钯炭（PdC）催化氢还原碱木质素的抗氧化性能详解.PDF

6 2013, Vol.34, No.07 食品科学 ※基础研究 钯/炭(Pd/C)催化氢还原碱木质素的抗氧化性能 蒲 伟，任世学，马艳丽，方桂珍* (东北林业大学材料科学与工程学院，黑龙江 哈尔滨 150040) 摘  要：以工业碱木质素为原料，采用购买和 自制两种钯/炭(Pd/C)为催化剂，氢气为还原剂，在高压条件下对其 进行还原反应，提高碱木质素的活性，并对其反应前后化学成分和抗氧化性能进行分析。结果表明：经过两种催 化剂高压催化活化后，购买催化剂还原碱木质素醇羟基含量为5.0 1%，酚羟基含量为3.64% 。自制催化剂还原碱木 质素醇羟基含量为5.35%，酚羟基含量为3.82% 。自制Pd/C催化剂催化体系的催化效果优于购买Pd/C催化剂；在抗 氧化性能分析实验中，碱木质素原料及两种被还原碱木质素在质量浓度范围为0.025～0.6mg/mL 内对DPPH 自由基 · 和 OH均有较强的清除能力，且随着木质素质量浓度的增加，清除率逐渐增加，还原力也增强，两种被还原碱木 质素DPPH 自由 · 基最大清除率分别达到80.91%和82.43%； OH最大清除率分别达到23.12%和26.21%。 关键词：钯/炭催化剂；碱木质素；抗氧化性能；还原；自由基 Antioxidant Activity of Hydrogen-Reduced Alkali Lignin Prepared Using Palladium/Carbon (Pd/C) as Catalyst * PU Wei ，REN Shi-xue ，MA Yan-li ，FANG Gui-zhen (College of Material Science and Engineering, Northeast Forestry University, Harbin 150040, China) Abstract ：In this study, commercial and laboratory-prepared Pd/carbon catalysts were used for the reduction of industrial alkali lignin by hydrogen under high pressure conditions in order to increase lignin activity. The chemical composition and antioxidant activity of alkali lignin and its reduced products were analyzed. The contents of alcohol hydroxyl groups and phenolic hydroxyl groups in commercial Pd/carbon activated alkali lignin were 5.0 1% and 3.64%, respectively, compared to 5.35% and 3.82% for laboratory-prepared Pd/carbon activated alkali lignin. Thus, the laboratory-prepared Pd/carbon has better catalysis performance than the commercial Pd/carbon. Both alkali lignin and its reduced products had strong radical scavenging activity against DPPH and hydroxyl radicals at a concentration ran