Unlocking the physicochemical, bioactive, and antioxidant potential of Indonesian Liberica coffee: roles of geographical origin and processing

Commercial interest in Liberica coffee (Coffea liberica) in Southeast Asia is growing, but evaluations of the impact of postharvest treatments on its physicochemical and bioactive characteristics remain limited. This study investigates the effects of geographic origin (Jambi, Kayong, Meranti) and postharvest methods (natural, honey) on the properties of Indonesian Liberica green coffee beans. The results indicate that geographic origin has a significant effect (p < 0.05) on most parameters, reflecting strong environmental influences. Postharvest processing primarily affects moisture content, lipid fractions, and antioxidant capacity. The Jambi honey-processed sample exhibited the highest alkaloid content (1.53 g/100 g db), while the highest diterpene content was recorded in Kayong natural-processed beans (304.70 mg/100 g db). The Meranti sample processed naturally exhibited the highest caffeoylquinic acids (CQAs) content (5.38 g/100 g db) and the strongest antioxidant activity (IC₅₀: 101-124 μg/mL). Multivariate analysis revealed primary clustering based on location, while processing methods served as a secondary distinguishing factor. These findings provide preliminary insights into the associations of geographical origin and postharvest processing with the physicochemical and antioxidant properties of Liberica green bean.