Ativação do sistema lactoperoxidase na conservação do leite cru para fabricação de queijo de coalho

Abstract

Based on the poor quality of the milk produced in Brazil and in the necessary improvements in the sanitary conditions to meet the Brazilian legislation and market products of adequate quality, this study aimed to evaluate the adequacy of raw milk preserved by the lactoperoxidase system under different conditions of preservation and storage for manufacturing "Queijo de Coalho", a fresh cheese from northeastern of Brazil. Were performed three distinct collections of raw milk from a dairy farm in the Brazilian state of Pernambuco and submitted to different conditions of preservation and storage - activation of lactoperoxidase system, refrigeration and pasteurization, totaling eight treatments that were processed to manufacture cheese. Were analyzed the effects of the activation of the lactoperoxidase system and of the conditions of preservation and storage on microbial activity in milk and then evaluated its effects on the yield of cheese manufacturing, physico-chemical composition and in the microbiological counts of Coliforms at 45 ºC, Escherichia coli , Staphylococcus coagulase positive, Salmonella spp. and Listeria monocytogenes. The treatments had significant effects determined by analysis of variance and means were compared by Tukey test at 5% significance. The lactoperoxidase system has determined a significant effect (P < 0.05) for Staphylococcus coagulase positive in milk with mean 38.36% lower. There was no effect of the system lactoperoxidase on the yield of cheese manufacturing, but its interaction with the refrigeration affected the technical yield and decreased the mean of the dry matter content. The system also caused an effect (P < 0.05) in the microbial load of the cheese that showed mean of 14.13 to 30.02% lower when produced from milk preserved by the lactoperoxidase system.