A green and efficient deproteination method for polysaccharide from Meretrix meretrix Linnaeus by copper ion chelating aerogel adsorption

Polysaccharides (PMM) from Meretrix meretrix Linnaeus exhibit a variety of biological activities; however, conventional purification methods are costly, time consuming and introducing toxic agents. This paper aimed to develop a green and efficient method for the deproteinization of PMM by copper ion chelating aerogel (CCA) adsorption. First, CCA was successfully prepared by copper ion chelating composite aerogel (CA). Then, CCA adsorption was applied to remove protein mixed in PMM. The optimal parameter conditions of this deproteinization method were screened, using the deproteinization rate (Dr%), polysaccharide recovery rate (Rr%) and selectivity coefficient (Kc) as evaluation indicators, by single factor experiment. The optimal conditions were obtained as follows: CCA dose of 1.4%, pH value of 5.0 and adsorption temperature of 30 °C. Under these conditions, equivalent Dr% (93.31 ± 1.33%), higher Rr% (93.34 ± 1.08%) and Kc (14.01 ± 0.46) were achieved compared with the latest reported deproteinization report. Finally, the effect of deproteinization between CCA adsorption and Sevag method, which is the most classical deproteinization method, were compared to verify the practicability of CCA adsorption. As a result, CCA adsorption not only showed much higher Rr% as well as Kc, but also would not cause any reagent contamination and environment pressure. In conclusion, CCA adsorption would be a green and highly efficient method with great potential in large-scale environmentally sustainable deproteinization of polysaccharides in the future.