Glycerol-based NaDES as green solvents for ultrasound-assisted extraction of phycocyanin from Arthrospira platensis— RSM optimization and ANN modelling

Phycocyanin, a natural blue phycobiliprotein extracted from cyanobacteria, recently focused the interest of food industry as promising pigment and antioxidant. Eco-extraction of phycocyanin via ultrasound using five glycerol-based NaDES was described here. Response surface methodology (RSM) and artificial neural network (ANN) were adapted for the generation of predictive models to simulate and optimize phycocyanin extraction. Input parameters were extraction time (15–60 min), temperature (25–50 °C) and water addition (20–60%). Two original glycerol-based NaDES, glycerol:glucose:betaine (4:1:1) and glycerol:glucose:proline (4:1:1), displayed the highest phycocyanin recovery, combined with high free radical scavenging activity. Additionally, a stabilizing effect of NaDES on phycocyanin was highlighted after accelerated ageing. Optimized extraction protocol developed here allowed then the extraction, pre-formulation and stabilization of phycocyanin in one step, opening the way to a sustainable formulation of this bioactive pigment for food industry.