舌状蜈蚣藻蛋白质的提取及其抗氧化活性研究

该研究以舌状蜈蚣藻(Grateloupia livida)为原料,以蛋白质提取率为指标,探究不同破壁技术对舌状蜈蚣藻蛋白质的提取效果,并通过单因素分析和正交试验对超声波辅助水提法进行工艺优化,所得蛋白质经硫酸铵盐析法粗提纯后考察其体外抗氧化能力。结果显示,溶胀法、反复冻融法、珠磨法的最高蛋白质提取率分别为(29.66±0.86)%、(24.52±0.04)%、(26.52±0.79)%,均低于超声波辅助水提法;超声波辅助水提法提取舌状蜈蚣藻蛋白质的最佳工艺为:液料比160 mL·g^?1,超声全程时间60 min,超声功率1440 W,pH 6.0,此条件下蛋白质提取率可达58.16%;舌状蜈蚣藻粗蛋白质量浓度在1~8 mg·mL^?1内均具有较强抗氧化活性,其质量浓度为8 mg·mL^?1时的还原力为0.43±0.01,对1,1-二苯基-2-三硝基苯肼(DPPH)自由基的半数清除浓度(IC50)为4.00 mg·mL^?1,对2,2'-二氮-双(3-乙基苯并噻唑-6-磺酸)(ABTS)自由基的IC50为3.96 mg·mL^?1。

Extraction and antioxidant activity of protein from Grateloupia livida

With Grateloupia livida as the raw material and protein extraction rate as the index,we explored the effect of different wall-breaking techniques on their protein extraction,and optimized the ultrasonic-assisted water extraction by single-factor analysis and orthogonal test.The antioxidant activity of the crude protein that was purified by ammonium sulfate salting-out was evaluated.Results show that the highest protein extraction rate of the swelling method,freeze-thawing method and bead milling method was(29.66±0.86)%,(24.52±0.04)%and(26.52±0.79)%,respectively,all lower than those of ultrasonic-assisted water extraction method.The best optimal conditions of extracting protein from Grateloupia livida by ultrasonic assisted water extraction(the protein extraction rate could reach 58.16%)are as follows:liquid-to-solid ratio of 160 mL·g^?1,total ultrasonic time of 60 min,ultrasonic power of 1440 W and pH of 6.0.The crude protein had strong antioxidant activity at the concentration of 1?8 mg·mL^?1(its reducing power at 8 mg·mL^?1 was 0.43±0.01),and the IC50 of DPPH free radicals and ABTS free radicals are 4.00 mg·mL^?1 and 3.96 mg·mL^?1,respectively.