Microbial Quality of Ready-to-Eat Foods Sold in School Cafeterias in Chongqing, China

Abstract

ABSTRACT The microbiological quality of ready-to-eat (RTE) foods from school cafeterias in Chongqing, People's Republic of China, was evaluated and compared with a guideline published by a provincial health commission. These RTE foods were divided into five types based on their preparation processes and potential risks: 1, general cooked and hot-held foods; 2, cooked meats; 3, heated aquatic products; 4, fresh fruits or vegetables; and 5, cooked foods with postcooking handling (e.g., cutting, cooling, or addition of ingredients or condiments). Food types 1 through 3 (subjected to thermal processes and hot-held) were microbiologically safer than types 4 and 5 (prepared by nonthermal process or with postcooking processes). None of the samples of types 1 through 3 were unsatisfactory based on their aerobic plate counts (APC) and total coliforms (TC), whereas 43.1% of type 4 and 8.3 and 71.7% of type 5 samples were unsatisfactory due to high counts of TC and high APC and TC, respectively. Two, 12, and 50 samples of types 2, 4, and 5, respectively, were unacceptable due to high levels of Staphylococcus aureus. Bacillus cereus and Vibrio parahaemolyticus were detected, but levels were below the unacceptable limits. None of the samples were positive for Salmonella, Listeria monocytogenes, or Escherichia coli O157. The bacterial profile can be used by policy makers and epidemiologists for microbiological risk assessments, which may be conducive to developing interventions to control hazards, improve food hygiene, and develop safety management systems for school cafeterias in China. HIGHLIGHTS