The Optimized Concentration and Purity of Spirulina platensis C-Phycocyanin: A Comparative Study on Microwave-Assisted and Ultrasound-Assisted Extraction Methods

Abstract

Microwave-assisted (MAE) and ultrasound-assisted (UAE) extraction methods to efficiently extract the C-phycocyanin (C-PC) from the blue-green algae, Spirulina platensis, were compared. The results showed that the linear and interaction effects of two parameters of extraction time and buffer pH on C-PC concentration and purity ratio were significant. The C-PC concentration was enhanced by increasing extraction time up to 7 and 25 min for UAE (2.84 mg/mL) and MAE (4.54 mg/mL) processes, respectively. The extraction time significantly had more effect than the buffer pH value on the purity ratio. The highest purity ratio of C-PC in UAE (0.65) and MAE (1.27) technologies was obtained in buffer pH values of 6.0 and 7.0, respectively. The C-PC extracted from the MAE system significantly had higher concentration and purity than that obtained using the UAE procedure. Thus, MAE as an efficient method can be applied to extract heat-sensitive C-PC from S. platensis in an industrial scale. Practical Applications C-phycocyanin (C-PC) is a blue-colored photosynthetic accessory pigment in all cyanobacteria that has high antioxidant activity to enhance the prolonged induction period for fats or oils by preventing peroxidation of unsaturated fatty acids. Finding a proper and novel extraction method is necessary to obtain high-quality C-phycocyanin for using in different food formulations. Optimization of experimental conditions can thus provide selection of a fast and cost-saving process in the extraction of this functional ingredient.