Determination of free and bound phenolics using HPLC-DAD, antioxidant activity and in vitro digestibility of Eragrostis tef
- Citation data:
Journal of Food Composition and Analysis, ISSN: 0889-1575, Vol: 46, Page: 15-21
- Publication Year:
- Repository URL:
- http://publikace.k.utb.cz/handle/10563/1005750; http://hdl.handle.net/10563/1005750
- Agricultural and Biological Sciences; Antioxidant activity; Eragrostis tef; Flavonoids; Food analysis; Food composition; Gluten-free cereals; In vitro digestibility; Phenolics; Teff
White and brown Eragrostis tef were assessed for total flavonoid and phenolic content, HPLC profile of the most common phenolics and antioxidant activity including both free and bound phenolics. Antioxidant activity was evaluated in correlation with free and bound phenolics and in vitro digestibility was determined. Content of flavonoids (0.52–1.02 mg RE/g) and phenolics (0.90–1.42 mg GAE/g) as well as antioxidant activity (1.70–4.37 μmol TEAC/g using ABTS method) was higher in free phenolic fraction. Correlation showed that bound flavonoids were not significant contributors to antioxidant activity ( R 2 = 0.4513 and 0.4893, respectively). The main free phenolics in brown teff were trans-p -coumaric, protocatechuic, ferulic and gallic acids, while the major free phenolics in white teff were rutin, protocatechuic and ferulic acids. The main bound phenolics in brown teff were ferulic and gallic acids, quercetin and catechin, in white teff ferulic acid, rutin, catechin and quercetin. Cooked teff showed very high level of in vitro organic matter digestibility (80.5–85.1%), whereas brown teff was significantly more digestible than white teff ( P < 0.05).