蝶豆花青素超声辅助提取工艺及抗氧化活性研究

Ultrasonic-assisted extraction processing and antioxidant activity of anthocyanins from Clitoria ternatea

通过研究蝶豆花青素的吸收特性确定花青素含量测定方法,采用超声辅助提取蝶豆花青素,以正交试验法筛选蝶豆花青素提取的最佳工艺,评价蝶豆提取物抗氧化活性,以期为蝶豆今后的开发利用提供参考依据。以蓝色重瓣蝶豆花为研究对象,采用单一pH法测定花青素含量,考察不同超声时间、料液比、乙醇体积分数、温度和超声功率对提取效果的影响;以抗坏血酸为阳性对照,评价蝶豆提取物抗氧化活性(DPPH自由基、ABTS+自由基清除率和总还原力测定)。结果表明:超声辅助提取蝶豆花青素,最佳提取工艺为超声时间20min,料液比1∶200(g/mL),乙醇体积分数65%,超声温度50℃,在此条件下蝶豆花青素提取量为13.604±0.145mg/g;抗氧化活性测定试验中,蝶豆花提取物浓度为0.8mg/mL时,对DPPH自由基和ABTS+自由基的清除率分别为87.83%和99%。本研究表明超声辅助可以有效提取出蝶豆花青素,蝶豆提取物具有较好的抗氧化活性。

In this study,the determination method of anthocyanin content was confirmed by studying the absorption characteristics of anthocyanin in Clitoria ternatea flowers(CTF). Ultrasonic extraction of CTF anthocyanins and orthogonal test were used to screen the best extraction process of CTF anthocyanins. Meanwhile,the antioxidant activity of the extract was studied to provide reference for the future development and utilization of CTF. The content of anthocyanin in CTF was determined by single pH method,and the effects of ultrasonic time,solid-liquid ratio,ethanol concentration,ultrasonic temperature and ultrasonic power on extraction efficiency were studied.The antioxidant activities(DPPH free radical and ABTS+ free radical scavenging and total reduction capacity)of the extracts of CTF were evaluated with ascorbic acid as the positive control. The results showed that the optimum extraction conditions were :ultrasonic time 20min,solid-liquid ratio 1∶200 g/mL,ethanol concentration 65%,and ultrasonic temperature 50℃. Under these conditions,the anthocyanins yield was up to 13.604±0.145(mg/g).In the antioxidant activity test,the scavenging rates of DPPH free radical and ABTS+ free radical were 87.83% and 99%,respectively,at the extract concentration of 0.8mg/mL. This study showed that the anthocyanins of CTF could be effectively extracted by ultrasonic-assisted extraction,and the extracts had good antioxidant activity.