Fate of food-associated bacteria in pork as affected by marinade, temperature, and ultrasound.

Abstract

The aim of this study was to test the effect of ultrasound, red wine, and yogurt marination on Brochotrix thermosphacta, Carnobacterium maltaromaticum, Listeria monocytogenes, and Campylobacter jejuni on pork meat. Two different marination procedures of the pork medallions were tested: (i) submersion of meat medallions in red wine during the entire experiment and (ii) vacuum packaging of meat medallions after different forms of marination. In the submersion procedure, the meat was either submerged in 42 degrees C red wine for 15 min prior to storage at 4 degrees C or submerged in 4 degrees C red wine during the entire experiment. In the vacuum procedure, the meat was either submerged in 4 degrees C red wine for 4 h or submerged in 42 degrees C red wine for 15 min prior to vacuum packaging and storage at 4 degrees C. The most efficient antimicrobial procedure was submersion of the pork meat in 42 degrees C red wine for 15 min and subsequent storage at 4 degrees C, still submerged in red wine. After 3 days, C. maltaromaticum, L. monocytogenes, B. thermosphacta, and C. jejuni were reduced approximately 1.5, 2, 3, and 6 log, respectively. The remarkable acid sensitivity of C. jejuni compared with the other bacteria was confirmed in an experiment with yogurt as a marinade. Ultrasound treatment in combination with red wine enhanced the antibacterial effect compared with ultrasound alone for L. monocytogenes, B. thermosphacta, and C. jejuni and resulted in approximately a 1-log reduction after 10 min. This synergistic effect of ultrasound and red wine was not observed for C. maltaromaticum.