Green tea-infused chitosan/pectin bionanocomposites with TiO₂ for sustainable active food packaging

The study focuses on the fabrication of multifunctional food packaging membranes consisting of Chitosan (CS) and Pectin (PC) as the polymer blend reinforced with TiO 2 nanoparticles (NPs) integrated with green tea extract (GTE). For this purpose, four films (GTE 1–GTE 4) were created by combining GTE, which were extracted using different conditions. Results indicated that the physicochemical and functional properties of CS/PC blended membranes were improved by adding TiO 2 NPs and GTE. Scanning Electron Microscopic (SEM) images showed reduced surface roughness and minimized particle agglomeration in the presence of GTE compared to the CS/PC/TiO 2 film. The incorporation of TiO 2 NPs and GTE has notably enhanced the thermal and mechanical properties of the films. Furthermore, films integrated with GTE and TiO 2 NPs demonstrated enhanced water and oil barrier properties, accompanied by a reduction in moisture content, water absorption, and surface hydrophilicity upon incorporating GTE. In addition, the combined incorporation of TiO 2 and GTE significantly reduced light transmission in the visible region. The GTE 4 film exhibited the highest antioxidant activity among all tested films. The antibacterial activity was evaluated using the disc diffusion method against Gram-positive ( Bacillus sp .) and Gram-negative ( Escherichia coli ) bacteria. The GTE 4 film, demonstrated effectiveness against both types of bacteria. Additionally, pH-dependent color changes were observed in GTE 4, indicating its potential applications as a pH-sensing food packaging material. GTE 4 was also employed for packaging red grapes to extend their shelf life, and the results highlighted the film’s potential for active packaging applications, highlighting its enhanced functional properties.