Cereal Chem 65:424-427   |  VIEW ARTICLE

Ratio of A Chains to B Chains in Rice Amylopectins.

B. S. Enevoldsen and B. O. Juliano. Copyright 1988 by the American Association of Cereal Chemists, Inc. 

The ratio of A chains to B chains of rice amylopectins from two pairs of near isogenic lines differing in the waxy gene was determined by the action of pullulanase and of beta-amylase plus pullulanase on the beta- limit dextrins followed by the determination of maltotriose in the digests by quantitative gel filtration chromatography. Maltotriose is derived from A chains by the action of pullulanase on the beta-limit dextrin and from A and B chains by the combined action of beta-amylase and pullulanase. Waxy and nonwaxy (low-amylose) rice amylopectin were shown to have similar ratios of A to B chains of 1.1-1.5, despite differences in [eta] and freeze-thaw stability.