Avaliação Entre Safras e Processos Pós-Colheita: Qualidade Sensorial e Composição Química do Coffea Arabica Cv. MGS Paraíso 2

Abstract

The quality of coffee results from the interaction between environmental, genetic, and post-harvest management factors, making it essential to understand how these variables impact the beverage’s chemical, physical, and sensory attributes. Controlled fermentation methods have been widely studied to enhance desirable characteristics, such as balanced acidity and aromatic complexity. However, variations between harvests pose a significant challenge to standardizing beverage quality. Despite advances in research, there is a gap in the detailed understanding of the effects of different fermentation processes over the years, with few studies addressing comparisons between successive harvests, especially considering the same variety under controlled experimental conditions. This gap compromises the understanding of the reproducibility and consistency of fermentation protocols applied in coffee production. In this context, the present study aimed to investigate the impacts of different fermentation approaches on the chemical composition and sensory quality of Coffea arabica cv. MGS Paraíso 2, analyzing the 2022 and 2023 harvests. Mechanically harvested cherries from Fazenda Londrina, located in Coromandel – MG (Brazil), were subjected to solid-state fermentation (SSF) and submerged fermentation (SMF), under both spontaneous conditions (SPF) and with starter culture (SCF), for both natural cherry (NC) and pulped cherry (CD) processing types. The experiments were conducted in polyethylene bioreactors, with temperature monitoring and sample collection at three distinct time intervals (24, 48, and 72 hours). Laboratory analyses included techniques such as high-performance liquid chromatography (HPLC) for the quantification of organic acids and sugars, as well as colorimetric and texture evaluation of the beans. Sensory characterization was performed by certified Q-Graders, following the standards of the Specialty Coffee Association (SCA). The data obtained were subjected to statistical tests, including ANOVA and Tukey’s test for mean comparison, as well as decision tree analysis to identify the most determining factors in the final beverage quality. The results showed that coffees from the 2023 harvest achieved higher scores, resulting in a more balanced beverage with greater sensory complexity. Additionally, temperature effects during fermentation in the bioreactors altered microbial dynamics, directly impacting the conversion of compounds responsible for aroma and flavor. Analysis of the beans’ physical structure demonstrated that prolonged fermentation times affected texture. From a sensory perspective, fermented coffees scored above 80 points on the SCA scale, being classified as specialty coffees. The highest scores were observed in spontaneous submerged fermentations (SMF SPF) exceeding 48 hours in the 2022 harvest, while in 2023, fermentation times above 60 hours yielded the highest-quality coffees. These findings reinforce the need for refined control of fermentation conditions to ensure high standards in specialty coffee production. It is concluded that fermentation is a key element in adding value to coffee, and post-harvest strategies must be improved to enhance the quality of C. arabica cv. MGS Paraíso 2.