OPTIMIZATION OF THE OPERATIONAL PARAMETERS OF ROTAEVAPORATOR FOR CONCENTRATION OF SOLUBLE SOLIDS IN ARABICA COFFEE EXTRACT FOR THE PRODUCTION OF SPECIAL SOLUBLE COFFEE

Study carried out with the aim of establishing ideal operational parameters for the operation of an IKA RV 10 Digital rotoevaporator in the stage of concentration of soluble solids in coffee extract, as part of the development of a methodology for the production of special soluble coffee. The concentration of soluble solids for the production of soluble coffee is essential to ensure body, intensity and sensory quality. The use of the rotaevaporator is a facilitator of the process, for greater fluidity, control and efficiency, thus minimizing the degradation of the extract. Coffea arabica beans from the Cerrado Mineiro were used, medium-dark roast made available by the Federation of Coffee Growers of the Cerrado. The extractions were carried out by hot and cold infusions, and the extracts obtained were subjected to concentration in the rotaevaporator, prioritizing the integrity of the compounds sensitive to heat and pressure. During the study, several tests were carried out, until the initial pressure parameter of 920 mbar was determined and gradually reduced at intervals of 50 mbar every two minutes, until reaching the minimum effective pressure of 120 mbar, with a constant temperature of 60 °C. The temperature chosen was based on the literature regarding the thermal stability of the main aromatic compounds of coffee, such as chlorogenic acids, caffeine and Maillard volatiles, avoiding their degradation. The pressure/temperature ratio has been optimized based on the water under vacuum conditions and the physicochemical characteristics of the extract, ensuring evaporation with minimal caramelization and browning. The parameters were validated by successive tests, and the process monitored by °Brix markings, up to the desired concentration. The correct adjustment of these parameters proved effective in concentrating the extract's soluble solids, thus meeting the main objective of the stage. The results obtained contribute to the consolidation of small-scale practices with the potential for industrial application.