Study on physicochemical properties, digestive properties and application of acetylated starch in noodles.

The physicochemical and digestive properties of acetylated corn starch with different degrees of substitution were studied, which were prepared by microwave pretreatment and acetate esterification. Native corn starch-wheat noodles, acetylated corn starch-wheat flour noodles and native wheat noodles were prepared and their properties were compared. The results showed that the transparency, condensation volume ratio, hydrophilicity and lipophilicity of modified corn starch increased with increasing of substitution degree, which were 4.0% to 12.1%, 21.11% to 31.78%, 0.73 g/g to 0.91 g/g and 0.66 g/g to 0.88 g/g, respectively and the rate of water evolution decreased from 44.9% to 33.3%. Fourier transform infrared spectroscopy showed that acetyl group was successfully introduced. Scanning electron microscopy showed that microwave pretreatment and group introduction made the surface of starch granules locally porous and rough. Differential scanning calorimetry showed lower onset temperature, peak temperature, conclusion temperature and enthalpy than native corn starch, which proved that acetylated corn starch reduced the content of rapidly digestion starch and increased the content of slow digestible starch and resistant starch. At the same time, the results showed that the color, texture and tensile properties of noodles with acetylated corn starch were improved. It showed that acetylated corn starch prepared by microwave pretreatment and acetate esterification had certain application prospects.