Progress on breeding and food processing efforts to improve chemical composition and functionality of intermediate wheatgrass (Thinopyrum intermedium) for the food industry

Background and objectives: Previously used as forage crop, the perennial cereal grain Thinopyrum intermedium or intermediate wheatgrass (IWG) is currently being investigated as a novel food crop. The motivation behind these endeavors lies in its perennial growth habit, which provides numerous ecosystem services. This paper discusses how IWG breeding has affected its chemical composition and how processing strategies can leverage its potential as an ingredient. Findings: Breeding has increased IWG seed size and starch contents, mostly at the expense of dietary fiber. While average protein contents have decreased, they still surpass those of most annual cereals such as bread wheat. Refined IWG displays better functional characteristics, presumably because it contains less insoluble fiber. However, refining may impact other nutritional properties of interest, for example, glycemic index. Tempering facilitates bran removal while maintaining protein and carotenoid contents. Steam treatment reduced enzymatic activity of whole and refined IWG flours over storage. Conclusions: The combination of breeding and processing can modify IWG’s chemical composition and enhance its functionality to make it competitive to commonly consumed annual cereal grains. Significance and novelty: A review on breeding effects on IWG composition and successful processing strategies can assist in product development work as the grain enters the marketplace.