The research of pH chantes in ripe smoke-dried sausvages during the whole technological process of production. The research is made at ŽŪB „Nematekas“ (agricultural company). The smoke-dried sausages were chosen as subject of research. One group of products was ripened for 7 days, the other one – for 13 days. The raw materials used for the production of all sausages were the same as follows: beef ham (I sort), beef (II sort), pork, pork or beef lard. The dynamics of pH and weight changes was researched. Following results were fixed: The biggest waste of weight – 25 % in 12 days were achieved by “Nerija”, “Karkle”, “Husarai” and “Airiska” sausages. The weight most dropped of in smoke-dried sausage “Nerija”, even 193 g and least in sausage “Kaimiska”, only 131 g. Remained part of smoke-dried products weight were various in scale from 190 to 155 g. The biggest alterations of smoke-dried sausages have happened in period of 2 days ripening. During that period most of production pH has reduced up to demanded 5,3 pH level. The biggest pH reduction were noticed in smoke-dried sausage “Airiska” – from 5,97 to 5,22, the smallest pH reduction were noticed in “Zemaitiskas Skilandis” – from 5,78 to 5,34. Remained specimens pH variations were from 5,42 to 5,29. Most significant pH alterations, noticed during first 2 days, were result of time, required for adaptation, for new microorganisms adaptation in new environment. In period of 5 -8 days because of reduced humidity microorganisms... [to full text]

Orientador: Arnaldo Yoshiteru Kuaye / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-10-05T13:38:14Z (GMT). No. of bitstreams: 1 Rosa_VanessaPiresda_M.pdf: 1497051 bytes, checksum: 8d777468991ab3f12abd697553a092b5 (MD5) Previous issue date: 2009 / Resumo: Os estabelecimentos de abate de bovinos no Brasil que realizam comércio internacional ainda encontram dificuldades quanto controle microbiológico da carne. Dentre elas, destaca-se o estufamento da embalagem da carne embalada a vácuo refrigerada, devido à contaminação por clostridios psicotróficos e psicrofílicos deteriorantes como o Clostridium estertheticum e Clostridium gasigenes. Além dos prejuízos econômicos, a contaminação causa forte impacto negativo às marcas comerciais dos produtos. Os objetivos deste trabalho foram avaliar a presença de C. estertheticum e C. gasigenes em amostras ambientais e de carnes embaladas a vácuo, resfriadas, provenientes diretamente de empresas produtoras, e em carnes bovinas resfriadas embaladas a vácuo comerciais, bem como avaliar o controle destes microrganismos pela utilização de agentes sanitizantes. A relevância desta pesquisa fundamenta-se na carência de trabalhos sobre o tema, associada à particularidade dos microrganismos anaeróbios estritos que exigem para a sua detecção, isolamento e caracterização metodologias de difícil execução. A análise dos resultados globais relacionados às diferentes técnicas utilizadas para detecção e isolamento dos microrganismos revelou que, embora a técnica de detecção direta por PCR apresente uma taxa bem maior de amostras positivas (20-26 amostras) em relação às técnicas de isolamento (6-11 amostras), a utilização de ambas pode representar uma importante ferramenta para o diagnóstico da contaminação microbiana ao longo do processamento destes produtos. A presença de C. estertheticum e C. gasigenes foi observada em amostras diversas como superfícies de equipamentos, carcaças e outras, além do próprio produto final, evidenciando um elevado nível de contaminação cruzada ao longo do processamento. Em particular, destaca-se a presença dos microrganismos em equipamentos que apresentam configuração física propícia ao acúmulo de sujidades e conseqüente dificuldade de higienização, como serra elétrica, rolete para retirada de couro e evaporador de câmara fria. A utilização da técnica PCR-RFLP permitiu verificar a existência de diferentes genótipos de isolados de C. estertheticum como também a constatação do elevado nível de contaminação cruzada da carne exposta ao longo das etapas de processamento por fontes como equipamentos, carcaças e ambientes diversos. O efetivo controle dos esporos de C .estertheticum e C. gasigenes por agentes químicos pôde ser observado in vitro e os sanitizantes a base de ácido perácetico a 500 mg/L e peróxido de hidrogênio a 200 mg/L apresentaram melhor ação esporicida para C .estertheticum e C. gasigenes quando comparado ao hipoclorito de sódio a 100 mg/L por 15 minutos. Os resultados do presente trabalho colocam em evidência a variedade de fontes de contaminação cruzada às quais a carne é submetida ao longo da cadeia produtiva, e a conseqüente necessidade de programas de higienização mais rigorosos e efetivos para o controle de C. estertheticum e C. gasigenes nos matadouros-frigoríficos / Abstract: The Brazilian bovine slaughterhouses involved in international commerce are still having difficulties with the microbiological control of their meat. Amongst these difficulties, the swelling of refrigerated vacuum packed beef due to contamination with deteriorative psychrotrophic and psychrophilic clostridia, such as Clostridium estertheticum and Clostridium gasigenes, stands out. Apart from the economic damage, such contamination causes a strongly negative impact on the commercial brands of these products. The objectives of this study were to evaluate the presence of C. estertheticum and C. gasigenes in beef samples maintained at room temperature and in chilled vacuum packed beef coming directly from the manufacturing companies, as well as in commercially produced chilled vacuum packed beef, and also evaluate the control of these microorganisms using sanitizing agents. The relevance of this research is based on the lack of studies about this subject, associated with the particularity of strict anaerobic microorganisms that require isolation and characterization for detection, since such methodology is very difficult to carry out. An analysis of the overall results related to the different techniques used in the detection and isolation of these microorganisms, showed that although the PCR direct detection technique presented a much higher rate of positive samples (20-26 samples) in relation to the isolation techniques (6-11 samples), the use of both techniques could represent an important tool in the diagnosis of microbial contamination throughout the processing of this product. The presence of C. estertheticum and C. gasigeneswas observed in various samples, such as equipment surfaces, carcasses and others, apart from in the final products themselves, providing evidence of a high level of cross contamination throughout processing. In particular, the presence of these microorganisms on equipment with a physical configuration facilitating accumulation of dirt with a consequent difficulty for sanitation, such as electric saws, leather removal drums and the cold chamber evaporator, stood out. The use of the PCR-RFLP technique allowed one to verify the existence of different genotypes of the C. estertheticum isolates, as also to show a high level of cross contamination by C. estertheticum and C. gasigenes of the beef exposed to various sources of contamination, such as equipment, carcasses and various other ambiences, during processing. The effective control of the C. estertheticum and C. gasigenes spores by chemical agents could be observed in vitro using 100 mg/L sodium hypochlorite for 15 minutes, and 500 mg/L peracetic acid or 200 mg/L hydrogen peroxide for 5 minutes. The results of the present work make the variety of sources of cross contamination to which the meat is submitted throughout processing, evident, and the consequent need for more rigorous and effective hygienization programs to control C. estertheticum and C. gasigenes in slaughterhouses-refrigerated packing houses / Doutorado / Doutor em Tecnologia de Alimentos