High pressure destruction kinetics along with combined effect of potassium sorbate and high pressure against Listeria monocytogenes in Indian white prawn muscle

Abstract

High hydrostatic pressure treatment not only inactivates the pathogenic and spoilage microorganisms present in the food but also preserves its sensory and organoleptic characters and nutrient value. In this study, the high-pressure destruction kinetics of an important food-borne pathogen Listeria monocytogenes ATCC 19115 was studied in Indian white prawn (Fenneropenaeus indicus) muscle. Headless muscle of prawn was artificially spiked with L. monocytogenes ATCC 19115 at the level of approximately 107 CFU/g. The spiked samples were vacuum-packed in an ethylene vinyl alcohol (EVOH) pouch and then subjected to high-pressure treatment at different pressure levels (250, 300, 350 and 400 MPa) for different durations of time. Pressure D values were estimated at different pressure levels. The pressureD values at 250, 300, 350 and 400 MPa were estimated as 34.521, 11.806, 5.92 and 5.099 min, respectively. It was observed that, even after 400 MPa pressure treatment for 12 min, the concentration of the L. monocytogenes population was found to be 3.387 Log10 CFU/g. The combination of high pressure and potassium sorbate dip treatment (in acidic pH) was found to be very useful in inactivating L. monocytogenes. Potassium sorbate (0.1 %) dip for 15min coupledwith 250 and 350MPa pressure reduced the level of L. monocytogenes by 2.345 and 5.908 Log10 CFU/g, respectively. Thus, it can be concluded that pressure treatment alone is not sufficient enough to inactivate this pathogen in prawn muscle. The combination of potassium sorbate with high-pressure treatment is a promising approach to inactivate L. monocytogenes in Indian white prawn muscle.