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Development of bacteriocin-containing packaging to reduce pathogenic and spoilage microorganisms associated with fresh poultry products

Posted on:1998-07-16Degree:Ph.DType:Thesis
University:North Carolina State UniversityCandidate:Natrajan, NandiniFull Text:PDF
GTID:2461390014974670Subject:Agriculture
Abstract/Summary:PDF Full Text Request
Nisin is a ribosomally-synthesized peptide produced by a food grade microorganism Lactococcus lactis subsp. lactis. It was affirmed by the United States Food and Drug Administration in 1988 as GRAS (Generally Recognized As Safe) substance. Nisin's ability to inhibit gram-negative bacteria when combined with food grade chelating agents such as EDTA had already been confirmed in our laboratory. The objective of this study was to evaluate the efficacy of applying nisin-based treatment formulations to fresh poultry products via primary packaging film and edible film systems to inhibit Salmonella typhimurium on broiler drumsticks. Packaging films and edible films were treated with an optimized treatment formulation composed of nisin, citric acid, EDTA and Tween 80. Reductions in the S. typhimurium population following exposure to treated polymeric packaging films at refrigeration temperatures ranged from 0.4 to 2.1 log cycles. The kill was found to be influenced by nisin concentration, film type and exposure time. A 0.6 to 2.2 day extension in the refrigerated shelf life of the drumstick was observed following a 3 minute dip in a nisin-containing treatment and subsequent storage in an absorbent tray pack overwrapped with a polyvinylchloride film treated with the nisin formulation. Additional experiments in which calcium alginate and agar based edible films treated with the nisin formulation were applied to contaminated drumstick skin at {dollar}sim{dollar}1:2 weight ratio (trt:skin) resulted in S. typhimurium skin population reductions between 99.9% to {dollar}>{dollar}99.99% following 72 to 96 hours of contact. Radiolabeling studies using a reductive technique were carried out to determine the rate of nisin migration from the polymeric film onto the surface of the broiler drumstick skin. Results demonstrated an initial rapid migration from the film of greater than 50% within one hour of application. In conclusion, the findings of this study confirm our hypothesis that commercial packaging and edible films can act as carriers for delivering effective antimicrobials to the surface of poultry products. The addition of antimicrobials to primary packaging on fresh poultry products has the advantage of providing a final safeguard for controlling pathogens following processing, and continued protection through marketing and distribution channels.
Keywords/Search Tags:Poultry products, Fresh poultry, Packaging, Nisin, Following
PDF Full Text Request
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