Preparation and characterization of antioxidant edible chitosan films incorporated with epigallocatechin gallate nanocapsules

Antioxidant edible films based on chitosan hydrochloride (CHC) and epigallocatechin gallate (EGCG)-loaded nanocapsules (NCs) were developed. The CHC films incorporated with NCs were prepared by a casting method in three different proportions. The obtained films were characterized using the techniques including scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. Meanwhile, the mechanical and color properties, optical transmittance, EGCG release profile and antioxidant activity were also determined. The addition of NCs to CHC films increased their tensile strength (TS) and the percent elongation at break (%E). Lightness was significantly decreased in the NCs embedded films compared to controls, which in turn led to high antioxidant activity and excellent barrier properties against visible light. EGCG was rapidly released into food simulant although the concentration fluctuates over time. Therefore, these films can prevent the oxidation of fatty food stuffs.