Effect of β-casein concentration in cheese milk on rennet coagulation properties, cheese composition and cheese ripening

Effects of the use of a beta-casein powder to enrich cheese milk on rennet coagulation properties of milk, cheese composition and cheese ripening were investigated. Casein content of control milk was 2.5%, whereas that for the three enriched milks was adjusted with beta-casein powder at 2.7%, 2.9% and 3.1%. The beta-casein to alpha-casein ratio of these cheese milks was, respectively, 0.70, 0.79, 0.89 and 0.99. Rennet coagulation properties were related not only to casein concentration but also to the proportion of beta-casein and alpha(s)-casein presents in milks. Milk with higher concentration of P-casein had poorer coagulation properties. Cheeses could be produced by using a miniature cheese making process. Moisture, ash and calcium contents decreased, while protein content and beta-casein increased in cheese as casein and beta-cascin concentration increased in milk. As a result, hardness was higher in enriched cheeses than in control cheese. During cheese ripening, alpha-casein was hydrolyzed, but the rate of degradation of alpha-casein decreased as protein and P-casein concentration increased in cheese. beta-Casein seemed to be not hydrolyzed. The rate of decrease of hardness was also slower for enriched cheeses. Crown Copyright (c) 2004 Published by Elsevier Ltd. All rights reserved.