甘藷為國產糧食作物中地位僅次於稻米，紫色甘藷葉富含花青素，是一種極佳的天然色素，可被廣泛利用及開發成各種商品。由於甘藷葉加工時會影響花青素抗氧化能力，因此，本計畫之目的乃希望藉由鑑定不同甘藷葉色之花青素種類及含量，並探討加工過程甘藷葉中抗氧化功能性變化與免疫調節方面的生理機能性變化，最後將甘藷葉製成具抗氧化之高價值產品。本研究擬以二年期完成之。第一年測定5種不同品種(系)甘藷葉之花青素含量及總酚含量，並找出最佳濃度之乙醇溶劑來回收花青素，以及較佳之乾燥條件，以決定後續加工之品種與加工條件。此外，也將比較不同萃取條件花青素在細胞培養系統中之免疫調節作用之生理機能。第二年藉最佳花青素萃取條件進行清除DPPH自由基能力、還原力、清除超氧陰離子力、清除過氧化氫力、以及螫合鐵離子力等抗氧化功能性之評估與。同時也將瞭解甘藷葉花青素之儲藏安定性，以作為新產品開發之參考。藉由本研究之完成，這些天然花青素原料將可適合運用於各類食品加工添加物，以提供保健食品原料業者之新選擇，並開發出符合市場需求並具保健功效之新產品，藉以提升甘藷加工利用多元性，增加甘藷葉之附加價值，提高農民的收益。
Sweet potato （Ipomoea batatas (L.) Lam.） is one of the most important cash crop (except rice) in Taiwan. Purple leaf of sweet potato contains high content of anthocyanins, one of natural pigments, and is widely utilized and developed as commercial products. However, antioxidant activity of anthocynin in sweet potato leaf can be damaged during processing. The objectives of our study are to identify the character and quantity of anthocyanins in leaves of different varieties, investigate the changes of antioxidant activity and immunomodulation during processing, and make high-value products from the selected leaves. The proposed work will be done in two years. During the first year, we will measure contents of anthocyanin and total phenolics from the leaves of five varieties, and calculate the recovery rate of anthocyanin using different concentrations of alcoholic solutions to identify the optimal process condition for anthocyanin extraction. In the second year, we will investigate the stability and storage of anthocyanin as a commercial product. The results of the study will be useful to food process industry and sweet potato farmers as well to increase their profits.
