Avaliação da microbiota de alface (Lactuca sativa) comercializada no município de Alegre-ES
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Data
2013-07-29
Autores
Silva, Nayara Benedito Martins da
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Universidade Federal do Espírito Santo
Resumo
Vegetables are an important source of vitamins, minerals and fibers, which are essential for good functioning of the organism; therefore its consumption has been grow. Lettuce is one of the most consumed vegetables in Brazil, especially raw, however in the recent years it has been associated to food outbreaks. Several methods can be used to determine micro-organism in food. Thus, the use of effective methods are increasing and can simultaneously provide faster results. The technique of polymerase chain reaction (PCR) has shown to be an effective tool for this purpose. The objective of this study was to evaluate the occurrence of Salmonella ssp. in lettuce (Lactuca sativa) type crisp, commercialized in the city of Alegre-ES. For this study, 60 samples of crisp type lettuces and conventional cultivation commercialized in outdoor markets, supermarkets and produce stores in the city were used. The determination of the presence of Salmonella ssp. was accomplished through the following steps: pre-enrichment, selective enrichment, selective-differential plating and to confirm the results, the PCR technique was utilized. Eleven establishments were evaluated. Furthermore, determinations of the following microbial groups in the tested samples were done: aerobic mesophilic, filaments fungi and yeast, total and thermotolerant coliforms. The samples analyzed presented average counts of aerobic mesophilic of 6.80 log CFU. g-1 and filaments fungi and yeast of 4.07 log CFU. g-1 . It was found that 100 % of the samples presented total coliform and in relation to the presence of thermotolerant coliforms 58 % of the sampled showed values <3 MPN g-1 , 30 % between 4 and 21 MNP g-1 , and 12 % between 43 and 93 MPN g-1. Through the PCR technique, 21,66 % (n=13) of the 60 samples of lettuce evaluated was considered positive for Salmonella spp. Salmonella spp. positive samples were obtained from 8 of the 11 establishments evaluated. From these results it is noteworthy the importance of adopting preventive measures to reduce the contamination of lettuce in natura and other fresh vegetables throughout the production chain as a way to reduce health risk associated with the consumption of this food.
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Lettuce , Salmonella spp. , Polymerase chain reaction (PCR) , Reação em cadeia da polimerase (PCR)