Optimization of extraction process of polysaccharides from wild Lactarius volemus by response surface method and investigation of antioxidant activity

In order to study the extraction process of wild Lactarius volemus polysaccharide ( LVP) and its antioxidant activity, Central-Composite Design ( CCD) of response surface design ( RSD) was used to optimize the extract conditions of LVP based on single factor tests and O₂^-·, ·OH, DPPH, ABTS radicals scavenging activities were tested for antioxidant activity evaluation.The results showed that the optimal condition for extraction of LVP was as follows: temperature of 90 ℃, water bath time of 4 h, ratio of water to raw material of 33∶ 1 m L/g, corresponding yield of LVP was 2.18%, containing 55.40% LVP, 11.37% protein and no starch. The IC50 of O₂^-·, ·OH, ABTS and DPPH radicals scavenging activities of LVP were 868.16, 280.00, 342.06, 167.65 μg/m L respectively.All in all, response surface design is reliable for the study of relationship between yield of LVP and temperature, water bath time, ratio of water to raw material, furthermore, LVP shows a higher antioxidant activity in radical scavenging experiments.