茶皂素的提取及其溶液的表面性质

Extraction of tea saponin and surface performance of its solutions

采用醇提法提取油茶饼粕中的茶皂素,考察了溶液pH值和电解质浓度对茶皂素表面张力和表面扩张模量的影响.结果表明:pH值升高,临界胶束浓度增大,表面扩张模量下降;电解质的加入对茶皂素的表面张力和临界胶束浓度影响不太,但会破坏表面活性剂分子在溶液表面上的氢键作用,从而降低表面扩张模量.在中性条件下茶皂素的表面扩张模量较大,可达200 m N/m以上,这可能是茶皂素泡沫稳定的主要原因.

The tea saponin was extracted from camellia cake by ethanol, and the influences of pH and electrolyte （NaCl） concentration on the surface performance of tea saponin solutions were investigated. It was shown that the critical micelle concentration （cmc） increased, while the surface dilational modulus decreased with increasing pH value of solution. NaCl has little effect on the surface tension and cmc, but it decreased the surface dilational modulus of tea saponin solution due to breaking the hydrogen bond between surfactant molecules on surface. The surface dilational modulus of tea saponin is more than 200 mN/m under neutral condition, which may be the main reason for it high foam stability.