Comparison of different methods of antioxidant activity evaluation of green and roast C. Arabica and C. Robusta coffee beans

Coffee beans contain a large amount of antioxidants, which are subjected to various changes during roasting. In this study, antioxidant potential of raw and roasted to different degree (light, medium, dark) C. arabica and C. robusta coffee beans was evaluated by the four antioxidant assay methods, TPC, FRAP, TEAC, and DPPH˙. The obtained results revealed significant differences between the coffee types, roasting degree, and antioxidant activity assessment methods. FRAP and TPC appeared to be the most appropriate methods for revealing the differences in antioxidant potential of different coffee types and the effects of roasting. The results obtained by these methods were in good correlation. ABTS and DPPH? methods are not enough sensitive for the determination of roasting degrees. In general, based on statistical data evaluation, antioxidant activity is more dependent on the coffee type than on the degree of roasting, however, the selection of analytical method may also be significant