Preparation and antioxidant activity of sodium alginate and carboxymethyl cellulose edible films with epigallocatechin gallate

The active edible films were prepared by incorporating epigallocatechin gallate (EGCG) into sodium alginate (SA) and carboxymethyl cellulose (CMC). The effects of EGCG addition on the physical and morphological properties of SA-CMC films were evaluated. Meanwhile, the release characteristics of EGCG from edible films and its antioxidant activity in fat food simulant (95% ethanol) were also detected. The results showed that the addition of EGCG could improve the tensile strength (TS) of edible films and reduce their elongation at break (E). Especially, the color of edible film added with EGCG deepened and the transmittance decreased. Scanning electron microscopy (SEM) images displayed that the films were dense and compact with a little roughness. Fourier transform infrared spectroscopy (FTIR) analysis indicated that the incorporation of EGCG into SA-CMC caused interactions occurring between SA-CMC and EGCG. In addition, the release and DPPH radical scavenging assay of incorporating EGCG in SA-CMC films showed that the obtained SA-CMC films with high EGCG content could release EGCG slowly and had strong antioxidant activity in fatty foods. Thus, incorporating EGCG into SA-CMC film was an effective way in order to develop active and environmental friendly packing materials for food industry. (C) 2019 Elsevier B.V. All rights reserved.