A meta analysis: the effects of types, roasting degrees and origins on antioxidant properties of coffee

This current work presents a meta-analysis to determine coffee bean specifications [types (Arabica and Robusta), roasting degree (light, medium and dark), roasting condition (time and temperature) and geographical origins by countries (Brazil, India and Thailand)] with the highest antioxidant activity. A total of 12 articles and 189 data points were employed for meta-analysis of subgroups. The results showed that the Arabica coffee bean was reported to have the highest antioxidant activity as assessed by ferric reducing antioxidant power (FRAP) and 2,2-azinobis-3 ethyl benzothiazoline-6-sulfonic acid (ABTS). In addition, the light roasting degree of coffee beans produced the highest antioxidant activity as assessed by FRAP and 2,2-diphenyl-1-picrylhydrazyl (DPPH). Roasting degree is a better parameter to obtain coffee beans with higher antioxidant activity compared to roasting conditions. Coffee from Brazil and India was found to have higher antioxidant activity compared with coffee from Thailand. This study concludes that Arabica coffee beans from Brazil or India with a light roasting degree are expected to have high antioxidant activity.