青海藜麦皂苷超声提取工艺及抗氧化活性

Ultrasonic extraction technology of saponins and its antioxidant activity in quinoa from Qinghai

通过单因素和正交实验对超声波辅助溶剂提取青海藜麦皂苷的工艺条件进行优化,并对青海不同藜麦皂苷含量及其抗氧化能力进行了评价。结果表明,超声波辅助乙醇提取皂苷的最佳工艺条件为:乙醇体积分数90%,料液比1∶15(g/m L),提取时间20 min、功率400 W、提取温度45℃,在此条件下藜麦皂苷含量达到115.74 mg/100 g。119份藜麦平均皂苷含量为(93.66±18.34)mg/100 g,不同藜麦间皂苷含量与抗氧化能力差异较大。不同粒色比较,红色藜麦的皂苷含量最高且抗氧化能力最强,白色藜麦的皂苷含量最低且抗氧化能力最差。以DPPH·清除能力、铁离子还原能力(FRAP)和ABTS+·清除能力为指标,采用Ward联接(平方欧式距离)法将119份藜麦分为三大类。第Ⅰ类包括69种藜麦,皂苷含量与抗氧化能力均较高;第Ⅱ类包括33种藜麦,皂苷含量与抗氧化能力中等;第Ⅲ类包括17种藜麦,皂苷含量与抗氧化能力均较低;三大类之间皂苷含量与抗氧化能力差异显著(p<0.05)。

Extraction conditions of quinoa saponins from Qinghai were investigated by single factor and orthogonal test on ultrasonic assisted solvents, the content of saponins and antioxidant capacity of different quinoas in Qinghai were analyzed.The results showed that ： the volume fraction of ethanol was 90% , solid-liquid ratio was 1 ： 15 （g/mL） , extraction time was 20 min, ultrasonic power was 400 W and extraction temperature was 45℃ .Under these conditions, the saponins content of quinoa was 115.74 mg/lO0 g. The average content of saponins in 119 quinoa was（93.66 ± 18.34） mg/100 g, saponins content and antioxidant activities among different quinoas were great different.Among different grain colors, the content of saponins in red quinoas was the highest and the antioxidant activities was the strongest, the saponins content of white quinoas was the lowest and the antioxidant activities was the worst.119 quinoas were divided into three classes by Ward connection（ square European distance） method based on DPPH. scavenging ability,iron ion reduction ability（FRAP） and ABTS＋ scavenging ability. Class I （ ineiuding 69 quinoas） showed relatively higher saponins content and antioxidant activities, while class Ⅱ （ ineiuding 33 quinoas）were midium, class Ⅲ （ineiuding 17 quinoas）showed relatively low saponins content and antioxidant activities. Saponins content and antioxidant activities among the three classes were significant different（p 〈 0.05 ）.