Gas Permeability Changes in Biodegradable Films and Litchi Preservation Performance

This study developed biodegradable Poly (butylene adipate‐co‐terephthalate) (PBAT)‐based composite films with tunable gas permeability by adjusting polylactic acid (PLA), polypropylene carbonate (PPC), calcium carbonate (CaCO 3 ), and talc ratios to enhance litchi preservation. The quality of litchis was assessed through various metrics, including apparent morphology, sensory evaluation, decay rate, color difference, weight loss, sugar content, respiration rate, ethylene content, and microbial diversity. Films with moderate gas permeability, specifically WVTR of 64–104 g/(m 2 day), OTR of 19–352 cc/(m 2 day), and CDTR of 8000–17,000 cc/(m 2 day), showed optimal performance by effectively inhibiting mold growth while preserving sensory quality (color, flavor, texture). Hydrophilic films preserved pericarp moisture and vibrancy, whereas hydrophobic variants accelerated dehydration. Microbial analysis revealed that Film 1# maintained closest similarity to the microbiota of fresh pericarps, thereby delaying spoilage. These gas‐selective films balanced respiration and ethylene production and extended shelf life by regulating microbial communities and physiological activity. These findings highlight the critical role of gas permeability modulation in designing eco‐friendly packaging to mitigate postharvest losses in perishable fruits.