• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 56
  • 9
  • 7
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 98
  • 27
  • 21
  • 20
  • 20
  • 18
  • 18
  • 18
  • 18
  • 13
  • 13
  • 12
  • 12
  • 11
  • 11
  • 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.
21

The Dismissive Actually

Egner, Alexander 06 May 2009 (has links)
This project is about giving in to the impulse of ideas. My mind is a little messy and cluttered, swirling with bits of stimuli. The spark of an idea happens when the bits collide. I prefer not to initiate or control the process so much as keep it fed and active. Through graphic design, I bear witness to these ideas, giving them form as a series of visible, tangible objects. Viewed comprehensively, the work establishes an ongoing chronicle of my creative life and mind.
22

The effects of four packaging systems and storage times on the survival of Listeria monocytogenes in shelf-stable smoked pork and beef sausage sticks and whole muscle turkey jerky

Lobaton-Sulabo, April Shayne S. January 1900 (has links)
Master of Science / Department of Food Science / Elizabeth A. E. Boyle / To validate how packaging and storage reduces Listeria monocytogenes (Lm) on whole muscle turkey jerky and smoked sausage sticks, four packaging systems, including heat seal (HS), heat seal with oxygen scavenger (HSOS), nitrogen flushed with oxygen scavenger (NFOS), and vacuum (VAC), and four ambient temperature storage times were evaluated. Commercially available whole turkey jerky and pork and beef smoked sausage sticks were inoculated with Lm using a dipping or hand-massaging method, respectively. There was no interaction on packaging and storage time on Lm reduction on smoked sausage sticks and an Lm log reduction of >2.0 log CFU/cm[superscript]2 was achieved in smoked sausage sticks packaged in HS, HSOS, and VAC. A >2.0 log CFU/cm[superscript]2 reduction was achieved after 24 h of ambient temperature storage, regardless of package type. NFOS was less effective in reducing Lm by more than 0.5 log CFU/cm[superscript]2 compared to HS, HSOS or VAC. After 30 d of ambient storage, Lm had been reduced by 3.3 log CFU/cm[superscript]2 for all packaging environments. In turkey jerky, Lm reduction was affected by the interaction of packaging and storage time. HS, HSOS, NFOS, or VAC in combination with 24, 48, or 72 h ambient temperature storage achieved <1.0 log CFU/cm[superscript]2. After 30 d at ambient temperature storage, Lm was reduced by >2.0 log CFU/cm[superscript]2 in HS and VAC, and could serve as a post-lethality treatment. Alternatively, processors could package turkey jerky in HSOS or NFOS in combination with 30 d ambient storage period as an antimicrobial process. Very little data has been published describing how packaging atmospheres affects Lm survival in RTE meat. The mechanism for Lm reduction under these conditions is not fully understood and additional research is needed.
23

Influência da matriz alimentar no efeito antimicrobiano de óleo essencial de orégano e nisina contra Listeria monocytogenes: avaliação em modelos cárneos / Influence of the food matrix on the antimicrobial effect of oregano essential oil and nisin against Listeria monocytogenes: evaluation in meat models

Biscola, Vanessa 31 July 2007 (has links)
Listeria monocytogenes é um microrganismo patogênico psicrotrófico e consequentemente de grande importância para alimentos conservados em refrigeração. Vários estudos têm demonstrado que é possível utilizar antimicrobianos naturais, como bacteriocinas e compostos fenólicos, para retardar a multiplicação desse patógeno em produtos cárneos refrigerados. Entretanto, sabe-se que a atividade antimicrobiana desses compostos pode ser influenciada pelos componentes da matriz alimentar. Esse trabalho de mestrado pretendeu avaliar a influência dos ingredientes de lingüiça frescal de suíno na ação inibitória de óleo essencial de orégano (OEO) e nisina sobre Listeria monocytogenes. Foram realizados testes com diferentes modelos alimentares preparados com carne suína moída adicionada de cada um dos ingredientes utilizados na fabricação de lingüiça frescal (sais de cura, açúcar, antioxidante, emulsificante, condimentos e NaCl) separadamente, comparando-se os resultados com os obtidos no modelo contendo todos os ingredientes simultaneamente. Pretendeu-se também avaliar a interferência do tempo de contato da nisina e óleo essencial de orégano com os diferentes modelos alimentares na ação antimicrobiana sobre L. monocytogenes. Os resultados indicaram que os antimicrobianos foram capazes de inibir a multiplicação de L. monocytogenes em todos os modelos analisados armazenados à 5ºC por até 72h. Comparando-se todos os modelos compostos por carne adicionada de apenas um dos ingredientes, a maior atividade antilisterial foi observada no modelo composto de carne com antioxidante. Entretanto, essa atividade inibitória foi menor do que a obtida no modelo contendo todos os ingredientes em conjunto. Quanto à influência do tempo prévio de contato entre os antimicrobianos e os modelos estudados na ação antilisterial, observou-se que na formulação com todos os ingredientes a ação foi mais intensa quando o contato foi de 2h. Entretanto, neste modelo o efeito mais duradouro foi obtido com 12h de contato prévio. Nos demais modelos, o maior efeito foi obtido no tempo zero. Os resultados permitem concluir que cada um dos ingredientes da formulação da lingüiça contribui com uma parcela na ação antilisterial do OEO e nisina nesse produto, e que essa ação é influenciada pelo tempo de contato prévio entre os modelos e os agentes antimicrobianos. / Listeria monocytogenes is psychrotrophic pathogen and, consequently, very important for cold-preserved foods. Many studies have demonstrated that natural antimicrobials such as bacteriocins and phenolic compounds can be used to inhibit the growth of this pathogen in refrigerated meat products. However, it is known that the antimicrobial activity of these antimicrobials may be influenced by components of the food matrix. The aim of the present study was to evaluate the influence of the ingredients of \"lingüiça\" in the inhibitory activity of O.E.O. and nisin against L. monocytogenes. The study was carried out with different food models prepared with minced raw pork meat added separately of each ingredient used for manufacturing \"lingüiça\" (curing salts, sugar, antioxidants, emulsifiers, condiments and NaCl), and results were compared to those obtained in a model containing all ingredients simultaneously. The study also aimed to evaluate the interference of the contact time between the food models and the antimicrobials on the effect against L. monocytogenes. Results indicated that the antimicrobials added to the models were able to inhibit the growth of the pathogen at 5ºC up to 72h. Comparing the models, the highest antilisterial activity was observed in the model containing pork meat and antioxidants. However, this inhibitory activity was lower than that observed in the model with all ingredients. What concerns the influence of contact time in antilisterial activity, we observed that in the model containing all ingredients the antilisterial activity was more intense after 2h of contact, but the more lasting effect was observed after 12h of contact. In the other models, the most intense effect was noted in time zero. The conclusions of the study are that each ingredient used in manufacture of \"lingüiça\" has its share in the antilisterial activity of nisin and OEO in this product and that this activity is influenced by the contact time between the food matrix and the antimicrobials.
24

Uso de extratos antioxidantes naturais obtidos de ervas aromáticas na elaboração de produtos a base de carne ovina / Use of natural antioxidant extracts obtained from aromatic herbs in developing products based on sheep meat

Fernandes, Rafaella de Paula Paseto 09 June 2015 (has links)
Atualmente, existem inúmeros questionamentos quanto aos prováveis efeitos mutagênicos e carcinogênicos dos antioxidantes sintéticos no organismo, e devido a isto, hoje em dia estudos tendem a promover a substituição destes compostos por naturais com o intuito de maior segurança do alimento, sendo que estes apresentam benefícios potenciais à saúde. O objetivo deste estudo foi o uso de antioxidantes naturais obtidos de ervas e especiarias no desenvolvimento de produtos cárneos a base de carne ovina buscando suas propriedades antioxidantes e sensoriais, bem como agregar valor ao produto final, desenvolvido com carne de baixo valor comercial. O apelo de saudabilidade dos produtos foi obtido pela adição de extratos antioxidantes naturais à base de ervas aromáticas selecionadas em função de seu poder antioxidante e harmonização de sabores com a carne ovina. Um primeiro experimento (Capítulo 2) consistiu na avaliação da capacidade antioxidante dos extratos de 13 espécies vegetais, sendo selecionados por Cluster analysis em relação a três métodos colorimétricos e sensorialmente após a adição em produto cárneo. O extrato selecionado foi avaliado quanto a acidez, à identificação e quantificação de compostos fenólicos e utilizado para a elaboração de hambúrguer congelado (Capítulo 3) e linguiça cozida (Capítulo 4), em diferentes concentrações, além de hambúrguer refrigerado sob atmosfera modificada (80% O2 + 20% CO2) (Capítulo 5), sendo comparados com tratamentos sem antioxidante (controle) e contendo antioxidante sintético (eritorbato de sódio ou BHT). Estes produtos cárneos foram avaliados durante armazenamento, respectivamente de 120, 135 e 20 dias, a partir de análises físico-químicas, sensoriais e microbiológicas, sendo inicialmente caracterizados quanto à composição centesimal. Orégano, manjerona, melissa e alecrim foram os extratos selecionados após agrupamento por similaridade quanto à capacidade antioxidante, sendo que os hambúrgueres elaborados com estes quatro extratos naturais não comprometeram a aceitação sensorial em relação ao eritorbato de sódio (P>0,05). Resumidamente, os produtos cárneos elaborados mostraram resultados relevantes quanto à estabilidade oxidativa, apresentando os tratamentos contendo extrato natural, efeitos antioxidantes melhores e/ou compatíveis aos antioxidantes sintéticos. Hambúrguer congelado apresentou mais de 50% de redução (P<0,001) para nível de substâncias reativas ao ácido tiobarbitúrico (TBARS), enquanto que linguiças cozidas apresentaram os menores valores para compostos voláteis (P<0,001) aos 135 dias de estocagem e a presença do extrato em hambúrgueres sob atmosfera modificada (ATM) manteve a qualidade sensorial por até 15 dias de armazenamento. Apesar de diferentes sistemas testados, o ensaio de redução férrica (FRAP) foi o método em comum mais eficaz para estimar a quantidade adequada de antioxidante natural a ser adicionada em comparação ao eritorbato de sódio. Em conclusão, extrato de orégano adicionado em produtos a base de carne ovina apresentou efeitos antioxidantes equivalentes aos antioxidantes sintéticos, não comprometendo a maioria dos parâmetros físico-químicos, microbiológicos e sensoriais, sendo considerado uma alternativa viável e favorecida pela grande vantagem da saudabilidade. / Currently, there are many questions concerning probable mutagenic and carcinogenic effects of synthetic antioxidants in the organism, and because of this, nowadays studies tend to promote the substitution of these by natural compounds with the aim of greater food safety and potential benefits for the health. The objective of this study was the use of natural antioxidants obtained from herbs and spices in the development of meat products ovine meat looking theirs antioxidant and sensory properties as well as add value to the final product, which was developed with low commercial value meat. The healthiness appeal of the product was obtained by adding natural antioxidants based extracts of aromatic herbs to be selected according to its antioxidant power and harmonization of flavors with the sheep meat. A first experiment (Chapter 2) was performed to evaluate the antioxidant capacity of 13 plant species extracts, being selected by Cluster analysis in relation to three colorimetric methods and sensory, after the addition in meat product. The selected extract was evaluated for acidity, identification and quantification of phenolic compounds and used for the preparation of frozen hamburger (Chapter 3) and cooked sausage (Chapter 4), at different concentrations, and refrigerated hamburger under modified atmosphere (80% O2 + 20% CO2) (Chapter 5), being compared to treatments without antioxidant (control) and containing synthetic antioxidant (sodium erythorbate or BHT). These meat products were evaluated during storage, respectively of 120, 135 and 20 days, from physical-chemical, sensory and microbiological analyzes, being initially characterized for chemical composition. Oregano, marjoram, lemon balm and rosemary were the extracts selected after grouping by similarity of the antioxidant capacity, and the hamburgers made with these four natural extracts did not affect the sensory acceptance in comparison to sodium erythorbate (P>0.05). Briefly, the meat products showed significant results in terms of oxidative stability, being the treatments containing natural extract presented best effects antioxidant and/or compatible to synthetic compounds. Frozen burger presented more than 50% reduction (P<0.001) for tiobarbituric acid reactive substance TBARS, while cooked sausages had the lowest values for volatile compounds (P<0.001) at 135 days of storage, and the extract presence in burgers under modified atmosphere kept the quality sensory up to 15 days. Although different systems tested, ferric reducing antioxidant power (FRAP) was more effective common method to estimate the appropriate amount of natural antioxidant to be used in comparison to sodium erythorbate. In conclusion, oregano extract added products in the sheep meat presented equivalent antioxidant effects without to compromise the majority of physical-chemical, microbiological and sensory parameters, being thus considered a viable alternative, favored by the great advantage of healthiness.
25

Desenvolvimento, caracterização e aplicação de microcápsulas de ácido ascórbico obtidas por spray chilling / Development, characterization and application of ascorbic acid microcapsules obtained by spray chilling

Matos Junior, Fernando Eustáquio de 05 December 2013 (has links)
O aumento da conscientização por parte da população em relação ao impacto da alimentação no estado de saúde tem imposto à indústria de alimentos uma série de novos desafios, entre eles a necessidade de desenvolver alimentos com maior apelo de \"saudabilidade\" e que promovam bem-estar físico e mental. Em função das recentes exigências do consumidor, os compostos bioativos, aqueles capazes de otimizar funções fisiológicas atuando na promoção e prevenção da saúde têm sido alvos de inúmeras pesquisas. Incorporar compostos bioativos em alimentos é um difícil tarefa, pois muitos compostos bioativos são altamente susceptíveis à degradação quando incorporado à matriz alimentícia. Entre esses compostos está o ácido ascórbico, considerado um composto bioativo por ser um potente antioxidante, que além do seu papel no organismo humano, inclusive vitamínico, também exerce função de aditivo alimentar atuando como um antioxidante natural capaz de evitar ou retardar a oxidação de componentes da matriz alimentícia, evitando assim, alterações de cor e/ou odor desagradáveis. Uma alternativa viável e promissora de incorporar ácido ascórbico à matriz alimentícia evitando sua degradação seria o uso da tecnologia de microencapsulação. Das numerosas técnicas de microencapsulação disponíveis, spray chilling, também conhecida como spray congealing ou spray cooling, vem recebendo especial atenção nos últimos anos em função do seu baixo custo e facilidade de execução. Neste sentido, este trabalho objetivou-se estudar a microencapsulação do ácido ascórbico pela técnica de spray chilling e aplicar as micropartículas carregadas em um produto cárneo emulsionado, não apenas para desenvolvimento de um alimento contendo composto funcional, mas também para substituir o antioxidante até então utilizado na indústria de alimentos para o produto cárneo em questão. O estudo foi dividido em 3 etapas, duas delas compreenderam o desenvolvimento e caracterização das micropartículas lipídicas sólidas carregadas com ácido ascórbico e a terceira à aplicação do ácido ascórbico encapsulado em salsicha produzida com carne de frango. A estabilidade do ácido ascórbico microencapsulado foi consideravelmente melhorada em comparação com sua forma livre. A tecnologia de spray chilling revelouse como uma técnica eficaz de microencapsulação para atender o objetivo proposto. A aplicação do ácido ascórbico encapsulado em salsicha foi bem sucedida, foi produzido um alimento com características similares ao convencional, inclusive, com aceitação sensorial favorável. Foi atendido o objetivo de microencapsular o ácido ascórbico e promover sua aplicação em uma matriz alimentícia. Os resultados desse trabalho poderão subsidiar novos estudos com intuito de microencapsular outros compostos bioativos e de aplicar o ácido ascórbico microencapsulado em outras matrizes alimentícias seja com objetivo de desenvolver alimentos funcionais e/ou de substituir aditivos alimentares atualmente utilizados que não oferecem nenhum benefício adicional à saúde do consumidor por um composto que além de atuar como antioxidante na matriz alimentícia, tem função vitamínica e de composto bioativo no organismo favorecendo a manutenção da saúde do consumidor, e assim, atendendo as novas tendências de busca por alimentos mais saudáveis. / The increased awareness on the part of the population in relation to the impact of food on health has imposed the food industry a series of new challenges, among them the need to develop foods with greater appeal of healthfulness and that promote wellbeing. Due to recents demands consumer, the bioactive compounds, those able to optimize physiological functions working in health promotion and disease prevention have been the targets of numerous studies. Incorporate bioactive compounds in foods is a difficult task because many bioactive compounds are highly susceptible to degradation when incorporated into the food matrix. Among these compounds is ascorbic acid, considered as a bioactive compound to be a potent antioxidant in addition to its role in the human body, including vitamin, also exerts a function as a food additive acting as a natural antioxidant can prevent or retard oxidation Component the food matrix, thus avoiding color change and/or unpleasant odor. A viable and promising alternative to incorporating ascorbic acid to the food matrix preventing their degradation would be the use of microencapsulation technology. Of the numerous techniques available microencapsulation, spray chilling, also known as spray congealing or spray cooling, has received special attention in recent years due to their low cost and ease of implementation. Thus, this work aimed to study the microencapsulation of ascorbic acid by spray chilling technique and apply the loaded microparticles in a emulsified meat product, not only for the development of a food containing functional compound, but also to replace the hitherto used antioxidant in the food industry for meat product in question. The study was divided into three stages, two of which comprised the development and characterization of solid lipid microparticles loaded with ascorbic acid and third application of ascorbic acid produced sausage with encapsulated in chicken. The stability of the microencapsulated ascorbic acid has been considerably improved compared to the free form. The spray chilling technology proved to be an effective technique of microencapsulation to meet the objective. The application of ascorbic acid encapsulated in sausage was successful food was produced with characteristics similar to conventional inclusive, with favorable sensory acceptability. Was served the purpose of microencapsulate ascorbic acid and promote its application in a food matrix. The results of this study may support further studies aiming to microencapsulate other bioactive compounds and apply ascorbic acid microencapsulated other food matrix is aiming to develop functional foods and/or replace currently used food additives that offer no additional benefit to health consumer for a compound that in addition to acting as an antioxidant in food matrix has vitamin function and bioactive compound in the body favoring the maintenance of the health of the consumer, and thus, given the new trends search for healthier foods.
26

Desenvolvendo compet?ncias com os alunos do curso t?cnico em agroind?stria: uso da carne ovina no processamento de embutido tipo salame

LACERDA, Maria de F?tima Alves Figueiredo de 17 December 2009 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-08-23T19:36:52Z No. of bitstreams: 1 2009 - Maria de F?tima Alves Figueiredo Lacerda.pdf: 2104751 bytes, checksum: add9aca0ab23ddb0dd016f85c4585f40 (MD5) / Made available in DSpace on 2018-08-23T19:36:52Z (GMT). No. of bitstreams: 1 2009 - Maria de F?tima Alves Figueiredo Lacerda.pdf: 2104751 bytes, checksum: add9aca0ab23ddb0dd016f85c4585f40 (MD5) Previous issue date: 2009-12-17 / The aim of this work was to stimulate the students of the Module on Processing of Animal Products (PPOA) of the Technical Course on Agri-Industries at the Federal Institute of Education, Science and Technology of Para?ba ? Sousa Campus (former Federal Agrotechnical School of Sousa ?PB) to develop skills and build their knowledge in the preparation of a fermented sausage of salami-type with mutton, observing the kinetics of fermentation and ripening. The understanding of the concepts of microbial ecosystems, strategies and tools to control microbial growth in food bioprocessing was explored. The aim is learning by research, and through integration of research, development, production and technical education. Two groups of students were used (H4 and H5). The group H4 (24 students) was stimulated to inquiry and questioning, and also to expand the information received from the instructors by searching technical literature. The other group (H5, 12 students) was approached by the methodology traditionally applied in the school, an approach of "reproductive action" without encouraging them to inquiry, and without a discussion of the scientific basis of the applied biotechnology. Two types of fermented salami-type sausage were made: using pork and mutton and a referencial product made out of pork and beef. Both products were innoculated with starter culture (Pediococcus pentosaceus). Colour, taste, texture and acceptability were evaluated. All batches had good overall acceptability. The verification of the learning was monitored by applying, to both group of students, questionnaires before and after the activities. It was observed that the students involved in the research-based activities (group H4) have developed the learning and understanding required for the processing of fermented sausages well beyond a instrumental-only knowledge. / Pretendeu-se, com esta pesquisa, incentivar os alunos do M?dulo de Processamento de Produtos de Origem Animal (PPOA) do Curso T?cnico em Agroind?stria do Instituto Federal de Educa??o, Ci?ncia e Tecnologia da Para?ba ? Campus de Sousa, antiga Escola Agrot?cnica Federal de Sousa-PB, a desenvolverem compet?ncias na constru??o dos seus saberes, na elabora??o de um embutido fermentado tipo salame com carne ovina, observando o bioprocesso durante o per?odo de fermenta??o e acompanhando sua matura??o. Al?m da familiariza??o com conceitos de ecossistemas, estrat?gias e ferramentas para o controle do crescimento microbiano no bioprocessamento de alimentos, objetiva-se o aprendizado, atrav?s do est?mulo ? pesquisa, integrando pesquisa, desenvolvimento e produ??o no ensino t?cnico. Foram utilizadas duas turmas, denominadas H4 e H5. A Turma H4 com 24 alunos foram estimulados a inquirir, questionar, e complementar as informa??es recebidas atrav?s da leitura e pesquisa bibliogr?fica. Enquanto que a Turma H5 com 12 alunos foi aplicada a metodologia tradicionalmente empregada na institui??o de ensino, numa abordagem de ?a??o reprodutiva?, sem estimul?-los a inquirir, e sem discorrer sobre as bases cient?ficas do processo biotecnol?gico empregado. Elaborou-se dois tipos de embutido fermentado tipo salame usando a carne su?na e ovina e outro com su?na e bovina, utilizando a cultura starter (Pediococcus pentosaceus) avaliando cor, sabor, consist?ncia e aceitabilidade. As amostras apresentaram boa aceitabilidade global. A verifica??o do aprendizado foi feita aplicando-se question?rio antes e ap?s o desenvolvimento da pesquisa nas duas turmas fazendo-se o acompanhamento e a compara??o do desempenho dos alunos nas etapas da pesquisa. Observou-se que os alunos envolvidos na pesquisa (turma H4) desenvolveram as compet?ncias necess?rias para o processamento do embutido fermentado tipo salame e tiveram a oportunidade de construir um conhecimento que foi al?m do simples fazer instrumental, mas do aprender.
27

Redução dos níveis de gordura em mortadela bologna e sua influência sensorial em provadores de diferentes idades / Reduced levels of fat in Italian sausages and its influence on sensory tasters of different ages

Spada, Fernanda Papa 15 July 2013 (has links)
A busca por um estilo de vida saudável é crescente sendo desafiante para a indústria alimentícia atender às demandas atuais de mercado. A idade do consumidor é variável importante frente às expectativas dos indivíduos. Pois os jovens em geral são saudáveis, estão em fase de descobertas, mudanças e em formação de opinião, enquanto os idosos possuem preferências consolidadas e geralmente apresentam restrições alimentares. Neste contexto, para produtos cárneos, o reduzido teor de gordura e a mastigabilidade são características atrativas. Para o desenvolvimento de produtos cárneos diferenciados são práticas usuais as combinações de ingredientes não cárneos passíveis de substituir a gordura, ou ainda a redução de ácidos graxos saturados por meio da utilização de óleos vegetais para substituir a gordura suína. Contudo, raros são os estudos que abordam simultaneamente a redução e a substituição de gordura avaliando a influência destas modificações na percepção sensorial de consumidores com diferentes idades. Assim, o presente estudo tem por objetivo principal viabilizar a obtenção de emulsionados com alta redução de gordura animal e aceitabilidade sensorial, utilizando ingredientes não cárneos (alginato, guar e soro de leite) associados à gordura vegetal; além de comparar os perfis sensoriais obtidos por jovens, adultos e idosos treinados. Nas formulações a gordura foi reduzida em 66% e o máximo de substituição foi de 100% do toucinho. Sendo as formulações: CA e CV os tratamentos controles contendo respectivamente 24% de gordura animal (A) e gordura vegetal (V) na massa; RGA (reduzida gordura animal) e RGV (reduzida gordura vegetal) com teor reduzido para 12% de gordura na massa; enquanto RGAH (reduzida gordura animal com hidrocolóides) e RGVH (reduzida gordura vegetal com hidrocolóides) possuem 12% de gordura e foram adicionados de soro de leite (1,2%), alginato (0,25%) e goma guar (0,05%). A substituição da gordura animal por vegetal modificou a qualidade do produto principalmente quanto à textura (elasticidade e mastigabilidade). A redução de gordura diminuiu o potencial oxidativo e o teor de ácidos graxos saturados, minimizou as perdas na cocção e apresentou a maior aceitação sensorial. Os resultados dos consumidores demonstrou que nenhum dos tratamentos foi estatisticamente (p>0,05) preferido, entretanto 64% dos consumidores preferiram os produtos com teor reduzido de gordura. Os consumidores com mais idade não conseguiram diferenciar as amostras. Entre os grupos treinados, os perfis sensoriais obtidos foram diferentes, porém os grupos treinados destacaram que a redução da gordura animal proporcionou a obtenção de produtos com características mais similares aos tradicionais quando comparados aos substituídos por gordura vegetal. Conclui-se que o novo produto deve possuir apelo à saudabilidade, ressaltando seu teor de gordura e suas características diferenciadas quanto à maciez e mastigação. Esta pesquisa aponta um caminho promissor para pesquisas envolvendo a utilização de fontes lipídicas diferenciadas associadas aos hidrocolóides em produtos cárneos. Além disso, ele estudo reforça a importância da seleção de grupos de provadores para testes sensoriais dependendo do público alvo do produto a ser desenvolvido. Destaca-se ainda a necessidade de aprimoramento das análises sensoriais descritivas, sendo os mapas de referências, utilizados neste trabalho, uma ferramenta simples que auxilia os provadores na obtenção de resultados. / The search for a healthy lifestyle, it have been a challenge for the food industry meet the demands of current market. The consumer age is an important variable to obtain the expectations of individuals. Young people in general are healthy, and they are in opinion formation, while the elderly have consolidated preferences and often should have dietary restrictions. In this context, for the low-fat meat products and chewiness are attractive features. For the development of meat products differentiated, are common to combine nonmeat ingredients that can substitute the fat, or the reduction of composition saturated by the use of vegetable oils to replace pork fat. However, few are the studies that consider both requirements: the reduction and replacement of fat assessing the influence of these changes in sensory perception of consumers of different ages. Thus, the present has the main objective to facilitate obtaining emulsified with high fat reduction and sensory acceptability, using nonmeat ingredients, associated with vegetable fat, in addition to compare the sensory profiles obtained by youth, adults and seniors trained. Three processes were performed at different time periods from the standardization of the raw material. In the formulations fat was reduced by 66% and the maximum was 100% replacement of fat. Being formulations: CA and CV treatments controls containing respectively 24% animal fat (A) and vegetable fat (V) the mass; RGA (reduced animal fat) and RGV (reduced vegetable fat) with content reduced to 12% fat mass, while RGAH (reduced animal fat with hydrocolloids), and RGVH (reduced fat with vegetable hydrocolloids) have 12% fat and added whey (1.2%), sodium alginate (0.25%) and guar gum (0.05%). The replacement of animal fat to vegetable modified product quality especially in regard to texture (elasticity and chewiness). The reduction of fat decreased the oxidative potential and of saturated fatty acids, downplayed cooking loss and had the highest sensory acceptance. The results demonstrate the consumer 110 that no treatment was considered preferred, though 64% of consumers prefer products with reduced fat content. Older consumers could not differentiate the samples. Among the groups trained sensory profiles obtained were different, the trained groups emphasized that the reduction in animal fat afforded to obtain products with characteristics similar to those when compared to traditional replaced by vegetable fat (RGV and RGVH). We conclude that the new product should have appeal to healthiness, highlighting its fat content and its distinctive characteristics as the softness and chewing. This result shows promising areas for future research involving the use of different lipid sources associated with hydrocolloids in meat products associated with different lipid sources. This study reinforces the importance of the selection of groups of assessors depending on the target audience of the product to be developed. Another important point is the need for improvement of sensory descriptive analysis, with the maps of references used in this work a simple tool that helps testers in getting results.
28

Effects of Micrococci on Improving Sensory Acceptability of Mutton Summer Sausage

Jung, Hoon 01 May 1986 (has links)
The effects of micrococci on sensory characteristics of different batches of summer sausages were determined. Sixty four salt-tolerant indigenous isolates were selected from beef or mutton treated with 1.5 or 3.0% sodium chloride and 120 ppm sodium nitrite, and held at 5 or 10 C for 5 days. These isolates (61/64) were identified as staphylococci and micrococci. Summer sausages were made from several lamb, ewe, and ram carcasses which were hand deboned and blended after grinding to contain 22% fat. Six summer sausage treatments were prepared using two different sources of commercial starter cultures including Micrococcus species or Micrococcus varians and Lactobacillus plantarum, an indigenous Micrococcus isolate, a microbial lipase, or encapsulated lactic acid. Three sensory panel sessions rated these products for consumer acceptability. Sensory panel results indicated that starter culture treatments did not improve sensory characteristics of the summer sausage over the treatment containing encapsulated lactic acid. Lipase addition caused a general reduction in sensory panel ratings for flavor, texture, appearance, and overall acceptability of the summer sausage (p = 0.05).
29

Mechanism of action and utilization of isothiocyanates from mustard against Escherichia Coli O157:H7

Luciano, Fernando 03 November 2010 (has links)
E. coli O157:H7 has been found to survive in dry sausages and cause disease. Isothiocyanates have been studied for their capacity to eliminate pathogens from foods and are attractive from the consumer perspective because of their natural origin. There is a need to better understand how isothiocyanates kill microorganisms and their behaviour in food matrices. It was found that glutathione and cysteine naturally present in meat can react with AIT, forming a conjugate with no or low bactericidal activity against an E. coli O157:H7. In addition, AIT presented higher anti-E. coli activity at lower pH values; therefore, it should be more efficient in acid foods. AIT was also found to inhibit the activity of thioredoxin reductase and acetate kinase; hence, enzymatic inhibition may represent a way in which AIT kills E. coli O157:H7. Mustard powder is used as a spice (active myrosinase) and/or binder (inactive myrosinase) in meat products. Both of these powders killed E. coli O157:H7 in dry fermented sausage. This was not expected since the powder lacking myrosinase is not able to produce isothiocyanates. Starter cultures and E. coli were found to consume significant amounts of glucosinolates. Pediococcus pentosaceus UM 121P and Staphylococcus carnosus UM 123M (higher myrosinase-like activity) were compared against P. pentosaceus UM 116P + S. carnosus UM 109M for their ability in reducing E. coli viability in dry sausage. Sausage batches containing powders of hot mustard, cold mustard, autoclaved mustard and no powder were prepared. Both pairs of starters yielded similar results. Reduction >5 log CFU/g of E. coli O157:H7 occurred after 31 d for hot powder and 38 d for cold powder; there was no reduction in the control. E. coli O157:H7 itself has greater effect on glucosinolate degradation than either pair of starters, which may be more important in determining its survival. Autoclaved powder caused >5 log CFU/g reduction after 18 d. This may be the result of synergistic/additive interaction among E. coli O157:H7 myrosinase-like activity, the presence of newly formed/released antimicrobials in the autoclaved powder and the multiple hurdles present in the dry sausage. Autoclaved mustard powder has potential as a novel food ingredient for the meat industry.
30

Wirkung von Starter- und Schutzkulturen sowie ihrer Metabolite auf die Infektiosität von murinem Norovirus S 99 und Influenzavirus H1N1 in kurzgereiften Rohwürsten

Lange-Starke, Anett 03 November 2014 (has links) (PDF)
Viren haben als Ursache lebensmittelassoziierter Infektionen eine große Bedeutung. Sie können vor allem über rohe oder unzureichend erhitzte Lebensmittel übertragen werden. In diesem Zusammenhang werden grüner Salat, Erdbeeren, Himbeeren, Frühlingszwiebeln, Muscheln, halbgetrocknete Tomaten, fäkal verunreinigtes Trinkwasser, Backwaren und Rohwürste als häufige Infektionsquellen genannt. Vor allem kurzgereifte Rohwürste gehören aus mikrobiologischer Sicht zu Risikoprodukten. Um eine gleichbleibende Qualität der Produkte zu gewährleisten, ist die Verwendung von Starterkulturen unerlässlich. Als sogenannte Schutzkulturen sollen sie gleichzeitig die Vermehrung unerwünschter bakterieller Pathogene unterbinden. Bisher ist allerdings nicht bekannt, inwieweit diese zur Virusinaktivierung in kurzgereiften Rohwürsten führen bzw. beitragen. Aus diesem Grund war es das Ziel dieser Arbeit, den Einfluss von rohwurstrelevanten Starter- und Schutzkulturen sowie deren Metabolite (Bacteriocine, Milchsäure) auf die Tenazität und Inaktivierungskinetik von Viren zu prüfen. Die Untersuchungen erfolgten mit dem murinen Norovirus (MNV) S 99 sowie dem humanen Influenzavirus H1N1 (A/WSN/33). Antivirale Effekte wurden zum einen anhand von in-vitro-Studien, zum anderen anhand von experimentell mit Viren kontaminierten kurzgereiften Rohwürsten (Mettwurst/Teewurst) geprüft. Die Bacteriocine Sakacin A und Nisin zeigten in phosphatgepufferter Salzlösung (PBS) keine viruzide Wirkung gegenüber MNV S 99 und H1N1 (pH 6,2; 24 °C; Exposition: 3 Tage). Weiterhin wurden anhand von in-vitro-Untersuchungen 29 verschiedene zellfreie Kulturüberstände [Milchsäurebakterien, Staphylococcus spp. (S.), Kocuria (K.) varians] hinsichtlich ihrer antiviralen Wirkung geprüft. Dabei konnte eine signifikante Titerreduktion von MNV S 99 bei Exposition mit dem Kulturüberstand eines Lactobacillus (Lb.) curvatus-Isolates festgestellt werden (p < 0,05). In mit dieser Kultur fermentiertem Tee- und Mettwurstbrät zeigte sich jedoch kein Effekt. Die Virustenazität von H1N1 und MNV S 99 konnte mit D,L-Milchsäure unter rohwurstrelevanten Bedingungen (pH 5,0 bis 6,2) sowohl in-vitro als auch im frischen Mettwurstbrät beeinflusst werden. In-vitro erzielte Titerreduktionen lagen bei 2,5 (H1N1) bzw. 3,25 log-Stufen (MNV S 99) nach drei Tagen (24 °C) Lagerung. Im Gegensatz dazu war MNV S 99 im Vergleich zu H1N1 im Mettwurstbrät stabiler. H1N1 konnte unterhalb von pH 5,5 bereits direkt nach dem Einmischen der Influenzaviren in das Wurstbrät nicht mehr nachgewiesen werden. MNV S 99 wurde hingegen erst nach einem Tag Lagerung (22 °C) maximal um 0,7 log-Stufen reduziert (pH 5,2). Die verwendeten Starter- und Schutzkulturen (Lb. sakei, Lb. curvatus, Lb. paracasei, Lb. plantarum, S. carnosus, S. xylosus, K. varians) zeigten im Mett- und Teewurstbrät im Vergleich zur Kontrolle (ohne Starterkultur) keinen zusätzlichen viruziden Effekt auf MNV S 99. Zunehmende Virustiterreduktionen konnten mit pH-Wert-Erniedrigung beobachtet werden. Nach der Reifung (1 Tag, 22 °C, pH 4,9) von Mettwurst mit Starterkulturen wurde das Virus um maximal 1,65 log-Stufen reduziert. In mit Einzel- beziehungsweise Mehrstamm-Mischkulturen fermentierter Teewurst (7 Tage, 22 °C, pH 4,9) betrug die Titerreduktion maximal 1,10 log-Stufen. Das Influenzavirus H1N1 konnte im Rohwurstbrät mit Starterkulturen auch nach Verwendung hoher Ausgangstiter bereits zu Beginn der Untersuchungen nicht mehr nachgewiesen werden. Aus den erzielten Daten kann geschlussfolgert werden, dass die Bacteriocine Sakacin A und Nisin nicht als antivirale Zusatzstoffe in Lebensmitteln (z. B. Rohwürste) geeignet sind. Das antivirale Potential von zellfreien Kulturüberständen war Bakterienstamm-spezifisch und nur in-vitro ersichtlich. Daher muss die Nutzung des Lb. curvatus 1-Stammes nicht anderen rohwurstrelevanten Starterkulturen vorgezogen werden. Die Verwendung von Milchsäure als Zusatzstoff im Rohwurstbrät eignet sich nur zum Ausschluss einer viralen Exposition im Zusammenhang mit H1N1. Frische Mettwurst muss allerdings hierzu adäquat gesäuert (pH < 5,5) werden. Neben dem antiviralen Effekt durch gebildete Säure, konnte keine weitere spezies-spezifische antivirale Wirkung verwendeter Starter- und Schutzkulturen auf MNV S 99 festgestellt werden. Die Säureleistung einzelner Kulturen ist demzufolge für eine Virusinaktivierung entscheidend. Das antivirale Potential verwendeter Starter- und Schutzkulturen in Rohwürsten ist im Zusammenhang mit MNV S 99 als gering einzuschätzen. Unter der Annahme, dass murine und humane Noroviren eine ähnliche Tenazität in kurzgereiften Rohwürsten aufweisen, sollten diese Produkte im Zusammenhang mit Noroviren als Risikoprodukte eingestuft werden.

Page generated in 0.4229 seconds