Ripening characteristics of Cheddar cheese made from bovine milks containing kappa-casein AA or BB genetic variants.

摘要

The ripening characteristics of Cheddar cheeses made from kappa-casein AA/beta-lactoglobulin AB and kappa-casein BB/beta-lactoglobulin AB genetic variant milks were investigated over a 274-day period. kappa-Casein variant had no significant effect on primary and secondary proteolysis, as monitored by nitrogen solubility at pH 4.6 or in 5% phosphotungstic acid, and total levels of free amino acids. Moreover, the profile of proteolysis products was not influenced by kappa-casein variant, as indicatedby the generally similar peptide molecular weight distribution profiles in cheeses from the kappa-casein AA or BB milks throughout the 274-day ripening period. Some amino acids, however, (methionine, leucine, phenylalanine, histidine and lysine) were significantly higher in kappa-casein BB cheese than in kappa-casein AA cheese after 274 days of ripening. kappa-Casein variant had no significant effect on the rheological (fracture stress and firmness) characteristics or sensory scores for flavour/aroma and body/texture.