Optimization of extraction process for bioactive compounds from Litsea cubeba fruits

Response surface methodology (RSM) was applied to evaluate the extraction of active compounds from Litsea cubeba fruits. A central composite design (CCD) with five levels and three process parameters (extraction temperature, extraction time and ethanol concentration) was used to investigate the influence of the extraction temperature, extraction time and ethanol concentration on the multiple response variables (TPC, DPPH and ABTS assays). The results of the ANOVA analysis show that the quadratic term of the ethanol concentration was significant for all the response variables. The quadratic model was highly significant (P<0.05) for all the response variables. After optimizing for multi-response, the optimal conditions were determined as an extraction temperature of 42.3 oC, extraction time of 126.4min and ethanol concentration of 51%. Moreover, the extract of Litsea cubeba fruit attested possessing tyrosinase inhibitory activity, with an IC50 value of 5,720 μg mL−1. The second-order kinetic model represented the kinetic data very well. In addition, the obtained values of the effective diffusivities were in the range of 2.28-5.83×10−11m2s−1.