Free sugars and non-starch polysaccharides–phenolic acid complexes from bran, spent grain and sorghum seeds.

Free sugars and non-starch polysaccharide-phenolic acid complexes were isolated from sorghum seeds and their
major by-products namely bran and spent grain. Total sugar (12.56%) and reducing sugar (10.47%) in free
sugars were highest in spent grain. The major soluble sugars identified in materials were maltose, glucose,
sucrose, fructose, and raffinose. Hemicelluloses B (2.95–10.82%) and calcium hydroxide extractable polysaccharides
(CHEP) (2.20–5.22%) were obtained with the highest yields. The CHEP fractions were completely
water-soluble. The major sugars identified in non-starch polysaccharides (NSP) fractions were arabinose, xylose,
galactose, and glucose. The Pentose/Hexose ratio was highest in CHEP, in spent grain, it was fourteen-fold that
of bran. Ferulic, coumaric and p-hydroxybenzoic acids were present in all the NSP and absent in the alkaliinsoluble
residues, ferulic acid (56.31–100.73 mg/100 g sample) being the major phenolic acid present. Ferulic,
coumaric and vanillic acids were identified as the major phenolic acids in CHEP fractions. Based on their solubility,
pentose and phenolic acid contents, NSP from sorghum by-products especially CHEP could exhibit high
functional properties when added to foods.