多種天然物的花青素萃取與抗氧化及抑制酪胺酸酶活性研究

花青素具有抗發炎、抗腫瘤、預防心血管疾病的功效並也是天然抗氧化劑之一，本研究以四種常見且含花青素的蔬果包括紫甘藍、紫甘藷葉、紫甘藷莖及紫甜椒以微波萃取的方式萃取其花青素，並探討花青素含量與抑制酪胺酸酶活性及清除DPPH自由基能力之間的相關性，從中選出最具發展潛力的花青素萃取物。實驗結果顯示紫甘藍萃取液有最高含量的花青素吸收峰(510-540nm)，並且抑制酪胺酸酶單酚酶或雙酚酶能力皆優於其他三種萃取液，花青素含量由高至低依序為紫甘藍＞紫甘藷葉＞紫甘藷莖＞紫甜椒。紫甘藍萃取液清除DPPH自由基能力稍遜於紫甘藷葉萃取液，但仍有高達80%的清除率。綜合實驗結果，花青素含量可能與抑制酪胺酸酶活性有關但與清除DPPH自由基能力較無關聯性，其中以紫甘藍最具發展潛力。

關鍵字

微波萃取；花青素；酪胺酸酶；抗氧化

並列摘要

Anthocyanins are potent natural antioxidants and have effects on anti-inflammatory, antitumor, and preventing cardiovascular diseases. In the present study, anthocyanins were extracted from four anthocyanin-containing fruits and vegetables, including purple cabbage, purple sweet potato leaves, purple sweet potato stems and purple sweet pepper by microwave-assisted extraction method. We evaluated the correlation between anthocyanin content and inhibition of tyrosinase activity and the ability of scavenging DPPH free radicals. We also screened the functional effects of each sample to select the best anthocyanin extract. The results showed purple cabbage extract has the highest content of anthocyanin absorption peak (510-540nm) and the effects on inhibition of monophenolase or diphenolase were better than the other three extracts. The extracts are listed in descending order of anthocyanin content (from most to least) as purple cabbage, purple sweet potato leaves, purple sweet potato stem and purple pepper. The DPPH free radical scavenging ability of purple cabbage extract is slightly less than purple sweet potato leaves extract, but the ability is still up to 80%. Results of the present study demonstrated that the content of anthocyanin could be related to the inhibition of tyrosinase activity, rather than to the ability of scavenging DPPH free radicals. Among 4 extracts, purple cabbage is the most promising anthocyanins extract for cosmetics.