Abstract:Fatty acids (FAs) and normal corn starch (NCS) complexes prepared by the HCl/KOH method, were analyzed for in vitro digestibility in terms of the curve for degree of hydrolysis. Additionally, the crystal structure was analyzed using an X-ray diffractometer and a Fourier-transform infrared (FTIR) spectrometer. The results identified seven fatty acids that exhibited the strongest complexation capability with corn starch at the crystallization temperature of 60 ℃. FT-IR spectroscopy confirmed FA-NCS complexation. Except for linolenic acid, the optimal complexation ratio for the six remaining FAs to NCS was 10:1. The time to form inclusion complexes with corn starch varied between the FAs. With increasing chain length and degree of unsaturation, the complexation ability of the FAs with NCS decreased gradually and the content of slowly digestible starch increased, whereas the hydrolysis rate, relative digestion rate, and glycemic index decreased. After forming complexes with FAs, the crystal structure of NCS changed from A to VI, while the degree of crystallinity decreased gradually with increasing FA chain length and degree of unsaturation.
