Improvement of hydration properties of pectin/nanochitosan films

Abstract

This study aims to develop hydration properties of pectin/nanochitosan films at different pectin: nanochitosan ratios (100:0; 75:25; 50:50; 25:75 and 0:100). The blending of pectin with nanochitosan at ratio of 50:50 (P/NaCS2) reduced moisture content, swelling degree, water solubility. Moisture sorption isotherms for all P/NaCS films had a sigmoidal shape. Moisture sorption isotherms indicated hydrophobic character of P/NaCS films. Moisture sorption isotherm showed that P/NaCS films should be used at lower than 86%RH. Some models such as GAB, BET, Peleg and Oswin were investigated for predicting the equilibrium moisture content of P/NaCS films. The results showed that the GAB model was the best estimator. SEM micrographs of cross - section morphology of P/NaCS films indicated that certain interactions between pectin and nanochitosan matrix were formed. Therefore, P/NaCS2 films can be used as active packaging to extend the shelf life of food.