Determining the Nutritional Potential of Ancient Wheat Species: A Closer Look at Starch and Protein Digestibility, and Phenolic Acid Content

ABSTRACT Background and Objectives The recent trend towards healthy food choices and sustainable agriculture has revived interest in underutilized wheat species such as emmer, einkorn, and spelt. Given these developments, the objective of the study was to compare the differences in chemical composition and digestibility characteristics among commercially available flour samples representing ancient wheat species. Findings Einkorn demonstrated higher protein (21.27%) and phenolic acids (free and conjugated) along with lower starch levels than other samples. Notably, its starch digestibility was marked by lower glucose release and reduced rapidly digestible starch (RDS) levels, which may partly reflect its lower starch content, while refined flour from common wheat exhibited the highest RDS with glucose release. Among the ancient wheat species, the highest glucose release was observed in emmer, which also had the highest content of RDS. In vitro protein digestibility (IVPD) was highest in refined flour (86.05%), with einkorn closely following at 84.29%. Both spelt and emmer exhibited lower IVPD values compared to common wheat samples and einkorn. Spelt was characterized by its significant level of bound phenolic acid content followed by einkorn. Conclusions The variation in chemical composition, particularly in einkorn with its higher protein and phenolic acid content, combined with its digestibility profile, highlights its potential nutritional and functional relevance. Significance and Novelty These findings emphasize the importance of further research on underutilized grains to fully comprehend their nutritional value.