Improving the quality of liquid smoke from oil palm fronds through adsorption and distillation processes

Abstract

This research aims to obtain information regarding purification of liquid smoke from the pyrolysis of oil palm fronds to be used as a preservative product following food quality standards. This research started by performing the pyrolysis of oil palm fronds at 250 °C for 2 hours to produce liquid smoke. Subsequently, the liquid smoke from the pyrolysis was purified in two stages, namely adsorption and distillation. The adsorption which was carried out at 60 °C for 1 hour by using an activated zeolite, resulted in liquid smoke which still contains a tar contaminant compound. The analysis of the liquid smoke after adsorption showed a decrease in the composition of carbonyl and phenol compounds but in trace amounts. Meanwhile, the distillation was carried out at 125, 150, 175, and 200 °C and at 15,30,45, and 60 minutes, which resulted in a liquid smoke that is free of tar. The research revealed that the recommended temperature and time of distillation was at 150 °C and 45 minutes with tar residue of 2.4 %, total acid of 5.15 % and a pH of 2.3. Furthermore, GC-MS analysis indicated that the resulting liquid smoke was dominated by acetic acid compounds of 45.46 % (w/w).