Squalene recovery from palm fatty acid distillate using pressure swing and conventional supercritical carbon dioxide extraction

Squalene is a natural lipid compound and has a good potential as an antioxidant,hence an excellent choice to be used as functional ingredient. The objectives of this study were to find the optimum conditions for squalene extraction from palm fatty acid distillate (PFAD) using two processes of supercritical carbon dioxide (SC-CO2) extraction, such as conventional extraction and pressure swing process and find the better process for squalene recovery. Response surface methodology (RSM) with central composite design (CCD) was used to determine optimum squalene recovery from PFAD using SFE. For both processes, extraction were set at temperatures ranged from 40 to 60 ⁰C and pressure from 200 to 400 bar for a 90 min dynamic extraction period. For pressure swing process, holding time was set from 20 to 40min. Fourteen and twenty runs were carried out for conventional extraction and pressure swing techniques, respectively. Squalene was quantified utilizing reverse phase high performance liquid chromatography (RP-HPLC). Comparison of the performance of the two processes was made based on total lipid extract and squalene concentration in the extract. Besides that, comparison was also made based on the squalene solubility study of both techniques. The results showed that optimum SFE conditions for conventional extraction process were at 200 bar and 50 ⁰C, which resulted in total lipid extract and squalene concentration of 13.87±0.52 % w/w and 418.31±18.40 ppm respectively. Meanwhile for pressure swing process, optimum condition were at 230 bar, 40 ⁰C and 20 min holding time, which yielded a total lipid extracts and squalene concentration of 19.19±2.47 % w/w and 368.28±18.10 ppm respectively. The experimental value agreed with that of predicted value at the optimal conditions. The results show that pressure swing process was the more effective than conventional extraction in producing higher total lipid extracts. However, squalene concentration from the extracts was found to be the higher in conventional extraction even though the pressure swing process gave better efficiency in terms of total lipid extracts. The solubility study shows that the squalene solubility in SC-CO2 was higher using conventional extraction (18.1207kg/kg) compared to pressure swing process (15.2374 kg/kg) since the main objective is the attainment of highest squalene concentration, hence, it can be concluded that SFE with conventional extraction is more desirable than pressure swing process