响应面试验优化超声波辅助提取山杏种皮黑色素工艺及其抗氧化活性

以山杏种皮黑色素得率为考察指标，在单因素试验的基础上采用Box-Behnken方法，通过响应面设计优化超声波辅助提取山杏种皮黑色素的工艺，并对山杏种皮黑色素的自由基清除能力、螯合金属离子能力、抗脂质过氧化等抗氧化活性进行了测定。结果表明，提取温度、料液比、NaOH浓度这3 个因素对提取效果均有显著影响（P＜0.05），超声波辅助提取山杏种皮黑色素的最优工艺为NaOH浓度0.33 mol/L、料液比1∶10（g/mL）、提取温度63.07 ℃，山杏种皮黑色素得率可达4.14%。山杏种皮黑色素具有较强的螯合金属离子的能力，对羟自由基也有一定的清除作用，能显著抑制大鼠肝脏自发性以及H2O2和Fe2＋-VC诱导的脂质过氧化反应，但铁还原能力、体外清除1,1-二苯基-2-苦肼基（DPPH）自由基和2,2’-联氮-二（3-乙基-苯并噻唑-6-磺酸）二铵盐自由基（ABTS＋·）的能力较弱。

Response Surface Optimization of Ultrasonic-Assisted Extraction of Melanin from Testae of Wild Apricots and Its Antioxidant Activities

In this work, we isolated melanin from the testae of wild apricots (MTWA) by ultrasonic-assisted extraction.
The optimization of the extraction process was carried out using by the combined use of one-factor-at-a-time method
and response surface analysis (RSA) with Box-Behnken experimental design. Then the antioxidant activities of MTWA
were analyzed including free radical scavenging capacity, metal ion-chelating capacity and lipid peroxidation inhibition.
The results showed that the optimal extraction conditions were determined as follows: NaOH concentration, 0.33 mol/L;
temperature, 63.07 ℃; time, 3 h; and solid-to-solvent ratio, 1:10 (g/mL). Under these conditions, the maximum yield of
MTWA of 4.14% was obtained. The in vitro antioxidant tests showed that MTWA had weaker 1,1-diphenyl-2-picrylhydrazyl
(DPPH) and 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate), radical scavenging activities and ferric reducing ability. However,
compared with synthetic melanin, MTWA had much stronger metal ion-chelating ability. MTWA also had stronger hydroxyl
radical-scavenging activity and provided significant inhibition of lipid peroxidation induced by H2O2 and Fe2+-VC.