Development and characterization of biodegradable films from whey protein concentrate, psyllium husk and oxidized, crosslinked, dual-modified lotus rhizome starch composite

BACKGROUNDThe combined effect of variously chemically modified lotus rhizome starch, whey protein concentrate, psyllium husk and glycerol was evaluated on developed biodegradable films. RESULTSDual-modified lotus rhizome starch composite films presented minimum solubility and water vapor permeability and maximum tensile strength among native and modified starch composite films. Elongation at break of dual-modified starch composite films (FLCOS1, FLCOS2) was found to be a maximum, whereas a decrease was observed for FLCOS3. Oxidized lotus rhizome starch composite films were the most transparent among native and modified starch composite films, whereas crosslinked lotus rhizome starch composite films were the least transparent. Scanning electron microscopy indicated a homogeneous compact surface of oxidized starch composite films, whereas troughs were observed in crosslinked and dual-modified starch composite films. Using whey protein concentrate, psyllium husk and glycerol without any phase separation, smoother films and with compact microstructures were produced. Fourier transform infrared analysis revealed additional peaks for modified starch films, confirming greater interaction among starch and film-forming components, whereas amorphous structure was indicated from X-ray diffraction results of modified starch composite films. CONCLUSIONSOwing to various properties of modified starches, these films find application in edible contact packages and can better be used for products where higher structural integrity and lower water vapor transmission are needed. (c) 2019 Society of Chemical Industry