Small grain cereals compared for dietary fibre and protein contents

Abstract

The content of dietary fibres (cellulose, hemicellulose, lignin, NDF, ADF), tryptophan and proteins, as well as their quality index were determined in whole grains of bread and durum wheat, rye, hull-less barley and hull-less oat, each represented with four genotypes. In addition, content of β-glucans in hull-less barley were determined. In average, hull-less barley and oat had the lowest content of hemicellulose (22.54 and 13.11% d.m., respectively), cellulose (1.36 and 1.41% d.m., respectively), lignin (0.98 and 0.49% d.m., respectively), as well as NDF (24.84 and 15.16% d.m., respectively) and ADF (2.30 and 2.04% d.m., respectively). In average, the highest content of hemicellulose was in durum wheat (33.47% d.m.), followed by rye (29.63% d.m.), and bread wheat (23.24% d.m.). Among tested hull-less barley genotypes the the content of β-glucans ranged from 4.1% d.m. (IWHBON 97-18) to 5.6% d.m. (Apolon). The highest content of proteins (on average 15.65% d.m.) and tryptophan (on average 0.206% d.m.) was in hull-less oat. Hull-less barley had the highest protein quality index (1.48%) followed by bread and durum wheat and hull-less oat (IQ 1.35, 1.34 and 1.31%, respectively), and rye (IQ 0.93%). The results indicate that there is genetic diversity in content of dietary fibres and proteins among tested genotypes and that it should be possible to selectively breed for lines with high nutrition capacities, as well as, to improved diet requirements.