本研究以雪蓮薯為試驗材料，測定其總酚類化合物含量及DPPH 自由基清除 能力，結果顯示雪蓮薯含有豐富的抗氧化成分，因此，進一步純化出雪蓮薯超氧 化物歧化酶，其純化步驟包括雪蓮薯粗酵素液的萃取、DEAE-Sepharose 陰離子交 換層析和Mono S 陽離子交換層析，經純化後酵素的比活性、回收率和純化倍率分 別為3691.3 units/mg、51% 和 274 倍，該酵素經聚丙烯膠體電泳分析後得知其分 子量為17,340 道爾頓，雪蓮薯超氧化物歧化酶在5.0~20℃恆溫90 分鐘，其酵素活 性幾乎不受影響，而在pH 7.0~7.5 下經37℃加熱60 分鐘，其酵素活性幾乎不受影 響，由此可知，雪蓮薯含有超氧化物歧化酶的活性，本研究之純化方法與生化特 性資料，將有助於其在食品工業上的應用與開發。

Superoxide dismutase (SOD; EC 1.15.1.1) had been isolated, purified and partially characterized from yacon (Smallanthus sonchifolius.). The purification was first extracted from crude extraction and then ion exchange chromatograph on DEAE-Sepharose and Mono S columns. The specific activity, yield and purification fold were 3691.3 units/mg, 51% and 274 fold, respectively. The molecular weight of the purified enzyme was 17,340 dalton measured by sodium dodecylsulfate-polyacrylamide gel electrophoresis. The enzyme remained highly enzyme activity at 5.0~20℃ within 90 min incubation. The purified enzyme remained relative stable at pH 7.0~7.5, 37℃for 60 min incubation. Accordingly, the yacon superoxide dismutase would have many worthwhile applications in functional food industry.