高沸醇溶剂法提取胡萝卜木质素

Extraction of Lignin from Carrot Root with High Boiling Solvent

以乙二醇水溶液为溶剂,采用高沸醇溶剂法(high boiling solvent,HBS)从胡萝卜中提取木质素。结果表明,将胡萝卜干粉投入到质量分数为80%的乙二醇中,在210℃、料液质量比为1∶6的条件下蒸煮2 h,木质素收率最高(17.79%)。采用红外光谱(FTIR)、紫外光谱(UV)和核磁共振(1HNMR)等测试技术对其结构进行了表征。结果表明,高沸醇法提取的胡萝卜木质素具有木质素类化合物的典型结构特征。通过元素分析和甲氧基含量的测定,得到胡萝卜木质素的C9结构模型为C9H9.62O1.99(OCH3)0.96。利用Fenton反应产生羟基自由基.OH,研究了胡萝卜木质素对羟基自由基的抑制效率。结果表明,胡萝卜木质素在较低的浓度(50 mg/L)下对羟基自由基就具有较强的抑制效果,抑制率最高可达64.9%。

Lignin was extracted from carrot root with high boiling solvent（HBS） 80% ethylene glycol aqueous solution as solvent.Results show that the optimum conditions were as follows：the mass ratio of raw solid materials to solvent was 1∶6,temperature was 210 ℃,reaction time was 2 h,the maximum yield was 17.79%.The chemical structure of the carrot lignin has been characterized by FTIR, UV,and 1H NMR.The chemical composition of HBS lignin from carrot root was determined by elemental analysis,and the content of methoxyl was tested with Viebck′s methods.The C_9 structure of lignin from carrot was estimated as C_9H_9.62O_1.99（OCH_3）_0.96.The elimination efficiency of ·OH free radical by lignin from carrot was studied.The results show that carrot lignin can inhibit the activity of ·OH free radical at low concentrations（50 mg/L）with a maximum inhibition efficiency of 64.9%.