Zewdu, Ashagrie (PhD)Boka, Bemhiretu2022-03-292023-11-092022-03-292023-11-092012-05http://10.90.10.223:4000/handle/123456789/30978Imbalanccd product ion and consumption of reactive oxygen species, reading to oxidative stress such as cancer, arteriosclerosis neu rodegenerative diseases and ageing processes. The protect ive effects of plants have long been attributed to their ant ioxidant compounds, such as phenolic compounds and flavono ids. The purpose of th is study was comparing antioxidat ive potenti"! of methanolic extracts of three tef varieties (white. brown and red tel) and the ir injeras (partly ferm ented and fu lly fermented) and their enriched one with fen ugreek. The antioxidant capacities of tef varieties and the ir flat bread, iI?jeras were evaluated by using different methods, name ly DPPH (2. 2-diphenyl-I-picryl hydrazyl) free radical scavenging activ ity, total reduc ing power. IOta I phenol contents and total flavo noid levels. Total phenol content (TPC) was determined by using folin-ciocalteau reagent. Total tlavonoid content (TFC) was determined by using colorimetric assay method, the absorbance of all parameters measured using UV-viz-spectropholOmetry. The level of Ie 50 values of free radical and total reducing power of various tefvarieties varied from 0.6 IlIg/ml to 0.88 mg.1 ml and 2.25 111g111l1 10 2.5 mg/ml respectively. The results Showed the highest scavenging activities (0.6 mg/ml) and reducing power (2 .25 mglm l ) observed in red tef while the lowest scavenging activities and reductive potential potent in white tef ( 0.86 mg/ml) and (2.5g1mi). Current results of lotal phenolic content assay indicate that total phellol co ntent was higher in red tef(II.47 mg GAE/g) as compared to brown (9.715 mg GAE/g) and white tef (8.28 mgl GAE/g). In addition: total tlavonoids for white, brown and red tef were 1.03 mg/CE/g. 1.78 mg CE/g and 2. 13 mg CE/g respective ly. The processing of tef flour ill to partly or fully fermented illjeras and their enrichment with fenugreek affect the lef antioxidant levels th:s has imp lications for the ir bioactive properties a nd pote nti al health bcnclits. The IC;o - values i'or free radical scavenging activit ies and reduc ing power of pa rtly fermented, fully fenncnted, c nriched partly tcnnented and enriched fully fermented white td' ily'eras were 2.8 111 g11ll1 ; 2.75 Illg/ml. 3.25 mglml ; 3.3 lng/m!. 2.63 mg/ml; 2.7 mglml ; 3 lll glmi ; 3 mg/m! respectively. Phenolic compos ition in the lef injeras examincd. The results showed that enriched partly fermented red tel' illjeras had remarkable phenol levds (ur to 9.12 GAE/g). The lotal phenol contents lor partly fermented , hilly fermented, and enriched fully fermented red tef injerus we re found lO be g.75. 7.36, and 8.24 mg GAE/g respectively. In brown I.efinjeras. the highest fla vonoid ,:Oittcnl was noticed in enriched partly fermented ily'era (1.9 mg eEl g).enEffect of ProcessingThesis