Qualitative and quantitative assessment of phycocyanin extracted from Spirulina (Arthrospira sp.) through absorption spectroscopy and denaturation electrophoresis SDS-PAGE

Abstract

The phycocyanin, a blue colour characterised protein, is widely used as a natural dye in food and cosmetic industries, and in pharmacy industry due to its beneficial bioactivities. In Vietnam, phycocyanin has been extracted and purified mainly from blue - green algae (Arthrospira platensis), but no studies have evaluated the purity as well as the amount of phycocyanin extracted. In this study, absorption spectroscopy at UV-Vis and denaturation electrophoresis SDS-PAGE were used to evaluate phycocyanin in crude extracts and purified samples. The obtained results showed that purifying phycocyanin from fresh biomass A. platensis in 2 steps (precipitated with ammonium sulfate following by LH20 column chromatography) gave the purity (expressed by A_620/280 of 1.2) which is suitable for applications in food and cosmetics. Evaluation of phycocyanin contents in commercial Spirulina products showed that a domestic product, namely Vinataor had a higher phycocyanin content than some imported commercial products.