Cereal Chem 52:44 - 56. | VIEW
Water-Soluble Pentosans of Wheat Flour. I. Viscosity Properties and Molecular Weights Estimated by Gel Filtration.
S. K. Patil, C. C. Tsen, and D. R. Lineback. Copyright 1975 by the American Association of Cereal Chemists, Inc.
Crude and purified water-soluble pentosans were obtained from flour and freeze-dried doughs (nonrested or rested 3 hr. at 30 C.; with and without added oxidants). Yields of pentosans increased in the order, flour, nonrested dough, rested dough. Specific viscosity of pentosans from nonrested doughs equaled that of those from flour, but adding potassium bromate and iodate (1 microequivalent oxidant per g. flour) to doughs during mixing increased pentosan viscosity. Presence of bromate in flour-water dough apparently did not, however, recover the gelling ability of pentosan lost during resting of the doughs. The increased viscosity of pentosans obtained from doughs treated with oxidizing agents indicated that fraction II (obtained from chromatography of the water-soluble pentosans on DEAE-cellulose) might be involved in the interaction with oxidizing agents (bromate and iodate) added during mixing. Gel filtration of individual DEAE- cellulose fractions from flour pentosans showed that fraction II, a glycoprotein responsible for gelation, contained a high-molecular-weight component (MW 95,000, as estimated by gel filtration), representing 26.7% of the total purified pentosans. About 46% of the purified pentosans had MW greater than 85,000, and about 91% had MW greater than 40,000.