title: Inactivation of Listeria monocytogenes on frankfurters by plant-derived antimicrobials alone or in combination with hydrogen peroxide.
abstract: Listeria monocytogenes is a significant foodborne pathogen associated with outbreaks involving contaminated ready-to-eat (RTE) products, including frankfurters. The USDA-FSIS has established a zero tolerance policy for L. monocytogenes in RTE products, thereby warranting effective post-processing interventions to control the pathogen on these foods. In the present study, the antilisterial activity of GRAS (generally recognized as safe)-status plant-derived antimicrobials (PDAs), namely β-resorcylic acid (BR), carvacrol (CR), and trans-cinnamaldehyde (TC) either alone or in combination with hydrogen peroxide (HP) as post-processing dip treatments on frankfurters was investigated. Frankfurters were surface inoculated with a five-strain mixture of L. monocytogenes (~6.0 log CFU per frankfurter), followed by dip treatment at 55 °C for 60s or 65 °C for 30s in sterile deionized water, or water containing BR (1.5%), CR (0.75%), or TC (0.75%) either alone or in combination with HP (0.1%). Treated frankfurters were vacuum-packaged, and stored at 4 °C for 70 days. Representative samples were analyzed on days 0, 1, 3, 7, 14, 28, 42, 56, and 70 of refrigerated storage for enumerating surviving L. monocytogenes on frankfurters. Six frankfurters were sampled at each time point for each treatment. On day zero, all PDAs reduced L. monocytogenes counts by >2 log CFU/frankfurter at both temperatures (P<0.05), compared to controls. From days 1 to 70, L. monocytogenes counts on PDA-treated frankfurters were consistently lower (P<0.05) and after 70 days of storage, the pathogen counts were reduced to undetectable levels on frankfurters treated with PDA-HP combinations at 65 °C, and by combinations of BR and TC with HP at 55 °C. Results suggest that PDAs alone, or in combination with HP could be effectively used as post-processing dips to reduce L. monocytogenes on frankfurters, although follow-up studies on sensory and quality characteristics of PDA-treated frankfurters are necessary.
authors.affiliation: Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
authors.forename: Abhinav
authors.initials: A
authors.lastname: Upadhyay
authors.forename: Indu
authors.initials: I
authors.lastname: Upadhyaya
authors.forename: Anup
authors.initials: A
authors.lastname: Kollanoor-Johny
authors.forename: Sangeetha
authors.initials: S
authors.lastname: Ananda Baskaran
authors.forename: Shankumar
authors.initials: S
authors.lastname: Mooyottu
authors.forename: Deepti
authors.initials: D
authors.lastname: Karumathil
authors.forename: Kumar
authors.initials: K
authors.lastname: Venkitanarayanan
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology / Q000379:methods*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000502:physiology; D008461:Meat Products / Q000382:microbiology*; D013696:Temperature
chemical_list: D000890:Anti-Infective Agents; D006861:Hydrogen Peroxide