Study on the optimization of enzymatic extraction technology of polysaccharide from Camellia japonica L.by response surface methodology and investigation on its antioxidant activity

Objective: This study aimed to optimize the enzymatic extraction technology of polysaccharide from Camellia japonica L. and investigate its antioxidant activity. Methods: The response surface method( RSM) was adopted to establish the mathematical model. The polysaccharides extraction rate was used as response value,and the ratio of water to material,cellulase concentration,extraction temperature and extraction time were used as experimental factors to optimize the polysaccharide extraction conditions from Camellia japonica L.. Antioxidant activity of polysaccharides was measured by DPPH and O-2·free radical elimination method.Results: The optimum conditions obtained by RSM were as follows,polysaccharide yield was most significantly affected by extraction time,followed by extraction temperature,water to material ratio and cellulase concentration. The concentration of cellulase was 5.0 mg / m L,extraction time was 71 min,the ratio of water to feedstock was 9 ∶ 1 m L / g,extraction temperature was 48 ℃. Under the optimal conditions,the predicted extraction rate by mathematical model was15.91%,while the experimental extraction rate was 15.28%,with a difference of less than 5%.IC50 of DPPH and O-2·were 0.974 mg / m L and 1.342 mg / m L,respectively.Antioxidant activity of sample polysaccharides was weaker than those of vitamin C.Conclusion: The optimum enzymatic extraction technology of the polysaccharides from Camellia japonica L.by RSM was convenient and feasible,and the extracted polysaccharides had good antioxidant activity.