Effect of preservatives for food grade C-Phycoerythrin, isolated from marine cyanobacteria Pseudanabaena sp.

C-Phycoerythrin is water soluble red color chromo-protein, which is used as a natural food colorant. The effect of selected edible preservatives like citric acid, sodium chloride, sucrose and calcium chloride on the stability of C-Phycoerythrin at 0 ± 5 °C and 35 ± 5 °C was studied in aqueous solution. Experiment was carried out to select a stabilizing agent having Hofmeister series behavior acting on hydrophobic interactions. The denaturation of phycoerythrin with urea as denaturant and effect of different pH on C-Phycoerythrin was studied. Citric acid (4 mg/ml) was observed to be one of the best preservative for C-Phycoerythrin at 35 ± 5 °C and 0 ± 5 °C in aqueous solution for 45 days. Citric acid was able to maintain the stability of C-Phycoerythrin in the solution. The amount of C-Phycoerythrin left in the solution containing citric acid after 30 and 45 days was 46 and 37.8% respectively at higher temperature.