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摘要：阿拉伯木聚糖（AX）是谷子细胞壁的主要结构多糖，具有高分子量、高粘度、氧化胶凝等物化特性。在小米糠中，AX主要分为水溶性AX和水不溶性AX两部分。本论文中，主要研究小米糠中水溶性AX的水提取法和水不溶性AX的酶水解和超声辅酶水解的提取方法。小米糠中水溶性AX的水提取法中，脱脂小米糠的细度筛选以及物料比（µg/mL）是影响水溶性AX提取率的重要因素。研究表明，脱脂小米糠的细度大于100目时，水溶性AX的提取产率较高；脱脂小米糠的料液比在1:12时水溶性AX的提取产率达到最大。小米糠中水不溶性AX的酶水解和超声辅酶水解的提取方法中，纤文素酶的作用温度、pH和时间以及木聚糖酶的添加量是影响水不溶性AX提取率的重要因素。实验研究表明，温度为45℃、pH为4.2、酶解时间为3h、木聚糖酶的添加量为180U/g的条件下，水不溶性AX的提取产率最高。在超声辅酶水解的方法中，超声与酶水解作用的先后顺序对AX的提取产率的影响不显著。在AX的提取液中含有大量的杂蛋白，运用sevege、硅胶土处理、TCA和TCA-正丁醇结合法四种方法去除AX提取液中的杂蛋白，证明TCA-正丁醇法结合法去除杂蛋白的效果最好。34604
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毕业论文关键词：小米糠；阿拉伯木聚糖；纤文素酶；木聚糖酶；超声辅助法；提取
Study on Isolation of Arabinoxylan from Millet bran
Abstract：Arabian xylan (AX) is the main structural polysaccharide of the millet cell wall, with high molecular weight, high viscosity, oxidative gelation and other physical and chemical properties. In the millet bran, AX is pided into water-soluble AX and water-insoluble AX two parts. In this paper, the water extraction of water-soluble AX and the hydrolysis of water-insoluble AX and the extraction of ultrasonic assisted enzyme were studied. In the water extraction method of water-soluble AX in millet bran, the fineness of defatted millet bran and the ratio of material to liquid of defatted millet bran in water extraction are important factors affecting the extraction rate of water-soluble AX. The results showed that the yield of water-soluble AX was higher when the fineness of defatted millet bran was higher than 100 mesh, and the yield of water-soluble AX was the highest at 1:12. The temperature, pH and time of the cellulase and the amount of xylanase are the important factors influencing the extraction rate of water insoluble AX. The results showed when the temperature was 45 ℃, the pH was 4.2, the time of enzymolysis was 3h, the dosage of xylanase was 180U / g, and the yield of water insoluble AX was the highest. In the method of ultrasonic assisted enzymatic hydrolysis, the order of ultrasound and enzymatic hydrolysis effect on the extraction yield of AX was not significant. AX extract contains a large amount of hybrid protein, then four methods of sevege, silica gel treatment, TCA and TCA-n-butanol were used to remove the protein from AX extract, results showed that TCA-n-butanol method was the best method to remove protein.
Key words：millet bran; arabinoxylan; cellulase; xylanase; ultrasonic-assisted method；isolation
目录
摘要 1
关键词 2
Abstract 2
Key words 2
1 材料与方法 2
1.1材料 2
1.1.1试验材料 2
1.1.2 主要试剂 2
1.1.3主要仪器设备 3
1.2 小米糠的脱脂处理 3
1.3小米糠中水溶性阿拉伯木聚糖的提取 3
1.3.1脱脂小米糠细度的筛选 3
1.3.2小米糠料液比的筛选 3
1.4小米糠中水不溶性阿拉伯木聚糖的分离提取研究[4] 4
1.4.1纤文素酶酶解温度的确定 4