Flavour development in aseptic cheese curd slurries prepared with single-strain starter bacteria in the presence and absence of adjuncts

Abstract

Summary - Eight strains of Lactococcus starter bacteria were tested under microbiologically controlled conditions for their ability to pro duce Cheddar cheese flavour, For this purpose, aseptic Cheddar chee se curds were prepared with each of the organisms, and the resulting curds slurried with sterile salt and water, and stored at 30 C for accelerated f1avour development. Distinct though weak Cheddar cheese flavour was produced by the Lactococcus lactis subsp cremoris strain SK Il, but not by strains ASCC457, ASCC50, ASCC 109, ASCC660, ASCC360, or the L lactis subsp lactis strain ASCC381, or the L lactis subsp lactis biovar diacetylactis strain ASCC250. Different starter strains produced different degrees of bitterness, with strains ASCC457, 109 and 660 producing the most bitter slurries. Strains SKII, ASCC50, ASCC360, and ASCC250 produced only slight bitterness in slurries ripened for 15 days, Free fatty acid concentrations in the slurries differed depending on the starter strain used, implying that different starter strains have different lipase activity. Cheese flavour development was slow in the slurries containing only starter bacteria. In contrast, slurries made with the strain SKII in the presence of the adjuncts Lactobacillus helveticus ASCC395, Brevibacterium linens CSCC750 or Lactobacillus casei subsp casei NCDOl51 underwent rapid f1avour development, giving distinct and strong chee se (but not Cheddar) flavours for each adjunct. These differences in flavour, however, cou Id not be explained in terms of differences in the non-sulphur volatile composition of the slurries determined by static headspace analysis.