Effect of soybean protein-isolate-catechin edible film and coating on the storage quality of bean bun

This study focused on creating an edible film and coating using soy isolate protein (SPI) and catechin (CC) composite, which were then applied to bean buns. The objective was to assess the changes in quality during storage. Initially, SPI films were enriched with different concentrations of CC (1%, 2%, 3%, and 4%) and were examined for their optical and barrier properties. The addition of CC improved the optical barrier of SPI films, resulting in reduced water vapor permeability (WVP) and oxygen permeability (OP), thereby enhancing their suitability for food preservation. Subsequently, the produced edible coatings were applied to bean buns to evaluate their impact on quality attributes and sensory evaluation. The results of the scanning electron microscopy (SEM) analysis showed that the SPI/CC coating exhibited a smoother and more compact surface compared to the uncoated sample. After 15 days of storage, the SPI/CC 3% coated samples displayed the lowest moisture loss of 4.6% and the lowest hardness of 342.97 ± 8.17 N. Additionally, the Avrami equation revealed a significant 31% reduction in crystallinity (K) when comparing the SPI/CC 3% coated samples to the uncoated samples. XRD measurements further confirmed the decrease in crystallinity of the coated samples, indicating that the SPI/CC coating effectively inhibits the aging of bean buns. Moreover, the SPI/CC coating enhances the antioxidant activity of the bean buns and prevents microbial deterioration. These findings suggest that the utilization of SPI/CC coating holds great promise for the preservation of bean buns.