The Influences of Concentrate Extract Properties and Ethanol Addition Amount on the Ethanol Precipitation Process of Salvia Miltiorrhiza

In this work, 10 batches of Salvia miltiorrhiza concentrate were prepared and purified with ethanol precipitation process. Dry matter content, pH value, conductivity and water content of the concentrates and supernatants were all determined. When more ethanol was used in ethanol precipitation, the pH value of the supernatant generally increased, but dry matter content, water content, and the conductivity decreased. Multivariate linear models were built with the most determination coefficient values greater than 0.7. More than 80% of stachyose was removed in the ethanol precipitation process. The removal rate of fructose, raffinose and sucrose were all higher than 30%. When ethanol addition amount increased, the purity of phenolic acids in the supernatant increased, but the retention of lithosperimic acid and salvianolic acid B decreased. The conductivity and pH value of concentrated extract show relatively small influences on ethanol precipitation indices. When fructose, raffinose, or stachyose contents in the concentrated extract were high, the retention rate of phenolic acids tends to be low on most occasions. The purity and retention rate of phenolic acids in the supernatants were also affected by the purity of phenolic acids in the concentrated. The sugar contents in the concentrate are suggested to be monitored in industry because they significantly affect ethanol precipitation process indices.