a method for the separation or purification of biopolymers comprises adsorbing the biopolymer on the surface of liquid oil droplets ; and separating the adsorbed biopolymer from the oil droplets . the adsorbed biopolymer is separated from the oil droplets by mixing the droplets in an aqueous liquid , removing the lower aqueous phase and adding a fresh aqueous phase to the droplets , cooling the mixture to solidify and coalesce the oil and to cause it to release the adsorbed biopolymer to the fresh liquid , separating the fresh liquid and the biopolymer from the coalesced oil , separating the biopolymer from the fresh liquid .