Process development for the decoloration of Panax notoginseng extracts: a design space approach

A systematic, yet simple method for the decoloration of Panax notoginseng extracts has been developed by static adsorption tests and response surface methodology. Through static adsorption experiment screening, acidic alumina was selected because of its high decoloration ratio and saponin recovery ratios. Using response surface methodology, the correlation between the process parameters (i.e., sample volume and flow rate) and decoloration performance was modeled. A design space of the decoloration process was subsequently established through the proposed models. The verification experimental values were in good agreement with the predicted values. The design space was proven reliable, because all the verification experimental results attained the criteria for design space development. Moreover, most of the saponins adsorbed by the acidic alumina could be recovered through dynamic desorption using water and ethanol. The method developed in the current study is highly efficient, flexible, and easy to control, thus providing a promising approach for the decoloration of Panax notoginseng extracts with consistent decoloration performance.