CHARACTERIZATION OF THE PROTEOLYTIC ACTIVITY OF STARTER CULTURES OF PENICILLIUM-ROQUEFORTI FOR PRODUCTION OF BLUE VEINED CHEESES

Citation
Md. Larsen et al., CHARACTERIZATION OF THE PROTEOLYTIC ACTIVITY OF STARTER CULTURES OF PENICILLIUM-ROQUEFORTI FOR PRODUCTION OF BLUE VEINED CHEESES, International journal of food microbiology, 43(3), 1998, pp. 215-221
Citations number
24
Categorie Soggetti
Food Science & Tenology",Microbiology
ISSN journal
01681605
Volume
43
Issue
3
Year of publication
1998
Pages
215 - 221
Database
ISI
SICI code
0168-1605(1998)43:3<215:COTPAO>2.0.ZU;2-T
Abstract
Thirty strains of Penicillium roqueforti used for the production of bl ue cheeses were examined for proteolytic activity by agar diffusion on casein agar, by the azocasein test and by capillary zone electrophore sis (CE). Distinct differences were seen between the strains by all th ree methods applied and the 30 strains could be subdivided in three gr oups being significantly different in their proteolytic activity as me asured by the agar diffusion test. The quantitative differences seen i n the agar diffusion test were confirmed by the azocasein test. Howeve r, a negative result on casein agar, i.e., no clearing of the agar was observed for one strain while it showed low proteolytic activity in t he azocasein test. CE proved to be a valuable method for revealing qua litative differences between strains of P. roqueforti in the breakdown of casein. Three strongly proteolytic strains broke down the specific casein fractions differently: one strain broke down beta A1-casein fa ster than beta A2-casein, the second preferred alpha(s1)-casein while the last strain broke down the casein fractions at equal rates. For a strain with medium proteolytic activity, the degradation of casein was seen by the appearance of a peak with migration time similar to alpha (s1)-I casein, a peptide normally produced by chymosin. (C) 1998 Elsev ier Science BN. All rights reserved.