茶渣蛋白的提取及酶解产物抗氧化性质研究

Extraction of Tea Residue Protein and Antioxidant Activity of Enzymatic Hydrolysates

我国是茶叶生产消费大国,茶渣中含有丰富的蛋白质,茶渣蛋白具有良好的营养价值和保健功效。以茶渣为原料,以超声波技术为辅助手段,得到茶渣蛋白的最佳提取工艺:料液比为1:70(g/mL)、超声功率150 W、超声波提取时间为70 min、提取温度为90℃、NaOH浓度为0.18mol/L,该条件下茶渣蛋白提取率最大值为(83.17±0.16)%。利用碱提酸沉法得茶渣蛋白,以抗氧化能力为指标利用复合蛋白酶对茶渣蛋白进行酶解得到抗氧化肽,优化得最佳条件:底物浓度1.0%、酶/底物8000 U/g、酶解温度为60℃、pH为8,得茶渣蛋白酶解产物DPPH自由基清除率达到(80.83±0.47)%。在亚油酸体系中,1.0 mg/mL茶渣蛋白酶解产物对亚油酸体系自氧化的抑制能力高于抗坏血酸和VE,略低于人工合成抗氧化剂BHT。

China is a main country in tea production and consumption.There are rich protein in waste tea residue.Tea residue protein has good nutritional value and health care effect.Tea protein was extracted from tea residue assisted by ultrasonic,the optimal extraction condition was determined:solid-liquid ratio was 1:70(g/mL),the ultrasonic power was 150 W,ultrasonic time was 70 min,extraction temperature was 90℃,the NaOH concentration was 0.18 mol/L,the maximum extracting rate of total protein was(83.17±0.16)%.Tea residue protein was extracted by a mixed solution,the optimum index of compound enzymes antioxidant capacity was 1.0%of substrate concentration,8000 U/g of enzyme/substrate,60℃of enzymolysis temperature,pH 8,the DPPH radical scavenging rate of enzymatic achieved(80.83±0.47)%.In LA system,the inhibition of 1.0 mg/mL tea residue protolysate on the autoxidation of linoleic acid system was higher than that of ascorbic acid and VE,slightly lower than that of synthetic antioxidant BHT.