Certain physical properties of water soluble non-starch polysaccharides from wheat, rye, triticale, barley and oats

Abstract

The yield of water soluble non-starch polysaccharides (WSNSP) prepared from whole grains of wheat, rye, triticale, barley and oats was 0.6, 1.8, 0.7, 1.2 and 1.0% respectively of the dry matter. The WSNSP from wheat, rye and triticale contained mainly pentoses (74, 86 and 81% respectively of the total monosaccharides), while in the WSNSP of barley and oats glucose (74 and 69% respectively of the total monosaccharides) was the main monosaccharide. All the WSNSP samples contained some amount of protein (7% in rye-WSNSP to 18% in triticale-WSNSP) attached to their low molecular weight fractions as observed in the gel permeation chromatographic separation. The major amino acids in these samples were aspartic and glutamic acids. No hydroxyproline was found in these samples. Their water binding capacity determined as the amount of unfreezable water using differential scanning calorimetry showed that the WSNSP of wheat, rye, triticale, barley and oats was 0.41, 0.47, 0.42, 0.49 and 0.44 g/g dry matter respectively. The WSNSP of wheat and barley showed higher emulsifying capacities determined as the amount of oil emulsified by one gram of the sample in water. The intrinsic viscosity of the water solutions of these non-starch polysaccharides shows a direct relation to their molecular weight and their simha shape factors indicated that all the samples were of an extended shape. However, the intrinsic viscosity of the water solution of rye-WSNSP was significantly higher than that of wheat, triticale, barley and oats.