Distribution of microbial flora, intracellular enzymes and compositional indices throughout a 12kg Cheddar cheese block during ripening

摘要

Two studies were carried out to investigate the distribution of microbial populations, intracellular enzymes and compositional indices within 12kg Cheddar cheese blocks. In Study A, at day 21, starter and non-starter lactic acid bacteria viability in the top sub-sections were lower than middle sub-sections, but at day 98 this trend was reversed. Lactate dehydrogenase (LDH) activity in cheese juice was significantly higher in the middle sub-sections of the cheese block, but for Pep X activity there was no apparent trend. In Study B, at day 1 and day 14 of ripening, pH values were greater in the top sub-sections compared with the middle sub-sections. Over ripening, percentage salt-in-moisture was significantly greater in middle sub-sections of the cheese block. A paired comparison of pooled data indicated significantly higher LDH activity in the middle sub-sections, with Pep X activity significantly higher in the top sub-sections of the cheese block. No differences were found in the numbers of either live or dead cells in cheese juice expressed from top or middle sub-sections of cheese blocks.