Hazard Analyses of Fried, Boiled and Steamed Cantonese-Style Foods

Abstract

Time-temperature exposures to which each stage of the preparation of a variety of fried, boiled or steamed Cantonese-style foods were subjected were evaluated at six restaurants. Samples of these foods were examined to determine their water activity, to detect the presence of Bacillus cereus and to count the number of mesophilic aerobic microorganisms. Temperatures of foods that were attained during cooking were usually high enough to cause rapid destruction of vegetative pathogenic foodborne bacteria. Food temperatures usually increased after cooking ended to provide additional lethal effect to any surviving vegetative microorganisms. During hot-holding in steam tables, the temperatures of the foods were such that multiplication of pathogenic foodborne bacteria would be unlikely and would cause additional lethal effect to vegetative forms of these organisms. Foods that were held in hot-air warmers, however, did not always reach sufficiently high temperatures to prevent multiplication of these organisms. Cooked foods were sometimes held at room temperature long enough to permit multiplication of bacteria that might have been present. This was confirmed by the finding of large numbers of mesophilic aerobic microorganisms in samples of such foods. Time-temperature control measures for cooked Cantonese-style foods include: (a) serve these items immediately after cooking or hold them at 55 C (131 F) or higher until served, refrigerated or reheated; (b) cool in layers not exceeding 9 cm (3.5 in) in walk-in refrigerators; and (c) thoroughly reheat cooked, chilled foods or foods left at room temperature to at least 74 C (165 F).