Os provadores tiveram procedimento considerado significativo, para alguns atributos, como aparência úmida, aroma característico de peixe e do produto, e sabor de barro e de geladeira; com isso, algumas interações dias versus provador foram significativas, tais como aparência úmida, aroma característico de peixe e do produto, maciez, suculência, elasticidade, sabor característico de peixe, de condimento, de barro e de geladeira, e gosto de sal, exceto a aparência homogênea. / To develop a new product, we seek to meet the needs of industry, market and consumer. In questions, quality and convenience, offering food with nutritional value referring to good health. The objective was developing the co-product Quenelle of tilapia and began the creative phase of development. Created formulation, settled the case study of life in order to determine the shelf life of the product, based on physicalchemical, microbiological and sensory parameters. In the first stage, 11 formulations were tested by sensory analysis and preference ordering, resulting in the final formulation containing the following ingredients: minced, vegetable fat, dehydrated onion, soy protein isolate, Hondashi seasoning, salt and annatto. The shelf life test was carried out in 120 days, and the physical-chemical, microbiological and sensory testing performed every 30 days. The results were obtained for moisture 69.63 g.100g-1; ash 2.46 g.100g-1; fat, 8.51 g.100g-1, protein 15.18 g.100g-1and, 4.23 g.100g-1 carbohydrate. The value of TBA was 0.45 mg malonaldehyde / kg and pH was 6.5. As microbiological analysis the values were to psicotrophic 3.24 log CFU.g-1 / g, fecal coliform, <3.0 MPN.g- 1, total coliforms, 3.6 MPN.g-1, Staphylococcus aureus, <10 MPN.g-1and absence of Salmonella 25 / g. The product was packaged in two types of packaging, polyethylene pouch with zipper (QA) and polyethylene packaging more waxed cardboard box (QB). The label for the serving of 40g quenelle was: 59 kcal, 2.1 g of carbohydrate, 5.64 g of protein, 2.84 g of total fat, 1.53 g of monounsaturated fat, 0.64 g of polyunsaturated, 0.04 g of omega 3 and 0.56 g of omega 6, 1.06 g of saturated fat, 0.39g trans fat, 0.63 mg of iron, 271 mg of sodium, 10 IU of vitamin A, 3.03 mcg of retinol. Sensory analysis was performed using a test evaluation of attributes with six trained testers, where the samples showed no significant difference (p> 0.05) during storage. Sensory analysis was performed by an evaluation test attributes of appearance (moisture, homogeneous, general impression), aroma (fish characteristic, typical of product), texture (tenderness, juiciness, elasticity), taste (salt), flavor (fish characteristic, spices, mud off flavor, storage off flavor) with six trained testers. The average values of the attributes evaluated Quenelles tilapia in different packages (QA and QB), during storage, showed no significant difference (p > 0.05). The taster versus treatment interaction was not significant (p> 0.05). When assessing the means of sensory attributes in the days of storage, also considering the average values for all days (0, 30, 60, 90 and 120) of storage, besides the different packages (QA and QB), it was noted that significant differences (p <0.05) for all attributes except tenderness. Tasters procedure were considered significant (p <0.05) for some attributes, such as moisture appearance, aroma of fish and product, and taste of mud and storage; with it, some days versus tester interactions were significant (p <0.05), such moisture, aroma of fish and product, tenderness, juiciness, elasticity, flavor of fish, spices, mud, storage and salt, except the appearance homogeneous. The treatments interaction versus days of storage, just taste of storage showed significant difference (p <0.05).