Department of Food Science, Swedish University of Agricultural Sciences, PO Box 7051, S-750 07 Uppsala, Sweden.
Carbohydr Res. 2012 Nov 1;361:105-13. doi: 10.1016/j.carres.2012.08.012. Epub 2012 Aug 31.
Building blocks represent the smallest, branched units found inside clusters of amylopectins. The building blocks from clusters of 10 different amylopectins, representing a wide variety of plants, were isolated and size-fractionated. The unit chain compositions were then analysed. It was found that the number of chains in building blocks increased in proportion to their size similarly in all samples regardless plant source. The smallest blocks (DP 5-9) consisted of 2 chains and the largest blocks (DP ≥45), of which generally only little existed, possessed ≥10 chains. Generally, the degree of branching increased with building block size, but the organisation of chains inside the blocks was unique for each sample. Nevertheless, compared to other plants, amylopectins from cereals (represented by rye, oats, rice and waxy maize) possessing elevated number of the shortest internal B-chains (DP 3-7), tended to have blocks with a lower ratio of A:B-chains, indicative of a preferred Haworth type of structure as opposed to the Staudinger configuration.
直链淀粉支链的最小分支单元是由直链淀粉簇中的结构单元组成的。从 10 种不同直链淀粉簇中分离出并按大小分级的结构单元，分析了其链组成。结果发现，所有样本中，不论植物来源，结构单元的链数与其大小成比例增加。最小的结构单元（聚合度 5-9）由 2 条链组成，而最大的结构单元（聚合度≥45）通常只存在少量的结构单元，其链数≥10。通常，分支度随结构单元的大小而增加，但各样本中链的排列方式是独特的。然而，与其他植物相比，含有大量最短内部 B-链（聚合度 3-7）的谷物直链淀粉（以黑麦、燕麦、大米和蜡质玉米为代表），其结构单元中 A-链与 B-链的比例较低，表明其具有更倾向于哈沃斯型结构而不是施陶丁格型结构。
