(57(1):33-48)Studies on Anthocyanidin and Total Phenolic Contents of Sweet Potato

Abstract

甘藷 (Ipomea batatas) 之不同品種具有豐富之色彩，其花青素組成份及抗氧化能力 值得開發研究。試驗結果得知紫紅色系之藷皮及藷肉均有花青素之合成，花青素之種類 有紫紅色的矢車菊素 (cyanidin) 及紅色的芍藥素 (peonidin)，顏色愈深花青素含量愈 高，但台農73 號藷皮及藷肉之花青素含量均比芋心甘藷低。烘乾藷皮及藷肉之花青素 含量比冷凍乾燥大幅減少，但冷凍乾燥及烘乾會比新鮮材料分別提高10 倍及3-5 倍之 抗氧化能力。花青素含量與抗氧化能力無正相關存在，而與總酚含量呈正相關，但大幅 提高花青素含量，對甘藷抗氧化能力有幫助，更可豐富甘藷色彩，增進甘藷多樣性利用， 所得結果可供新品種紫肉甘藷台農73 號之利用及未來育種方向參考。Anthocyanidin composition and antioxidant activity of sweet potato (Ipomea batatas (L.) Lam) storage roots with plentiful colors were studied. The results showed that cyanidin and peonidin were synthesized in purple-red skin and storage root, and more anthocyanidins were found in darker color ones. The skin and storage root of Tainung 73 cultivar contained less anthocyanidin than that of Purple sweet potato. 70℃ drying had less anthocyanidin content of skin and storage root than freeze drying, but freeze-drying and 70℃ drying increased antioxidant activity 10 times and 3-5 times respectively as compared with fresh materials. Antioxidant activity was positively correlated to total phenolic content, but not to anthocyanidin content. However, increased anthocyanidin content was good for enhancing antioxidant activity of sweet potato. The results could be applied as a reference for the utilization of Tainung 73 cultivar and future breeding of sweet potato