Comparative analysis of total phenol, total flavonoid and in vitro antioxidant capacity of white and brown teff (Eragrostis tef), and identification of individual compounds using UPLC-qTOF-MS

There is a growing global demand for teff (Eragrostis tef (Zucc.) Trotter) grain due to its gluten-free nature, high level of essential amino acids, high mineral content, low glycemic index, high crude fiber content, longer shelf life, and slow staling of its bread products compared to those of wheat, sorghum, rice, barley, and maize. However, only a limited and less reliable data exists on phenolic profiles of teff grain. This article aimed at exploring phenolic contents and chemical compositions of four teff grain samples (two white and two brown) as well as their in vitro antioxidant capacity. Identification of individual bioactive compounds in white teff was also conducted using UPLC-qTOF-MS. In general, teff grain was found to have a much higher phenolic content compared to other commonly consumed grains and pseudo cereals; brown teff contained higher than the white one. Antioxidant activity was also relatively higher than other common whole flour food sources. Furthermore, combination of UPLC separation, qTOF‐MS detection and automated data processing software with scientific library using UNIFI ver. 1.8 allowed us to identify a total of 61 bioactive compounds mainly phenolic compounds and saponins in teff for the first time. The findings of this study significantly contribute to enhancing the limited data on teff phenolics.