Valorization of wheat bran and corn husk via steam explosion for antioxidant starch/poly(butylene...

Guided by the Field-Film-Field (F-F-F) eco-circular strategy, in which agricultural by-products from the field are converted into functional films and ultimately returned to the field as biodegradable mulch, this study investigated the effects of incorporating steam-explosion-modified wheat bran and corn husk into starch/PBAT films. The results demonstrated that the incorporation of these biomass fillers, even at low loading levels, effectively enhanced the mechanical properties, water resistance, and gas barrier performance of the films. Compared with the control, the film containing 1% (w/w) corn husk exhibited the best overall mechanical performance, with tensile strength and elongation at break increasing by 11.9% and 12.0%, respectively, while the water contact angle increased from 72° to 88°. In contrast, films containing 5% (w/w) biomass fillers displayed excellent gas barrier performance and antioxidant activity. In a fresh-cut potato packaging trial, the active films reduced the peak activity of polyphenol oxidase (PPO) by 20%, effectively retarding enzymatic browning and helping maintain sensory quality. Furthermore, soil germination experiments with tobacco seeds indicated that the film degradation products exhibited no phytotoxicity and showed potential to serve as a "carbon fertilizer" that promotes seedling growth. Overall, this study demonstrates the feasibility of an F-F-F closed-loop utilization strategy for agricultural by-products, providing a promising technical pathway for the development of low-cost, biodegradable, and functional food packaging materials.