羧甲基壳聚糖/氧化羧甲基纤维素/姜黄素复合膜的制备及其在草莓涂膜保鲜中的应用

A water-soluble chitosan hydrogel, carboxymethyl chitosan/oxidized carboxymethylcellulose/curcumin (CMCHS/OCMC/CR) ternary composite, was prepared by the casting method. FTIR and SEM showed that the cross-section structure of the composite film was uniform without stratification, but the surface roughness was higher than that of the CMCHS/OCMC film. Compared to the film with no curcumin, CMCHS/OCMC/CR showed better fracture stress (20.10 MPa), elongation at break (18.97%), anti-fungal properties (Aspergillus niger inhibition zone 15.33 mm, Penicillium inhibition zone 14.58 mm), and water vapor permeability (2.11×10^-3 g·m^-1·kPa^-1·h^-1). The film-coating experiments indicated that coating with CMCHS/OCMC/CR composite could effectively decelerate the weight loss as well as the decrease in titratable acid, soluble solids, and reducing sugar contents in strawberry during storage. After storage for eight days, the weight loss rate of strawberry in the CMCHS/OCMC/CR group decreased by 11.38% and 1.27% compared to those in the blank and positive control groups. Moreover, the hardness, titratable acid, soluble solids, and reducing sugar of strawberry in the CMCHS/OCMC/CR group decreased by 10.00%, 42.72%, 7.39%, and 9.32% compared to the blank control and by 5.54%, 7.42%, 2.39% and 11.12% compared to the positive control, respectively. Therefore, the CMCHS/OCMC/CR (1%, m/m) composite film showed good preservative effects of color preservation and inhibition of mold growth and could be used as an effective antibacterial coating material in food packaging materials.