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Improving the extractability of arabinoxylans and the molecular weight of wheat endosperm using extrusion processingAbdulmannan, Fadel; Jason, Ashworth; Andrew, Plunkett; Mahmoud, Ayman M.; Yazan, Ranneh; University of Leeds; Manchester Metropolitan University; Beni-Suef University; Universiti Putra Malaysia; University of Chester (Elsevier, 2018-09-14)Cereal derived arabinoxylans (AXs) are non-starch polysaccharides that have immunomodulatory activities. These activities are thought to be related to the low molecular weight fractions of AXs. Wheat and wheat by-products are rich in AXs, however, the water extractable fraction of AXs in wheat products is low. Water extraction of AXs can be improved by extrusion processing, which increases the extractability of the water soluble fraction. The aim of this study was to determine the extractability and molecular weight of the water soluble fraction of AXs from wheat endosperm after extrusion at screw speeds of 80 and 160 rpm. Extrusion processing significantly (P<0.05) increased the water extractability of AXs in a screw-speed dependent manner (13.07±0.12% at 80 rpm and 15.45±0.16% at 160 rpm compared to8.95±0.10% in the non-extruded control) due to a significant increase (P<0.05) in low molecular weight fractions of AXs in extruded samples.
Regulation of Inducible Nitric Oxide Synthase by Arabinoxylans with molecular characterization from Wheat Flour in Cultured Human MonocytesZhengxiao, Zhang; Christopher, Smith; Jason, Ashworth; Weili, Li; Manchester Metropolitan University; University of Chester (Wiley, 2018-01-08)The immunomodulatory activity of the arabinoxylans (AXs) extracts from cereal sources has been reported to impart health benefits in terms of immune enhancement. This study investigated the effect of enzymatic extraction on extraction yield and structure of AXs from wheat flour pentosan fraction. Under the optimised conditions, the extraction yield of AXs reached up to 81.25%. Furthermore, the study determined whether water-extracted AXs (WEAXs) and enzyme-extracted AXs (E-WEAXs) from wheat flour were able to differentially stimulate nitric oxide (NO) secretion through increased levels of inducible nitric oxide synthase (iNOS) in human U937 monocytes. The results indicated that AXs concomitantly induced (P < 0.05) both NO and iNOS productions in U937 monocytes compared to untreated cells. Compared with WEAXs, E-WEAXs resulted in a higher proportion of low Mw (1–10 KDa) AXs (49.51% vs. 19.11% in WEAXs), a higher A/X ratio (0.83 vs. 0.48 in WEAXs) and a higher yield (12.83 ± 0.35% vs. 7.54 ± 0.47% in WEAXs). Moreover, E-WEAXs induced significantly (P < 0.05) greater NO and iNOS production per million viable cells (61.8 ± 2.7 μm and 42.41 ± 3.83 ng respectively) than WEAXs (51.6 ± 2.6 μm and 33.46 ± 1.48 ng, respectively). The findings suggest AXs may heighten innate immune activity in the absence of infection or disease through an iNOS-mediated stimulation of NO production. The immunomodulatory activity of the wheat-derived AXs was enhanced by enzyme treatment, with low Mw and high A/X ratio associated with elevated NO/iNOS levels in human monocytes compared to water extraction.