QUALIDADE MICROBIOLÓGICA E FÍSICO-QUÍMICA DO LEITE PASTEURIZADO PRODUZIDO NA REGIÃO OESTE DO PARANÁ

O presente trabalho teve como objetivo avaliar a qualidade do leite pasteurizado produzido em Palotina - PR, comparando-se os resultados com os padrões da legislação nacional vigente, através de análises microbiológicas e físico-químicas. Foram coletadas aleatoriamente, 40 amostras de leites pasteurizados de diversos estabelecimentos comerciais de Palotina(PR). Deste total 16 amostras foram da marca X (08 tipo B e 08 desnatados, com inspeção estadual - SIP), 16 amostras da marca Y (08 tipo C e 08 desnatados com inspeção federal - SIF) e 08 amostras da marca Z (tipo C com inspeção federal - SIF). Após a coleta, as amostras foram enviadas imediatamente ao Laboratório de Controle Microbiológico de Água e Alimentos LACOMA, da UFPR Campus Palotina e estocadas em geladeira por um período máximo de 1 hora até o início das análises. Os resultados demonstraram que o produto estava dentro dos padrões aceitáveis para a contagem de mesófilos, psicrotróficos e coliformes fecais. Foi encontrado elevado percentual de amostras de leite peroxidase negativa (12 amostras 30%). Foi possível identificar 07 leites aguados, 05 suspeitos de aguagem, 01 com desnate parcial e 01 suspeito de desnate. Com os resultados obtidos pode-se concluir que as três marcas de leite comercializadas em Palotina apresentaram-se dentro dos padrões microbiológicos o que pode estar relacionado ao alto percentual de superaquecimento e que os resultados físico-químicos foram, de forma geral, insatisfatórios. Microbiological and physicalchemistry quality of pasteurized milks produced in the west region, Parana Abstract A survey has been carried out by means of microbiological and physical chemistry methods on the quality of pasteurized samples of milk from Palotina, Parana State, Brazil. Forty samples of pasteurized milks were gathered at several retail stores from Palotina. Sixteen samples labeled as X - 8 B and 8 skimmed milk, 16 samples labeled as Y - 8 C and 8 skimmed milk, and 8 samples labeled as Z - C milk, were analyzed at the Federal University of Paraná Laboratory for Water and Food Microbiological Control at Palotina Campus. After being stored at the refrigerator for one hour before the beginning of the analysis. According to the results found, all the milk samples analyzed were within the acceptable limits for mesophilic, psychrotroph and fecal coliform countings. An important data was the high percentage, as much as 30%, of negative peroxidase samples. In regard to the physical chemistry analysis carried out - fat, density at 15o C, total dry extract, unfat dry extract, cryoscopic index, phosphatase and peroxidase, the results were in general not satisfactories

Gene detection and toxin production evaluation of hemolysin BL of Bacillus cereus isolated from milk and dairy products marketed in Brazil

Bacillus cereusis an ubiquitous, spore-forming bacteria that can survive pasteurization and the majority of the heating processes used in the dairy industry. Besides, it is a pathogen responsible for different types of food poisoning. One type of foodborne disease caused by B.cereusis the diarrheal syndrome, which is caused by the ingestion of vegetative cells producing toxins in the small intestine. One virulence factor for the diarrheal syndrome is the toxin hemolysin BL (HBL), a three-component protein formed by the L1, L2 and B components. In order to evaluate the presence of diarrheal strains isolated from milk and dairy products, 63 B. cereus isolates were obtained from 260 samples of UHT milk, pasteurized milk and powdered milk, sold in commercial establishments and from different brands. The isolates were subjected to the Polymerase Chain Reaction (PCR) for the detection of the encoding genes for the L1, L2 and B components and the toxin production capacity were evaluated with an immunoassay. A total of 23 [36.5%] isolates were identified carrying simultaneously the three tested genes, from which, 20 [86.9%] showed toxigenic capacity. 26 [41.3%] isolates did not carry any of genes tested and the other 14 [22.2%] were positive for one or two of them. The results showed a high toxigenic capacity among the B. cereus isolates able to produce the HBL, indicating a potential risk for consumers