The highest purity ratio of phycocyanin extract was obtained when fresh biomass was used as raw material. The crude extract was purified by membrane process using microfiltration and ultrafiltration. Membrane of pore sizes 5 mu m, at feed flow rate of 150 mL min(-1), permeate flux of 58.5 L h(-1) m(-2) was selected for coarse filtration and membrane with pore size 0.8/0.2 mu m at the flow rate of 100 mL min(-1), permeate flux of 336 L h(-1) m(-2) was selected for fine filtration, giving phycocyanin recovery of 88.6% and 82.9%, respectively. For ultrafiltration, membrane with MWCO at 50 kDa, 69 kPa and 75 mL min(-1) of flow rate with a mean permeate flux 26.8 L h(-1) m(-2) and a retention rate of 99% was found to be optimal. Under these filtration conditions, food grade phycocyanin with the purity around 1.0 containing c-phycocyanin as the major component was obtained. (C) 2011 Elsevier Ltd. All rights reserved.