β-carotene enrichment in crude palm oil using subcritical water extraction and its relationship with the solubility

Abstract

Subcritical water extraction (SWE) was applied for β-carotene enrichment in crude palm oil (CPO) extraction. Investigated SWE operating condition were the pressure of 30, 40 and 50 bar and temperature from 120 to 180 °C. SWE processes were conducted semi-batch for up to 60 min of extraction time. Dynamic method using low solvent rate was used to develop the solubility trend for β-carotene. The pressure and temperature in SWE process gave significant effect to the β-carotene concentration as determined by f value (2, 18) = 158.26, p < 3.78 × 10−12 and f value (3, 18) = 5.91, P < 5.43 × 10−3 respectively. Maximum β-carotene concentration of 857.72 ± 0.34 ppm is obtained at 160 °C and 40 bar. The process was successfully modelled using second order mass transfer coefficient model with r2 between 0.939 and 0.995. Solute solubility cannot be associated directly to extraction efficiency in SWE process for β-carotene enrichment.

Keywords

• Subcritical water extraction (SWE)
• β-carotene
• Solubility
• Dielectric constant