Improvement of barrier properties of fish gelatin films promoted by gelatin glycation with lactose at high temperatures

Glycation has been used as a natural method for protein modification. Fish gelatin-based films were prepared at pH 10 by mixing gelatin with different lactose concentration and plasticized with glycerol. The influence of lactose content and temperature was analyzed in order to prepare biodegradable films for food packaging. All films obtained were transparent and showed higher tensile strength than other protein-based films. Furthermore, films with lactose and heat-treated to promote the glycation reaction improved both water and light resistance. The effect of lactose addition and temperature was explained by solubility tests, Fourier transform infrared (FTIR) spectroscopy and UV-vis spectroscopy. Results indicated that film solubility noticeably decreased as a consequence of glycation, highlighting the potential of these modified fish gelatin films as food packaging materials in high humidity environments.