Optimization of Circulating Extraction of Polysaccharides from Gracilaria Lemaneiformis Using Pulsed Electrical Discharge

Gracilaria lemaneiformis (GL) is considered as a valuable plant because of its high content of polysaccharides. The purpose of this study was to optimize and validate the circulating extraction of polysaccharides from GL using pulsed electrical discharge (PED) through single factor analysis. The maximal yield of polysaccharides (164.34 ± 4.62 mg/g) was obtained under the optimal operating conditions: 24 min extraction time, 250 mL/min flow rate of materials, 50 mL/g liquid to solid ration, 13 kV voltage, and distilled water was considered as the solvent. Compared with continuous PED and reflux extraction, circulating PED had the highest yield, shortest extraction time, and lowest specific energy input, while the monosaccharide compositions of polysaccharides were mainly composed of galactose and glucose with slight xylose, fucose, mannose, and arabinose. These results indicated that circulating PED method was time-saving and energy-saving for economical extraction of polysaccharides from plant materials and presented prospective in large-scale application.