Purification of pecan shell liquid smoke using the distillation method to separate polycyclic aromatic hydrocarbons (PAHs)

Abstract

Pecan (Carya illinoinensis) is one of the macadamia nuts that is used as a source of oil and spices. Its shell is an organic waste that is not utilized optimally. Pecan shells can be the raw material to produce liquid smoke to minimize waste. Liquid smoke obtained from the pyrolysis pecan shell contains antibacterial and antioxidant compounds. Liquid smoke purification is performed to remove polycyclic aromatic hydrocarbons (PAHs) and tar to obtain clear yellow liquid smoke. The purification is carried out by a distillation process with temperature variations of 150 °C, 175 °C, and 200 °C. The distillation process time is varied by 30, 60, and 90 minutes. The phenol, acid, and carbonyl components determine the characteristics of pecan shell liquid smoke. At 175°C and 90 minutes, the best phenol content was 15.53%. Acid content of 7.65% was obtained at 175°C and 90 minutes. While the carbonyl content of 14.44% was obtained at 125°C for 60 minutes. Determination of liquid smoke quality by utilizing the distillation method produces grade 1 liquid smoke at 175°C for 90 minutes, grade 2 at 200°C for 30 minutes, and grade 3 at 200°C for 90 minutes.