Poly(butylene adipate-co-terephthalate) film coated with allicin-loaded sodium carboxymethyl cellulose for plum preservation

To delay postharvest quality deterioration and maintain the commercial quality of plums, a novel active packaging film was developed by coating poly(butylene adipate-co-terephthalate) (PBAT) film with sodium carboxymethyl cellulose (CMC) and incorporating an allicin-based preservation emulsion. The effects of the CMC concentration in the coating on the physicochemical properties of the composite films and their preservation performance for plums were investigated. The results showed that the film prepared with 1.0% CMC exhibited a uniform and compact coating structure, resulting in improved surface wettability, mechanical properties, thermal stability, and barrier properties against water vapor, oxygen, and carbon dioxide. Furthermore, plums packaged with the Allicin/CMC-1/PBAT film showed better appearance and greater color retention during storage, accompanied by slower decreases in hardness, springiness, and chewiness. The composite film effectively reduced the consumption of total soluble solids and titratable acidity and helped retain characteristic aroma compounds. In addition, the Allicin/CMC-1/PBAT film significantly inhibited malondialdehyde accumulation by 25.76% relative to the control group, while maintaining peroxidase activity and suppressing polyphenol oxidase activity during storage. These findings demonstrate that the PBAT film coated with sodium carboxymethyl cellulose containing an allicin emulsion offers a promising approach for developing biodegradable active packaging materials for postharvest fruit preservation.