METHOD EMPLOYING COMPOSITE CHITOSAN FLOCCULATION TO PREPARE STEVIA POLYPHENOL

摘要

Disclosed are a method employing composite chitosan flocculation to prepare stevia polyphenol and stevia polyphenol prepared by the method. The method comprises: flocculating a stevia leaf water extract with a composite chitosan at room temperature to remove impurities, and adsorbing the supernatant with a macroporous polar resin, wherein the effluent is to be further used for the extraction of stevioside; eluting the resin with aqueous alcohol solutions of different concentrations, and after elution with a low-concentration aqueous alcohol solution, combining the resultant separated solution with the effluent produced before separation to obtain a combined solution, the total phenol content in the combined solution being less than 0.5% (on a dry basis), and the combined solution being reserved for extraction of stevioside; and drying the eluent produced from elution with a high-concentration aqueous alcohol solution, to give stevia polyphenol mainly composed of isochlorogenic acid.