Optimization of subcritical fluid extraction of carotenoids and chlorophyll a from Laminaria japonica Aresch by response surface methodology

BACKGROUND The carotenoids and chlorophyll a of Laminaria japonica Aresch were extracted using ethanol-modified subcritical 1,1,1,2-tetrafluoroethane (R134a). In the present study, the effects of pressure (5–17 MPa), temperature (303–333 K) and the amount of cosolvent(2–6% R134a, w/w)were investigated. Response surface methodology (RSM) combined with a Box–Behnken design was applied to evaluate the significance of the three independent variables on each response. A desirability function was conducted to simultaneously optimize the multiple responses. RESULTS The optimum extraction conditions were as follows: extraction temperature 324.13 K, extraction pressure 17 MPa and a cosolvent amount of 4.73%. Under these conditions, the yields of carotenoids and chlorophyll a were predicted to be 0.239 and 2.326 g kg−1, respectively. CONCLUSION It has been proved that subcritical R134a is a potential solvent, which can be an alternative to supercritical CO2 for extraction of natural ingredients under mild conditions. © 2013 Society of Chemical Industry