Control of growth of L. monocytogenes in fresh salmon using Microgard™ and Nisin

Abstract

Pathogens like Listeria monocytogenes in fresh, or even in cold smoked salmon, have become a major public health concern for the salmon processing industry and government agencies. The effect of bacteriocin solutions (Microgard™ and Nisin) on reducing total microbial counts, inhibiting Listeria monocytogenes, and prolonging the shelf-life was evaluated. Listeria monocytogenes was inoculated onto chilled and on frozen and thawed salmon samples. The combination of Nisin and Microgard reduced the total aerobic bacteria populations of fresh chilled salmon by 2 log (P < 0.05) and increased its shelf-life, at 6°C, by 3-4 d, as compared with the control. The above bacteriocin combination also reduced the growth of inoculated Listeria monocytogenes in frozen-thawed salmon and increased its shelf-life from 5 to 10 d at 6°C. The bacteriocin treatment did not affect surface pH values or color of the fish. © 2002 Elsevier Science Ltd. All rights reserved.