Abstract: Objective: To explore the optimal extraction parameters for water-soluble polysaccharides from litchi flesh. Methods:  A series of single-factor investigations followed by response surface analysis were carried out to optimize conditions for the extraction of water-soluble polysaccharides from litchi fresh. Sulfuric acid-phenol method was used to quantify polysaccharides. Results: The optimal extraction parameters were litchi flesh-to-water ratio of 1:17 (g/mL), extraction temperature of 90.5 ℃, and extraction time of 4.0 h. Under these conditions, the extraction rate was up to 10.06%, and the crude extract obtained showed an average polysaccharide content of 6.71%. Conclusion: It is feasible to optimize extraction parameters of water-soluble polysaccharides from litchi flesh using response surface methodology.

Key words: litchi flesh, water-soluble polysaccharides, extraction, optimal parameters