采用碱法和二甲亚砜法从苹果膳食纤维中提取出4种半纤维素,分别命名为半纤维素A、B、C和E,通过红外分析和电镜扫描对其化学组成和表面微观结构进行了研究。结果表明:苹果膳食纤维中半纤维素由木葡聚糖(半纤维素A)、木聚糖1(半纤维素B)和木聚糖2(半纤维素C)以及半乳甘露聚糖(半纤维素E)等组成,4种半纤维素的表面微观各不相同,木聚糖1颗粒表面呈规则的晶形外观,具有成晶性;木葡聚糖颗粒表面具有很多颗粒状结构,具有一定的成晶性;木聚糖2和半乳甘露聚糖颗粒表面呈不规则形状,不具有成晶性。

In this paper,four hemicelluloses were extracted through alkali or dimethyl sulfoxide form the apple dietary fiber,hemicellulose A,B,C and E.The chemical composition and surface micro-structure of the four hemicelluloses were studied by FTIR and SEM.It was found that the hemicelluloses in apple dietary fiber were composed of xyloglucan(hemicellulose A),xylanase 1(hemicellulose B)and xylanase 2(hemicellulose C)and galactomannan(hemicellulose E).Surface micro-structure on four hemicellulose grain were very different,xylanase 1 has regular appearance of the crystal shape,crystalline nature.Xyloglucan has granular appearance,a certain degree of crystalline nature.xylanase 2 is non-crystalline with irregular surface.