In comparison to the annual grain crops dominating current agricultural production, perennial grain species require fewer chemical and energy inputs and improve soil health and erosion control. The possibility for producing sustainable grain harvests from marginal land areas is motivating research initiatives to integrate perennial grains into commercial cropping and food processing systems. In this study, the feruloylated arabinoxylans from intermediate wheat grass (Thinopyrum intermedium, IWG), a promising perennial grain candidate in agronomic screening studies, were investigated. Insoluble fiber isolated from IWG whole grain flour was subjected to either mildly acidic (50 mM TFA, 100 °C, 2 h) or enzymatic (Driselase) hydrolysis. The liberated feruloylated arabinoxylan oligosaccharides were concentrated with Amberlite XAD-2, separated with gel chromatography (Sephadex LH-20, water), and purified with reversed-phase HPLC (C18, water-MeOH gradient). Thirteen feruloylated oligosaccharides were isolated (including eight structures described for the first time) and identified by LC-ESI-MS and NMR. Linkage-type analysis via methylation analysis, as well as the monosaccharide and phenolic acid profiles of the IWG insoluble fiber were also determined. IWG feruloylated arabinoxylans have a relatively simple structure with only short feruloylated side chains, a lower backbone substitution rate than annual rye and wheat varieties, and a moderate phenolic acid content.
Bibliographical noteFunding Information:
The authors thank Dr. Lee DeHaan for providing the intermediate wheat grass grain used in the study. NMR measurements were performed at the Minnesota NMR Center in Minneapolis, MN, USA. The Minnesota NMR Center receives funding for NMR instrumentation from the Office of the Vice President for Research , the Medical School , and the College of Biological Science at the University of Minnesota-Twin Cities , as well as NIH , NSF , and the Minnesota Medical Foundation .
©2015 Elsevier Ltd. All rights reserved.
Copyright 2015 Elsevier B.V., All rights reserved.
- Ferulic acid
- Feruloylated oligosaccharides
- Intermediate wheatgrass
- Thinopyrum intermedium