乾燥型態與溫度對牛蒡茶泡飲成分溶出之影響

The Effects of Drying Types and Temperatures on the Dissolution of Functional Components in Burdock Tea

牛蒡（Arctium lappa L.）含有豐富的綠原酸、咖啡酸、菊糖、β-胡蘿蔔素、精胺酸與抗氧化物質。研究表明，牛蒡茶具有降血脂與抗氧化等功效，除做為食材外，沖泡飲也是越趨受歡迎的保健養身用途。本研究探討乾燥型態與溫度對牛蒡茶泡飲成分溶出之影響，並與市售產品比較。結果顯示以100°C浸泡20 min可溶出較多的綠原酸。而牛蒡切丁後烘乾較切片後烘乾可溶出較多的綠原酸。將片狀烘乾的牛蒡切成丁狀亦可增加溶出量，但再磨成更細粉狀則反會降低。自丁狀烘乾的牛蒡直接磨粉後則會些微增加溶出量。使用40或60°C的溫度乾燥牛蒡，能較100或180°C溶出較多的機能成分如菊糖與精胺酸，同時具有較高的DPPH自由基清除活性。使用較高溫度100或180°C進行乾燥，則能溶出較多的抗氧化物質如綠原酸、咖啡酸、酚類化合物與類黃酮，同時具有較高的ABTS自由基清除活性。

Burdock (Arctium lappa L.) is rich in chlorogenic acid (CGA), caffeic acid (CA), inulin, β-carotene, arginine, and antioxidants. Studies have shown that burdock tea has the effects of lowering blood lipids and anti-oxidation. In addition to being used as a vegetable food, brewing drinks of burdock is also an increasingly popular health care purpose. This article studied the effects of different drying types and temperatures on the dissolution of burdock tea brewing ingredients and compared them with commercially available products. The results showed that more CGA could be disintegrated after soaking at 100°C for 20 min. The diced dried burdock released more CGA than sliced burdock. Chopping sliced burdock released more CGA, but grinding into powder reduced the dissolution of CGA; while grinding the diced dried burdock could slightly increase the dissolution of CGA. Drying burdock at 40 or 60°C could make the burdock tea dissolve more functional components, such as inulin and arginine, and had higher 1, 1-Diphenyl-2-Picrylhydrazyl (DPPH) free radical scavenging ability. Drying at 100 or 180°C could dissolve more antioxidants, such as CGA, CA, phenolic compounds and flavonoids, and had higher 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging ability.