芝麻蛋白水解物之抗氧化性探討

Studies on the Antioxidant Activity of Sesame Protein Hydrolysate

唐宗豪(Tsung-Hao Tang)

指導教授 ： 劉炳嵐

朝陽科技大學/理工學院/生化科技研究所/碩士(2012年)

摘要

芝麻為國人飲食中常用的食材，有許多文獻指出芝麻具有抗凝血、抗氧化、以及預防心血管疾病等功能。目前已有研究證實，蛋白質在人體內部分是以胜肽的形式被人體吸收，且具有較高的生理活性功能。本實驗以芝麻蛋白為原料，利用胰蛋白酶(Trypsin)、鳳梨酵素(Bromelain)、Actinase E (protease from Streptomyces griseus)三種蛋白質水解酵素，於50°C、pH 7.0的條件下進行水解芝麻蛋白四個小時，所得之三種蛋白水解物AH (Actinase E hydrolysate)、BH (Bromelain hydrolysate)、TH (Trypsin hydrolysate)進行TEAC (Trolox equivalent antioxidant capacity)總抗氧化能力測試、TBARS (Thiobarbituric acid reacting substance)脂質過氧化反應及抑制LDL氧化能力測試。在總抗氧化能力的試驗中，以水解物AH所增加之自由基清除率為最佳(21.91±2.00%)，優於BH (12.74±1.84%)及TH (7.80±1.36%)。三種水解物TEAC能力分別為0.249±0.013 mM、0.167±0.074 mM、0.104±0.014 mM。經SDS-PAGE電泳圖比對清除率及水解效果後可知，芝麻蛋白經三種不同之酵素水解30分鐘後，清除率皆開始逐漸上升，至水解150分鐘後清除率的增加趨於平緩。水解物於TBARS試驗中的結果顯示，三種蛋白酶水解物之MDA抑制率於水解150分鐘後有最高的抑制率，AH (12.61±1.08%)及TH (12.70±2.04%)的MDA抑制率最佳，優於BH (9.27±2.04%)。之後選用抗氧化效果較佳的AH進行抑制LDL氧化能力測試，添加AH水解物之實驗組於6個小時內的共軛雙烯生成量較未水解芝麻蛋白來的低，證明水解後抑制LDL氧化能力較水解前好。

關鍵字

TBARS (Thiobarbituric acid reacting substance) ； 芝麻 ； 抗氧化能力 ； LDL (Low-density lipoprotein) ； 脂質過氧化 ； TEAC、(Trolox equivalent antioxidant capacity)

並列摘要

Sesame is the commonly used for cooking and has the ability of anticoagulant, antioxidant activity, prevention of cardiovascular disease, and other functions. Enzymatic hydrolysis can used to improve the functional properties of proteins. It has been reported that the extent of proteolytic degradation of food proteins affects greatly the functional properties of the hydrolysates. In this study, the sesame protein was hydrolyzed using tyrpsin, bromelain, or actinase E at pH 7.0 and 50°C for 4 hours. Subsequently, the three different hydrolysates: AH (Actinase E hydrolysate), BH (Bromelain hydrolysate), and TH (Trypsin hydrolysate) were tested for various antioxidative activities, including the trolox equivalent antioxidant capacity (TEAC) assay, inhibition of lipid peroxidation in a liposome model system as well as the Cu2+-induced oxidation of human LDL. The scavenging activity of AH (21.91±2.00%) is better than BH (12.74±1.84%) and TH (7.80±1.36%) in TEAC assay. The TEAC values of AH, BH, and TH, were 0.249±0.013 mM, 0.167±0.074 mM, and 0.104±0.014 mM trolox equivalent, respectively The scavenging activity was increased with hydrolysis time during the first 30 minutes as monitored in SDS-PAGE. No significant scavenging effects were found beyond the 150 minutes hydrolysis. Moreover, the inhibition of malondialdehyde (MDA) by three hydrolysates would reach a plateau of progress after 150 minutes. Among, the AH (12.61±1.08%) and TH (12.70±2.04%) exhibited a better inhibitory activities than BH (9.27±2.04%). The antioxidant capacity for Cu2+-induced oxidation of human LDL was conducted using the AH samples. The formation of conjugated diene within six hours was lower in the case of AH than the non-hydrolyzed sesame protein. This demonstrated that the inhibition of LDL oxidation by sesame protein was more effectiveness after hydrolysis.

並列關鍵字

LDL (Low-density lipoprotein) ； Lipid peroxidation ； Antioxidant capacity ； TEAC (Trolox equivalent antioxidant capacity) ； Sesame ； TBARS (Thiobarbituric acid reacting substance)

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