Investigation Effect of Liquid Arenga Sugar’s Evaporation Temperature under Vacuum Pressure

The use of high temperatures in conventional liquid arenga sugar processing can trigger the Maillard reaction, which causes some of the nutritional content of liquid arenga sugar to decrease. Therefore, liquid arenga sugar processing needs to be processed below 100 °C, using the vacuum evaporator process. The evaporation rate in the previously developed liquid arenga sugar processing technology is still lower than the conventional technology, which is due to the unoptimized temperature and vacuum pressure settings. In this study, a number of experiments were carried out with the aim of investigating the vacuum pressure and temperature that has the optimum evaporation rate. By utilizing the venturi effect, it can maintain vacuum conditions during the experiment. Data acquisition starts when the sample is boiling and finishes when the sample mass remains at 20%. The temperature variants comprise 60, 70, and 80 °C. While the vacuum pressure variants were 0.4 bar(-0.6 gauge), 0.3 bar(-0.7 gauge), and 0.2 bar(-0.8 gauge). Based on the conducted experiments, at a vacuum pressure of 0.3 bar(-0.7 gauge), the temperature variable dominantly affects the evaporation rate. Variant C3, at a temperature of 80 °C and a vacuum pressure of 0.2 bar(-0.8 gauge), showed better performance than the other variants. The peak value of mass loss of 7.18 kg and the peak value of mass reduction percentage of 73.12% represented it. Based on the vacuum pressure and temperature conditions of variant C3, it is estimated that processing 10 kg of liquid arenga sugar takes 2 h and 17 min, there was a reduction of almost 80% from the previous process which took 9 h 20 min.