Heat-induced coacervation for purification of Lycium barbarum polysaccharide based on amphiphilic polymer-protein complex formation

Heat-induced coacervation of triblock copolymer solution was described, and its application in the purification of Lycium barbarum polysaccharide (LBP) was investigated. The formation of coacervate micelles-protein complex combined with the incompatibility between coacervate micelles and polysaccharide made it an ideal system for the separation of protein and LBP. This separation process was governed by a series of parameters including polymer concentration, amount of crude LBP solution, and pH. In the primary coacervation extraction process, LBP was preferentially distributed to dilute phase with a high recovery ratio of 82%, whereas 87% of protein was partitioned to the coacervate phase. The coacervate micelles-protein interaction and the interphase potential was regulated by temperature and electrolytes, respectively, which contributed to the recovery and recycling of the polymer. After phase separation, LBP was precipitated with the addition of ethanol. The FTIR spectrum was used to identify LBP. In addition, the antioxidant activity of LBP was measured.