Zn^(2+)对制麦中苹果酸脱氢酶和呼吸消耗的影响

Effect of Zn^(2+) on the activity of malate dehydrogenase and respiration consumption in the process of malting

研究了在制麦过程中添加Zn2+对苹果酸脱氢酶(MDH)活性和大麦呼吸消耗的影响。结果表明在制麦过程中添加浓度为0.50mmol/L、0.75mmol/L、1.00mmol/L的Zn2+均可有效的抑制MDH活力,进行动力学分析得出Zn2+对大麦MDH的抑制类型为非竞争性抑制;添加浓度为0.75mmol/L、1.00mmol/L的Zn2+可降低制麦过程中的呼吸消耗,其中添加1.00mmol/L Zn2+的试验组的呼吸消耗率最低,相对于对照组,两种大麦的呼吸消耗分别降低了5.22%和10.7%。同时研究了Zn2+对于麦芽中的α、β淀粉酶和果胶酶活力影响,表明对α、β淀粉酶有促进作用,对果胶酶影响不明显。

The effect of different Zn2＋ concentration on the activity of malate dehydrogenase （MDH） and respiration consumption in the process of malting were determined. The results showed that the activity of MDH was inhibited by Znv, and the inhibition was noncompetitive type. The respiration consumption was reduced in the process of malting when Zn2＋ concentration was 0.75mmol/L and 1.00mmol/L. The treatment group of 1.00mmol/L Zn2＋ had the lowest respiration consumption compared with those of other group. Compared to the control group, the respiration consumptions of two kinds of barley were decreased by 5.22% and 10.7% when Zn2＋ concentration was 1.00mmol/L, respectively. The activities of α,β amylase can be stimulated by Zn2＋, and Zn2＋ had little effect on pectinase.