黑小麦麦麸多糖的制备与分析

Preparation and Analysis of Polysaccharides from Black-Grain Wheat Bran

分别以水和饱和Ba(OH)2溶液为提取介质,采用高压辅助水提取、Ba(OH)2碱提取和碱后水提取等方法制备黑小麦麦麸中的水溶性和水不溶性多糖,并采用气相色谱(GC)、高效液相色谱(HPLC)和红外光谱(IR)分析黑小麦麦麸多糖组分的理化性质。结果表明:高压辅助水提组分(WEPH)主要由葡萄糖(G lc)、阿拉伯糖(Ara)和木糖(Xyl)组成,是β-葡聚糖和戊聚糖的混合物;Ba(OH)2碱提组分(AEPH)主要由Ara和Xyl组成,物质的量比为Ara:Xyl=1:1.66,表明含有较纯的戊聚糖,其Ara/Xyl比值为0.60;碱后水提组分(AEPH-H2O)的85%由葡萄糖(G lc)和半乳糖(Man)组成,主要为β-葡聚糖和阿拉伯半乳聚糖,以及少量戊聚糖。富含戊聚糖的AEPH组分相对分子质量最高,为3.81×105,而以β-葡聚糖为主的WEPH和AEPH-H2O组分的相对分子质量较低,其中单一峰组分AEPH-H2O为2.40×105。

Polysaccharide from black-grain wheat bran was prepared and characterization.Water soluble and water nonsoluble polysaccharides were obtained by sequentially extracting black-grain wheat bran with water assisted by high pressure,saturated barium hydroxid,or distilled water as extraction medium respectively.Physicochemical properties were analyzed using instruments GC,HPLC,and IR.Results： The fractions extracted with water assisted by high pressure（WEPH） are composed of glucose,arabinose,and xylose,which was the mixture of β-glucan（73%） and pentosan（27%）.The fractions extracted with saturated barium hydroxid（AEPH） are mainly composed of arabinose and xylose;the Ara/Xyl value is 0.60,indicating relative pure pentosan.The fractions extracted with distilled water（AEPH-H2O） are composed of glucose and galactose,mainly β-glucan,arabino-galactan and minor part of pentosan.AEPH,which is rich in pentosan,has a high Mw of 3.81×105,whereas WEPH and AEPH-H2O have relative low Mw,the Mw of AEPH-H2O is 2.40×105.