An Active Film Based on Glutaraldehyde‐Cross‐Linked Polyvinyl Alcohol and Tea Polyphenol Microcapsules: Application in the Controlled‐Release Preservation of Blueberries

ABSTRACT To address the quality deterioration of blueberries caused by high metabolism after harvest, this study constructed a composite cling film system based on tea polyphenol microcapsules (TPMCs) synergized with glutaraldehyde‐cross‐linked polyvinyl alcohol (GA‐PVA). Using a solvent evaporation–response surface optimization coupling technique, the TPMCs, fabricated with tea polyphenol (TP) at its core and ethyl cellulose (EC) as the encapsulating layer, achieved an embedding rate of 82.28 ± 1.3%, exhibited a uniformly dispersed spherical morphology ( D = 44.2 μm), and demonstrated excellent antioxidant, slow‐release and bacteriostatic properties. The GA‐PVA‐TPMC composite film (6% TPMCs) demonstrated outstanding overall performance, including mechanical properties, thermal stability and barrier performance. Shelf‐life testing revealed that the film helped preserve blueberries for approximately 6 days by adjusting the surrounding gas balance, inhibiting the intensity of fruit respiratory metabolism (24.1%), synergistically scavenging reactive oxygen species to maintain fruit firmness, and reducing the levels of total phenols and titratable acids. Under simulated shelf‐life conditions, the film system demonstrated sustained antioxidant and barrier performance, contributing to intelligent post‐harvest management of fruits and vegetables through a resource‐efficient and sustainable approach.