Submitted to: Letters in Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 27, 1998
Publication Date: N/A
Interpretive Summary: Generally, small muscles of high quality or lean trimmings obtained from carcasses are processed into low-value products such as sausages, meat snacks, or raw ground products. To revalue these muscles and trimmings, a cold meat binding system can be used to adhere whole muscle or pieces of fresh meat, poultry, fish, or seafood together into one piece. In this study, nisin, a naturally occurring, antimicrobial protein associated with cheese making, was incorporated into a meat binding system (Fibrimex) to reduce populations of the meat spoilage organism, Brochothrix thermosphacta, on fresh or vacuum- packaged beef surfaces. Beef surfaces were left untreated (U), treated with Fibrimex (F), nisin (N), or nisin incorporated in Fibrimex (FN). Treated beef was stored with or without vacuum packaging, held under refrigeration, and sampled for bacterial populations and antimicrobial activity up to 14 and 7 days, respectively. Under either condition, N and FN treatments equally suppressed bacterial growth at all days examined and antimicrobial activity was apparent throughout the study. Based on these findings, the application of nisin into a meat binding system may be useful in reducing undesirable bacteria in restructured meat products made from whole muscles or trim.
Technical Abstract: In two separate experiments, the bacteriocin, nisin, was incorporated into a commercially available meat binding system (Fibrimex, F. N. A. Foods, Calgary, Alberta) and applied to meat surfaces as a way to inhibit the meat spoilage organism, Brochothrix thermosphacta during extended refrigerated storage. In experiment 1, prerigor lean beef carcass tissue (BCT) was inoculated with B. thermosphacta, left untreated (U), treated with 10 ug/ml nisin (N), Fibrimex (F), or Fibrimex containing 10 ug/ml nisin (FN), held aerobically at 4 deg C for up to 7 days, and populations of B. thermosphacta and nisin activity determined. Experiment 2 determined the effects of the same treatments but on post-rigor, frozen and thawed lean BCT that was inoculated, vacuum packaged, and stored at 4 deg C for up to 14 days. In both experiments, N- and FN-treated tissues exhibited significantly lower populations of B. thermosphacta, as compared to U- and F-treated tissues, for the duration of refrigerated storage. Nisin activity was detected up to 7 days in N- and FN-treated samples from experiment 1. However, activity was detected only to days 0 and 2 in FN- and N- treated samples, respectively, from experiment 2. These studies indicate that the addition of a bacteriocin to a meat binding system and application to meat surfaces may be useful in reducing undesirable bacteria in restructured meat products.