Influência do tempo, do uso de Saccharomyces cerevisiae e das condições de processo na fermentação de café arábica descascado

Abstract

Coffee producers are increasingly striving to achieve bean quality standards that result in specialty coffees. In this context, this study was conducted at Fazenda Sementes Gaúcha, using hulled Arabica coffee beans of the MGS Paraíso 2 cultivar. The objective was to evaluate the physicochemical parameters of the beans over 96 hours of fermentation using a SIAF (Self- Induced Anaerobic Fermentation) system, applying different treatments. Fermentation kinetics were analyzed based on the concentration of organic acids, sugars, and alcohols formed and consumed, in addition to temperature monitoring using electronic sensors inside the fermenters. The treatments involved solid-state and submerged fermentation, with and without the addition of inoculum, conducted in hermetically sealed 200 L polyethylene bioreactors. A decrease in pH was observed, associated with temperature monitoring, demonstrating microbial activity during fermentation. Characteristic metabolites were identified, including organic acids (lactic, malic, acetic, citric, and succinic), residual sugars (glucose, fructose and sucrose), and alcohols (ethanol). The results demonstrate that different fermentation conditions significantly influence the chemical profile of coffee, directly impacting its acidity and sensory complexity. These findings are relevant for the coffee industry, which constantly seeks differentiated coffee beverages with unique sensory profiles for participation in national and international competitions, as well as for adding financial value to the bags of coffee sold. Each fermentation treatment has its own specific kinetics, increasing the production of organic acids and alcohols and the consumption of sugars over time.