Influence of the β-Casein Genotype of Cow’s Milk (A1, A2) on the Quality and β-Casomorphin-7 (BCM-7) Content of a Semi-Hard Cheese During Production

Cow's milk contains A1- and A2-β-caseins. The breakdown of A1-β-casein produces β-casomorphin-7 (BCM-7), a peptide with opioid-like properties that is associated with health aspects. In addition, A1- and A2-β-casein have different technological properties. The aim of the present study was to investigate whether cheese produced from the milk of homozygous A1A1 and A2A2 cows varies in terms of its physicochemical parameters and BCM-7 concentration. These parameters were analyzed during initial cheese processing, six weeks of ripening and 84 days of storage, including additional microbiological analyses during the storage period. The pH values of the A1A1 cheeses were higher than those of the A2A2 cheeses from the beginning of production until the starter culture bacteria were added. The yellowness values of the A1A1 cheeses were lower until the salt bath treatment. Water activity, lightness, hardness, fat, protein, NaCl and dry matter content, as well as color and microbiological parameters, were not affected by the β-casein genotype. BCM-7 concentrations were higher in the A1A1 cheeses after pressing and during ripening. We found mainly comparable quality characteristics and slightly different BCM-7 levels in the A1A1 and A2A2 cheeses. From this point of view, both varieties are equally suitable for cheese production.