A novel green method for deproteinization of polysaccharide from Cipangopaludina chinensis by freeze-thaw treatment

The purpose of this paper was to develop a green method for deproteinization of polysaccharide (PCC) from Cipangopaludina chinensis by freeze-thaw treatment (FIT). Based on single-factor experiments of FIT, firstly, the optimal deproteinization parameters of PCC were obtained by comparing their deproteinization ratio (D-r%), recovery ratio (R-r%) and selectivity coefficient (K-c) as follows: freezing temperature of -40 degrees C, freezing time of 96 h, thawing temperature of 10 degrees C and freeze-thaw cycles of 11 times. Under optimal conditions, The D-r%, R-r% and K-c of PCC were 87.10 +/- 1.91%, 84.91 +/- 2.45% and 5.77 +/- 0.43, respectively. Then, the deproteinization performance of FIT for PCC under optimal conditions was compared with the most typical Sevage method. We found that there were no significant differences between FIT and Sevage method on the D-r%, monosaccharide composition, characteristic group and molecular weight degradation. However, compared with Sevage method, FIT not only had higher R-r% and K-c, but also were non-pollution. The results demonstrated that FIT would be a promising and green method for deproteinization of PCC. (C) 2016 Elsevier Ltd. All rights reserved.