The Effect of Roasting Degrees and Brewing Techniques on the Physicochemical and Sensory Characteristics of Anaerobically Fermented Liberica Coffee (Coffea liberica)

Liberica coffee from Banyuwangi, Indonesia, is distinguished by its unique flavor and high antioxidant content but is often considered inferior to Robusta and Arabica. This study investigated the effects of roasting degrees and brewing methods on the physicochemical and sensory properties of anaerobically fermented Liberica coffee. Coffee beans were roasted at light and medium levels and brewed using V60, French Press, and Vietnam Drip methods. The results indicated that the roasting degree significantly influenced the pH, antioxidant activity, and total dissolved solids (TDS) of the brewed coffee. Light roasting enhanced fruity and acidic notes, particularly a jackfruit-like aroma, while medium roasting pronounced stronger chocolate, roasted, and caramel flavors. Sensory analysis confirmed that roasting had a greater impact on flavor than brewing methods. HS-SPME/GC-MS analysis identified 72 volatile compounds, demonstrating that medium roasting yielded a higher concentration of furans, pyrazines, and ketones, as the most dominant compounds. These findings emphasize the importance of carefully selecting roasting and brewing techniques to optimize the chemical and sensory qualities of Liberica coffee. By refining these methods, Banyuwangi Liberica coffee can be positioned as a distinctive and appealing choice in the global coffee market. HIGHLIGHTS Roasting degree significantly influences physicochemical properties, including pH, antioxidant activity, and total dissolved solids (TDS). Brewing techniques, including V60, French Press, and Vietnam Drip, modulate sensory attributes, with V60 highlighting acidic and fruity notes and French Press delivering a fuller body. Roasting degree, however, has a more substantial impact on flavor profiles. Light roasting pronounced fruity and acidic characteristics, including a distinctive jackfruit-like aroma, while medium roasting enhances chocolate, roasted, and caramel flavors. HS-SPME/GC-MS analysis detected 72 volatile compounds, with medium roasting achieving higher concentrations of key flavor-enhancing compounds, such as pyrazines and furans. GRAPHICAL ABSTRACT