Xylan-cellulose core structure of oat water-extractable β-glucan macromolecule: Insight into interactions and organization of the cell wall complex.

Water-extractable β-glucan with high molar mass (HM) determines health benefits of oat food. Oat β-glucan was extracted by a standardized in vitro digestion method and co-existing water-extractable polysaccharide (WEP) fraction and its HM-arabinoxylan (HM-AX) subfraction were isolated to identify their highly acid-resistant subunit and investigate molecular interactions between constituent polymers. The WEP and HM-AX samples consisted of arabinoxylans (AXs) (74 and 76 %, respectively), however, cellulose constituted the secondary component (6.

Evidence of intermolecular associations of β-glucan and high-molar mass xylan in a hot water extract of raw oat groat.

High molar mass (HM) β-glucan present in oat products can reduce the risk of diet-related diseases, mainly owing to significantly increased digesta viscosity in human small intestine. To verify a research hypothesis that arabinoxylan (AX) present in oat water extract is associated with HM-β-glucan and thus may influence its functionality, multi-detection HPSEC coupled with enzymatic hydrolysis, sugar and H NMR analyses were performed. Isolated cell wall polysaccharide fraction comprised branched AX (arabinose-to-xylose ratio, Ara/Xyl ~ 0.

Soluble and cell wall-bound phenolic acids and ferulic acid dehydrodimers in rye flour and five bread model systems: insight into mechanisms of improved availability.

Background: The bread-making process influences bread components, including phenolics that significantly contribute to its antioxidant properties. Five bread model systems made from different rye cultivars were investigated to compare their impact on concentration of ethanol-soluble (free and ester-bound) and insoluble phenolics.

Results: Breads produced by a straight dough method without acid addition (A) and three-stage sourdough method with 12 h native starter preparation (C) exhibited the highest, genotype-dependent concentrations of free phenolic acids.

Mode of endosperm and wholemeal arabinoxylans solubilisation during rye breadmaking: genotypic diversity in the level, substitution degree and macromolecular characteristics.

Insight into solubilisation mechanisms of rye arabinoxylans during breadmaking is important for understanding the biochemical processes that affect bread attributes. Purified ethanol precipitated water-extractable arabinoxylans (WE-AX) and residual unextractable counterparts (WU-AX) were isolated from rye flours and resulting breads. While the endosperm flours had lower endoxylanase activities and higher arabinose-to-xylose ratios of WU-AX than those of corresponding wholemeals, there were not any significant differences between them in the mean amounts of WU-AX hydrolysed during breadmaking.

Depolymerization degree of water-extractable arabinoxylans in rye bread: characteristics of inbred lines used for breeding of bread cultivars.

The water-extractable arabinoxylans (WE AXs) present in rye bread govern its viscous properties, which may be related to reduced risk of cardiovascular diseases and diabetes. Breads made from rye cultivars generally exhibit higher AX-dependent extract viscosities (Cyran, M. R.

Genetic variation in the extract viscosity of rye (Secale cereale L.) bread made from endosperm and wholemeal flour: impact of high-molecular-weight arabinoxylan, starch and protein.

Background: To verify the viscous potential of rye bread made from population and hybrid cultivars, the overall extract viscosities (EVs) of endosperm and wholemeal breads (EBs and WMBs respectively) were assessed using extractants of different pH. Also, arabinoxylan-dependent EV (AX-EV) was determined after combined action of starch- and protein-degrading enzymes.

Results: The synergistic effect of a combination of α-amylase, amyloglucosidase and protease on EV was almost two times higher than the effects observed after single addition of each of them.

Structural characterization of feruloylated arabinoxylans and xylans released from water-unextractable cell walls of rye outer layers upon treatment with lichenase and cellulase.

Destarched and deproteinated water-unextractable material (WUM) of rye outer layers was sequentially treated with lichenase and cellulase to digest beta-glucans and a part of the cellulose. As a result, the polymeric cell-wall material (CWM) initially associated with these polysaccharides was released into solution (AXL and AXC for lichenase- and cellulase-extractable fractions, respectively). A portion of the material that self-aggregated during extractions was further solubilized with DMSO (XD and XD-P for the fraction left in the solution and that precipitated during dialysis, respectively).

Association and structural diversity of hemicelluloses in the cell walls of rye outer layers: comparison between two ryes with opposite breadmaking quality.

Looking for potential quality indicators, which could be used in early selection of breeding materials, the structural features of cell wall arabinoxylans (AX) from outer layers of the grain (pooled shorts and bran fractions) were studied in two ryes with diverse breadmaking quality. The successive alkaline extraction of water-unextractable material with saturated Ba(OH)2, followed by water and 1 and 4 M NaOH, resulted in four purified fractions, Ba, BaH, 1Na, and 4Na, respectively, that became water soluble after their isolation. The AX present in these fractions constituted approximately 43, 12, 14, and 4% of their total amount recovered.

Cell wall fractions isolated from outer layers of rye grain by sequential treatment with alpha-amylase and proteinase: structural investigation of polymers in two ryes with contrasting breadmaking quality.

Recent studies have indicated that some structural features of arabinoxylans, the major cell wall polysaccharides, might be potential quality markers in the selection of rye breeding materials. To specify the most appropriate characteristics, the differences in the structure of cell wall components were studied in two ryes with high and low breadmaking qualities. Two cell wall fractions were isolated from the outer layers of the grain (pooled shorts and bran fractions) by a consecutive water extraction with alpha-amylase (WE-A) and proteinase K (WE-P).