Estimation of Total Phenolic Contents and In vitro Antioxidant and Antimicrobial Activities of the Most Common Coffee Brews Available in the Local Markets of the Northern Region of Saudi Arabia

Abstract

Background: Coffee is the most preferred morning beverage throughout the world due to its pleasant flavor and stimulating properties. It contains a multipart combination of chemicals constituents, which associated with health benefits. In the Kingdom of Saudi Arabia there are many types of coffee in the local markets with different characteristics. Aims: The present study was designed to identify the total phenolic contents, antioxidant properties and antimicrobial activities for three of the most commonly consumed coffee brews; Intenso (Arabica), Reebass (Turkish) and Lavazza (Brazilian) purchased from some local markets at the Northern region in Kingdom of Saudi Arabia. Study Design: It was an in-vitro study. Methodology: The purchased coffee types were extracted using the boiling water method. Determination of total phenolic content of the obtained extracts was carried out using the Folin-Ciocalteu method. Antioxidant activity was measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. Measurement of antimicrobial activity was determined by disk diffusion method against number of microbial test strains. The obtained data were statistically analyzed and results with p < 0.05 were considered statistically significant. Results: The obtained results showed that, the estimated phenolic contents were arranged as 745.50 ± 10.5, 668.86 ± 11.2 & 651.25 ± 13.0 mg/g of gallic acid/1 g of coffee for Lavazza (Brazilian), Reebass (Turkish) & Intenso (Arabica) respectively. DPPH radical scavenging activity was higher 78.83% for Turkish coffee than Arabica 71.59% and Brazilian 65.90% types. Regarding antimicrobial activity; Arabica coffee extract was the highest antimicrobial activity compared to the other two extracts of both Turkish and Brazilian types where the mean diameter of inhibition zone for three coffee types were ranged from 11.0 ± 0.15 to 16.0 ± 0.40; 9.0 ± 0.25 to 11.0 ± 0.10 and 9.5 ± 0.10 to 13.0 ± 0.50 mm for Arabica, Turkish and Brazilian coffee extracts respectively. Conclusion: The present study concludes that coffee types under investigation showed high phenolic content and strong antioxidant activity as well as promising antimicrobial activity.