Abstract
The purpose of the current study is to determine the antioxidant activity of the most commonly used coffee brews in the Western region of Saudi Arabia. Further, total phenolic and flavonoid contents were measured and antioxidants properties including ferric reducing antioxidant power and ferrous ion chelating activity, DPPH radical scavenging activity, and scavenging of hydrogen peroxide assays were also determined. Results of study revealed that phenolic contents were 741, 835 and 578 mu g/ml of gallic acid/2 g of coffee, and the total flavonoid contents were 711, 802, and 828 mu g/ml of catechin/2 g of coffee for Nescafe red mug, Turkish coffee and Espresso, respectively. The inhibition percentage of hydrogen peroxide showed highly significant reduction (p<0.001) in Turkish coffee compared to Nescafe red mug. Further, DPPH activity also showed highly significant reduction (p<0.01) in Espresso and Turkish coffee compared to Nescafe red mug, whereas, Espresso showed a highly significant increase (p<0.01) in reducing power activity. Regarding the metal chelating activity, Espresso showed a significant decrease (p<0.05) in metal chelation activity as compared to Nescafe red mug. The current study demonstrated that Nescafe red mug, Turkish coffee and Espresso, were the most consumed coffee types in the Western region of Saudi Arabia according to the survey. These three types of coffee showed high phenolic and flavonoid contents as well as a high antioxidant activity.