In vitro Antioxidant Properties of E uryale ferox Seed Shell Extracts and their Preservation Effects on Pork Sausages

Abstract

Seed kernels of Euryale ferox are considered a healthy food product in China, and the shells containing high levels of polyphenols are currently unused. To examine the utilization of these by-products, three extracts were obtained from E. ferox seed shells (EFSS) using different solvent systems (EEA, EE-100 and EE-50 extracts). The major composition of the phenolic compounds in these extracts, their in vitro antioxidant properties and their preservative effects on pork sausages were investigated. The major phenolic compounds were gallic acid, epicatechin and rutin. Each extract exhibited strong antioxidant properties, high radical scavenging capacity and inhibition of lipid peroxidation. EE-50 was found to inhibit pH increases and prevent sausage products from lipid oxidation during storage. Furthermore, EE-50 was more effective when used in combination with monascus and NaNO2. The results suggest that EFSS extracts are a potential source of natural antioxidants and could be used for preservation of meat products. Practical Applications Euryale ferox seed shell is the main by-product of E. ferox seed processing. The production of E. ferox seed shells is in the range of dozens of tons in China every year and this component is currently unused. Previously, I found that the seed shells contain high levels of polyphenols. Here, I show that extracts of E. ferox seed shells have significant antioxidant properties and contain high levels of rutin and catechin compounds. Thus, E. ferox seed shells can be a source of natural and functional antioxidants and serve as an alternative to synthetic antioxidants in food processing.