Preparation of corn starch-fatty acid complexes by high-pressure homogenization

Aqueous mixtures of defatted corn starch and different fatty acids were heated and processed with high-pressure homogenization to form starch-lipid complexes. A variety of fatty acids with chain lengths of 12-18 carbons and with varying degrees of unsaturation were studied regarding their ability to form amylose-lipid complexes. Linoleic acid (65.7%) displayed the greatest complex forming ability with defatted corn starch, followed by lauric acid (63.2%), oleic acid (62.2%), myristic acid (61.2%), palmitic acid (59.8%), and stearic acid (54.6%). The XRD analysis showed that the complexes presented the well-known V-helical type diffraction. DSC was used to analyze the thermal properties. Based on the 85-110 degrees C transition temperature and the 60-95 degrees C synthesis temperature, the experimental complexes are less ordered type I complexes. The in vitro digestibility studies indicated that long-chain saturated fatty acids increased digestibility more than the short-chain saturated and unsaturated fatty acids when in complex with defatted corn starch.