CONTENTS AND STRUCTURAL FEATURES OF WATER-EXTRACTABLE ARABINOGALACTANIN WHEAT-FLOUR FRACTIONS

In Camp Remy Buhler MLU-202 roller mill flour fractions, the levels of water-extractable arabinoxylan (WE-AX) (0.30-0.41%, dry basis) were c omparable to those of water-extractable arabinogalactan (WE-AG) (0.29- 0.38%, dry basis). Minaret had more WE-AX (0.49-6.68%, dry basis) than WE-AG (0.27-0.36%, dry basis). The ratio of WE-AG to WE-AX for the di fferent flour fractions varied between 0.83 and 1.03 for Camp Remy and between 0.46 and 0.57 for Minaret. For both wheat varieties, the perc entage of WE-AX and WE-AG was higher for the second and third reductio n roll fractions than for the three break and the first reduction roll fractions. There was little structural variation in WE-AG of differen t flour fractions. The arabinose to galactose (A/G) ratio (w/w) varied between 0.63 and 0.69 for Camp Remy WE-AG and between 0.66 and 0.72 f or Minaret WE-AG. The molecular weight range of the water-extractable arabinogalactan-peptide (WE-AGP) isolated from the different flour fra ctions of Camp Remy and Minaret was 5 x 10(4)-10 x 10(4). The H-1 NMR spectra of the WE-AGP isolated from the different flour fractions were comparable and display the following diagnostic peaks (300 MHz, D2O, 85 degrees C): delta 5.26, anomeric protons of a-linked arabinofuranos yl residues; and delta 4.47-4.54, anomeric protons of beta-linked gala ctose residues.