Determination of water-extractable polysaccharides in triticale bran

Abstract

The content, composition, and molecular weight distribution (MWD) profile of water-extractable polysaccharides (WEP) in triticale (×Triticosecale Whitm.) bran were determined. Results were compared against wheat (Triticum sp.) and rye (Secale sp.) bran, as well as triticale straw and flakes. The effects of the following conditions on the extractability of sugars were compared and respective fractions obtained: (1) boiling water extraction, WEP-I; (2) successive enzyme treatment and dialysis, WEP-II; (3) successive ethanol fractionation, WEP-III. Although the highest yield of WEP was generally found in fraction II, fraction III had the least level of simple sugars as unwanted co-extractives. The extractability of xylose (Xyl) and arabinose (Ara) in all bran samples significantly increased (P<0.05) by up to 23.3% and 3.2% respectively, after precipitation with 80% ethanol. Amongst the cereal brans, wheat bran possessed a significantly higher (P<0.05) molar % of Ara (19.5%) and Xyl (29.6%), followed by triticale bran (14.5% Ara, 17.2% Xyl), and lowest in rye bran (7.2% Ara, 13.4% Xyl). Triticale bran (TB) had higher molecular weight (MW) polysaccharides and the widest MWD range (4400–401,000Da) of WEP, suggesting greater bioactive potential and high grain hardiness; prospects to be further investigated in future studies.