Establishment and Application of Liquefying Power Detection Method for Raw Wheat Qu of Chinese Huangjiu

In order to determine the liquefying power detection method for raw wheat Qu of Chinese Huangjiu,the research studied the reaction system of liquefying power for raw wheat Qu on the basis of industrial liquefying enzyme detection method and liquefying power detection method for Daqu of Chinese liquor. Besides,the extraction conditions of raw wheat Qu were studied by single factor experiment. The results showed that the reaction system was starch concentration of 1 g/L,reaction time of 10 min,wavelength of 580 nm,the amount of iodine-potassium iodide solution of 1 mL,and the measurement completed within 15 minutes after color development. The recovery experiment found that the method was suitable for detection. The raw wheat Qu crushing degree of 50 mesh,the extraction conditions were extraction solution of diluted 10 times of 0.2 mol/L pH4.60 phosphate buffer,material to liquid ratio of 1:200 g/mL,extraction time of 1 h,extraction temperature of 40 ℃,the measured value of liquefying power of raw wheat Qu increased by 19.23%. The method was applied to the determination of 12 raw wheat Qu samples from different regions and companies. The liquefying power was in the range of 1.22~3.17 U/g,and the relative standard deviation was between 0.50%~5.80%. The applicability and accuracy of this method were good.