Abstract: In this paper, the ultrasonic-assisted enzymatic extraction and purification of polysaccharides from Patinopecten yessoensis were optimized using one-factor and orthogonal array design methods. For the deproteinization of crude polysaccharides, D-glucono-δ-lactone (GDL) was used in this study for the first time and its performance was evaluated in comparison with trichloroacetic acid (TCA). The results showed that the optimum conditions for extraction were as follows: solvent/solid ratio, 40:1 (mL/g); enzyme dosage, 2.5%; and 3 h extraction at 60 ℃, resulting in the highest polysaccharide yield of 10.90%. The optimum conditions for TCA deproteinization were as follows: deproteinization time, 5 h; final TCA concentration, 5%; and 3 deproteinization cycles. The optimal conditions for GDL deproteinization were as follows: deproteinization time, 1 h; reaction temperature, 45 ℃; and final concentration, 0.3%. Three parallel experiments conducted under the optimized conditions gave an average deproteinization rate of 88.654% and 99.062% with relative standard derivation (RSD) of 0.905% and 0.679% for TCA and GDL, respectively. Comparison of the two deproteinization methods showed that the deproteinization efficiency of GDL method was higher and more stable.

Key words: Patinopecten yessoensis, polysaccharide, trichloroacetic acid, D-glucono-δ-lactone, deproteinization