Changes in the microbiological and chemical characteristics of an artisanal, low‐fat cheese made from raw ovine milk during ripening

Abstract

Changes in the microbial flora of batzos cheese made from raw ovine milk were studied during ripening. Lactic acid bacteria and Enterobacteriaceae were the predominant groups of micro‐organisms. Cheeses manufactured in summer had higher microbial counts than those made in spring, with the exception of staphylococci. Nevertheless, Enterobacteriaceae and coliforms decreased more rapidly in cheese made in summer and counts at the end of storage were lower than those in spring cheese.Enterococci predominated in the ripened curd of cheese made in spring, whereas lactobacilli were the most abundant lactic acid bacteria in cheese made in summer. Enterococcus faecium was the predominant species in spring, and Lactobacillus paracasei ssp. paracasei predominated in cheese made in summer. The pH of the cheeses was > 5.0 throughout ripening, and NaCl‐in‐moisture content (> 8.0%) permitted the growth and survival of salt‐tolerant micro‐organisms. αs1‐Casein degraded at a faster rate than β‐casein; both caseins were hydrolysed more rapidly in spring than in summer. The free amino acid content became higher in summer cheese (566.24–3460.25 µg/g of glycine equivalent) than in spring cheese because of the progress of ripening. Moreover, the milk fat of the cheese was degraded more in the summer than in the spring. The results suggest that there could be advantages to using starter cultures and improving the level of hygiene during milk and cheese production in order to eliminate undesirable micro‐organisms and standardize cheese quality.