Antioxidant and antimicrobial edible zein/chitosan composite films fabricated by incorporation of phenolic compounds and dicarboxylic acids

Edible films and coatings can not only function as barriers of water vapor, gases and volatile compounds but also serve as carriers of functional ingredients. Composite edible films fabricated with zein and chitosan as base materials and supplemented with phenolic compounds (ferulic acid or gallic acid) and dicarboxylic acids (adipic acid or succinic acid) were prepared. The composite films exerted better water vapor barrier and mechanical properties. While the recovery percentage of phenolic compounds from composite films was 71–84%, the recovery of dicarboxylic acids was 48–65%. The composite films also possessed antioxidant activities as shown by DPPH and ABTS free radical scavenging tests. The antimicrobial activity of composite film was demonstrated by using Staphylococcus aureus and Escherichia coli as test microorganisms.