Background and Aims: The ready-to-eat foods, before and after preparation, usually kept in a refrigerator before consumption for a relatively long time, increase the risk of food poisoning. The aim of this study was to determine the effect of refrigeration in the fast-food shops on the microbial contamination of fast foods.

Materials and Methods: A total of 100 samples, including 46 cooked beef livers and 54 cooked sausages were collected from fast-food shops in the south of Tehran and analyzed according to the procedures of the Office of Food Control Laboratories (OFCL). The samples were tested randomly for the microbial contamination on the first, third, fifth and seventh days of storage in the refrigerator.

Results: Results of microbial analysis showed that 35 cooked sausage samples (64.8%) and 34 cooked liver samples (73.9%) on the first day, 44 cooked sausage samples (81.5%) and 42 cooked liver samples (91.3%) after the third day, 47 cooked sausage samples (87.1%) and 44 cooked liver samples (95.6%) after the fifth day, and 50 cooked sausage samples (92.3%) after the seventh day were unfit for consumption Frying of the food items before consumption would decrease, though to a small extent, microbial contamination (P<0.05). Increased total micrbial counts of the food items, exceeding the respective standards, is the most important inhibitory factor for their consumption.

Conclusion: The results of this study showed that keeping cooked foods for a long time in the refrigerator causes increased microbial contamination over time.