  2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center  |
|
261
Starch from hull-less barley: I. Granule morphology, composition and amylopectin structure. J. H. LI (1), T. Vasanthan (1), B. Rossnagel (2), and R. Hoover (3). (1) Dept. of Agricultural, Food & Nutritional Sci., University of Alberta, Edmonton, AB, T6G 2P5, Canada; (2) Crop Development Centre, University of Saskatchewan, Saskatoon, SK; (3) Dept. of Biochem., Memorial University of Newfoundland, St. John's, NF.
The granule morphology, granule size distribution, and amylopectin structure of the starches extracted from ten hull-less barley genotypes [waxy (CDC Candle, CDC Alamo, SB 94912, SB 94917), normal amylose (Phoenix, CDC Dawn, SR 93102, SB 94860), and high amylose (SB 94893, SB 94897)] were studied by SEM, image analysis, and MALDI-MS. The starches from all genotypes consisted of a mixture of large lenticular and small irregularly shaped granules. The granules of most starches were intact, whereas in SB 94917, SR 93102, and SB 94860 they were compound. The total number and total weight of small and large granules (diameter greater than 10 micrometer) differed among genotypes. The debranched amylopectins of all starches exhibited the highest peak in the MALDI-MS spectrum at DP12. The average chain length and degree of branching ranged from 17.6 - 22.7% and 4.4 - 5.5%, respectively. The short (DP5-17) and long (DP bigger and equal to 35) chains ranged from 58.2 - 59.1% and 3.0-12.8%, respectively. The study showed that amylose/amylopectin ratio and amylopectin branch chain length correlated with granule size and size distribution in this set of barley genotypes.
Copyright 2001
The American Association of Cereal Chemists