A comparative study of water-steam distillation with water-bubble distillation techniques to increase the quality of patchouli essential oil

A comparative study of the quality of patchouli oil using Water-Steam Distillation (WSD) and Water Bubble Distillation (WBD) techniques has been studied. The raw materials were Patchouli plants from Samigaluh village, Kulon Progo district, Yogyakarta. This study is aimed to compare two distillation techniques in order to find out the optimal distillation technique to increase the content of patchouli alcohol (patchoulol) and the quality of patchouli oil. Pretreatment such as withering, drying, size reduction and light fermentation were intended to increase the yield. One kilogramm of patchouli was moisturized with 500 mL of aquadest. The light fermentation process was carried out for 20 hours in a dark container. Fermented patchouli was extracted for 6 hours using Water-Steam and Water Bubble Distillation techniques. Physical and chemical properties test of patchouli oil were performed using SNI standard No. SNI-06-2385-2006 and the chemical composition of patchouli oil was analysed by GC-MS. As the results, the higher yield oil is obtained using Water-Steam Distillation, i.e. 5.9% versus 2.4%. Spesific gravity, refractive index and acid number of patchouli oil in Water-Steam Distillation results did not meet the SNI standard, i.e. 0.991; 1.623 and 13.19, while the Water Bubble Distillation met the standard, i.e. 0.955; 1.510 and 6.61. The patchoulol content using Water Bubble Distillation technique is 61.53%, significant higher than those using Water-Steam Distillation, i.e. 38.24%. Thus, Water Bubble Distillation promises a potential technique to increase the content of patchoulol in the patchouli oil.