食品科学

• 基础研究 • 上一篇    下一篇

葵花籽壳木质素的结构分析及抗氧化活性

龚卫华1,2,马 玥1,吕 霞1,叶发银1,赵国华1,3,*   

  1. 1.西南大学食品学院,重庆 400715;2.吉首大学师范学院,湖南 吉首 416000;3.重庆市特色食品工程技术研究中心,重庆 400715
  • 出版日期:2017-04-15 发布日期:2017-04-24

Structural Features and Antioxidant Activities of Lignin Extracted from Sunflower Seed Shell

GONG Weihua1,2, MA Yue 1, LÜ Xia1, YE Fayin1, ZHAO Guohua1,3,*   

  1. 1. College of Food Science, Southwest University, Chongqing 400715, China; 2. College of Normal, Jishou University, Jishou 416000, China; 3. Chongqing Engineering Research Centre of Regional Foods, Chongqing 400715, China
  • Online:2017-04-15 Published:2017-04-24

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(Mw)、数均分子质量(Mn)和多分散度(Mw/Mn)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。

关键词: 葵花籽壳, 醋酸法, 木质素, 结构分析, 抗氧化活性

Abstract: Lignin was extracted from sunflower seed shell using acetic acid. The structural features of the isolated lignin were characterized by gel permeation chromatography (GPC), ultraviolet spectroscopy (UV), infrared spectroscopy (FT-IR), hydrogen-1 nuclear magnetic resonance spectrocopy (1H-NMR) and thermogravimetry (TG). In addition, the antioxidant activity of the lignin was evaluated by 1,1 diphenyl-2-trinitrobenzene hydrazine (DPPH) radical scavenging activity assay. The results showed that the yield and purity of lignin extracted from sunflower seed shell were 70.12% (based on Klason lignin) and 88.54%, respectively, and the content of lignin-associated carbohydrates was 2.92%. The lignin was GS-type lignin with β-O-4 ether bond as the major inter-unit linkage, having a high proportion of guaiacyl (G) units. The weightaverage molecular (Mw), number-average molecular (Mn) and polydispersity (Mw/Mn) of the lignin were 2 977, 1 931 D and 1.54, respectively. It major decomposition temperature was 200–400 ℃ and the maximum weight loss rate was 0.32%/℃. We found that the lignin showed stronger antioxidant activity than butylated hydroxytoluene (BHT) with free radical scavenging index (RSI) of 1.54 versus 0.94. The results suggested that acetic acid extraction provides a promising way to prepare lignin from sunflower seed shell with a good potential as an antioxidant in food and other industries.

Key words: sunflower seed shell, acetic acid extraction, lignin, structural feature, antioxidant activity

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