Abstract:

The physicochemical properties of Rhizoma Pinelliae starches from four different regions were investigated. The contents of amylose in different Rhizoma Pinelliae starches ranged from 18.60% to 23.91%. The shapes of Rhizoma Pinelliae starch granules varied from round to oval or hemisphere with the sizes between 2~20 μm. All Rhizoma Pinelliae starches show the typical C-type crystal form but with crystallinity in the range of 15.0% to 37.9%. The transition temperatures (T_O, T_P and T_C) and enthalpies of gelatinization were determined via differential scanning calorimetry(DSC). T_O, T_P and T_C varied from 71.58 to 77.75, 83.03 to 83.84, and 89.41 to 90.99 ℃, respectively. The enthalpy of gelatinization ranged from 4.316 J/g to 5.809 J/g. According to the viscosity measurements with a rapid visco analyser(RVA), the peak visc, hot visc, cold visc, breakdown and setbake of these Rhizoma Pinelliae starches varied from 149.5 to 226.2, 97.7 to 127.2, 141.8 to 194.3, 50.4 to 99.0, and 44.2 to 67.2 RVU, respectively. The pasting temperature and peak time for these starches were 77.8 to 79.9 ℃ and 8.3 to 8.7 min, respectively.

Key words: Rhizoma Pinelliae,starch,pasting property,X-ray diffraction