The combined effects of lysozyme and ascorbic acid on microstructure and properties of zein-based films

Abstract Edible zein-based films containing lysozyme (LY) and ascorbic acid (AA) were developed in the presence of polyethylene glycol 400 (PEG 400), the combined effects of LY and AA on the microstructure, mechanical properties and release properties of developed zein films were investigated in detail. The results of microstructure characterization indicated that zein-based films became compact and smooth, and LY aggregates were well distributed in the zein matrix because of the simultaneous addition of LY and AA. The results of mechanical tests showed that because of the synergistic effects of LY and AA on zein film, elongation at break of zein-based film could be up to 138%, which was 34.5 times higher than that of zein control film. LY release tests showed that when the concentration of AA was less than 3.1 mg·cm − 2 , the release rate of LY significantly decreased by 33.7%, and the total release increased by 80.6%. While the release profiles of AA showed that the release rate and total release of AA from the films containing LY increased by approximately 68.9% and 61.7% than the films without LY. Good antioxidant and sustained antimicrobial activities were found for the developed zein films.