| 摘要: | 本研究以抑制低密度脂蛋白過氧化系統評估14種山藥之抗氧化力。其中中國長與紫玉血薯把外皮另外分開。山藥切細冷凍乾燥後磨成細粉，以甲醇或正己烷萃取山藥粉狀物，所得之粗萃取物以不同濃度測其在低密度脂蛋白(low density lipoprotein,' LDL)系統之抗氧化力，即丙二醛(malonyl dialdehyde, MDA)生成抑制率。甲醇萃取物普遍比正己烷萃取物之抗氧化力高許多，此顯示山藥所含抗氧化物較富極性。依甲醇萃取物之抗氧化力，山藥大致可分為四群，分別是（台農一號、桃改batatas、泰雅）、（台農二號、日本青森、罐型薯）、（名間長紅、中國長、基隆長薯、大陸淮山）、與（汕二、汕三、二刺、紫玉血薯）。依正己烷萃取物之抗氧化力，山藥亦可分為四群，分別是（中國長、基隆長薯、名間長紅、桃改batatas、泰雅）、（汕二）、（大陸淮山、日本青森、罐型薯）、（台農一號、台農二號、二刺、汕三、紫玉血薯）。不同種山藥甲醇萃取物之LDL氧化延滯期亦有顯著不同。綜合前面結果，以中國長、名間長紅、桃改batatas、大陸淮山、泰雅與罐型薯之抗氧化力最強；其次為日本青森、汕二、台農一號、基隆長薯；而以台農二號、汕三、二刺與紫玉血薯最弱。
This study applied the low density lipoprotein system to evaluate the antioxidant activity of 14 yam tubers. All yam tubers tested were ground to fine powder after lyophilized. Antioxidant activity of methanol and n-hexane extract were determined by the inhibition percentage of malonyl dialdehyde (MDA) under low density lipoprotein peroxidation (LDL) system. The antioxidant activity of methanol extract is higher than that of n-hexane extract, suggesting the antioxidant chemical structure in the former is more polar than that in the latter. Based on the antioxidant activity of methanol extract, the 14 yam tubers examined can be divided into 4 groups. They are group 1 (TN.1;TK batatas; Taiya),group 2(TN.2;Chinsheen;Can-shape),group 3(MC long red; China long; KL long; ML faisan),and group 4 (San 2;San 3;Erchu,Purple red).According to the antioxidant activity of n-hexane extract, the tested yams can also be classified as 4 groups. They are group 1(China long, KL long, MC long red, TK batatas, Taiya), group 2(San 2), group 3 (ML faisan, Chinsheen, Canshape), and group 4 (TN1,TN2,Erchu San 3,Purple red). The lag phase of LDL peroxidation of methanol extract of 14 yam tubers are different. All the data suggest the first group with higher antioxidant activity includes China long, MC long red, TK batatas, ML faisan, Taiya, and Can-shape; the second group with medium level antioxidant activity are Chinsheen, San 2,TN 1,and KL long; the worst group areTN2,San 3,Erchu,and Purple red. |
