Department of Food Science, University of Guelph, Guelph, ON N1G 2W1, Canada.
Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55108, USA.
Carbohydr Polym. 2014 Nov 4;112:325-33. doi: 10.1016/j.carbpol.2014.05.051. Epub 2014 May 27.
Changes in internal structure of amylopectin (AP) during wheat endosperm development were studied by isolating clusters and building blocks of AP from both large A-type and small B-type starch granules at different maturity stages up to harvest time at 49 days after anthesis (DAA). Clusters isolated from B-type granules had a degree of branching (DB) of 16.5-16.8% and were more tightly branched than those isolated from A-type granules (DB 15.7-16.2%). The degree of polymerization (DP) of the clusters increased in both types of granules during the pre-physiological maturity stage up to 28 DAA. Clusters at maturity were smaller with less branches and building blocks than at the end of the pre-maturity stage. It is suggested that this was due to a continuous trimming of the cluster structure after the active period of starch synthesis. Differences were evident between A- and B-type granules with regards to glucan trimming and the type of new chains produced.
在小麦胚乳发育过程中，支链淀粉（AP）内部结构的变化通过从大 A 型和小 B 型淀粉颗粒中分离 AP 簇和构建块进行研究，这些颗粒取自授粉后 49 天（DAA）收获时间的不同成熟阶段。从 B 型颗粒中分离出的簇的分支度（DB）为 16.5-16.8%，比从 A 型颗粒中分离出的簇（DB 15.7-16.2%）更紧密。在预生理成熟阶段，两种类型的颗粒中簇的聚合度（DP）均增加，直至 28 DAA。与成熟阶段相比，簇在预成熟阶段末期的分支更少，体积更小。这表明，这是由于淀粉合成的活跃期过后，簇结构的不断修剪。A-型和 B-型颗粒在葡聚糖修剪和产生的新链类型方面存在明显差异。
