Enhanced stability of C-phycocyanin colorant by extrusion encapsulation.

C-phycocyanin (C-PC) a blue color phycobiliproteins used as a food colorant, therapeutics, medicines, health food and biomarkers. In the present study, morphological property of encapsulated C-PC and its stability under various conditions like temperature, pH conditions are discussed. Microencapsulated droplets formed by extrusion found to be spherical with average size 1.2 ± 0.1 mm. SEM micrographs of freeze dried encapsulate confirmed the spherical shape. The effect of droplet formation with varying alginate percentage (1.5%, 2.0% and 2.5% w/v) was studied. In the stability test at 70 °C and 80 °C relative concentration (CR  %) was found to be 86.89 and 88.19%, respectively. The encapsulated C-PC showed a slow degradation at higher temperature compared to without encapsulated C-PC which was confirmed by UV-visible absorbance. At 45 °C and 55 °C temperatures the stability was studied at various pH conditions (pH 4.5, 5.5, 6.5, and 7.0) and reported. Aggregation of C-PC protein will not change during encapsulation was confirmed by SDS-PAGE. FTIR analysis of encapsulate and the alginate depicted similar characteristics of the compound compared to that of native C-phycocyanin colorant. Microencapsulation improves the stability and increases the shelf life of colorant.

Single step aqueous two-phase extraction for downstream processing of C-phycocyanin from Spirulina platensis.

C-phycocyanin, a natural food colorant, is gaining importance worldwide due to its several medical and pharmaceutical applications. In the present study, aqueous two-phase extraction was shown to be an attractive alternative for the downstream processing of C-phycocyanin from Spirulina platensis. By employing differential partitioning, C-phycocyanin selectively partitioned to the polymer rich (top) phase in concentrated form and contaminant proteins to the salt rich (bottom) phase. This resulted in an increase in the product purity (without losing much of the yield) in a single step without the need of multiple processing steps. Effect of process parameters such as molecular weight, tie line length, phase volume ratio, concentration of phase components on the partitioning behavior of C-phycocyanin was studied. The results were explained based on relative free volume of the phase systems. C-phycocyanin with a purity of 4.32 and yield of about 79 % was obtained at the standardized conditions.