Chickpea flour‐based biofilms containing gallic acid to be used as active edible films

ABSTRACT Chickpea is an easily accessible nutritious legume. Besides, gallic acid is a widespread phenolic found in various plants. In this study, it is aimed to investigate the effects of pH (9 and 11), glycerol concentration (1 and 3% w/v of film solution) and gallic acid concentration (5 and 10% w/w of total solid) on color, opacity, mechanical strength, water vapor permeability (WVP), microstructure, chemical characteristic, antioxidant activity, and phenolic content of films. At pH 11, films are stronger, darker and have higher antioxidant activity. Higher glycerol concentration makes the films more flexible but less strong and more hydrophilic. Higher gallic acid concentration makes great contribution to the films by decreasing WVP but by increasing opacity, antioxidant activity, phenolic content, lightness, and elongation. Film containing glycerol of 1% and gallic acid of 10% and prepared at pH 11 was found to be a great combination for obtaining antioxidant rich edible composite films. HIGHLIGHTS Chickpea flour‐based active films were successfully obtained with addition of gallic acid. Higher gallic acid concentration decreased WVP, increased opacity, antioxidant activity, phenolic content, lightness, and elongation. Higher pH provided stronger mechanical properties, low lightness, and higher antioxidant activity. Lower glycerol concentration resulted lower WVP and stronger tensile properties. Chickpea flour‐based active films at pH 11 with 1% glycerol and 10% gallic acid can be used as active packaging material in especially highly oxidative food products. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47704. Cross‐sectional image of SEM micrograph of chickpea flour‐based biofilm containing gallic acid (%10 w/w) with %3 w/v glycerol at pH 11