Evaluation of physicomechanical and release properties composite polymers containing catechin natural antioxidant

Chitosan is a natural polymer that is typically extracted from the marine crustacean chitin shell and capable of film forming. Polyvinyl alcohol is a synthetic and biodegradable polymer that can be used in combination with natural polymers to improve structural properties. Chitosan nanoparticles were produced by ion gelation  method and the nanoparticles with an average size of 69.92 nm and a zeta potential of + 30.3 mV were used for application in the composite films. After mixing different ratios of polyvinyl alcohol (P) with chitosan (C) (1: 3, 1: 1 and 3: 1), the resulting solutions with different ratios of nanoparticles (np) (0, 2, 4, 6) ml of chitosan gel In 100 ml of film  forming solutions were mixed and glycerol was added to 25% w / w dry film powder and then poured into mold and dried in oven at 40 ° C. The results showed that increasing the ratio of polyvinyl alcohol and application of nanoparticles in polymer structure improved the physico-mechanical properties of the films. Fourier transform infrared spectroscopy results showed that some interactions have taken place between the polymer network and the nanoparticles. Thermogravimetric analysis results showed that the addition of nanoparticles slightly increased thermal stability of the polymers compared control samples without nanoparticles. Release results in the high-fat and low-fat food simulant showed that the release rate decreased with increasing polyvinyl alcohol ratio. Also, increasing the nanoparticle to np4 ratio decreased the release rate. The aim of this study was to determine the optimum ratio of two polymers and the amount of chitosan nanoparticles containing natural antioxidant catechin for use in food packaging.