Effect of cook temperature on starter and non-starter lactic acid bacteria viability, cheese composition and ripening indices of a semi-hard cheese manufactured using thermophilic cultures

Semi-hard cheeses were manufactured using Streptococcus thermophilus and Lactobacillus helveticus cultures and their ripening was characterised. During cheese manufacture, curds were cooked to a maximum temperature of 47, 50 or 53 degrees C, pre-pressed under whey at pH 6.15, moulded, pressed and brined. Increased cook temperature resulted in increased manufacture time, a significantly reduced growth rate of S. thermophilus during manufacture in the order 47 approximate to 50 degrees C > 53 degrees C and in significantly lower mean viable cell counts of S. thermophilus up to 56 d of ripening. Increasing cook temperature had no significant effect on mean viable cell numbers of L. helveticus or non-starter lactic acid bacteria (NSLAB). Cheeses produced from curds cooked to 47 degrees C had significantly higher levels of moisture in non-fat substances (MNFSs), salt-in-moisture and a significantly lower pH and levels of butyrate compared with cheeses produced from curds cooked to 50 or 53 degrees C. (c) 2006 Elsevier Ltd. All rights reserved.