Microbiological and sensory quality changes in cabbage casserole and mixed vegetable salad with mayonnaise during storage

The microbiological and sensory quality of cabbage casserole and mixed vegetable salad with mayonnaise was assessed after production, on the sell-by date and 7 d later. Samples were taken directly from five different plants, stored at 4°C and analyzed by three different laboratories. Sell-by periods were 8 to 14 d after the day of production. No Bacillus cereus, Clostridium perfringens, Staphylococcus aureus (salad), fecal streptococci or coliforms (casserole) were detected. Casseroles had median aerobic plate counts (APC) of 1.5 × 102, 3.3 × 102 and 4.5 × 103 cfu/g on different analysis times. Yeasts were detected in some casseroles on the sell-by dates. A few more had yeasts and/or molds a week later. Taste, odor, consistency and appearance scores showed a steady decrease during storage. Nine casseroles were deemed unfit for human consumption 7 d after the sell-by dates. Main defects were sliminess and acid, fermented taste and visible mold spots. Salads had a median APC of 5.2 × 103 cfu/g after production, which remained constant during storage. Salads from all companies contained lactobacilli and counts increased slightly during storage. Molds were encountered in samples of only one company and yeasts primarily of another. Median sensory scores decreased slightly during storage. One salad was deemed unfit on the sell-by date and six a week later. Main defects were musty and/or fermented taste and odor and watery consistency. Linear regression equations between taste and log10 microbial counts showed very low or no correlation. Also, the counts of sensorially unfit samples varied from low to high.