INFLUENCE OF THE FAT-CONTENT OF CHEDDAR CHEESE ON RETENTION AND LOCALIZATION OF STARTERS

Microbiological counts of fat-free, 50% reduced-fat and full-fat Chedd ar cheeses were obtained to determine the population of starter bacter ia in the different cheeses. Microbiological counts and observations o n the cheese curd by transmission electron microscopy indicated that b acterial populations in the curd were directly related to the fat cont ent of cheese. Electron microscopy examinations of cheeses ripened for less than one month showed that cells were either directly in contact with the fat globule membrane or located at the casein-fat interface. However, a higher number of bacterial cells appeared to be in close c ontact with the fat globule membrane. After one and two months of ripe ning, the number of ghost cells increased and bacteria seemed to be em bedded in the milkfat globule membrane or directly in contact with the inside of fat globules. Copyright (C) 1996 Elsevier Science Limited