MONITORING OF PHYSICOCHEMICAL PARAMETERS AND BROMATOLOGICAL ANALYSIS OF ARABICA COFFEE FRUITS SUBMITTED TO FERMENTATION

Microbial fermentation has the capacity to enhance coffee quality, producing beverages with different sensory profiles. However, if mismanaged, fermentation can harm coffee quality. Therefore, the objective of this study was to monitor the physicochemical and bromatological parameters of coffee fruits during fermentation. Paraíso variety coffees were subjected to submerged fermentation for 24 hours. During the experiment, temperature, pH, moisture content, ash content, and citric acid quantification by liquid chromatography were measured. All analyzes were performed in triplicate, and the statistical analysis consisted of ANOVA followed by Tukey's test considering means (p<0.05) to be significant. At the end of the 24 hours, the coffee mass temperature was 19.92°C ± 0.40, and pH was 4.71 ± 0.05. Fermentation temperatures ranging between 18-26°C and pH around 4 over a period of 24-30 hours are favorable for successful fermentation and the production of desirable volatile compounds. The moisture content was 63.66%a ± 2.31 (initial: 63.11%a ± 2.81), and ash content was 1.77%a ± 0.05 (initial: 1.77%a ± 0.14). It is observed that the moisture and ash contents did not change, indicating that the coffee fruits did not absorb water in a significant amount and the mineral content was not lost to the environment through leaching. The citric acid content was 0.92a ± 0.33 mg/g (initial: 1.15a ± 0.07 mg/g). Therefore, no reduction (p<0.05) of citric acid was observed and the amount detected was within the range reported in the literature (0.57-1.66mg/g) after 24h of fermentation process. This result is positive, since citric acid is a compound present in coffee beans that decomposes during the roasting process and, together with other compounds, generates important active flavor metabolites. Thus, it is concluded that the results of the monitored parameters indicate good process control and positive fermentation.