Modeling the inactivation kinetics of Salmonella Typhimurium and Pseudomonas aeruginosa on eggshell surfaces using gaseous ozone

Abstract

Eggs are a vital component of the human diet, but they are highly susceptible to microbial contamination by pathogens, such as Salmonella spp., and spoilage bacteria, particularly Pseudomonas aeruginosa. This study aimed to evaluate the efficacy of gaseous ozone (O3 -75 and 110 ppm) in inactivating Salmonella Typhimurium and Pseudomonas aeruginosa on eggshell surfaces and to assess its effects on egg quality. Three predictive models were tested, with the Shoulder + Log Linear model providing the best fit to the microbial inactivation kinetics. The results indicated that S. Typhimurium had higher 4D values, showing greater resistance to ozone than P. aeruginosa, with 4D values of 52.5 and 51.8 min at 75 ppm and 49 and 44.8 min at 110 ppm, respectively. Application of gaseous ozone at 75 and 110 ppm for 70 min reduced microbial counts to below detectable levels (1 log CFU/egg) for both bacteria. No significant quality differences were observed between ozonated and control eggs during storage. These findings demonstrate that gaseous ozone is an effective technology to ensure the microbiological safety of eggs without adversely affecting egg quality, presenting a viable alternative to control Salmonella Typhimurium and Pseudomonas aeruginosa in eggs, eliminating the use of water and industrial waste.