Protein profiles and total antioxidant capacity of water soluble and insoluble protein fractions of white cow cheese at different stage of ripening

Abstract

This research is focused on proteolysis and total antioxidant capacity of proteins of white brined cheese prepared from overheated (90 degrees C, 10 minutes) cow milk. White brined cow cheese of overheated milk went through specific proteolytic changes during ripening that were result of high level of whey proteins incorporated into the gel matrix. Specificity was reflected through the relatively low level of soluble nitrogen fractions, the intensive and continual decrease of alpha(s)-caseins up to 15.42 % of initial content, slow degradation of beta-casein throughout the whole ripening period and high level of proteolytic products tightly bounded into gel matrix. Strong negative correlations (-0.97, -0.98 and -0.91; p lt 0.05) between ripening time and resudual alpha(s)-caseins, beta-casein and low molecular weight products were observed. Proteolysis also affected the total antioxidant capacity of both water soluble and water insoluble nitrogen fractions, but to different extents and with different trends. Total antioxidant capacity of water insoluble fraction increased slowly during the whole ripening period, wherease significant improvement of total antioxidant capacity of water soluble fraction started after 30 days of ripening. These findings could be useful for better understanding and control of the white brined cow cheese production.