EVALUATION OF MICROBIOLOGICAL SHELF LIFE AT DIFFERENT TEMPERATURES AND FATE OF ESCHERICHIA COLI O157:H7 INOCULATED IN PASTEURIZED MILK**.
According to a Centers for Disease Control and Prevention report, achieving safer and healthier foods had been one of the top 10 achievements of 20th century. Shiga-toxin-producing Escherichia coli O157:H7 is a well-known food-borne pathogen that can cause food borne diseases in humans. To control E. coli O157:H7 in foods, thermal process has been widely used, but there is a possibility to recover some sub – lethal microorganisms during storage period. Providing the additional assurance of thermal processing of food, some natural bioactive compounds can be the effective possible alternatives. There is not much information about the shelf life of food against E. coli O157:H7 at different temperatures has been reported. So, there is a need of some study to understand the fate and survival of E. coli O157:H7 during storage period. The current study investigated persistence of wild-type E. coli O157:H7 serovars in sterile milk stored aerobically for up to 28 days at 4°C and 37°C. Additionally, survival of E. coli O157:H7 against the synergistic effect of heat and caprylic acid in sterile milk were monitored after heat shock at 4°C and 37°C for 28 days. In this study 107 CFU/ml inoculum level and 0.5% caprylic acid were used. Inoculated samples were heat shocked with 63 ℃ for 30 minutes and 72 ℃ for 15 sec. Treatments at 63 ℃ for 30 minutes and the synergistic effect of caprylic acid with 63 ℃ for 30 minutes exhibited the similar trend for survival which were about 4.1 and 3.2 log CFU/ml reduction of E. coli O157:H7 respectively after 28 days at both 4°C and 37°C. Our study thus indicates the occurrence of contamination could lead to prolonged survival of these microorganisms in high and low-nutrient environments and highlights the need for preventive measures.
Kabir, Md Niamul; Henley, JaTorious; and Ojo,, Olabisi O.
"EVALUATION OF MICROBIOLOGICAL SHELF LIFE AT DIFFERENT TEMPERATURES AND FATE OF ESCHERICHIA COLI O157:H7 INOCULATED IN PASTEURIZED MILK**.,"
Georgia Journal of Science, Vol. 81, No. 1, Article 47.
Available at: https://digitalcommons.gaacademy.org/gjs/vol81/iss1/47