Development of antimicrobial composite materials for food packaging applications

Abstract

Due to increasing environmental concerns regarding plastic waste, the development of composite film materials from biodegradable polymers and natural food additives is gaining more attention. Over the last few decades, the safety of synthetic additives that are commonly added as food additives has also been questioned because of their potential toxicity, carcinogenicity and teratogenicity effects. Natural antimicrobial agent could be a promising and versatile component in food packaging materials to improve their physiochemical, antioxidant and antimicrobial properties and hence, improve food quality and shelf life. In this study, novel chitosan/acetylated starch and polyvinyl alcohol/chitosan composite films were developed via a solution casting technique. In addition, a novel Escherichia phage, CAM-21, was isolated from a slurry lagoon at a local dairy farm before incorporating into soy protein isolate-based films. The results indicate that the chitosan/acetylated starch films incorporated with cinnamon and clove essential oils displayed enhanced light, water vapor, and oxygen barrier characteristics, as well as excellent antibacterial activity against spoilage bacteria and the pathogen, Escherichia coli O157:H7, on beef. Polyvinyl alcohol/chitosan films incorporated with aminosilane-modified bacterial nanocellulose and 4-hexylresorcinol exhibited improved mechanical, water vapor barrier, antioxidant, and antimicrobial properties against spoilage bacteria on vacuum packaged refrigerated raw beef. Also, CAM-21 has a broad host spectrum against various serotypes of Shiga toxin-producing E. coli. The growth of E. coli O157:H7 was effectively controlled in phage-treated milk, ground beef and baby spinach. Soy protein isolate films incorporated with CAM-21 showed excellent antimicrobial activity against E. coli O157:H7 in broth and refrigerated beef products. This project demonstrates the potential application of natural antimicrobial agents to produce novel composite films for antimicrobial food packaging.