Menzies A R, Osman M E, Malik A A, Baldwin T C
Research Division, North East Wales Institute, Clwyd, UK.
Food Addit Contam. 1996 Nov-Dec;13(8):991-9. doi: 10.1080/02652039609374485.
The physiochemical and immunological properties of three Sudanese gum arabic samples and four gum tahla samples (two Sudanese, one West African and one Tanzanian--Acacia seyal var. seyal) were compared. The optical rotation (ca -30 degrees) and rhamnose (12-14%), arabinose (24-29%), galactose (36-42%), glucuronic acid (16-17%), nitrogen (0.327-0.365%) and protein (2.16-2.41%) contents of the gum arabic samples were consistent with the FAO (1990) specification for Acacia gum. In contrast the gum tahla samples had positive [alpha]D values (+45 degrees to +54 degrees), lower rhamnose (3-4%) and higher arabinose (41-45%) contents and lower nitrogen (0.147-0.175%), and hence protein (0.97-1.15%), contents. All of the gum arabic samples precipitated with beta-glucosyl Yariv reagent and hence were shown to contain arabinogalactan-protein(s) (AGPs), whereas in all but one of the gum tahla samples AGPs were not detected. The strong interaction of gum tahla with a monoclonal antibody known to recognize arabinose residues present in AGPs and arabinogalactans (AGs) was consistent with the observed higher levels of arabinose present in the gum tahla samples relative to the gum arabic samples. The data presented confirm that there are a number of physicochemical and structural differences between gum arabic (A. senegal gum) and gum tahla (A. seyal gum), and that a quick and simple immunological technique (immunodot blots) using an antiAGP/AG monoclonal antibody (MAC 207) could be used to screen for the presence of gum tahla in gum arabic consignments.
对三个苏丹阿拉伯树胶样品和四个塔赫拉胶样品（两个苏丹的、一个西非的和一个坦桑尼亚的——阿拉伯胶树塞内加尔变种）的物理化学和免疫学特性进行了比较。阿拉伯树胶样品的旋光度（约 -30 度）以及鼠李糖（12 - 14%）、阿拉伯糖（24 - 29%）、半乳糖（36 - 42%）、葡萄糖醛酸（16 - 17%）、氮（0.327 - 0.365%）和蛋白质（2.16 - 2.41%）含量符合粮农组织（1990 年）对阿拉伯树胶的规范。相比之下，塔赫拉胶样品的[α]D 值为正（+45 度至 +54 度），鼠李糖含量较低（3 - 4%），阿拉伯糖含量较高（41 - 45%），氮含量较低（0.147 - 0.175%），因此蛋白质含量也较低（0.97 - 1.15%）。所有阿拉伯树胶样品都能与β - 葡萄糖基亚里夫试剂沉淀，因此表明含有阿拉伯半乳聚糖蛋白（AGPs），而除了一个塔赫拉胶样品外，在其他所有塔赫拉胶样品中均未检测到 AGPs。塔赫拉胶与一种已知能识别 AGPs 和阿拉伯半乳聚糖（AGs）中阿拉伯糖残基的单克隆抗体有强烈相互作用，这与观察到的塔赫拉胶样品中阿拉伯糖含量相对于阿拉伯树胶样品更高的情况一致。所呈现的数据证实，阿拉伯树胶（塞内加尔阿拉伯胶）和塔赫拉胶（阿拉伯胶树胶）之间存在许多物理化学和结构差异，并且一种使用抗 AGP/AG 单克隆抗体（MAC 207）的快速简单免疫学技术（免疫斑点印迹）可用于筛查阿拉伯树胶货物中是否存在塔赫拉胶。
