A new approach to the characterization of Streptococcus salivarius subsp thermophilus based on acidification rates

Abstract

The acid-producing capability of 37 strains of Streptococcus salivarius var. thermophilus (isolated from cheeses and starter cultures from 8 Italian cheese factories) was studied, using 6 parameters derived from acidification curves (pH/time). Data were analysed using principal-component analysis and indicated a wide variation between strains, enabling them to be classified into 3 groups. Experimental manufacture of Montasio cheese using starters composed of strains from 2 of the groups showed a close correlation between the differences in strains indicated by the data and the variation in characteristics of the cheeses