Enhanced fresh-cut moso bamboo shoot preservation using chitosan films reinforced with cinnamon essential oil emulsion stabilized by cellulose nanofibers prepared by different methods: A comparison

Lignification and quality deterioration caused by high moisture content and physiological activity remain key challenges in postharvest bamboo shoots management. In this study, cellulose nanofibers were successfully extracted from juvenile pomelo residue (PCNFs) using two methods: ultrasonication (UCNF) and TEMPO oxidation (TCNF). The enhancement effects of the two CNF-stabilized CEO emulsions on chitosan (CS) films and the performance of the corresponding composite films in fresh-cut moso bamboo shoots preservation were compared. TEM results confirmed that UCNF formed a denser fiber network, which contributed to the highest tensile strength and Young's modulus in both dry and wet states, as well as the lowest oxygen permeability, rendering the film suitable for packaging foods with high moisture content. In contrast, the stronger interaction between TCNF and CS further enhanced the water resistance and water vapor permeability of the composite film. TCNF had a higher degree of crystallinity (73.89%) and emulsification capacity than UCNF, leading to enhanced thermal stability and antimicrobial performance (especially stored at 4 °C) in TCNF-based films. Furthermore, the composite films effectively extended the shelf life of fresh-cut bamboo shoot slices. The TCNF/CEO-CS coated group demonstrated the highest preservation efficacy: significantly reducing nutrient loss (e.g., total and soluble sugars), suppressing the activities of browning-related enzymes (due to the slow release of CEO), and delaying the increase in cellulose and lignin content associated with lignification. These findings not only confirm the potential of CNF-stabilized emulsions in enhancing chitosan-based films for bamboo shoot preservation but also provide theoretical guidance for developing biodegradable preservation materials with different CNF structures.