Effect of gelatin type on the structure and properties of microfibrillated cellulose reinforced gelatin edible films

Abstract

AbstractThe physical and mechanical properties of gelatin edible films need to be significantly improved to meet the increasing requirements of food and pharmaceutical industry. This study investigates the effect of gelatin type on the structure and properties of glycerol plasticized gelatin films reinforced by microfibrillated cellulose (MFC). Results indicate that the tensile strength of type‐A and type‐B gelatin (GelA and GelB) films increases by 48% and 90% respectively at an optimum MFC content of 15 wt% in comparison to control gelatin films without MFC. The incorporation of MFC also has a more pronounced impact on optical properties and moisture absorption capability of GelB films than on those of GelA films. Scanning electron microscopy and polarized optical microscopy studies show that the MFC fibrils are uniformly distributed in both types of gelatin matrices. X‐ray diffraction and attenuated total reflectance‐Fourier transform infrared analyses reveal that the interactions between MFC and GelB are stronger than those of between the MFC and GelA. The mechanism behind the more significant mechanical performance improvement of GelB films by the addition of MFC is speculated to be that stronger hydrogen bonding interactions contribute to enhanced structural integrity and stability of the gelatin‐based films.