Qualidade microbiológica e ocorrência de leveduras em leite pasteurizado tipos A, B e C
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Data
2005-03-04
Autores
Gusmão, Viviane Vieira [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
No Brasil, o leite possui uma posição de destaque, tanto do ponto de vista social como do econômico. Devido a sua composição peculiar rica em proteínas, gorduras, carboidratos, sais minerais e vitaminas, é considerado como um excelente meio de cultura, pois constitui um ambiente adequado para o desenvolvimento de vários microrganismos. A contaminação microbiana altera a qualidade do alimento e pode agir como veículo de microrganismos patogênicos, que podem provocar o desenvolvimento de doenças infecciosas ou intoxicações alimentares, que colocam em risco a saúde do consumidor e levam à condenação do leite, além da perda da qualidade nutricional do produto. O leite é freqüentemente relacionado com surtos de toxinfecções alimentares, o que justifica a necessidade de avaliações constantes de sua qualidade garantindo a sua condição de consumo. Neste trabalho foram coletadas 23 amostras de leite pasteurizado tipos A, B e C, obtidas no comércio varejista da região de São José do Rio Preto - SP, que foram submetidas as seguintes análises microbiológicas: contagem de bactérias aeróbias mesófilas, enumeração de bolores e leveduras, determinação do Número Mais Provável (NMP) de coliformes totais e fecais, pesquisa de Escherichia coli e de Salmonella spp. Das amostras de leite analisadas foram isoladas 31 culturas de leveduras, submetidas às provas taxonômicas, morfológicas, fisiológicas e de assimilação de diversas fontes de carbono. De acordo com os resultados obtidos, observou-se que apenas 2 (8,70%) amostras apresentaram coliformes fecais acima do limite da legislação, resultado este, inferior aos diversos trabalhos encontrados em leite pasteurizado desenvolvidos em diferentes regiões do Brasil. A presença de Escherichia coli foi constatada em apenas 3 amostras, sendo todas do tipo C. A de Salmonella spp não foi verificada em nenhuma...
In Brazil, milk has a prominent position, as much of social point of view as of economic, due to its particular composition rich in proteins, fats, carbohydrates, mineral salts and vitamins, and consequently it is considered like an excellent medium, because it s an adequate atmosphere for the development of several microorganism. The microbial contamination changes the food quality, so that it may act like vehicle of pathogenic microorganism, promoting disease or food poisoning, risking consumer s health and milk may be condemned; besides the loss of product s nutritional quality. Milk is frequently related to outbreaks of food toxinfection, what justify the need for constant evaluations of its quality as well as the guarantee of its condition of consumption. In this study 23 samples of kinds A, B and C pasteurized milk were obtained from the retail trade of São José do Rio Preto (SP) region and were done the following microbiological analyses: counting of mesophilic aerobic bacteria, listing of molds and yeasts, determination of most probable number (MPN) of total coliforms and fecal coliforms, research of E. coli and Salmonella spp.. Thirty one yeast cultures were isolated from the samples. They were submitted to taxonomic, morphological, and physiological tests and to carbon source assimilation test. According to the results obtained, only 2 (8.70%) had fecal coliforms above the regulation limit. The percentage out of the microbiological standard (8.70%) was lower than several studies found in pasteurized milk, developed in different regions of Brazil. E. coli was detected in 3 samples of kind C. Salmonella spp. was not detected in any sample analyzed, what is in accordance with the current regulation. In conclusion, most of the samples (91.30%) had coliforms a 45°C 4 MPN/mL, xii consequently were labeled as products in satisfactory sanitary conditions, therefore products...(Complete abstract click electronic access below)
In Brazil, milk has a prominent position, as much of social point of view as of economic, due to its particular composition rich in proteins, fats, carbohydrates, mineral salts and vitamins, and consequently it is considered like an excellent medium, because it s an adequate atmosphere for the development of several microorganism. The microbial contamination changes the food quality, so that it may act like vehicle of pathogenic microorganism, promoting disease or food poisoning, risking consumer s health and milk may be condemned; besides the loss of product s nutritional quality. Milk is frequently related to outbreaks of food toxinfection, what justify the need for constant evaluations of its quality as well as the guarantee of its condition of consumption. In this study 23 samples of kinds A, B and C pasteurized milk were obtained from the retail trade of São José do Rio Preto (SP) region and were done the following microbiological analyses: counting of mesophilic aerobic bacteria, listing of molds and yeasts, determination of most probable number (MPN) of total coliforms and fecal coliforms, research of E. coli and Salmonella spp.. Thirty one yeast cultures were isolated from the samples. They were submitted to taxonomic, morphological, and physiological tests and to carbon source assimilation test. According to the results obtained, only 2 (8.70%) had fecal coliforms above the regulation limit. The percentage out of the microbiological standard (8.70%) was lower than several studies found in pasteurized milk, developed in different regions of Brazil. E. coli was detected in 3 samples of kind C. Salmonella spp. was not detected in any sample analyzed, what is in accordance with the current regulation. In conclusion, most of the samples (91.30%) had coliforms a 45°C 4 MPN/mL, xii consequently were labeled as products in satisfactory sanitary conditions, therefore products...(Complete abstract click electronic access below)
Descrição
Palavras-chave
Microbiologia industrial, Alimentos - Microbiologia, Leite - Microbiologia, Levedos como alimentos, Alimentos - Conservação, Microbiologia de alimentos, Microbiology, Food preservatives and thermal treatment, Pasteurized milk
Como citar
GUSMÃO, Viviane Vieira. Qualidade microbiológica e ocorrência de leveduras em leite pasteurizado tipos A, B e C. 2005. 102 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências, Letras e Ciências Exatas, 2005.