Antimicrobial gas phase treatments for apples and other moisture sensitive produce to enhance food safety and shelf-life

点击翻译按钮获取中文摘要

The recent outbreak of listeriosis linked to contaminated candy apples results in 34 confirmed cases and 3 deaths. The outbreak underlined the susceptibility of produce to contamination and need for intervention steps to inactivate field acquired contamination. The challenge with apples destined for candy apple production is the process requires dry apples to ensure adherence of the caramel coating. In any event, washing has been demonstrated to have limited efficacy with respect to pathogen reduction. The proposed project will demonstrate proof-of-principle of combination of antimicrobial gas treatments to inactivate pathogens (Listeria, E. coli and Salmonella) on and within intact apple fruit. The gases to be studied will include ozone, chlorine dioxide and hydroxyl radicals. The gas treatment will be incorporated into apple pre-conditioning process whereby the fruit are raised to processing temperature. Here, the apples within totes are stacked then an air stream introduced to remove surface moisture. The gas treatments will be optimized with respect to gas concentration, composition, time and relative humidity. Laboratory based studies will determine the process conditions required to support a 5 log reduction of pathogens and spoilage microbes whilst retaining fruit quality. The studies will be supplemented with in-plant verification trials. The technology to be developed can be applied to other water sensitive produce such as soft fruit, tender fruit and mushrooms, in addition to others.