Solid–liquid extraction of phycocyanin from Spirulina platensis: Kinetic modeling of influential factors

• Solvent pH and temperature significantly affected the extraction performance.
• A second-order kinetic model for the extraction was successfully developed.
• The calculated activation energy indicated that the extraction was endothermic.

To effectively extract value-added phycocyanin from Spirulina platensis, the effects of processing parameters (pH and temperature) on extraction performance and global kinetics were systematically studied. The extraction kinetics was investigated by varying pH levels (5–8) and temperatures (30–60 °C). An empirical kinetic model incorporating the aforementioned factors was developed. A good agreement between the experimental and fitted data was obtained, which indicated that the extraction process followed second-order kinetics. Furthermore, the model parameters (equilibrium concentration, extraction rate constants, and initial rates of extraction) were calculated and formulated as a function of the operating factors. The activation energy of the extraction was 67.1 kJ mol−1, indicating that the process was endothermic. The predictions obtained from the developed model were compared with the experimental data under the same operating conditions. The predicted and experimental data were consistent, indicating the reliability of the model.