Eff ects of Selected Yeasts on the Chemical Profi les and Antioxidant Activity of Fermented Coff ee Beans during the Aging Process

Abstract

Coffee, a globally popular beverage, undergoes various processing methods such as natural (also known as dry process), washed (also known as wet processed), and honey (also known as pulped natural), impacting bean composition and beverage quality. Microorganisms, especially yeasts, play a crucial role in these processes. We investigated three yeasts’ effects on chemical profi les and antioxidant activity during coffee bean aging. Our fi ndings indicate signifi cant infl uences of processing method and yeast choice on antioxidant potential and physicochemical properties. Dry-processed beans demonstrated a heightened DPPH scavenging capacity, surpassing other processing methods by approximately 69.21%, while Saccharomycopsis fi buligera fermentation exhibited superior antioxidant activity, outperforming other yeasts by 69.42%. However, no signifi cant impact on SOD-like activity was observed. Coffee bean aging, not yeast or processing method, affected total phenolic content, while total fl avonoid content showed temporal variations. Quality and sensory evaluations suggest the potential for specialty-grade coffee. Coffee beans fermented by S. fi buligera using dry methods scored 83.31, while those fermented by Pichia kluyveri with wet methods scored 82.31 in SCAA evaluations. Our study emphasizes the role of specifi c yeasts in controlled fermentation for enhanced coffee sensory qualities.