Characterization of proso millet starches from different geographical origins of China

The influence of geographical origin (Lvliang, Baotou, Gulang, and Jilin) on the physicochemical properties of proso millet (Panicum miliaceum L.) starches from China, and starch chemical compositions were studied. Scanning electron microscopy showed that starch granules from millet starches were polygonal and spherical with smooth surfaces with sizes ranging from 2.5 to 12 μm. X-ray diffraction showed that millet starches were typical of A-type starch granules with a mean crystallinity of 35.81%. The transition temperatures (To, Tp, and Tc) and enthalpy of gelatinization (ΔH) of Lvliang, Baotou, Gulang, and Jilin proso millet starches were 66.81 to 70.01°C, 72.79 to 76.55°C, 78.30 to 82.44°C, and 10.4 to 14.46 J/g, respectively. Significant differences (p<0.05) were observed for the amylose content, granule size, peak temperature, gelatinization enthalpy, and peak viscosity temperature among the millet starches. Millet starches may have potential applications in production of puffed starch food products and other food items.