Extraction of anthocyanins from red cabbage using high pressure CO2

The extraction kinetics of anthocyanins from red cabbage using high pressure CO2 (HPCD) against conventional acidified water (CAW) was investigated. The HPCD time, temperature, pressure and volume ratio of solid–liquid mixture vs. pressurized CO2 (R(S+L)/G) exhibited important roles on the extraction kinetics of anthocyanins. The extraction kinetics showed two phases, the yield increased with increasing the time in the first phase, the yield defined as steady-state yield (y∗) was constant in the second phase. The y∗ of anthocyanins using HPCD increased with higher temperature, higher pressure and lower R(S+L)/G. The general mass transfer model with higher regression coefficients (R2 > 0.97) fitted the kinetic data better than the Fick’s second law diffusion model. As compared with CAW, the time (t∗) to reach the y∗ of anthocyanins using HPCD was reduced by half while its corresponding overall volumetric mass transfer coefficients kL×akL×a from the general mass transfer model increased by two folds.