Development and antioxidant stability of edible films supplemented with a tamarind seed extract

This study was conducted in order to evaluate the effects of the incorporation of tamarind seed extract (TSE) into previously optimized biodegradable edible films made with native potato starch (NPS) and whey protein isolate (WPI). Variations on mechanical, antioxidant and colour properties were evaluated over storage. First, films were formulated using the response surface methodology, modifying three factors: pH, denaturation temperature of WPI, and the amount of glycerol (Gly) as a plasticizer. The combination of 6.2% Gly at pH of 7.9 and temperature of 76°C provided the optimal elongation (%ɛ), as well as, tensile strength (s) and Young’s elastic modulus (E). The TSE was added to the optimized edible films contained polyphenols (187±0.11 mg GAE/g) and antioxidant activity (62.5±0.04% DPPH• and 45.6±0.14% ABTS+• radicals).

Keywords: edible film, tamarind seeds, antioxidant activity, whey protein isolate-native, potato starch.