Enhanced fresh walnut preservation using chitosan films reinforced with cinnamon essential oil and bacterial cellulose pickering emulsion
Fresh walnuts are prone to browning and microbial spoilage post-harvest due to their high water content and enzyme activity. Although chitosan-based preservation materials shows great potential for the preservation of fruits and vegetables, their effectiveness is hindered by limited antibacterial, antioxidant, and mechanical properties. In this study, a novel biomass composite film was developed by integrating bacterial cellulose (BC) stabilized cinnamon essential oil Pickering emulsion (CEO-BC-PEs) into chitosan (CS) through hydrogen bonding. The physicochemical characteristics, biodegradability, antioxidant capacity, and antibacterial properties of the CS-BC-CEO composite film were evaluated, and its preservation effect on fresh walnuts was assessed. Results indicated that hydrogen bonding between the CEO-BC-PEs and the CS matrix significantly improved the composite film's thermal stability, mechanical strength, and barrier properties. Specifically, the incorporation of CEO-BC-PEs enhanced the tensile strength (TS) and elongation at break (EAB) by 51.24% and 28.79%, respectively, while reducing water vapor permeability (168.19 mg mm·kPa −1 ·h −1 ·m −2 ) and ultraviolet light transmittance (<75%). Additionally, the film demonstrated excellent antioxidant activity (up to 60%), antibacterial efficacy (up to 65%), and biodegradability. When used for preserving fresh walnuts, the composite film effectively reduced nutrient loss, delayed lipid oxidation, and suppressed the activity of browning-related enzymes, thereby significantly extending the shelf life of the walnuts. These findings highlight the potential of the CS-BC-CEO composite film as a promising solution for fresh walnuts preservation and suggest its applicability in developing sustainable active biomass packaging materials.
危险品化学品经营许可证（带存储）