Application Of Novel Amylases In The Processing Of Crystalline Dextrose From Corn Starch

The technologies of liquefaction and saccharification are the key factorswhich determine the DE value, the quality of glucose and the productionperiod in the processing of crystalline dextrose from corn starch, and theapplication of amylase performs a decisive function. In order to make a gooduse of the abundant domestic resource of corn starch, enhance the glucoseconversion rate and improve the filterability of glucose solution, affectingfactors of corn starch liquefaction and saccharification were studied in thispaper with the liquefying enzyme of novel thermostable α-amylase and withthe saccharifying enzyme of glucoamylase and novel pullulanase bydual-enzyme method. At the same time, the technological parameters of cornstarch liquefaction and saccharification were also optimized.The main results are as follows:The liquefaction period was shortened and the quality of liquefyingsolution as well as the coherency of impurities such as protein in liquefyingsolution both could be improved with the aid of the novel thermostable α-amylase.Saccharifying with the cooperation of glucoamylase and novelpullulanase, saccharification period could be shortened and glucoseconversion rate was also enhanced.Due to the novel liquefying enzyme, the thermostable α-amylase andwith the help of the saccharifying enzyme, glucoamylase and pullulanase, thefinal conversion rate of glucose reached the top when the liquefaction DEvalue was controlled between 15% and 20% in the processing of crystallinedextrose from corn starch, and the conversion rate of glucose declined whenthe DE value was lower than 15% or higher than 20%.The optimal numeric area of all factors affecting liquefaction wereobtained as follows by single factor test: corn starch concentration 20%~30%,liquefaction period 60 minutes or so, dosage of thermostable α-amylaseabout 32 u / (g starch), temperature above 91℃, pH value 5.6~6.2.