Dual‐Modified Elephant Foot Yam Starch/Polyvinyl Alcohol Biocomposite Films Incorporated With Anthocyanins for Intelligent Freshness Monitoring of Mushrooms

Abstract

Environmental concerns over conventional plastics have accelerated the development of biodegradable intelligent packaging for real‐time food quality monitoring, particularly for highly perishable mushrooms. In this study, a pH‐responsive film was developed by blending elephant foot yam starch modified by sequential ultrasonication and acetylation (EFYS) with polyvinyl alcohol (PVA) and incorporating anthocyanin‐rich Hibiscus rosa‐sinensis extract (HBE). LC–MS/MS‐QTRAP analysis identified 17 metabolites, including anthocyanins, pelargonidin‐, and cyanidin‐derived anthocyanins responsible for pH sensitivity and bioactivity. Films containing 0%–4% HBE were evaluated for physicochemical, mechanical, structural, optical, antioxidant, and antimicrobial properties. Increasing HBE content enhanced thickness, swelling, solubility, redness, and color difference, while reducing intrinsic water vapor permeability. UV–visible (vis) spectra analysis confirmed distinct and pH‐dependent color changes across a wide pH range (pH 1–12). Structural characterization (FTIR, FE‐SEM, TGA, and XRD) indicated improved intermolecular interactions, reduced crystallinity, and enhanced flexibility, with only a slight reduction in thermal stability. The films exhibited dose‐dependent antioxidant and antimicrobial activity and showed clear colorimetric responses to pH changes associated with mushroom spoilage. These findings demonstrate the potential of HBE‐functionalized EFYS/PVA films as sustainable intelligent packaging materials for real‐time freshness monitoring.