The quality of Valle del Belice sheep’s milk and cheese produced in the hot summer season in Sicily

Abstract

In response to the growing consumer demand for fresh cheese in summer, this investigation was aimed to evaluate the chemical and microbiological characteristics of sheep’s milk and cheese produced in Sicily in the hot summer months. A total of 810 bulk milk samples collected from 17 farms rearing ewes of the Valle del Belice breed were analysed for chemical composition, somatic cell count, total bacterial count and clotting parameters. Samples (n=18) of Protected Designation of Origin Vastedda della valle del Belice cheese produced in six dairies were collected in summer, autumn and spring and analysed for chemical composition, microbiological profile and fatty acid (FA) composition. Univariate and multivariate analyses were performed to assess variations by season. Sheep’s milk produced in the summer had higher fat and casein contents, less lactose and urea and slightly higher total bacterial count and, similar to milk produced in winter, had a weaker clotting ability. Vastedda cheese produced in spring had less thermophilic lactococci and a high rumenic acid content. Cheese produced in summer had more fat; less saturated FA; and more linoleic acid, monounsaturated FA and omega-3 polyunsaturated FA. A dual approach to data analysis revealed a strong influence of production season on bulk milk and Vastedda cheese characteristics due to climate conditions and ewes’ feeding regimen. Although this study provides evidence of the good nutritional properties of summer sheep’s cheese, management and feeding strategies could aim to further improve the quality of milk and cheese produced in the summer months.