|Scullen, O - Butch|
|Jin, Zhonglin - Tony jin|
Submitted to: Food Control
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/7/2013
Publication Date: 11/1/2013
Publication URL: http://handle.nal.usda.gov/10113/57325
Citation: Guo, M., Yang, R., Antenucci, R., Mills, B., Cassidy, J.M., Scullen, O.J., Sites, J.E., Rajkowski, K.T., Sommers, C.H., Jin, Z.T. 2013. Inactivation of natural microflora and Listeria innocua on raw whole shrimp by ozonated water, antimicrobial coatings, and cryogenic freezing. Food Control. 34:24-30. Interpretive Summary: Many foodborne outbreaks are associated with imported foods. 99.7% shrimp in US market are imported. Our survey shows that 21.9% of shrimp samples were found Listeria positive, and 12.5% were identified as Listeria monocytogenes. To improve microbiological safety and quality of shrimp, the antimicrobial effects of ozone, antimicrobial coating and cryogenic freezing, used alone or in combination, on the survival of Listeria innocua and natural bacteria on shrimp was investigated. Among them, antimicrobial coating in combination with cryogenic freezing reduced more than 99.999% of L. innocua and natural bacteria. The information is valuable for seafood processors and distributors to adopt intervention strategies to enhance the safety and extend the shelf-life of shrimp.
Technical Abstract: Shrimp have been associated with foodborne illness outbreaks. A survey was conducted to investigate the microbiological safety and quality of frozen raw whole shrimp in local US markets. Results from 32 brands of raw whole shrimp samples available in local retail markets representing 9 countries of origin shows that the average numbers of total aerobic plate count, psychrotrophic count, coliform count, and Enterobacter were 3.64, 4.06, 0.02 and 1.43 log CFU/g, respectively; 21.9% of shrimp samples were found Listeria positive, and 12.5% were identified as L. monocytogenes. No Salmonella spp., Escherichia coli O157:H7, Vibrio spp., or Staphylococcus aureus were detected. Based on our survey results, the antimicrobial effects of ozone, antimicrobial coating and cryogenic freezing, used alone or in combination, on the survival of natural microflora and Listeria innocua on shrimp was investigated. Ozone, cryogenic freezing and antimicrobial coating treatments used alone reduced natural bacteria or L. innocua by less than 2 log. However, their combination provided additive or synergistic effects against naturally occurring bacteria and L. innocua. Among them, chitosan coating with allyl isothiocyanate, in combination with cryogenic freezing achieved more than 5 log reduction of L. innocua and natural bacteria. The information may be valuable for seafood processors and distributors to adopt intervention strategies to enhance the safety and extend the shelf-life of shrimp.