Effect of Different Processing Methods on Stability of Anthocyanin and Phycocyanin of Spirulina platensis

A blue-green Spirulina microalgae is a Cyanobacterium, that is one of the most interesting functional sources of food ingredients with nutraceutical properties. It is a perishable product and should be processed immediately after harvesting. In the present study the stability and changes colorimetric properties and optical density of extracted phycocyanin and also anthocyanin content of Spirulina platensis after different processing condition (shade-, sun-, oven-, microwave-, vacuum oven-, freeze- and spray-drying and freezing with and/or without blanching) were investigated. The results indicated the processing condition significantly affected the pigments content of sample.Non-blanched freezing was preferred in pigments conservation.In dehydrated samples, the freeze-dried sample had the least change in optical density of extracted phycocyanin than fresh sample.The levels of anthocyanin in frozen, spray-dried, freeze-dried and microwave-dried samples in comparison to fresh Spirulina were increased significantly (P< 0.05). In this regards, spray drying could be a practical drying method for processing SP, although, freezing is preferred.