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Page No. : 111-116

ABSTRACT

The present investigation was envisaged to study the inhibitory potential of food grade preservatives such as 150 ppm sodium nitrite (SN) and 0.1% potassium sorbate (PS), as well as their combination on VTEC O157:H7 in simulating media for beef gravy (pH 7.0 and 5.4) stored at 25°C for 48 h and at 4°C for 45 days. During storage at 25°C at pH 7.0 and 5.4, SN and PS showed no significant impact on reduction of VTEC O157:H7. The combination of SN (150 ppm) and PS (0.1%) exerted maximum inhibitory effect on VTEC at pH 7.0 and 5.4 on Day 31 and 24, respectively, during storage at 4°C. Inhibition of VTEC was significantly higher (P<0.05) in simulating medium (pH 5.4, pH adjusted with 2% lactic acid) with SN and PS compared to the simulating media for beef gravy (pH 5.4, pH adjusted with 6N HCl) and the same preservatives at 4°C.

Keywords: Potassium sorbate, sodium nitrite, Verocytotoxic E. coli, VTEC O157:H7, VTEC survivability