Optimization of the vacuum drying process for Spirulina platensis

To improve the concentration of the bioactive component phycocyanin in drying Spirulina products, the vacuum drying process of Spirulina platensis was optimized by the method of response surface analysis based on three major drying factors, including material thickness, drying temperature and vacuum pressure. A polynomial regression analysis was performed on the experimental data by using Design-Expert software, and a mathematical model between the three primary factors and the concentration of phycocyanin was established. According to response surface analysis, the optimal vacuum drying condition of Spirulina platensis was determined as follows: material thickness 3 mm, drying temperature 45℃ and vacuum pressure 0.08 MPa, of which the phycocyanin concentration in Spirulina platensis reached up to 12.500×10-3 mg/mL. The research provided a great potential for improving the drying quality of Spirulina powder.