Qualidade bacteriológica de queijos artesanais comercializados em estradas do litoral norte do Rio Grande do sul, Brasil

Abstract

O consumo de queijo artesanal, vendido em estabelecimentos de beira de estrada, é comum no Estado do Rio Grande do Sul. Geralmente estes produtos não são fabricados em acordo com as boas normas de fabricação e podem constituir perigo à saúde do consumidor. Objetivouse, com o presente trabalho, verificar a qualidade bacteriológica de queijos artesanais comercializados em estradas litorâneas por meio da contagem de coliformes e pesquisa de Listeria spp. e Brucella spp. Foram analisados 80 queijos, sendo 62 do tipo Colonial, dez do tipo Provolone, seis do tipo Ricota e dois do tipo Caccio Cavallo. No momento da coleta, 71% das amostras não estavam sob refrigeração. Todas as amostras apresentaram contagens de coliformes totais e, destas, 62 foram testadas para a presença de coliformes fecais. Um total de 84% das amostras apresentou contagens de coliformes fecais acima de 2,73- 3,7 log.UFC g- 1 (de 500 a 5000UFC mL-1), previsto como limite máximo a ser encontrado em queijos. Dos 29 estabelecimentos, 27 tinham produtos fora destes limites. Das 80 amostras, 16% continham Listeria spp., sendo 3,7% identificadas como Listeria monocytogenes. As estações do ano influenciaram no isolamento de Listeria spp., sendo a primavera considerada a estação do ano com maior número de isolados. Brucella spp. não foram isoladas nas 80 amostras de queijos analisadas. A alta freqüência de coliformes fecais e a presença de L. monocytogenes revelam que o consumo destes queijos constitui perigo de infecção à população em geral e especialmente àquelas pessoas imunocomprometidas.

The consumption of homemade cheese, which is sold in little shops along the road, is very common in the state of Rio Grande do Sul, Brazil. Generally, these products are not manufactured according to the good hygiene guidelines; and may be a risk to the consumers’ health. The aim of this research was the assessment of the bacteriological quality of homemade cheese sold in the region along the northern coast of Rio Grande do Sul. Cheese samples were taken and total and faecal coliform counting per gram sample were established. The samples were also examined for the presence of Listeria spp. and Brucella spp. In total, 80 samples, from 29 commercial establishments were analysed, of which 62 of Colonial type; 10, of Provolone; 6 of Ricotta and 2, of Cacciocavallo type. At the moment of sampling, 71% of them were not stored under refrigeration conditions. In all the samples the presence of total coliform could be demonstrated and 62 of these were tested for the presence of faecal coliforms. In 84% of the samples more then 2.73 - 3.7log.UFC g- 1 (from 500 to 5000UFC mL-1) of faecal coliform could be demonstrated, with is considered the maximum limit still allowed to be present in cheese samples. Of the 29 establishments analysed, 27 had products with coliforms counts above these limits. Of the 80 samples, 16% had Listeria sp., of which 3.7% were identified as Listeria monocytogenes. A correlation was found between the season and the isolation of Listeria spp.: in the spring the highest number was detected. Brucella spp. could not be detected in the 80 samples analysed. The high frequency of faecal coliforms and the presence of L. monocytogenes revealed that the consumption of these homemade cheeses can become a risk of infection to the population, especially for immunocompromised persons.