Characterization of (Glucurono)arabinoxylans from Oats Using Enzymatic Fingerprinting

Abstract

Cell wall material from whole oat grains was sequentially extracted to study the structural characteristics of individual arabinoxylan (AX) populations. Araf was singly substituted at both O-3 (mainly) and O-2 positions of Xylp, and no disubstitution of Xylp with Araf residues was found in oat AXs. Both highly substituted and sparsely substituted segments were found in AXs in Ba(OH)2 extracts, whereas AXs in 1 and 6 M NaOH extracts were rarely branched and easily aggregated. Both O-2-linked GlcA and 4-O-MeGlcA residues were present in oat AXs. A series of AX oligomers with galactose as a substituent was detected for the first time in oats. The present study suggested that the distribution of Araf was contiguous in oat AXs, different from the homogeneous distribution of Araf in wheat and barley AXs, which might result in different fermentation patterns in humans and animals.

Effects of pectin supplementation on the fermentation patterns of different structural carbohydrates in rats

“…Dry matter was determined by drying samples overnight in an oven at 103°C. Crude ash was measured by incineration at 550°C . Titanium dioxide in diets and digesta was analyzed using a UV spectrophotometer at 410 nm as described previously .…”

“…Starch and mixed linkage (1‐3),(1‐4)‐ β ‐D‐glucan ( β ‐glucan) contents were analyzed using the total starch and β ‐glucan kits from Megazyme (Bray, Ireland), respectively. The constituent monosaccharide composition of pectins and DF fractions present in the digesta was determined as described previously . Cellulose content was calculated from the difference between glucose present in NSP and glucose present in β ‐glucan.…”

Effects of pectin on fermentation characteristics, carbohydrate utilization, and microbial community composition in the gastrointestinal tract of weaning pigs

“…Feces and digesta were analyzed for dry matter by drying to a constant weight at 103°C . Protein content (N × 6.25) was determined using a Thermo Quest NA 2100 Nitrogen analyzer (Interscience, Breda, The Netherlands).…”

Endo-xylanases as tools for production of substituted xylooligosaccharides with prebiotic properties

“…The production of specific substituted XOS cleavage products, including AXOS and uronic acid xylooligosaccharides (UXOSs), has successfully been performed with members of both GH10 and GH11 families (Falck et al 2014 ; Tian et al 2015 ). However, xylanases belonging to family 10 are preferred due to their open substrate-binding cleft which can, for example, take in arabinose side groups at the − 2 and + 1 subsites and 4-O-methyl- d -glucuronic acid side groups at the − 3 and + 1 subsites (Mathew et al 2017 ) (Table 1 ).…”