亚麻籽蛋白酶解肽的降胆固醇作用研究Cholesterol-lowering effect of flaxseed protein hydrolysate peptides

旨在为亚麻籽蛋白的深加工利用提供参考，以低温压榨亚麻籽饼为原料，采用碱溶酸沉法制备亚麻籽蛋白，再采用酶解法制备亚麻籽蛋白酶解肽。采用超滤分离降胆固醇活性最高的亚麻籽蛋白酶解肽，并以其为原料进行动物实验探究其降胆固醇作用。结果表明：在酶解时间为4 h时，亚麻籽蛋白酶解肽的胆固醇胶束溶解度抑制率最高，为47.57%；分子质量不大于3 kDa的超滤组分的胆固醇胶束溶解度抑制率最高，为70.96%；与高胆固醇饮食组相比，亚麻籽蛋白酶解肽不大于3 kDa的超滤组分能够增加小鼠的摄食量和体质量，降低血清总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）水平，提高血清高密度脂蛋白胆固醇（HDL-C）水平，降低肝脏指数和肝脏中TC、TG水平，改善肝脏脂肪变性程度，增加粪便总胆汁酸（TBA）的排泄量，并且可以通过降低丙二醛（MDA）水平，提高超氧化物歧化酶（SOD）活力来减轻高胆固醇饮食导致的氧化应激反应。综上，亚麻籽蛋白酶解肽不大于3 kDa的超滤组分具有一定的降胆固醇作用，有望成为新型的降胆固醇功能性成分。To provide a reference for the deep processing and utilization of flaxseed protein, the flaxseed protein was prepared by alkali-soluble and acid-precipitation method from low-temperature pressed flaxseed cake, and then the flaxseed peptides were prepared by enzymatic hydrolysis. Ultrafiltration membranes were used to isolate flaxseed peptides with the highest cholesterol-lowering activity in vitro, and animal experiments were conducted to explore its cholesterol-lowering effects. The results showed that when the enzymatic hydrolysis time was 4 h, the cholesterol micelle solubility inhibition rate of flaxseed peptide was the highest (47.57%), and the cholesterol micelle solubility inhibition rate of the ultrafiltration fraction with a molecular weight of no more than 3 kDa was the highest (70.96%). Compared with the high-cholesterol diet group, the ultrafiltration fraction(≤3 kDa ) could increase the food intake and body weight of mice, reduce the serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) levels, increase the serum high-density lipoprotein cholesterol (HDL-C) level, reduce liver index and TC and TG levels in the liver, improve the degree of hepatic steatosis, increase fecal total bile acid (TBA) excretion, and reduce the oxidative stress caused by high-cholesterol diet by reducing malondialdehyde (MDA) level and increasing superoxide dismutase (SOD) activity. In conclusion, the ultrafiltration fraction (≤3 kDa )of flaxseed peptides has a certain cholesterol-lowering effect, and is expected to become a new cholesterol-lowering functional component.