Alternative use of coffee beans and leaves from seven regions of Guatemala for its antioxidant activity and chemical composition

Introduction: Coffee is a Rubiaceae with great economic importance for many countries. Guatemala is the largest producer from Central America, cultivating basically Arabic (Coffea arabica L.) type, which is sell internationally as high quality coffee and the sale of beans has been the main national revenue for two centuries. Nevertheless the recent coffee rust crisis evidenced the need for alternative management, as well as innovative utilization of beans and leaves.Methods: Beans and leaves from four varieties of coffee were collected from seven regions of Guatemala with the aim to characterize the chemical composition and evaluate the antioxidant activity. Ethanol extracts were prepared by percolation and concentrated by rotaevaporator. It was determined by spectrophotometry the concentration of total phenolics, caffeine, and chlorogenic acid as chemical markers, as well as total sugars.Results: Extraction yields were high (beans: 29.8, leaves: 48.3%). Both organs showed antioxidant activity by DPPH (IC50 0.81, 0.63 mg/mL), ABTS (IC50 1.48, 0.92 mg/mL), ferric reducing antioxidant power (FRAP) (7.37, 7.94 Fe+2/g), and total phenolics (90.40, 87.50 μg gallic acid/mg), as well as chlorogenic acid (4.91, 1.04%), caffeine (1.19, 0.72%) and total sugars (3.20, 2.98%), respectively.Conclusion: The results confirmed the good quality of the beans for its chlorogenic acid and caffeine content. It was also demonstrated the potential of the leaves for its phenolic content and antioxidant activity, considered an underutilized resource that might be used for industrial diversification of coffee by-products. The antioxidant activity of both organs suggests a potential application as functional food and for phytocosmetic application.