New insights in cheese yield capacity of the milk of Italian Brown and Italian Friesian cattle in the production of high-moisture mozzarella

The aim of the present study is to investigate the effect of k-casein B content in milk on the yield of high-moisture mozzarella cheese. The study was carried out by monitoring the production of eight mozzarella cheese batches at four cheesema king factories. At each factory, two cheesemaking trials were performed in parallel: one using bulk milk from Italian Brown cattle and the other using bulk milk from Italian Friesian cattle. The average k-casein B content was 0.04 g per 100 g in the Italian Friesian cows' milk, whereas it was four times higher in the Italian Brown cows' milk, reaching values of 0.16 g per 100 g. Both the k-casein B content and K-casein B to casein ratio were positively correlated with actual cheese yield. Both parameters showed correlation coefficient values over 0.9, higher than for any other protein fraction. The influence of the level of k-casein on the increase of the yield is probably due to smaller and more homogeneous micelles, with more efficient rennet coagulation. Consequently, milk with higher k-casein B content produces a more elastic curd that withstands better the technological treatments and limits losses during curd mincing and stretching. In conclusion, the Italian Brown cows' milk, characterized by higher k-casein content than the Italian Friesian's one, allowed a yield increase of about 2.65%, which is a very relevant resultfor both farms and cheesemaking factories.