小麦籽粒在制麦过程中胚乳降解酶活性变化的研究

Changes of Endosperm Enzyme Activity during Malting for Wheat

为揭示和探讨小麦籽粒在制麦过程中酶活变化的规律,以小麦样品为研究材料,以啤酒大麦品种为对照,采用断水浸麦方式和降温发芽工艺,分析小麦和啤酒大麦籽粒在制麦过程中淀粉酶、蛋白酶、β-葡聚糖酶、极限糊精酶活性的变化规律。结果表明:小麦籽粒在制麦过程中α-淀粉酶活力在发芽中不断增长,并在发芽第3天后快速增长;β-淀粉酶和总淀粉酶的活性变化趋势与啤酒大麦相同,均在发芽第4天达到峰值后下降,而β-淀粉酶活性水平高于α-淀粉酶;β-葡聚糖酶活力一直保持上升趋势;蛋白酶和极限糊精酶的活力在发芽第4天达到峰值后开始下降。啤酒大麦的蛋白酶、β-葡聚糖酶、极限糊精酶的活力在发芽期间一直处于上升趋势,并且在发芽结束后酶活还保持较高的水平;小麦籽粒在发芽后其淀粉酶活力较啤酒大麦高。小麦和啤酒大麦在发芽中的酶活变化有较大的差异;发芽小麦的酶活水平可作为制定合理制麦工艺的重要依据,发芽至第4天的酶活都能保持较高水平。

Changes in endosperm enzyme activity during malting of two wheat cv. （ 13 Yangmai and 38 Wanmai） and I barley cv. （Strling） were studied. Samples were tested for activities of α - amylase, β - amylase, overall amylase, proteinase, β - glucanase, and limit dextrinase. Results show that the α - amylase activity of wheat keeps increasing in germination, and accelerates after the 3rd day of germination; the β- amylase and the overall amylase activity come to peak value at the 4th day in germination and then decrease, and the β - amylase shows higher activity level than the α - amylase; the β - glucanase activity always keeps increasing tendency; the proteinase and the limit dextrinase activities increase during the first 4 days of germination. The activities of proteinase, β - glucanase and limit dextrinase of barley keep increasing tendency in all process of germination. The amylase activity of wheat after germination is higher than that of barley. It is concluded that there is a big difference for changes in enzyme activity between wheat and barley. The level of enzyme activity in germination provides a base for making a reasonable malting processing.