Development and evaluation of titanium dioxide/chitosan nanocomposite coatings for enhanced food preservation and nutrient retention

This study investigated the development and application of TiO₂/chitosan nanocomposite coatings for food preservation, focusing on their physicochemical properties and preservation efficacy. The nanocomposite synthesis achieved uniform particle dispersion with an average size of 85 ± 5 nm and zeta potential ranging from + 35.2 mV to + 42.8 mV. FTIR analysis revealed characteristic coordination bonds at 1384 cm-1 between Ti atoms and chitosan amino groups, while XRD patterns confirmed successful incorporation of TiO₂ nanoparticles without phase transformation. The optimal formulation (1.0 % TiO₂) demonstrated remarkable preservation effects, reducing respiratory activity by 42 % compared to controls and maintaining peroxidase activity 65 % lower than untreated samples. MDA levels in treated samples remained at 1.68 μmol/kg compared to 4.25 μmol/kg in controls after 15 days. The nanocomposite coating effectively suppressed microbial growth, maintaining total aerobic counts below 3.5 log CFU/g throughout storage, while preserving essential nutrients with 78 % retention of ascorbic acid content. The addition of thymol enhanced antimicrobial efficacy, generating inhibition zones of 18.5 mm against E. coli. The coating's stability was maintained over 30 days with less than 5 % variation in particle size distribution, demonstrating its potential for commercial food preservation applications.