Maness N O, Ryan J D, Mort A J
Department of Biochemistry, Oklahoma State University, Stillwater 74078-0454.
Anal Biochem. 1990 Mar;185(2):346-52. doi: 10.1016/0003-2697(90)90306-t.
A procedure for the determination of the degree of methyl esterification of pectin in virtually any sample is described. Samples were dissolved or suspended in 1 M imidazole buffer, pH 7.0, cooled on ice, and reduced with sodium borohydride. Quantitative reduction of samples was accomplished after 1 h using at least 20 mg sodium borohydride/mg sample. The degree of methyl esterification was determined by either the increase in galactose content as determined by GLC of the sugar or by the change in galacturonic acid content by colorimetric uronic acid analyses. Sample requirements were at least as low as 100 micrograms per determination by GLC or 2 to 3 mg per determination by colorimetric uronic acid analysis compared to 5 mg or more per determination for other published procedures. The degrees of methyl esterification determined by the methods described have compared very favorably with those determined by established methods.
本文描述了一种用于测定几乎任何样品中果胶甲酯化程度的方法。将样品溶解或悬浮于pH 7.0的1 M咪唑缓冲液中，在冰上冷却，并用硼氢化钠还原。使用至少20 mg硼氢化钠/mg样品，1小时后可实现样品的定量还原。甲酯化程度可通过糖的气相色谱法测定的半乳糖含量增加或比色法测定的半乳糖醛酸含量变化来确定。与其他已发表方法每次测定至少需要5 mg或更多样品相比，本方法的样品需求量低至气相色谱法每次测定至少100微克或比色法每次测定2至3 mg。通过所述方法测定的甲酯化程度与通过既定方法测定的结果相比非常有利。
