Isolating phycocyanin from microalgae typically begins with solid–liquid extraction using aqueous solvents [5]. In general, solvent type, extraction temperature, and solid–liquid ratio are influential factors in the extraction process [5] and [7]. The response surface methodology has been used to optimize these operating factors for phycocyanin extraction [5]; however, this empirical approach does not account for the mechanism governing the process [13]. Developing a kinetic model coupling the operating factors on phycocyanin extraction is a solution that is crucial for designing an efficient phycocyanin extraction process. However, a relevant kinetic model of phycocyanin extraction has not been developed.
In this study, Spirulina platensis was used as a source for phycocyanin. The effects of the operating factors (solvent pH and extraction temperature) on the aqueous solid–liquid extraction of phycocyanin from S. platensis were examined. Because a second-order kinetic model effectively depicts solid–liquid extraction processes [13], [14], [15] and [16], the kinetic model was used to determine corresponding kinetic parameters and predict the extraction process. Finally, the predicted phycocyanin concentrations were verified using actual experiments under the same conditions. This study is required before developing and performing a systematic process for phycocyanin extraction from S. platensis.