炒焙芝麻條件對芝麻粕甲醇萃出物抗氧化性之影響   全文下載

Effect of Roasting Condition on the Antioxidative Activity of the Methanolic Extract from Defatted Sesame Meal

芝麻常用來壓榨製造芝麻油使用，炒焙壓榨後之芝麻粕甲醇萃出物含有lignan glycosides 物質。本研究以緬甸黑芝麻為試驗材料，在 180-220°C 炒焙溫度下，進行不同炒焙時間（5-30 min）之炒焙試驗，並以未炒焙者作為對照實驗組。抗氧化活性以 DPPH 自由基清除能力及 LDL 抗氧化能力作為指標，此外，實驗中也探討不同炒焙芝麻條件對芝麻粕褐變程度及甲醇萃出物總酚類化合物含量之影響。實驗結果顯示，隨著炒焙溫度與時間之增加，DPPH 自由基清除能力及 LDL 抗氧化能力也隨之增加，同時也發現，芝麻粕褐變程度及甲醇萃出物總酚類化合物含量也有相同的趨勢。經相關性分析後，推論炒焙芝麻粕抗氧化效果之增加可能與總酚類化合物含量及梅納反應產物有關。

Sesame seeds are usually roasted prior to expelling oil. The defatted sesame meal contains lignan glycosides in its methanolic extract. The objective of this study was to investigate the antioxidative activity of methanolic extract from defatted black sesame meal roasted at three different temperatures (180, 200, 220°C) for different durations (5-30 min). The antioxidative activities were evaluated by the 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) radical scavenging ability and the inhibition of Cu2+ induced oxidation of human low-density lipoprotein (LDL). The effects of roasting condition on the browning index of sesame meal and the total phenolic content of the methanolic extract were also investigated. Results showed that as roasting temperature and time increased, the DPPH radical scavenging ability and the inhibition of Cu2+ induced oxidation of human LDL also increased. Meanwhile, the total phenolic content in the methanolic extract from defatted sesame meal and the browning level of sesame meal also increased with roasting temperature and time. These results suggested that the enhancement of antioxidative activity would probably be due to total phenolic compounds and Maillard reaction products formed during roasting process.