摘要
Engineered a TP/GB-assisted polysaccharide quaternary preservation coating. • Extended mango shelf life over 11 days via physiology and antibacterial action. • Identified C. siamense via morphology and Koch's postulates. • Revealed TP-enhanced binding of polysaccharide-CSH by molecular docking. • Confirmed ecological safety after washing using soil and aquatic bioassays. Climacteric mangoes suffer a short shelf life due to rapid postharvest nutrient loss and pathogen invasion. Herein, a strategy of quaternized chitosan (QCS)/cellulose nanocrystal (CNC) coating incorporating complementary glycine betaine (GB) and tea polyphenols (TP) functionalities was developed through integrated metabolic regulation and antifungal-antioxidant functionalities. The prepared QCS/CNC/TP/GB-10 coating exhibited water vapor permeability (WVP) of 0.41 × 10 −3 g m −1 ·kPa −1 ·h −1 and oxygen permeability (OP) of 0.10 cm 3 μm·m −2 ·d −1 ·kPa −1 , respectively, with improvements of 38.1% and 61.5% over QCS. The 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rate reached 91.93 ± 1.49%, 75.29% higher than QCS. Mangoes treated with QCS/CNC/TP/GB-10 extended shelf life by 11 days, with weight loss of 23.22 ± 0.83% and firmness loss of 32.69 ± 2.20%, respectively. The titratable acidity (TA) was maintained at 0.20%, significantly higher than controls (<0.07%). Colletotrichum siamense ( C. siamense ) was identified as the causal agent, and the QCS/CNC/TP/GB-10 coating achieved 67.02 ± 2.35% inhibition, 2.23-fold higher than QCS. Molecular docking suggested TP-assisted binding enhancement between QCS/CNC and the CSH protein of C. siamense , with GB showing limited contribution. Soil and aquatic organism models demonstrated no ecological risks of the coating solution. This study provides a design paradigm for developing promising polysaccharide-based coatings for climacteric fruit preservation.
危险品化学品经营许可证（带存储）