Abstract:

[Objective] The purpose of this study was to determine the optimized extraction process of condensed tannin from Caragana korshinskii. [Method] The Caragana korshinskii collected from Siziwang Banner of Inner Mongolia was used as experimental material. The condensed tannin was extracted from Caragana korshinskii by using ultrasonic assisted solvent extraction method, and the content of condensed tannin was determined by using phosphomolybdic and phosphotungstic acids chromogenic method. The effects of extraction temperature, extraction time, liquid to material ratio and acetone volume fraction on the yield of condensed tannin from Caragana korshinskii were assessed by single factor experiment. [Result] As the increase of extraction temperature, the yield of condensed tannin from Caragana korshinskii increased first and then decreased. When the extraction temperature was 60 ℃, the yield of condensed tannin was the highest, which was 34.24 mg/g. As the extension of extraction time, the yield of condensed tannin from Caragana korshinskii increased first and then decreased. When the extraction time was 80 min, the yield of condensed tannin was the highest, which was 26.38 mg/g. As the increase of liquid to material ratio, the yield of condensed tannin from Caragana korshinskii increased first and then decreased. When the liquid to material ratio was 30∶1, the yield of condensed tannin was the highest, which was 25.34 mg/g. As the increase of acetone volume fraction, the yield of condensed tannin from Caragana korshinskii increased first and then decreased. When the acetone volume fraction was 70%, the yield of condensed tannin was the highest, which was 30.61 mg/g. [Conclusion] The optimum extraction temperature, extraction time, liquid to material ratio and acetone volume fraction was 60 ℃, 80 min, 30∶1 and 70%, respectively.

Key words: condensed tannin from Caragana korshinskii, extraction temperature, extraction time, liquid to material ratio, acetone volume fraction