Development of modified starch/sodium alginate films incorporating black rice extract: Application and efficacy...

To address the rapid lipid oxidation and quality deterioration of coated peanuts during storage, an edible film based on a heterogeneous acetylated starch‑sodium alginate matrix loaded with black rice anthocyanin extract (BRA) was developed in this study, and the content of BRA was optimized. When the BRA content was 0.75‰, the film exhibited the most uniform and dense microstructure. It showed excellent mechanical strength, improved thermal stability and optimal light/water vapor/oxygen barrier performance. Films with different BRA loadings were further applied to coated peanuts, followed by accelerated oxidation of the film-treated samples under thermal and UV conditions. The films achieved stable coverage on the surface of coated peanuts and achieved high sensory acceptance. After 20 days, the films not only improved the retention rate of anthocyanins by 30%, but also slowed down the oxidative deterioration of the samples. The films significantly inhibited the increases in peroxide and acid values, reducing them by 17-31% and 12-21%, respectively, compared to the control. Furthermore, the films effectively maintained the unsaturated fatty acid profile by mitigating lipid degradation. Meanwhile, these films effectively maintained the appearance, color, flavor and texture of the samples, with the film containing 0.75‰ BRA achieving the highest overall sensory acceptance. In general, this film combined physical barrier protection with the antioxidant activity of BRA to maintain the overall quality of coated peanuts.