无机盐对小麦胚芽脂肪酶结构和活性的影响

Effect of Inorganic Salt on the Activity of Wheat Germ Lipase

为探索一种新型的小麦胚芽稳定化方法,采用圆二色谱和荧光光谱对无机盐处理后的商品化麦胚脂肪酶的结构进行了研究,同时,考察了不同无机盐对麦胚中脂肪酶活力及麦胚酸价的影响。结果表明,当NaCl浓度为4×10^(-9)mol/L时,对商品化麦胚脂肪酶的抑制效果最好,其活力降低了21.8%,而KCl对脂肪酶的活力无显著影响,CaCl_2和MgCl_2均对脂肪酶有激活作用;所选无机盐对脂肪酶二级结构均无明显影响,但NaCl对脂肪酶的三级结构有一定影响;当添加无机盐后,麦胚中的脂肪酶活力和麦胚的酸价均低于未添加无机盐的麦胚,其中1.30%NaCl使脂肪酶活力降低了62.49%,0.75%KCl使脂肪酶活力降低了61.27%。由以上结果可知,添加无机盐可作为有效抑制脂肪酶的活力的手段,利于延长麦胚的贮藏期。

To exploit a new method to stabilize wheat germ,the structure of wheat germ lipase were analyzed after adding inorganic salt using circular dichroism and fluorescence spectrum. Moreover, the activity of lipase in wheat germ and the acid - value of germ were also studied after adding different inorganic salt. The results showed that when the content of NaCl was 4 × 10^-9 mol/L, the activity of lipase decreased by 21.8% , while KCl had no significant effect on the activity of wheat germ lipase. However, the activity of wheat germ lipase increased after adding CaCl2 and MgCl2. After adding salts, the secondary structure of the lipase was not changed, while the tertiary structure of the lipase was changed after adding NaCl. Compared to the wheat germ without adding inorganic salt, the activity of the lipase in wheat germ and acid - value of the wheat germ decreased, the content of NaCl was 1.3% and KCl was 0. 75 % , the activity of lipase decreased 62. 49% and 61.27 %. Therefore, adding salt could be used to inhibit the activity of wheat germ lipase and extend the storage period of wheat germ.