title: Development of a predictive model for Salmonella spp. reduction in meat jerky product with temperature, potassium sorbate, pH, and water activity as controlling factors.
abstract: The objective of this study was to develop a predictive model for the inactivation of Salmonella spp. in ground beef jerky as a function of temperature (T), pH, potassium sorbate (PS), and final water activity (aw). Following a central composite design, ground beef was combined with PS (0 to 0.3%, w/w), pH adjusted from 5 to 7, inoculated with a cocktail of 6 serotypes of Salmonella spp. and heat processed at temperatures between 65 and 85°C until the final aw ranging from 0.65 to 0.85 was achieved. Surviving Salmonella cells were enumerated on tryptic soy agar overlaid with xylose lysine deoxycholate agar (pre-tempered to 47°C) after incubation for 48h at 30°C. Bacterial inactivation was quantified in terms of logarithmic reductions of Salmonella counts (log10CFU/g) and inactivation rate (log10(CFU/g)/h). The results indicated that pH, PS and T significantly (p<0.05) interacted to inactivate Salmonella in beef jerky. Decreasing meat pH significantly (p<0.05) increased the efficacy of PS and T to reduce the levels of Salmonella spp. Beef jerky processed at 82°C, pH5.5, with 0.25% PS to a final aw of 0.7 resulted in a maximum Salmonella logarithmic reduction of 5.0log10CFU/g and an inactivation rate of 1.3log10(CFU/g)/h. The predictive model developed can be used to effectively design drying processes for beef jerky under low humidity conditions and thereby, ensuring an adequate degree of protection against risks associated with Salmonella spp.
authors.affiliation: USDA ARS Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19308, USA. Electronic address: vijay.juneja@ars.usda.gov.
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Juneja
authors.affiliation: Centro de Investigación en Alimentación y Desarrollo, A.C. Laboratorio de Ciencia y Tecnología de la Carne, Carretera a la Victoria Km 0.6, Hermosillo, Sonora CP 83304, Mexico.
authors.forename: Martin
authors.initials: M
authors.lastname: Valenzuela-Melendres
authors.affiliation: Istanbul Technical University, Department Food Engineering, 34469 Maslak, Istanbul, Turkey.
authors.forename: Dilek
authors.initials: D
authors.lastname: Heperkan
authors.affiliation: Del Monte Foods, Inc., 205 N. Wiget Ln., Walnut Creek, CA, USA.
authors.forename: Derrick
authors.initials: D
authors.lastname: Bautista
authors.affiliation: Big Heart Pet Brands, 375 North Shore Drive, Pittsburgh, PA 15212, USA.
authors.forename: David
authors.initials: D
authors.lastname: Anderson
authors.affiliation: USDA ARS Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19308, USA.
authors.forename: Cheng-An
authors.initials: CA
authors.lastname: Hwang
authors.affiliation: Centro de Investigación en Alimentación y Desarrollo, A.C. Laboratorio de Ciencia y Tecnología de la Carne, Carretera a la Victoria Km 0.6, Hermosillo, Sonora CP 83304, Mexico.
authors.forename: Aida
authors.initials: A
authors.lastname: Peña-Ramos
authors.affiliation: Centro de Investigación en Alimentación y Desarrollo, A.C. Laboratorio de Ciencia y Tecnología de la Carne, Carretera a la Victoria Km 0.6, Hermosillo, Sonora CP 83304, Mexico.
authors.forename: Juan Pedro
authors.initials: JP
authors.lastname: Camou
authors.affiliation: Universidad Autónoma de Baja California, Instituto de Ciencias Agrícolas, Carretera a Delta/Oaxaca S/N, Ejido Nuevo León, CP 21705 Valle de Mexicali, Baja California, Mexico.
authors.forename: Noemi
authors.initials: N
authors.lastname: Torrentera-Olivera
mesh_terms: D000818:Animals; D002417:Cattle; D015169:Colony Count, Microbial; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D006813:Humidity; D006863:Hydrogen-Ion Concentration; D008460:Meat / Q000382:microbiology*; D008461:Meat Products / Q000382:microbiology; D008954:Models, Biological; D012475:Salmonella / Q000502:physiology*; D013011:Sorbic Acid; D013696:Temperature
chemical_list: D013011:Sorbic Acid
keywords: Beef jerky; Quantitative microbiology; Salmonella; Temperature