Hydrolysis of alpha(s) and beta-caseins during ripening of Serra cheese

• Type: Article in International Scientific Journal
• Date: 1997

Authors

Macedo, AC (Author) Other; F. Xavier Malcata (Author) Other

Journal

Title: Food Chemistry

Vol. 58

Pages: 43-48

ISSN: 0308-8146

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 19 Citations

Scopus - 22 Citations

Other information

Authenticus ID: P-001-CDM

DOI: 10.1016/s0308-8146(96)00194-x

Abstract (EN): Hydrolysis of the major caseins in Serra cheese manufactured from raw sheep's milk coagulated with a plant rennet (Cynara cardunculus, L.) was monitored by urea-PAGE electrophoresis throughout a 35 day ripening period (with sampling at 0, 7, 21 and 35 days) and throughout the cheesemaking season (with sampling at November, February and May). The alpha(s)- and beta-caseins were degraded up to 82 and 76%, respectively, by 35 days of ripening. The alpha(s)-casein variants (alpha(s2)- and alpha(s3)-) displayed similar degradation patterns to one another, but different from those of beta-casein variants (beta(1)- and beta(2)-). Although the alpha(s)-caseins were broken down more slowly than beta-caseins at early stages of ripening (97, 95, 80, and 60% of alpha(s2)-, alpha(s3)-, beta(1)-, and beta(2)-caseins, respectively, were still intact by 7 days), this observation was reversed for later stages of ripening (18, 18, 30, and 20% of alpha(s2)-, alpha(s3)-, beta(1)-, and beta(2)-caseins, respectively, were still intact by 35 days of ripening). The position along the cheese-making season significantly affected the hydrolysis of only the beta(2)- and alpha(s3)-caseins. Degradation of alpha(s3)-casein was slower in February than in November or May for 21-day old cheeses; cheeses ripened for 7 days or 21 days showed more intact beta(2)-casein when manufactured in May than in November or February. The magnitude of the correlation coefficients pertaining to concentrations of intact alpha(s)- and beta-caseins indicated that the products of proteolytic breakdown with higher mobility than alpha(s)-caseins (tentatively termed alpha(1)-I, alpha(2)-I, and alpha(3)-I) were preferentially correlated with alpha(s)-caseins, the products of proteolytic breakdown with mobility between beta-caseins and alpha(s)-caseins (tentatively termed beta(1)-I and beta(2)-I) were preferentially correlated with beta(1)- and beta(2)-caseins rather than with alpha(s)-caseins, and the products of proteolytic breakdown with the highest mobility (tentatively termed alpha/beta(1)-II and alpha/beta(2)-II) were preferentially correlated with beta-caseins. Copyright (C) 1996 Elsevier Science Ltd.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6