γ射线辐照降解木聚糖的机理研究

发布时间：2018-12-24 13:42

【摘要】：为了探讨γ射线辐照降解半纤维素的机理,以木聚糖为模型化合物,经0、200、400、600、800、1 000、1 200 k Gy剂量的辐照后,采用扫描电镜(SEM)、傅里叶拉曼光谱(FT-Raman)、气相色谱质谱联用仪(GC-MS)研究其表观形貌结构、分子结构及降解产物的变化特征。结果表明,γ射线辐照处理后木聚糖表观形貌结构发生破坏,多孔性增加;随着辐照剂量升高,木聚糖3 354 cm~(-1)处拉曼光谱峰强度降低且峰位发生红移,1 122 cm~(-1)和1 093 cm~(-1)处拉曼光谱峰强度逐渐减弱,表明木聚糖分子中的氢键、糖苷键发生破坏;木聚糖降解产物的GC-MS分析表明,辐照处理后木聚糖乙酸乙酯提取液中共检测到18种脂肪酸类化合物、5种糖类化合物和2种呋喃类化合物,其相对含量分别在1 200、800和1 200 k Gy达到最大值(16.59%、1.46%和1.03%)。本研究结果为木聚糖γ射线辐照降解产物全利用提供了支持。
[Abstract]:In order to investigate the mechanism of hemicellulose degradation by 纬 -ray irradiation, xylan was used as a model compound. After irradiation at a dose of 600,000,000,000,000k Gy, (SEM), Fourier Raman spectroscopy (FT-Raman) was used to investigate the degradation of hemicellulose by scanning electron microscope. Gas chromatography-mass spectrometry (GC-MS) was used to study the morphology, molecular structure and degradation products. The results showed that the apparent morphology of xylan was destroyed and the porosity increased after 纬 -ray irradiation. With the increase of irradiation dose, the intensity of Raman peak at 3 354 cm~ (-1) decreased and the peak position shifted red, and the intensity of Raman peak at 1 122 cm~ (-1) and 1 093 cm~ (-1) gradually decreased, indicating the hydrogen bond in xylan molecule. The glycoside bond was destroyed; GC-MS analysis of xylan degradation products showed that 18 fatty acids, 5 carbohydrates and 2 furans were detected in irradiated xylan ethyl acetate extract. The relative content reached the maximum at 1 200800 and 1 200 k Gy (16.5995% and 1.03%, respectively). The results of this study provide support for the full utilization of 纬-ray degradation products.
【作者单位】：湖南省农业科学院湖南省核农学与航天育种研究所/湖南省农业生物辐照工程技术研究中心;湖南省农业科学院湖南省农业生物技术研究中心;湖南农业大学湖南省种质创新与资源利用重点实验室;
【基金】：公益性行业(农业)科研专项(201503135-12)
【分类号】：O636.1

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