Effect of ethanol concentration on the physicochemical properties of waxy corn starch treated by hydrochloric acid

摘要

Waxy corn starch was treated in 50.70 or 90%of ethanol solutions containing 0.36 or 1.39%HC1 at 65 degC for 1 h.The recovery yields of treated starch were higher than 96%.The average granule size,maximum wavelength of the spectrum of iodine coloration(gamma_max),pasting viscosity,gelatinization onset temperature(Ta),average molecular weight and average chain length of starch decreased after treated,while no obvious change on X-ray diffraction pattern and increase in solubility of treated starch was also found.The changes on pasting viscosity,T_0,average molecular weight and solubility of treated starch increased with increasing ethanol and acid concentrations.It was found that the solubility of acid-ethanol treated waxy starch was a function of 77T_0(T was the temperature used for solubility measurement).At T/T_0 below 1.2,the solubility of starch linearly con-elated with TIT0 value(r~2=0.984).