Determination of total phenolic content and antioxidant activities of five different brands of Ethiopian coffee
High consumption of coffee has been considered to have negative health consequences, often attributed to the stimulant effects of caffeine. However, coffee is also one of the largest sources of antioxidants in the diet and contains various compounds with potential beneficial effects on glucose metabolism, inflammation and blood vessel function. The present work was carried out to determine the total phenolic content and antioxidant activity of five different Ethiopian coffee varieties, namely Sidamo, Yirgacheffe, Harare, Wollega and Jimma coffee. Total phenolic content was determined by the Folin-Ciocalteu method and expressed as Gallic acid equivalents whereas antioxidant activities were determined by 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, reducing power and total antioxidant activity. The tested coffee beans contained appreciable amounts of total phenolic contents (54.87-80.51 g GAE /g); DPPH Scavenging capacity (73.33-84.16%), reducing power (0.634 ± 0.62 – 0.887 ± 0.14) and total antioxidant activity (0.198-0.346) at 0.2 mg/mL extract concentration. The study showed that total phenolic content and antioxidant activities of the coffee extracts were capable of protecting against free radical mediated damage and may have applications in preventing and curing various diseases.
Total phenolic and antioxidant capacity of flower, leaf and seed of Moringa oleifera
The Moringa oleifera it is considered one of the most useful trees in the world because almost all parts of this plant can be used as food, in medicines and for industrial purpose. Is versatile as a medicine, functional food and nutraceutical. Thus, the objective was to estimate the total phenolic content and antioxidant capacity of the flower, leaf and seeds of Moringa oleifera Lam. Were purchased flowers, leaves and seeds of Moringa oleifera Lam., in the city of Seropédica, Rio de Janeiro, Brazil and harvested in January 2013. The determination of total phenolic content was assessed following to the Folin-Ciocalteu assay and the antioxidant capacity was determined by the method of DPPH (2.2-definil-1-picrilidrazil). It has been verified that the content of phenolic compounds from the leaf of Moringa oleifera (170.07 ± 0.43 mg /100 g gallic acid) were better when compared to the results found in the flower and seed (114.49 ± 3.95 mg / 100 g gallic acid and (22.43 ± 2.35 mg / 100 g gallic acid), respectively. The leaf presented a kidnap largest free radical antioxidant compared in flower and seed. The present study suggests that M. oleifera could be a potential source of compounds with strong antioxidant potential. Hence consumption of diet supplemented with M. oleifera could protect against diseases induced by oxidative stress.
