Prebiotic edible coatings with biopreservatives: Quality and safety of fresh apple cubes

Abstract

Apple fiber (2g/L) was incorporated along with vanillin (2.5g/L) and geraniol (0.6mL/L) into gellan coatings and their effects on the microbiological, physicochemical, nutritional and sensory quality of fresh-cut apple (12 days at 5±1 °C) were studied. Also, the impact of coatings on the evolution of Escherichia coli O157:H7 and Listeria innocua inoculated on apples was evaluated. Geraniol enhanced antioxidant properties of apples and allowed growth rate reduction of native microbiota. Vanillin minimized color changes, improved firmness, reduced yeasts/molds growth and prolonged sensory shelf-life by 4 days. Moreover, both biopreservatives exerted initial bactericidal effects on E. coli and geraniol reduced E. coli counts. Also, a bacteriostatic effect against L. innocua was found during the first 4 days. Therefore, these functional coatings might be good alternatives for enhancing quality and assuring safety of apples cubes. Vanillin showed the greatest potential to be applied technologically for improving the overall quality of apple cubes. Practical applications: The use of natural and functional coatings to enhance the quality of minimally processed fruits constitutes a novel technological alternative to respond to the growing rejection of consumers of foods that contain chemical preservatives that could damage their health. Apple fiber enriched-gellan coatings added with vanillin provide a safe product with high nutritional quality and a prolonged shelf life.