Optimization of Polysaccharides Extraction from Mulberry Leaves Fu Brick Tea by Response Surface Methodology and Its Antioxidant Activities & Hypolipidemic Effects in Vitro

The mulberry leaves of fu brick tea was used to extracted polysaccharides by water extraction method and evaluate the antioxidant activity and hypolipidemic function. Based on the effects of extraction time, extraction temperature, liquid-solid ratio and extraction times on the yield of polysaccharides were investigated by single factor experiment, response surface methodology was used to optimize the extraction process, results showed that the optimum condition were as follows:extraction time 1.6 h, ratio of liquid to solid 16:1 mL/g, extraction temperature 51℃, with 1 time extraction, under the best condition, mulberry leaves of fu brick tea polysaccharides was 10.43%, and which was consistent with the predicted results, it showed that the extraction process is stable and feasible. When the mulberry leaves fu brick tea polysaccharides concentration was 80 μg/mL, the rate of scavenging DPPH radicals was 84.35%, and when the polysaccharides concentration was 130 μg/mL, ABTS⁺·scavenging rate was 72.30%, when the mulberry leaves fu brick tea polysaccharides concentration was 1.75 mg/mL, the rate of scavenging·OH was 74.08%, it showed mulberry leaves of fu brick tea polysaccharides had good antioxidant activity effect. When the mulberry leaves of fu brick tea polysaccharides concentration was 3.50 mg/mL, the combination rate of sodium taurine sodium cholate and sodium glycine sodium cholate respectivelyreached to 59.96% and 41.97%, it showed mulberry leaves of fu brick tea polysaccharides had good effect on hypolipidemic.