Study on Properties of Corn Starch-based Fat Mimics

摘要

Corn starch was partially hydrolyzed by treating the starch dispersions with heat stable a-amylase. Dextrose equivalent (DE) value of 2.5-6.5 was achieved by hydrolyzing the starch samples (30% w/w) at 95°C. The hydrolyzed starch granules with different DE values were analyzed by textural analyzer and rheometer. The results showed that the corn starch-based fat mimics with the concentration of 30% and DE value of 3.5 could form relatively firmer gel. The corn starch-based fat mimics with DE value of 3.5 were analyzed by X-ray diffraction, scanning electron microscopy and dynamic mechanical analyzer (DMA). The X-ray diffraction analysis showed that the hydrolysis of corn starch-based fat mimics mainly occurred in the amorphous region. The scanning electron micrographs showed that the size of the fat mimics was about 5μm. and the DMA analysis showed that the glass transition temperature (Tg) of the fat mimics decreased 5°C than the original corn starch, which suggested that the corn starch-based fat mimics had the similar storage stability as the original corn starch.