Environmental impact of phycocyanin recovery from Spirulina platensis cyanobacterium

Multifunctional extracts from Spirulina platensis are suggested as food additives, due to their high content in functional ingredients and specifically phycocyanin. The recovery of phycocyanin from the microalgal biomass is performed by using ultrasounds and polar solvents such water, ethanol or buffer. The application of drying pretreatment in combination with the use of different solvents presents variation in the yields, affecting the actual recovery of the protein and hence the environmental impact of the production of 1 kg phycocyanin. Life cycle analysis on the recovery techniques for the isolation of the desired phycocyanin was performed in order to evaluate the selected extraction processes' sustainability. Drying exhibited increased environmental footprint due to the energy demand, while at the same time affecting not only the yielding but also the quality of the extracts. The use of aqueous solvents can lead to an environmental and efficient extraction, replacing organic solvent systems sufficiently.Industrial relevancePhycocyanin is a pigment-protein complex which is used into various food products to enhance their nutritional qualities acting as food colorant, antioxidant and emulsifier, which can sufficiently replace or reduce the use of synthetic additives. For the effective recovery of phycocyanin, the nutrient should be extracted from the microalgae biomass of Spirulina platensis. The steps to achieve that include the cultivation and harvesting of the microalgae, the drying of the biomass if necessary and the extraction process. However, these steps are resource and energy demanding processes which can affect the environmental footprint and the cost of the final product. Looking for more efficient practices combinations of materials (wet or dried biomass) and solvents (water, buffer and ethanol), which are currently used industrially, were examined in order to evaluate and suggest the most sustainable production line for phycocyanin.