Water unextractable polysaccharides from three milling fractions of rye grain
Water unextractable polysaccharides from three milling fractions of rye grain
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DOI：
10.1016/s0144-8617(96)00071-9
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发表时间：
1996-08-01
影响因子：
11.2
通讯作者：
Aman, P
中科院分区：
文献类型：
--
作者：
Nilsson, M;Saulnier, L;Aman, P
用饱和氢氧化钾、水、4M氢氧化钾和水在室温下依次提取麦麸皮、中间制粉和过筛黑麦籽粒中的水不可浸出物，然后在沸水浴中用2M氢氧化钾萃取，得到了可重复回收的萃取物和收集级分中的多糖残留物。不同水浸出物提取液和残留物中多糖残留量的总回收率为78-88%。提取液中90-93%的碳水化合物为阿拉伯糖和木糖残基。随后用水提取得到一组分，其中-68%的碳水化合物是葡萄糖残留物。采用热碱提取法得到的萃取物中，85-89%的碳水化合物为阿拉伯糖和木糖残基。收集的馏分中的Ara/Xyl比值在0.1-1.3之间，其中4M氢氧化钾萃取物中和后沉淀的馏分中的比值最低，而未萃取残渣中的比值最高。H-1-核磁共振波谱的结构表征表明，不同提取物中阿拉伯木聚糖的取代模式不同，提取物中的葡萄糖残留量主要来自混合连接的β-葡聚糖。与其他主要提取物相比，氢氧化钡提取物中二取代木糖残基的比例较低。采用热碱提取法提取了高支化杂木聚糖。在所有起始原料的相应提取物中发现的多糖具有基本相似的结构特征，但得率有很大差异。版权所有(C)1996爱思唯尔科学有限公司
Water unextractable material from bran, an intermediate milling fraction and sieved flour of rye grain were sequentially extracted at room temperature with saturated barium hydroxide, water, 4 M potassium hydroxide and water followed by extraction with 2 M potassium hydroxide in a boiling water bath, giving repeatable recoveries of extracts and polysaccharide residue compositions in collected fractions. Total recoveries of polysaccharide residues in extracts and residue from the different water unextractable materials were 78-88%. Extracts in which 90-93% of the carbohydrates were arabinose and xylose residues were obtained by extraction with saturated barium hydroxide. Subsequent extraction with water yielded a fraction in which 64-68% of the carbohydrates were glucose residues. The extraction with hot alkali resulted in extracts in which 85-89% of the carbohydrates were arabinose and xylose residues. The ara/xyl ratio in the collected fractions ranged from 0.1-1.3, with the lowest ratios in fractions that precipitated after neutralisation of the 4 M potassium hydroxide extract and the highest ratios in the unextractable residues. Structural characterisation with H-1-NMR spectroscopy revealed varying substitution patterns for arabinoxylans in the different extracts and that glucose residues in the extracts essentially originated from mixed-linked beta-glucan. The proportion of disubstituted xylose residues was lower in barium hydroxide extracts compared to the other main extracts. A highly branched heteroxylan was extracted with hot alkali. The polysaccharides found in the corresponding extracts for all the starting materials had generally similar structural features, but the yield differed considerably. Copyright (C) 1996 Elsevier Science Ltd