Health-related effects and improving extractability of cereal arabinoxylans

Abstract

Arabinoxylans (AXs) are major dietary fibers. They are composed of backbone chains of β-(1-4)-linked xylose residues to which α-l-arabinose are linked in the second and/or third carbon positions. Recently, AXs have attracted a great deal of attention because of their biological activities such as their immunomodulatory potential. Extraction of AXs has some difficulties; therefore, various methods have been used to increase the extractability of AXs with varying degrees of success, such as alkaline, enzymatic, mechanical extraction. However, some of these treatments have been reported to be either expensive, such as enzymatic treatments, or produce hazardous wastes and are non-environmentally friendly, such as alkaline treatments. On the other hand, mechanical assisted extraction, especially extrusion cooking, is an innovative pre-treatment that has been used to increase the solubility of AXs. The aim of the current review article is to point out the health-related effects and to discuss the current research on the extraction methods of AXs.

Non-Starch Polysaccharides in Wheat Beers and Barley Malt beers: A Comparative Study

“…The polysaccharide component of arabinogalactan-peptide was given as arabinogalactan [9] by Equation 5, which was calculated as a ratio of 0.70:1 for arabinose to galactose [8]. Mannose polymers content was calculated as mannan according to Equation (6).…”

“…AX is composed of a chain of β-D-xylopyranosyl residues, connected by β-1,4-glycosidic linkages, being either non-substituted or substituted with α-L-arabinofuranose at the C3 or C2 positions or at both in varying patterns [6]. The (1,3;1,4)-β-glucans are unbranched chains of D-glucopyranose residues with β-(1,4) linkages and β- (1,3) linkages in ratios ranging from 3.2:1 to 6.6:1 [7].…”

Improving the extractability of arabinoxylans and the molecular weight of wheat endosperm using extrusion processing

“…The chemical structure of AXs is based on backbone chains of -(1-4)-linked dxylopyranosyl residues to which -1-arabinofuranose units are linked as side chains in the second and/or third carbon positions, often called pentosans. Recently, AXs have been reported to have biological activities, such as antioxidant properties, lowering serum cholesterol, enhancing haemoglobin A1c concentration, improving glucose tolerance and promoting immunity (Fadel et al 2017a;Fadel et al 2017b;Fadel et al 2018).…”

“…The solubility of AXs depends on the balance between chain-chain interactions and any change in the structural features such as molecular weight, chain length, branching pattern and degree of branching (Saulnier et al 2007). The amount of AXs is different from one plant to another; total AXs in rice comprise 5.63 -7.15 % of the grain, with only 0.90 % of this being waterextractable (Fadel et al 2017a). In contrast, the amount of total AXs in wheat is 6-8 % (Li et al 2013), 25 % of which is water-extractable (Fadel et al 2017a).…”

“…The amount of AXs is different from one plant to another; total AXs in rice comprise 5.63 -7.15 % of the grain, with only 0.90 % of this being waterextractable (Fadel et al 2017a). In contrast, the amount of total AXs in wheat is 6-8 % (Li et al 2013), 25 % of which is water-extractable (Fadel et al 2017a). Differences in the amounts of AXs between plant species gives rise for the need to apply different extraction techniques to optimize the extraction of AXs.…”