Physicochemical and microbiological characteristics, proteolytic, and lipolytic activities of sheep milk produced in different seasons / Características físico-químicas e microbiológicas, atividades proteolíticas e lipolíticas do leite de ovelha em diferentes estações

Abstract

The aim of this study was to evaluate the physicochemical parameters, microbial count, and enzymatic activities of sheep milk at different collection periods. Analyses showed that only the contents of lactose and ash did not vary between the seasons. The milk collected in autumn presented higher lipolytic activity, while in winter presented higher values for total solids, fat, and acidity. Higher levels of protein were observed in summer and winter. Samples from spring presented higher values for pH, mesophilic and psychrotrophic counts, and proteolytic activity. The mesophilic count was lower than the one established by the European Union legislation for all seasons. The psychrotrophic count was lower than the minimum required to cause degradation problems by proteolytic and lipolytic enzymes. The results indicated that climatic condition affected the evaluated characteristics, and this information is relevant to establish criteria to produce sheep milk and dairy products.