Physicochemical studies of defatted wheat starch complexes with mono and diacyl-sn-glycerophosphatidylcholine of varying fatty acid chain lengths

Starch inclusion complexes with mono- and diacyl-sn-glycerophosphatidyl-choline (GPC) having various acyl (myristoyl, palmitoyl, stearoyl) chain lengths were studied. The physicochemical properties, such as the iodine affinities; crystallinity; water sorption and thermal properties of the defatted starch inclusion complexes were examined. Iodine affinity and thermal properties of the complex showed that 1- or 2-monomyristoyl-sn-GPC had the highest complexing ability, followed by decrease with the increasing chain length of GPC. Fourier transform infrared spectroscopy (FT-IR) revealed an increasing peak area ratio at 1654 cm(-1), which is correlated with the increase in water sorption of starch-GPC. The water sorption and degree of crystallization strongly correlated with enthalpy value of starch gelatinization and starch-GPC complex formation. According to the Avrami equation, the retrogradation rate of starch-monoacyl-sn-GPC complex was slower than the starch-diacyl-sn-GPC complex during storage, whereas the retrogradation rates of 1- and 2-monomyristoyl-sn-GPC were the slowest among the GPCs. (C) 2003 Elsevier Science Ltd. All rights reserved.