Some properties of starch isolated from Radix Cynanchi bungei

摘要

The physicochemical and scanning electron micrograph characteristics of Radix Cynanchi bungei (RCb) starch were investigated. RCb starch presented an apparent amylose content of 20.1%, less than that of potato starch (23.6%), with a granule size ranging from 5 to 15 mu m with round, spherical and polygonal shapes and B-type X-ray diffraction pattern. The RVA pasting properties of RCb starch were similar to those of potato starch, with pasting temperature of 60.8 degrees C, lower than that of potato starch (64.3 degrees C). The gelatinization parameters of RCb starch were found to be 55.9 degrees C (T-o), 60.0 degrees C (T-p), 66.6 degrees C (T-C) and 13.2 J/g (Delta H) while those of potato starch were 58.9 degrees C, 63.5 degrees C, 68.6 degrees C and 13.2 J/g. Both RCb and potato starch pastes behaved as high shear-thinning liquids. RCb starch pastes had lower apparent viscosity than potato starch pastes at the same shear rate.