Effects of glycerides with different molecular structures on the properties of maize starch and its film forming capacity

Abstract

To investigate the effect of glycerides with different molecular structures on the properties of maize starch (MS) and its film forming capacity, the complexing index, swelling power, diffraction patterns and thermograms of MS-glyceride complexes were measured, and the moisture resistance and mechanical properties of MS-based films were studied. The glycerol monolaurate (GML) more strongly interacted with amylose molecules than did glycerol monostearate (GMS) or glycerol tristearate (GTS). The swelling power of MS decreased with the addition of glycerides. X-ray diffraction demonstrated that the diffraction intensities of amylose-lipid inclusion complexes decreased with increasing acyl chain lengths and increased as the number of stearyl chains increased. Addition of glycerides inhibited the gelatinization process of native MS. The melting enthalpies (△H) of amylose-lipid complexes followed the order: GML > GTS > GMS. MS-based film with glycerides showed higher tensile strength values, lower elongation at break values and better moisture resistance than native starch-based film. The composite film with GML showed better mechanical properties and moisture resistance than the composite film with GMS and GTS.