Objective: The aim of the study was to determine the effect of the roasting process on the content of phenolic compounds, antioxidant activity, and colour of infusions prepared from coffee beans (Coffea arabica) originating from Central and South America. Methodology: Green and roasted coffee samples from selected growing regions (Brazil, Nicaragua, and Peru) were used for the study. The total polyphenol content was determined using the Folin-Ciocalteu method, antioxidant activity was determined using the ABTS and FRAP methods, and the colour parameters of the infusions were determined using a colorimeter. The results obtained were subjected to statistical analysis (ANOVA, Duncan's test). Results: The roasting process significantly affected the polyphenol content, antioxidant activity, and color of coffee brews. The highest values of the analysed parameters were found in medium and dark roasted coffee samples, especially those from Peru and Nicaragua. A positive correlation between polyphenol content and antioxidant activity was shown. The coffee grounds remaining after brewing retained significant amounts of bioactive compounds, indicating their potential for reuse in the context of the circular economy and sustainable development. Implications and recommendations: The results of the study indicate the need for further analysis of roasting processes in order to develop optimal parameters that allow for the preservation of high levels of bioactive compounds in the brew while maintaining the desired sensory characteristics. Further research should explore the possibility of using coffee grounds as a secondary raw material in the food, cosmetics, and materials industries. Originality/value: The originality of the work stems from its comprehensive approach to the coffee roasting process, which includes the analysis of both raw and roasted beans, as well as the infusions and grounds prepared from them. This approach allows for a complete understanding of the changes in the chemical composition and bioactive properties of coffee at all stages of its processing, from raw material to final product.
Karolina Toczek (Wed,) studied this question.