State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China.
J Dairy Res. 2013 Aug;80(3):367-73. doi: 10.1017/S0022029913000320.
To isolate and identify antioxidant peptides from enzymatically hydrolysed whey protein, whey protein isolate was hydrolysed by different protease (trypsin, pepsin, alcalase 2·4L, promatex, flavourzyme, protease N). The hydrolysate generated by alcalase 2·4L had the highest antioxidant activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, superoxide radicals and in a linoleic acid peroxidation system induced by Fe2+. The IC50 values of DPPH and superoxide radical scavenging activities of the hydrolysate decreased significantly (6·89 and 38·88%, respectively) after treatment with macroporous adsorption resin. Seven different peptides showing strong antioxidant activities were isolated from the hydrolysate using consecutive chromatographic methods including gel filtration chromatography and high-performance liquid chromatography. The molecular mass and amino acids sequences of the purified peptides were determined using a Quadrupole time-of-flight mass spectrometer (Q-TOF MS). One of the antioxidative peptides, Trp-Tyr-Ser-Leu, displayed the highest DPPH radical scavenging activity (IC50=273·63 μm) and superoxide radical scavenging activity (IC50=558·42 μm). These results suggest that hydrolysates from whey proteins are good potential source of natural antioxidants.
为了从酶解乳清蛋白中分离和鉴定抗氧化肽，用不同的蛋白酶（胰蛋白酶、胃蛋白酶、碱性蛋白酶 2·4L、普鲁兰酶、风味蛋白酶、蛋白酶 N）水解乳清蛋白分离物。碱性蛋白酶 2·4L 水解生成的水解产物对 1,1-二苯基-2-苦基肼（DPPH）自由基、超氧自由基和 Fe2+诱导的亚油酸过氧化体系具有最高的抗氧化活性。水解产物对 DPPH 和超氧自由基清除活性的 IC50 值分别显著降低（分别为 6.89%和 38.88%）经过大孔吸附树脂处理后。采用凝胶过滤色谱和高效液相色谱等连续色谱方法，从水解产物中分离出 7 种具有较强抗氧化活性的不同肽。使用四极杆飞行时间质谱仪（Q-TOF MS）确定了纯化肽的分子量和氨基酸序列。一种抗氧化肽，色氨酸-酪氨酸-丝氨酸-亮氨酸，表现出最高的 DPPH 自由基清除活性（IC50=273.63 μm）和超氧自由基清除活性（IC50=558.42 μm）。这些结果表明，乳清蛋白水解产物是天然抗氧化剂的良好潜在来源。
