Iranian Association of Chemical Engineering (IAChE) Iranian Journal of Chemical Engineering (IJChE) 1735-5397 Articles in Press 2026 07 06 Preliminary Purification of C-Phycocyanin through the Foam Fractionation 77 91 246799 10.22034/ijche.2026.579517.1592 EN Shadi Azar Faculty of Chemical and Petroleum Engineering, Razi University, Kermanshah Alireza Habibi Faculty of Chemical and Petroleum Engineering, Razi University, Kermanshah 0000-0002-4448-2924 Farshad Rahimpour Faculty of Chemical and Petroleum Engineering, Razi University, Kermanshah 0000-0002-8564-9436 Journal Article 2026 05 11 Objective: C-Phycocyanin (C-PC) is a blue-colored protein antioxidant produced in the microalgae Spirulina platensis (S. platensis) that is used in the food, cosmetic and pharmaceutical industries. The purification methods are often time-consuming and expensive. In this study, Foam fractionation (FF) was used as a simple, rapid, cost-effective, and environmentally friendly method for the purification of C-PC.<br>Methods: C-PC pigment solution was extracted from dry S. plantensis biomass in phosphate buffer. FF method for the purification of C-PC was optimized using the response surface methodology (RSM). A UV-Vis spectrophotometer was used to determine the identifying absorbance peaks of the C-PC solutions.<br>Results: The RSM obtained an optimal setting at a pH = 6, aeration rate of 3.5 vvm, and operation time of 21 min for achievement of the highest purification fold (PF), purity index (PI), and C-PC recovery percentage (R) of about 1.56 ± 0.02, 0.59 ± 0.02, and 45.59 ± 0.72%, respectively.<br>Conclusion: In FF method there are no additional chemicals, also it is fast and has low operating costs, which make it an attractive method.