Chitosan-Based Aerogel Cushioning Packaging for Improving Postharvest Quality of Wax Apples

Mechanical damage and microbial contamination are major challenges in the postharvest logistics of perishable fruit. In this study, two types of functionally modified chitosan-based aerogel pads were developed to enhance cushioning and preservation of wax apples. A chitosan/polyvinyl alcohol (CP) aerogel was first optimized by adjusting solid content, CS:PVA ratio, and crosslinker concentration. The optimal formulation (2% solids, 1:1 CS: PVA, 3% glutaraldehyde) exhibited a uniform porous structure and improved compressive strength. A chitosan/montmorillonite (CM) aerogel with 5% montmorillonite (MMT) showed high porosity, low density, and excellent cyclic stability. Incorporating 10% copper nanoparticle-loaded antibacterial fibers (CuNPs-TNF) into CM aerogels yielded CM-Cu aerogels with enhanced cushioning and antimicrobial properties. Under simulated transport and cold storage conditions, all aerogel-packaged groups reduced mechanical damage and decay of wax apples. Compared to the control, the CM-Cu group showed 66% lower decay, 5% less weight loss, 6 N greater firmness, 7% less juice yield, and a 13% reduction in relative electrical conductivity. Additionally, it better preserved fruit color and total soluble solids, extending shelf life by 4 d at 20 °C. These results demonstrate the potential of chitosan-based aerogels as multifunctional packaging materials that combine mechanical protection with antimicrobial activity for perishable fruit preservation.