Survival of Escherichia coli in Food at Hot-Holding Temperatures

Foods usually served hot were held at various hot-holding temperatures [40°C (104°F) - 60°C (140°F] and were contaminated with fecal Escherichia coli . The contaminated hot foods were held for 1 h at each of the hot-holding temperatures during which the survival of the pathogen in each food type was evaluated. Results showed that E. coli survived hot-holding temperatures in each food type for the whole period of evaluation. A population increase occurred with time at temperatures below 50°C (122°F), while at and above this temperature there was a decrease in population with increasing time in each food type. A two-way analysis of variance using relative rates of increase or decrease (± b) showed food type to be unimportant for survival of the bacteria. A three-way analysis of variance of the same results using mean log CFU/g food showed holding temperature, food type, holding time, and the interactions of temperature and food type; and temperature and time to be significantly important for survival of the bacteria. The public health significance of these findings are discussed.