Relationships amongst South African processed, young and matured Cheddar cheese pertaining to organic acid content and non-starter population

Ion-exclusion HPLC and selective media were used to analyse the organic aci ds and microbial population in processed, young and matured Cheddar cheeses . Microbial counts for young and matured Cheddar were much alike, with the exception of total acid formers and citrate fermenters which were higher fo r matured Cheddar. The total mesophilic count for processed Cheddar cheese was considerably higher than for conventional (young and matured) Cheddar c heeses, whereas the fungi count for processed Cheddar was lower. Total acid formers, lactobacilli, homofermentatives, citrate fermenters and aerobic s pore-forming bacteria were all present in lower quantities in processed Che ddar than in the conventional Cheddars. Anaerobic spore-forming bacteria we re detected only in the processed Cheddar cheese. Although HPLC chromatogra ms appeared relatively similar amongst the cheeses, a greater number of org anic acids could be detected in matured Cheddar cheese than in young and pr ocessed Cheddar, respectively. The matured Cheddar cheese was clearly more developed with regard to propionic, butyric, citric, lactic, acetic, isoval eric and n-valeric acids. From radar plots it was deduced that microbial an d organic acid profiles could be utilised as evaluation parameters for chee se varieties. (C) 1999 Canadian Institute of Food Science and Technology. P ublished by Elsevier Science Ltd. All rights reserved.