Optimization of phycocyanin extraction from Spirulina platensis using different techniques

Phycocyanin is an important commercially available blue food colorant. Herein we report an optimization study of various phycocyanin extraction methods from Spirulina platensis cyanobacterium biomass (dry, frozen and wet). Three different solvents i.e. distilled water, Na-Phosphate pH: 7.4 suspension and 1.5% CaCl2 (w/v) water solution were applied as the extraction medium. The highest total phycocyanin content (55.33 mg/g) was extracted from frozen biomass using 1.5% CaCl2 (w/v aq.) solution. Process variables of classical, ultrasound and microwave extraction methods (biomass/solvent ratio, extraction time, vibration, speed, and power) were optimized considering the CCRD experimental design to enrich phycocyanin. The optimum conditions of extraction methods; classical, ultrasound and microwave were determined as: 1.71% biomass/solvent ratio, 6237.66 homogenization rate and 15 min extraction time; 1% biomass/solvent ratio, 60% amplitude and 16.23 min extraction time; 2.34% biomass/solvent ratio, 133.29 W and 165.96 s extraction time. Classical extraction method provided vivid blue color, a higher amount of phycocyanin, and maximum antioxidant activity as compared to other extraction methods.