Effects of different treatment methods on properties of potato starch-lauric acid complex and potato starch-based films.

The effects of different treatment methods on the physicochemical properties of potato starch (PS) and PS-based films were studied. The complexing indices of PS-lauric acid (LA) complexes followed the order: pullulanase debranching (PD) > ultrasound treatment (UT) > dimethyl sulfoxide heating (DSH) > Control. Light microscopy showed that PS-LA complexes exhibited irregularly shaped fragments. X-ray diffraction indicated that the diffraction intensity of the PD sample was stronger than that of the other samples. The melting enthalpies (△H) of the DSH, UT and PD samples were higher than that of the Control. PD sample had the lowest enzymatic-hydrolysis rate among all of the tested samples. PS-LA composite films showed higher tensile strength, lower elongation at break, and lower moisture permeability than native starch-based film, and the films prepared by PD method had the highest tensile strength and lowest water vapour permeability among all of the tested films.