Valorization of Coffee By-Products through Biorefinery Approaches for a Sustainable Bioeconomy

This review explores the concept of coffee biorefineries as a feasible approach for producing value-added products while promoting sustainability and the circular bioeconomy. Coffee, one of the most widely consumed commodities worldwide, generates substantial quantities of by-products during processing—such as coffee pulp, husk, and spent grounds—which are often discarded as waste. This review highlights several biorefinery strategies that utilize these by-products to produce high-value substances, including biofuels, antioxidants, and functional compounds for food, pharmaceutical, and cosmetic applications. The study analyzes statistical data on research related to coffee biorefineries conducted over the past 15 years, along with global coffee production data from the top ten exporting countries. The advantages of adopting coffee biorefinery technologies are discussed from both economic and environmental perspectives, emphasizing waste reduction, carbon emission mitigation, and the creation of new revenue streams. The conceptual framework of biorefineries highlights the potential of coffee as a feedstock for generating value-added outputs, and includes a statistical analysis to map recent research trends in coffee-based biorefinery systems. Furthermore, this review underscores the diverse applications of coffee and the valorization of its processing by-products while examining various pretreatment methods and their effects on enhancing the yield of value-added products.