Abstract:

An alkaline-ethanol extraction technique was developed to extract LBP and the extraction condition was optimized by a single factor test and orthogonal experiments. The in vitro radical scavenging activity of LBP against ·OH was also discussed. Results indicated that the yield of LBP was significantly affected by the iquid/Solid ratio, ethanol concentration, pH, extraction temperature and extraction time. The optimum conditions for alkali-ethanol extraction were: liquid/solid ratio of 50:1 (ml/g), ethanol concentration of 8%, pH 10.5, 70 ℃ and 6.5 h of extraction time. Under this condition, the yield of LBP could reach the maximum of 29.19%, which was increased by 9.51% compared to the traditional water extraction technology. The radical scavenging activity of LBP samples against ·OH was up to 44.90% at 2.35 mg/ml.

Key words: Lycium barbarum polysaccharids (LBP), alkaline-ethanol extraction technology, optimize, radical scavenging activity