Relationship between morphometric characteristics of milk fat globules and the cheese making aptitude of sheep's milk

The morphometric characteristics of fat globules from sheep's milk were investigated in order to determine their relationship in terms of milk composition and cheese yield. Bulk milk samples from 13 flocks of Massese ewes were collected and analysed for size and number mL−1 of milk fat globules, and the physico-chemical, hygienic and rheological parameters (r, k20, a30) of milk. Cheese yield (g of cheese per 100 g−1 of milk) and the weight loss of the cheese at 10, 30 and 60 days of ripening were also determined. Negative and significant correlations were found between the value of the average diameter of milk fat globules and the number of fat globules per mL−1 of milk. The morphometric characteristics of milk fat globules were significantly correlated with the percentage of protein, casein, non-fat dry matter, calcium, phosphorus, the value of density, casein to fat ratio, clotting parameters and cheese yield. Worst milk chemical composition, rheological parameters and lower cheese yield were found to be associated with an increased percentage of milk fat globules with a diameter greater than 5 μm.