Strategies To Enhance The Safety Of Fresh Produce And Improve The Microbial Quality Of Fruit Juice

Recent outbreaks of produce-related foodborne illness have increased consumer awareness of the potential health risks associated with the consumption of fresh leafy greens. Additionally, microbial spoilage of fruit juice and juice beverages through contamination with Alicyclobacillus spp. has caused significant economic losses worldwide. The first part of the study focused on methods to enhance the safety of minimally processed green onions and baby spinach. The individual and combined inactivation efficacies of ultraviolet light (254 nm), acidified sodium chlorite (ASC), and mild heat treatments were evaluated and optimized for surface and infiltrated E. coli O157:H7 contamination on green onions and baby spinach. Due to the limited efficacies of these methods for infiltrated pathogens, a novel method utilizing gaseous antimicrobial ethyl pyruvate (EP) was proposed. In the second part of the study, the distribution of Alicyclobacillus spp. allelic types (ATs) collected from fruit juices, beverages, ingredients, and environmental samples over a period of ten years was analyzed. Our results suggest a predisposition for certain ATs of Alicyclobacillus spp. depending on the juice or ingredient isolation source. A further characterization of the thermal resistance, guaiacol production, and genetic properties of Alicyclobacillus acidoterrestris, the most common Alicyclobacillus species implicated in juice spoilage, was investigated. This iii information will assist in controlling Alicyclobacillus spp. contamination through the development of thermal processing regimes tailored to the relevant Alicyclobacillus spoilage organisms in different juice and beverage products, while avoiding excessive processing that would lead to diminished quality in the final product. i