Ratnasari Nisita, Walters Mallory, Tsopmo Apollinaire
Food Science and Nutrition Program, 1125 Colonel By Drive, K1S 5B6, Ottawa, ON, Canada.
Institute of Biochemistry Carleton University, 1125 Colonel By Drive, K1S 5B6, Ottawa, ON, Canada.
Heliyon. 2017 Jul 10;3(7):e00351. doi: 10.1016/j.heliyon.2017.e00351. eCollection 2017 Jul.
This study used polysaccharide degrading enzymes and protein precipitation to extract polyphenols from oats and to determine their bioactivity. Duplicate oat brans were treated with viscozyme (Vis), cellulase (Cel) or no enzyme (control, CTL) then, proteins were removed in one set (Vis1, Cel1, CTL1) and not in the other (Vis2, Cel2, CTL2). HPLC analyses showed that for cellulase treated brans, precipitation of proteins increased phenolic acids and avenanthramides by 14%. Meanwhile, a decreased of 67% and 20% respectively was found for viscozyme and control brans. The effect of protein precipitation on soluble polyphenols is therefore dependent of the carbohydrase, as proteins with different compositions will interact differently with other molecules. Radical scavenging data showed that Cel1 and Vis1 had higher quenching effects on ROO radicals with activities of 22.1 ± 0.8 and 23.5 ± 1.2 μM Trolox Equivalents/g defatted brans. Meanwhile, CTL2 had the highest HO radicals inhibition (49.4 ± 2.8%) compared to 10.8-32.3% for others. Samples that highly inhibited lipoxygenase (LOX), an enzyme involved in lipid oxidation were Cel1 (23.4 ± 2.3%) and CTL1 (18 ± 0.4%).
本研究使用多糖降解酶和蛋白质沉淀法从燕麦中提取多酚，并测定其生物活性。将两份燕麦麸分别用粘性酶（Vis）、纤维素酶（Cel）处理或不进行酶处理（对照，CTL），然后，一组去除蛋白质（Vis1、Cel1、CTL1），另一组不进行处理（Vis2、Cel2、CTL2）。高效液相色谱分析表明，对于纤维素酶处理的麸皮，蛋白质沉淀使酚酸和燕麦酰胺增加了14%。同时，粘性酶处理的麸皮和对照麸皮分别下降了67%和20%。因此，蛋白质沉淀对可溶性多酚的影响取决于碳水化合物酶，因为不同组成的蛋白质与其他分子的相互作用不同。自由基清除数据表明，Cel1和Vis1对ROO自由基具有较高的淬灭作用，活性分别为22.1±0.8和23.5±1.2μM Trolox当量/克脱脂麸皮。同时，CTL2对HO自由基的抑制作用最高（49.4±2.8%），而其他样品的抑制作用为10.8 - 32.3%。对参与脂质氧化的脂氧合酶（LOX）具有高度抑制作用的样品是Cel1（23.4±2.3%）和CTL1（18±0.4%）。
