Enzymatically modified gellan gum

Abstract

The present invention relates to process for preparing partially deacylated gellan gum, the process comprising subjecting native or high acyl gellan gum to treatment with an esterase capable of partially deacylating gellan gum.

1 . A process for preparing partially deacylated gellan gum, wherein the process comprises:
 subjecting native or high acyl gellan gum in a fermentation broth to treatment with an esterase capable of partially deacylating gellan gum, and   isolating a partially deacylated gellan gum from the fermentation broth after the esterase treatment.   
     
     
         2 . The process of  claim 1 , wherein the esterase is an acetyl esterase of the carbohydrate esterase family or a pectin acetyl esterase. 
     
     
         3 . The process of  claim 1 , wherein the esterase is pectin acetyl esterase 12B derived from  Clostridium thermocellum.    
     
     
         4 . The process of  claim 1 , wherein the esterase treatment is carried out at a pH in the range of 5.5-7.5. 
     
     
         5 . The process of  claim 1 , wherein the esterase treatment is carried out at a temperature in the range of 40-80° C. 
     
     
         6 . The process of  claim 1 , wherein the amount of esterase is 100-2000 units per L of fermentation broth. 
     
     
         7 . The process of  claim 1 , wherein the esterase treatment is carried out for 10-1440 minutes. 
     
     
         8 . A partially deacylated gellan gum produced by the process of  claim 1 , wherein:
 the deacylated gellan gum has a molecular weight that is less than 10% reduced compared to the molecular weight of native gellan gum,   the deacylated gellan gum comprises a polysaccharide chain comprising repeating units, and   between 0% and 48% of the repeating units of the polysaccharide chain comprise an acetate residue.   
     
     
         9 . The partially deacylated gellan gum according to  claim 8 , wherein between 0% and 25% of the repeating units comprise an acetate residue. 
     
     
         10 . The partially deacylated gellan gum according to  claim 8 , wherein the partially deacylated gellan gum exhibits a gelling temperature between 60 and 85° C. 
     
     
         11 . A food product, wherein the food product:
 comprises the partially deacylated gellan gum according to  claim 8 ; and   is selected from the group consisting of beverages, jams, jellies, bakery fillings, confections, dairy products, dessert gels, frostings, icings, glazes, low-fat spreads, microwavable foods, baked goods, puddings, sauces and dressings, structured foods and toppings.   
     
     
         12 . A food product according to  claim 11 , wherein the concentration of the partially deacylated gellan gum is 0.02-2% by weight. 
     
     
         13 . A pharmaceutical formulation, wherein the pharmaceutical composition:
 comprises a partially deacylated gellan gum according to  claim 8 ; and   is selected from the group consisting of tablets, capsules, gels, creams and lotions.   
     
     
         14 . A pharmaceutical formulation according to  claim 13 , wherein the concentration of the partially deacylated gellan gum is 0.02-2% by weight. 
     
     
         15 . A personal care product, wherein the personal care product:
 comprises a partially deacylated gellan gum according to  claim 8 ; and   is selected from the group consisting of toothpaste, liquid soap, shampoo, shower gel, cream, body lotion, body gel and deodorant gel.   
     
     
         16 . A personal care product according to  claim 15 , wherein the concentration of the partially deacylated gellan gum is 0.02-2% by weight. 
     
     
         17 . The process of  claim 1 , wherein the esterase treatment is carried out at a pH in the range of 6.0-6.5. 
     
     
         18 . The process of  claim 1 , wherein the esterase treatment is carried out at a temperature in the range of 65-75° C. 
     
     
         19 . The partially deacylated gellan gum according to  claim 8 , wherein between 0.5% and 5% of the repeating units comprise an acetate residue. 
     
     
         20 . The partially deacylated gellan gum according to  claim 8 , wherein the partially deacylated gellan gum exhibits a gelling temperature between 70 and 80° C.