20种食/饲用大麦与啤酒大麦Triumph极限糊精酶活性、耐热性的比较研究

极限糊精酶是决定麦芽品质的关键酶.选用我国20个食用或饲用大麦品种和一个欧洲主栽大麦Triumph作为材料,对极限糊精酶活性和耐热性进行了检测和比较研究.结果表明,品种间极限糊精酶的活性和耐热性差别较大.ZDM1467酶活低,但耐热性强;ZDM3593酶活高,但耐热性差.65℃处理10 min,各品种极限糊精酶活性均降低65%以上,表明该酶不耐高温.同Triumph相比,供试的20个国产大麦极限糊精酶活性、耐热性普遍较低,仅ZDM1616与Triumph略为接近.

Comperative Study of Activity and Thermostability of Limit Dextrinase in 20 Feed Barley Varietes and one Brewing Barley Triumph

Limit dextrinase (LD) is a key enzyme in determining the malting quality.A survey of one variety of European brewing barley and 20 varieties of Chinese feed barley varieties shows a wide range of variation for the enzyme activity and thermostability.ZDM1467 shows low enzyme activity and high thermostability while ZDM3593 shows high activity and low thermostability.The enzymatic activity of LD drops dramatically at temperatures 65 ℃,indicating that this enzyme is heat liable.Compared to the European barley variety Triumph,the levels of enzymatic activity and thermostability of limit dextrinase in most Chinese barley varieties are low,except for ZDM1616,which is nearly equal to Triumph.