Caracterização de queijos tipo minas frescal e ricota comercializados no município de Barra do Garças-MT

Abstract

The ricotta and Minas Frescal cheese types can be produced with raw or pasteurized milk, which may contain a large number of undesirable microorganisms responsible for spoilage, and serve as indicators of poor hygienic conditions, poor handling, and use of contaminated or poorly sanitized utensils or equipment. In these regards, it is important to maintain the microbial and physicochemical control of cheeses over its shelf life. Because it is a typical product of the Southeast of the region, the ricotta and Minas Frescal cheese are highly consumed by the population that are looking for a food standard with low sodium content and high nutritive value. The aim of this work was to evaluate changes in ricotta and Minas Frescal cheese types marketed in Barra do Garças– MT. For this purpose, physicochemical analysis of pH and titratable acidity, microbiological analyzes of coliforms at 30ºC and thermotolerant coliforms (MPN), as well as total fungi and yeast counts. Also, Salmonella sp., Staphylococcus aureus and Listeria monocytogenes detection were performed. Microbiological analyzes results for the group of coliforms at 30 °C complied with the current legislation. Concerning tolerant coliforms, it was observed count variation, due to the supermarkets, where part of the samples was outside the standards established by the current legislation, which is 5.0x102 MPN.g-1. Presence of E. coli was found in samples of ricotta and Minas Frescal cheese from supermarkets A and B, and it was also observed that all the samples of different types of supermarkets presented counts of fungi and yeasts within the recommended where the values cannot exceed 5.0x103 CFU.g-1. When evaluating the counts of S. aureus it was found that 95% samples of both types of cheeses, of all the supermarkets, presented counts outside the standards established by the current legislation that is 5.0x102 MPN.g-1, except for the ricotta cheese samples from supermarket C, that were within the required limits. Regarding the analysis of Salmonella spp. in ricotta and Minas Frescal cheese types, the absence of this microorganism was observed in all samples. This result is satisfactory, considering that the current legislation establishes microorganism absent in 25g of cheese. Presence of Listeria monocytogenes was found in all samples of ricotta and Minas Frescal cheese types of all the supermarkets evaluated, which are not in conform to the existing laws that recommend microorganism absence in 25g of product. Further, physicochemical analysis showed that Minas Frescal cheese from supermarkets A and B did not present statistical difference in acidity. However, samples of supermarket C were statistically different from the others. Regarding the pH parameter, all samples of Minas Frescal cheese differed among them. Therefore, it is concluded that part of the analyzed samples was out of the acceptable standards for microbiological analyzes, since the contamination can occur at any point from the arrival of the raw material until the final product.