Total phenolics and antioxidant capacity of the white and brown teff [Eragrostic tef (Zuccagni) trotter] varieties cultivated in different parts of Ethiopia

Abstract

ABSTRACT. This study was aimed to determine the total phenolics contents and antioxidant capacity of white and brown teff grain samples. The free total polyphenolic content (TPPC), bound TPPC and total flavonoids content ranged from 62.1–129.9, 84.6–189.6 mg GAE/100 g and 84.4–195.1 mg QE/100 g, respectively, in white teff samples, and, 118.6–196.7, 141.1–195.1 mg GAE/100 g and 97.8–202.5 mg QE/100 g, respectively, in brown teff samples. Besides, the free 2,2-diphenyl-1-picrylhydrazyl (DPPH) and bound DPPH ranged from 74.8–98.3, 77.1–99.9 mg AAE/100 g, respectively, for white teff samples, and, 68.7–93.1 and 71.2–99.4 mg AAE/100 g, respectively, for brown teff samples. This study revealed that total phenolics content was higher in brown teff samples than white teff samples and is in agreement with other reports. However, their DPPH scavenging activities were nearly equal, indicating that both varieties of teff are relevant for human nutrition and health. Furthermore, the dendrogram has shown sharp separation of the samples based on their origin and variety related to the total phenolics parameters. Hence, findings of this study can help consumers appreciate the nutritional value of white and brown teff grains; provide them guidance for teff purchase and production.
 
 KEY WORDS: Teff, Phenolics, Gallic acid, Ascorbic acid, Anti-oxidant, DPPH
 
 Bull. Chem. Soc. Ethiop. 2022, 36(4), 749-766. 
 DOI: https://dx.doi.org/10.4314/bcse.v36i4.3

Ascorbic Acid Content and Antioxidant Activities of White and Brown Teff [Eragrostic tef (Zucc.)Trotter] Grains and Injera

“…Grains and Injera Samples. Yisak et al [9] described the adopted method to extract the ascorbic acid content of white and brown tef grains and injera samples. In brief, 0.25 g of ground white tef, brown tef, and injera samples was soaked for 10 min in 20 mL of the extraction solvent (deionized water).…”

“…Teff's global demand is currently increasing due to its healthier nutritional quality, and when compared to other grains, it plays an important role in food security [ 5 , 10 ]. Furthermore, teff grain is a gluten-free superfood that may benefit people with celiac disease and is gaining acceptance as a medicinal ingredient [ 3 , 5 , 9 ]. Its antioxidative activities, for example, can help prevent malaria and hemoglobin levels in the human body; it can also help prevent diabetes.…”

“…Its antioxidative activities, for example, can help prevent malaria and hemoglobin levels in the human body; it can also help prevent diabetes. Furthermore, teff bread has a longer shelf life and a slower aging rate than rice, wheat, maize, sorghum, and barley [ 9 , 11 ]. Teff can also be used as a fat substitute in producing low-calorie foods due to its high viscosity and low gelling ability [ 4 ].…”

“…The inclusion of antioxidant foods in daily diet is critical to deactivating free radicals [ 24 ]. Teff grains have shown better antioxidant potential than other cereals [ 9 ]. This makes injera (ready-to-eat food) to be healthy food.…”

“…It is commercially classifed as white and brown cultivars [6]. Tef cultivars outperform all cereal grains in terms of nutritional values, as they contain high levels of carbohydrate, protein, fat, dietary fbers, starch, essential minerals, essential amino acids, vitamins [7][8][9], polyphenols, volatiles such as aldehydes, ketones, and alcohols, and fatty acids [3]. Tef's global demand is currently increasing due to its healthier nutritional quality, and when compared to other grains, it plays an important role in food security [5,10].…”