Exploring non-Saccharomyces yeasts for sensory enhancement in coffee fermentation

This study evaluated the fermentative performance of potential starter cultures, Meyerozyma caribbica (CCMA1993, CCMA1950, CCMA1992, CCMA1617, CCMA1735), Hanseniaspora uvarum (CCMA1944), Pichia kluyveri (CCMA1658), Meyerozyma guilliermondii (CCMA1737), and Cytofilobasidium ferigula (CCMA1647), in the natural and pulped fermentation processes of the Acaiá coffee cultivar, using metabolomic and sensory analysis. The metabolic activity of yeasts was evaluated through carbohydrate degradation (high-performance liquid chromatography, HPLC), organic acid production (HPLC), and volatile compound synthesis (gas chromatography-mass spectrometry, GC-MS), with these metabolic changes correlated to sensory attributes. In pulped coffee, H. uvarum CCMA1944 and M. caribbica CCMA1617 produced high concentrations of ester compounds, accounting for 15% and 16% of the total esters, respectively. C. ferigula CCMA1647 stood out for its high ketone production in pulped coffee. In natural coffee, H. uvarum CCMA1944 produced succinic acid (3.691 g/kg). Furthermore, P. kluyveri CCMA1658 exhibited elevated levels of acids, alcohols, ketones, and aldehydes. M. caribbica CCMA1735 and P. kluyveri CCMA1658 contributed to a greater diversity of sensory descriptors in pulped and natural fermentations, respectively. These findings highlight the role of specific yeast strains in modulating desirable sensory attributes during coffee fermentation. • Non- Saccharomyces yeasts exhibit distinct metabolic activities • H. uvarum CCMA1944 showed a strong potential for succinic acid production • C. ferigula CCMA1647 increases ketone production in pulped coffee fermentations • M. caribbica CCMA1735 and P. kluyveri CCMA1658 enhance flavor complexity in coffee • Strain-specific modulates sensory profiles, enhancing fruity and floral notes