Cell wall composition of 1B/1R translocation wheat grains

Abstract

AbstractThe cell wall composition and total dietary fibre content of 12 different winter wheat cultivars both without and with 1B/1R gene were analysed. Translocation wheat (with 1B/1R gene) had higher contents of extractable xylose and unextractable mannose residues than standard wheat (without 1B/1R gene). Three sieved flours of standard wheat, translocation wheat and rye respectively were used for further detailed studies. Water‐extractable arabinoxylan was isolated and fractionated on a DEAE‐cellulose column. The water‐eluted fraction of translocation wheat had a higher proportion of monosubstituted xylose residues than the same fraction of standard wheat, which is a typical feature of rye arabinoxylan. Molecular weight determination showed that rye water‐eluted arabinoxylans were larger than those of wheat. The molecular weight of translocation wheat arabinoxylan was lower than that of standard wheat and had a high polydispersity. Xylanase‐resistant arabinoxylan was extracted from all three flours, and NMR studies showed that wheat xylanase‐resistant arabinoxylan had a lower amount of monosubstituted xylose residues, while the rye fraction was rich in consecutive disubstituted xylose residues. Translocation wheat xylanase‐resistant arabinoxylan resembled that of standard wheat.© 2002 Society of Chemical Industry