A synergistic influence of gallic acid/ZnO NPs to strengthen the multifunctional properties of methylcellulose: A conservative approach for tomato preservation.

Biodegradable and sustainable food preservation materials have gained immense global importance to mitigate plastic pollution and environmental impact. Biopolymers like cellulose offer significant advantages for food preservation, including biodegradability and the ability to extend shelf life. Therefore, the present study aims to prepare gallic acid (GA) and zinc oxide nanoparticles (ZnO NPs) incorporated methylcellulose (MC) composite films by employing a solvent casting technique. The homogeneous SEM micrographs and FTIR spectra evidenced high compatibility among MC and GA/ZnO NPs. The UV barrier capacity, mechanical properties and surface hydrophobicity are remarkably enhanced by GA/ZnO NPs. However, the water vapour permeability and oxygen permeability of MGZ films were reduced by 49.19 % and 57.75 % respectively. Moreover, the MGZ films demonstrated exceptional antioxidant efficacy (∼94.48 %) and inhibition against food-borne pathogens such as B. subtilis, S. aureus (Gram-positive), E. coli, P. aeruginosa (Gram-negative), and C. albicans fungi. Furthermore, the GA/ZnO NPs extended the shelf life of MGZ coated tomato samples up to 27 days and exhibited controlled microbial growth after the preservation study. These results support the application of MGZ films as suitable and effective coating materials for food packaging applications.

Physicochemical and antioxidant properties of tannic acid crosslinked cationic starch/chitosan based active films for ladyfinger packaging application.

In the present study, cationic starch (CS)/chitosan (CH) incorporated with tannic acid (TA)(CSCT) eco-friendly films were prepared by employing an inexpensive solvent casting technique. Influence of TA on the physicochemical and antimicrobial properties of CS/CH polymer matrix were studied. The FTIR findings and homogeneous, dense SEM micrographs confirms the effective interaction of TA with CS/CH polymer matrix. CSCT-3 active film displayed tensile strength of 26.99±1.91 MPa, which is more substantial than commercially available polyethylene (PE) (12-16 MPa) films. The active films exhibited excellent barrier properties against moisture and water, supported by increased water contact angle values (86.97±0.29°). Overall migration rate of active films was found to be below the permitted limit of 10mg/dm2. The active films showed around 56% of degradation in soil within 15 days. Besides, the active films showed concurring impact against food borne pathogens like E. coli, S. aureus and C. albicans. The CSCT-3 active film presented 90.83% of antioxidant capacity, demonstrating the effective prevention of food oxidation related deterioration. Ladyfinger packaging was inspected to examine the ability of active films as packaging material resulted in effectively resisting deterioration and extending shelf life in comparison with traditional PE packaging.