Optimization of compound enzyme extraction of safflor yellow by response surface methodology.

[Objective] The compound enzyme extraction process for safflor yellow from Carthamus tinctorius L. was optimized to provide references for utilizing safflor yellow. [Method] Based on the single factor experiments including four factors (enzymatic concentration, enzymolysis temperature, enzymolysis time, pH) and three levels, response surface methodology (RSM) was used to optimize the compound enzyme extracting safflor yellow with its yield as the indicator. [Result] Quadratic regression model of safflor yellow extraction yield (Y) on enzymatic concentration (X₁), enzymolysis temperature (X₂), enzymolysis time(X₃) and pH(X₄) was Y=-1.16333+24.9875X₁+0.14083X₂+0.6X₃+0.375X₄- 0.06875X₁X₂+0.075X₁X₃+0.4125X₁X₄+0.013X₂X₄-0.0075X₃X₄-18.55208X₁²-0.0016833X₂²-0.14833X₃²-0.13208X₄²(R²=0.976), which showed good fitting degree. Enzymatic concentration had extremely significant effects on safflor yellow extraction yield (P<0.01) and pH had significant influence (P<0.05, the same as below). The interactive role between pH and enzymolysis temperature & enzymolysis temperature and enzymatic concentration also had significant influence. The optimal conditions were: enzymatic concentration (the ratio of pectinase to cellulose = 1:1) of 0.64% (w/w), enzymolysis temperature of 47 °C, enzymolysis time of 2 h, and pH of 4.7. Under these conditions, the safflor yellow extraction yield was up to 11.59%, close to 11.65%, the theoretical prediction. [Conclusion] Using RSM for compound enzyme extracting safflor yellow is highly applicable, which should be extended in production. [ABSTRACT FROM AUTHOR]