Structure-property relationships in edible starch films: Roles of acetylation, cross-linking, oxidation, and dual modifications

Abstract

This study systematically investigated the effects of chemical modifications (acetylation, oxidation, cross-linking, and their dual combinations) on the key properties of starch-based edible films. The optimal formulation was identified as the oxidized-crosslinked starch (OCS) film. Compared to native starch film, the OCS film exhibited 35.6 % reduction in water vapor permeability and 225 % increase in tensile strength. When applied to graded Huangguan pears, the OCS coating significantly reduced weight loss (22.0 % decrease after 28 days), delayed the decline in total phenolic content (28.7 % increase after 28 days), and effectively suppressed the activities of POD and PPO. These findings provide both a theoretical foundation and technical support for the application of chemically modified starch films in fruit preservation.