Abstract:The ultrasound-enzyme assisted on red raspberry seed proanthocyanidins was optimized by response surface methodology，also evaluated its ability of binding bile salts in this research.Based on Box-Benhnken central combination design，extraction rate of proanthocyanidins was taken as index，effects of four crucial factors on extraction rate of proanthocyanidins were investigated by response surface analysis.The optimum extraction conditions that provided the maximum extraction rate （16.42 mg/g）of proanthocyanidins were determined as follows：ratio of solid to liquid，1∶31（g/mL）；enzyme dosage，0.8%；ultrasound power，190 W；extraction time，39 min.At the beginning of the reaction，the proanthocyanidins combines three cholic acid salt was faster and the adsorption equilibrium was reached in 30 min.Sodium taurocholate was better than sodium glycocholate and sodium cholate in their binding ability to red raspberry seed procyanidins.Compared with cholestyramine，its combination with the sodium cholate，sodium glycocholate and sodium taurocholate values were，54.50%，71.79%，72.34%.Thus red raspberry seed proanthocyanidins have good binding capacity with bile salts in vitro.