Enhanced antibacterial and antioxidant activities of chlorogenic acid loaded sweet whey/starch active films for edible food packaging

Starch and whey protein are potential biomaterials for the development of biodegradable and edible food packaging. In this study, chlorogenic acid (CGA), an eco-friendly natural extract, was firstly added to sweet whey/starch matrix as a bioactive compound to develop biodegradable active packaging materials. The results showed that when the ratio between starch and sweet whey was 10:1, water resistance and toughness of sweet whey/starch blend films were improved significantly. After the addition of CGA, the active films showed excellent UV barrier, antibacterial and antioxidant properties. When the addition of CGA reached 3%, UV barrier (at 315 nm), antibacterial (against Escherichia coli) and antioxidant (ABTS method) properties of the active films were increased by 54.6%, 47.5% and 74.5% compared with sweet whey/starch matrix. The presence of CGA could form new hydrogen bonds in the matrix and affect the interactions between sweet whey and starch, which increased swelling rate and toughness of the active films. Preservation experiments of fresh bananas could indicate that the presence of CGA can effectively exert antioxidant effects and inhibit the browning of bananas. As an edible inner coating or film, CGA loaded sweet whey/starch active material has good application potential in the field of food packaging.