title: Optimization of subcritical fluid extraction of carotenoids and chlorophyll a from Laminaria japonica Aresch by response surface methodology.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Food Science and Engineering, Ocean University of China, Qingdao, 266003, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Lu
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Feng
authors.forename: Yuqian
authors.initials: Y
authors.lastname: Han
authors.forename: Changhu
authors.initials: C
authors.lastname: Xue
mesh_terms: D002338:Carotenoids / Q000302:isolation & purification*; D002734:Chlorophyll / Q000302:isolation & purification*; D000077194:Chlorophyll A; D002851:Chromatography, High Pressure Liquid; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D000431:Ethanol; D006845:Hydrocarbons, Fluorinated; D007795:Laminaria / Q000737:chemistry*; D011312:Pressure; D012997:Solvents; D013696:Temperature; D004980:Ethane / Q000031:analogs & derivatives; D005466:Fluorocarbons
chemical_list: D002338:Carotenoids; D002734:Chlorophyll; D000077194:Chlorophyll A; D000431:Ethanol; D006845:Hydrocarbons, Fluorinated; D012997:Solvents; C063006:norflurane; D004980:Ethane; D005466:Fluorocarbons
keywords: Laminaria japonica Aresch; RSM; pigments; subcritical fluid extraction