No abstract

With the massive use of cotton fibers in textile industries, the wastes produced have continuously increased, causing environmental problems. Valorization of these viable and sustainable cellulose sources may offer a variety of value-added products. Cellulose nanocrystals (CNCs) have gained attention as they are renewable, inexpensive, biocompatible materials with excellent properties that allow them to be used in many applications. In this study, CNCs were isolated from cotton linters by sulfuric acid hydrolysis, characterized by FTIR analysis for functional groups identification. XRD revealed a crystallinity value of 63.2 % with an identical peaks pattern to CNCs. TEM analysis illustrated rod-shaped structures in the nanorange. The degradation temperature for the CNCs was 170 oC based on TGA analysis.

Novel pectin-based films reinforced with crystalline nanocellulose (CNC) and activated with zinc oxide nanoparticles (ZnO NPs) were prepared by solvent-casting method. Film ingredients enhanced UV-blocking, thermal, and antibacterial properties of active films against well-known foodborne pathogens. Optimal active films exhibited higher mechanical, water vapor barrier properties compared to pristine pectin films. SEM confirmed the even distribution of CNC and ZnO NPs in pectin matrix and their interactions were proven using FTIR. Wrapping hard cheese samples artificially contaminated with Staphylococcus aureus and Salmonella enterica with the ternary nanocomposite film at 7 °C for 5 days significantly reduced the total population counts by at least 1.02 log CFU/g. Zn2+ migrating to wrapped cheese samples was below the specific limit (5 mg/kg), confirming their safety for food contact. Overall, ZnO/CNC/pectin nanocomposite films represent promising candidates for active food packaging as safe, eco-friendly alternatives for synthetic packaging materials.