Chemical Characterization of the Perennial Grain Intermediate Wheatgrass (Thinopyrum intermedium) for Food Applications.

Intermediate wheatgrass (IWG) is a perennial crop that shows great potential to be developed as a grain crop. The environmental benefits of perennial crops in comparison to annual crops include reduced soil and water erosion, reduced soil nitrate leaching, increased carbon sequestration, and reduced inputs of energy and pesticide. From a consumer perspective, the engagement in purchasing habits that can improve the environment is gaining prominence. The use of perennial crops in food products will allow consumers to feel good about their purchase, and their role in supporting a sustainable agricultural system. Therefore, the objective of this study was to evaluate chemical characteristics related to functionality and nutritive properties of IWG.

Samples of IWG were screened for protein, fat, ash, starch, amylose to amylopectin ratios, and dietary fiber contents utilizing standard analytical procedures. Gluten-forming proteins (GFPs) were analyzed qualitatively by SDS-PAGE following solvent extraction. Antioxidant activity of all samples was measured using the Trolox equivalent antioxidant capacity (TEAC) assay. Lipase and lipoxygenase activities were assessed as indicators for rancidity. Statistical analysis of differences in enzyme activities and nutrient composition was performed through ANOVA.

IWG samples were higher in protein, fat, ash, and dietary fiber, but lower in starch, than the wheat control. Starch contents showed some variation among IWG samples. However, the amylose to amylopectin ratio in all tested samples was not significantly different from that of the wheat control. Lipase activities were significantly different among IWG varieties. Interestingly, IWG samples had higher antioxidant activity than the wheat control. GFP analysis indicated that IWG samples are mostly deficient in higher molecular weight glutenins, which negatively impacts dough formation.

This work provided valuable feedback to the breeding program for the continued screening and breeding efforts to ultimately develop IWG with good yield, size and quality traits for food applications.