Application of a combined treatment using natural antimicrobials and modified atmosphere packaging to enhance safety, quality, and shelf-life of fresh-cut beet leaves

Abstract

Fresh-cut horticultural products have a very limited shelf-life and have been associated with several foodborne illnesses. In previous studies, natural antimicrobials green tea (GTE) and nisin have shown great effect on microbial control, while modified atmosphere packaging (MAP) with modified initial atmosphere (MIA) was great for nutritional preservation. The aim of this study was to select an adequate combination of those treatments to enhance safety, quality, and shelf-life of fresh-cut beet leaves. Results shows synergistic behavior with the combination of 2.5% GTE, 500 UI/g nisin and MAP with MIA for native microbiota, Listeria, and Escherichia coli control. During refrigerated storage, combined treatment showed a significant reduction in microbial counts and generate a “fortification” increasing greatly its total polyphenols content and antioxidant capacity. While control samples presented a shelf-life of less than 7 days, an adequate combination of technologies improved greatly the overall quality and prolonged shelf-life to at least 14 days. Practical applications: In the context of a growing demand for healthy, nutritious, minimally processed, free of additives, and environmentally friendly products, this study proposes the use of the modified atmospheres packaging technology in combination with the application of natural antimicrobials to improve overall quality and enhance safety of minimally processed vegetable products. The combination of these two technologies for the preservation of minimally processed beet leaves has proven to be an alternative that not only allows microbiological control of the product, but also causes a significant improvement in nutritional and sensory quality. The results presented in this study have a clear practical application in the minimally processed vegetable industries. Indeed, developments as the one presented in this research are needed by the industry to reach the demanding requirements of consumers as well as the new regulatory requirements and to increase the added value of this kind of products.