The potential of wheat as a functional food: from the sprouts and microgreens production to the nutraceutical effects

Polyphenols are one of the most important phytochemicals derived from plants like fruit, however, wheat are also good sources of polyphenol. The present study summarized all the information regarding 10 dietary polyphenols including the main polyphenols of wheat and their association with the BCS classification. Polyphenol content is affected by the genotype of plants, as well as storage and processing method. In general, the polyphenol content and antioxidant activity of whole wheat flour decreased after storage for 8 weeks. However, these parameters were not significantly influenced by the storage conditions (aerated or vacuum). Among the wheat varieties (Verna, Timilia, Sagittario and Claudio) analyzed, Verna exhibited the high levels of polyphenol content and antioxidant activity. Germination is a processing method which can maintain or improve nutritional value of cereal by avoiding milling or baking. In general, the effect of light was not obvious in wheat sprouts, but much greater and species-specific for wheat microgreens. LED light was beneficial for the increase of polyphenol and pigment contents and antioxidant activities compared to fluorescent light. Claudio microgreens grown under LED light exhibited the highest polyphenol content and antioxidant properties. Although wheat polyphenols were influenced by storage and processing method, our results showed their benefits on human health. It provides more information for developing a new food supplement of wheat polyphenol. However, the results of present study showed that ferulic and gallic acids had toxic effects on in vitro cell models with high dose. Overall, the results of present study validate the effect of the storage time on polyphenol of whole wheat flour, also indicate that LED light should be a good light source for production of wheat microgreens. In addition, it provides more evidence about safe dose avoiding toxic effects on intestinal wall of wheat polyphenol when they will be developed as supplement.