Microbiological evaluation of a hospital delivered meals service using precooked chilled foods.

A delivered meals service supplying centrally produced, precooked, chilled foods to 24 hospitals was introduced in Plymouth Health District between August 1985 and July 1986. Over 18 months, 3393 food items were examined microbiologically, using the criteria recommended by the Department of Health and Social Security (DHSS) (1980). No Salmonella spp., Staphylococcus aureus or Clostridium perfringens were detected. Seventy-five (8.6%) of 876 cooked vegetable items had total viable counts (TVC) greater than 1 x 10(5) cfu g-1 (the recommended limit) after aerobic incubation at 37 degrees C for 48 h, whereas only 2.6% (66) of 2517 foods other than vegetables had TVC above this limit. Reasons for high counts were investigated and mostly corrected so that, whereas 8.4% of samples had TVC above recommended limits in the first 4 months of the study, only 1.6% exceeded this limit in the last 3 months. The value of microbiological standards for cook-chill food and their use in hygiene control are assessed.