Patent ID: 8609377
Filing Date: 2013-12-17
Classification: C08B,C12P

Abstract:
1. A post extraction process for preparing low acyl gellan, comprising the following steps: (1) Deacylation treatment of fermentation broth: The temperature of the fermentation broth is raised to 80˜90° C., and an antioxidant is added and a base is added to adjust the pH value to deacylate the gellan gum, after the deacylation treatment is completed, an acid is added to lower the pH value; (2) Enzyme treatment of fermentation broth: Into the fermentation broth of Step (1), different enzyme preparations are added to remove the insoluble impurities and bacterial debris from the fermentation broth as much as possible; (3) Flocculation of fermentation broth: Into the fermentation broth treated in Step (2) with enzymes, a water-soluble alkali metal is added to flocculate, and the pH value is adjusted to a basic condition; a solid-liquid separation is conducted to remove a large part of water and pigments from the fermentation broth so that the raw product of gellan gum is obtained; (4) Clarification treatment of gellan gum: The raw product of gellan gum obtained in Step (3) is clarified so that a clarified low acyl gellan gum solution is obtained; (5) Dehydration treatment of the deacylated gellan gum solution: Into the gellan gum deacylated and clarified solution obtained in Step (4), an alkali metal ion is added to form a gel and a solid-liquid separation is conducted; (6) Removal of divalent or polyvalent cations and decoloration treatment The gellan gum obtained in Step (5) is cut into grains, most of the divalent or polyvalent cations in the gellan gum are removed by ion exchange or chelating; and a slight drying is conducted by press, the slightly-dried gellan gum is further immersed with a lower alcohol and along with agitation; and the solution is filtered to reach the effect of complete removal of the colored substances; (7) Drying and milling: The solid materials of gellan gum obtained in Step (6) are dried and milled, so that a highly transparent, low acyl, and clarified gellan gum product is obtained.