Caffeine content, pH, and brightness of decaffeinated robusta coffee beans using controlled maceration machine, and the sensory of the coffee brew

This study aims to improve the efficiency and speed of decaffeination through maceration extraction using a Controlled Maceration Machine. Using water as a solvent offers a simpler, safer, and more environmentally friendly approach. It has considerable potential as an economically feasible and sustainable decaffeination technology, particularly for small-scale coffee processing industries. The study combines two treatments: temperature and duration of maceration. The maceration durations used are 2, 4, and 6 h. The extraction temperatures used are 50, 60, and 70 °C. Based on De Garmo’s effectiveness test, the best treatment was found to be at a temperature of 60 °C and a duration of 4 h. At 60 °C for 4 h, heat energy is sufficient to increase the heat and mass transfer coefficients without causing significant damage to the cell wall structure. Consequently, caffeine release is rapid and selective, while loss of flavor and bioactive compounds is minimal. The decaffeinated robusta coffee with the best treatment has a brightness value of 34.3; a pH value of 6.56; a caffeine content of 0.40% (decrease 79,17% from control); a color preference of 5.1 (Somewhat Liked); an aroma preference of 4.8 (Neutral); a taste preference of 3.9 (Somewhat Disliked); and an overall preference of 4.4 (Neutral).