Thermal Inactivation Kinetics of Three Heat-Resistant Salmonella Strains in Whole Liquid Egg

• Published in: Journal of food protection 2019-09, Vol.82 (9), p.1465-1471
• Main Authors: Gurtler, Joshua B, Juneja, Vijay K, Jones, Deana R, Purohit, Anuj
• Format: Article
• Language: English
• Subjects: Acids; Agriculture; Capillary tubes; CFR; Colony Count, Microbial; Deactivation; Distributors; Eggs; Eggs - microbiology; Experiments; Food contamination & poisoning; Food Microbiology; Food processing industry; Food safety; Heat resistance; Hot Temperature; Inactivation; Kinetics; Listeria; Microbial Viability; Nalidixic acid; Pasteurization; Product safety; Pyruvic acid; Reduction; Regulatory agencies; Ribosomal DNA; Salmonella; Salmonella - physiology; Shoulder; Sodium; Sodium pyruvate; Stainless steel; Studies; Survival; Temperature; Thermal resistance; Water baths; Water circulation
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028X.JFP-18-438

The heat resistance of three heat-resistant strains of was determined in whole liquid egg (WLE). Inoculated samples in glass capillary tubes were completely immersed in a circulating water bath and held at 56, 58, 60, 62, and 64°C for predetermined lengths of time. The recovery medium was tryptic soy agar with 0.1% sodium pyruvate and 50 ppm of nalidixic acid. Survival data were fitted using log-linear, log-linear with shoulder, and Weibull models using GInaFiT version 1.7. Based on the and mean square error, the log-linear with shoulder and Weibull models consistently produced a better fit to survival curves obtained at these temperatures. Contaminated WLE must be heated at 56, 60, and 64°C for at least 33.2, 2.7, and 0.31 min, respectively, to achieve a 4-log reduction of ; 39.0, 3.1, and 0.34 min, respectively, for a 5-log reduction; and 45.0, 3.5, and 0.39 min, respectively, for a 6-log reduction. The -values calculated from the -values were 3.67 and 4.18°C for the log-linear with shoulder and Weibull models, respectively. Thermal death times presented in this study will be beneficial for WLE distributors and regulatory agencies when designing pasteurization processes to effectively eliminate in WLE, thereby ensuring the microbiological safety of the product.