| A study was conducted to evaluate five microbiological tests and their ability to rapidly and accurately predict the "potential" shelf-life of fluid milk products. Reduced-fat and whole-chocolate milk samples were obtained on the day of processing. Samples were subjected to preliminary incubation at 21°C for 18 +/- 1 hour followed by SPC, VRB, CVT, Gram negative count, and bioluminescence testing. Samples were stored at 7°C. Sensory evaluation was conducted at day 7, day 10, and every other day thereafter until off-flavors resulted. Reduced-fat milk samples displayed a two day longer shelf-life than whole-chocolate samples. The CVT count and bioluminescence (ATP as related to relative light units) correlated overall more frequently with actual shelf-life. Using combined data from reduced-fat and whole-chocolate samples, it was decided that each individual plant must determine the type of microbiological testing used. |
