葵花籽壳木质素的结构分析及抗氧化活性

发布时间：2018-05-10 19:29

  本文选题：葵花籽壳 + 醋酸法　； 参考：《食品科学》2017年07期

【摘要】：以葵花籽壳为原料,采用醋酸法提取木质素,并利用凝胶渗透色谱、紫外光谱、傅里叶变换红外光谱、核磁共振氢谱和热重分析对提取的木质素进行结构表征,并对提取木质素的抗氧化活性进行评价。结果表明:醋酸法木质素提取率为70.12%(相对于Klason木质素),纯度达到88.54%,结合少量的碳水化合物(2.92%)。葵花籽壳木质素为GS型木质素,含有较高的愈创木基结构单元(G),结构单元之间的连接键以β-O-4结构为主,重均分子质量(M_w)、数均分子质量(M_n)和多分散度(M_w/M_n)分别为2 977、1 931 D和1.54。葵花籽壳醋酸提取的木质素主要降解温度在200~400℃之间,最大失质量速率为0.32%/℃。抗氧化活性研究表明,木质素清除1,1-二苯基-2-三硝基苯肼自由基指数值为1.54,显著高于商业合成抗氧化剂二丁基羟基甲苯(0.94),具有很好地应用于食品及其他工业做抗氧化剂的前景。
[Abstract]:The lignin extracted from sunflower seed shell was extracted by acetic acid method. The structure of lignin was characterized by gel permeation chromatography, ultraviolet spectrum, Fourier transform infrared spectroscopy, nuclear magnetic resonance (NMR) and thermogravimetric analysis (TGA). The antioxidant activity of extracted lignin was evaluated. The results showed that the extraction rate of lignin by acetic acid method was 70.12 (relative to Klason lignin, the purity was 88.54 and a small amount of carbohydrate was combined with 2.92%). Sunflower husk lignin is GS type lignin, which contains a high guaiac-based structure unit, and the connecting bonds between the structural units are mainly 尾 -O-4 structure. The weight average molecular weight (WMW) and the number average molecular weight (MN) and the polydispersity of MW / M _ (n) are 2997 1 931 D and 1. 54 respectively. The main degradation temperature of lignin extracted by acetic acid from sunflower seed shell was between 200 鈩，

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