Debranching enzyme modified starch, the preparing method and use thereof in hard capsule production

Abstract

The present invention relates to a modified starch and a method for obtaining the modified starch by using a debranching enzyme, such as isoamylase, pullulanase, limit dextrinase and the like. The debranching enzyme modified starch of present invention exhibits excellent film-forming capacity, film strength, and gelation ability, so as to be used as a material for making hard capsules without the use of coagulants and plasticizers.

1 . A modified starch gel composition for producing hard empty capsules, comprising a debranching enzyme modified starch solution, wherein the modified starch has a degree of branching that is reduced by 30% to 70% and posesses gelation ability and sufficient film strength for preparing hard empty capsules without additional plasticizer and coagulant. 
     
     
         2 . The modified starch gel composition according to  claim 1 , wherein the starch solution is prepared from a starch which is selected from the group consisting of natural starch. 
     
     
         3 . The modified starch gel composition according to  claim 1 , wherein the modified starch has a degree of branching that is reduced by 30% to 50%. 
     
     
         4 . The modified starch gel composition according to  claim 1 , wherein the modified starch gel has a viscosity of 500 to 5,000 cP measured at a gel temperature of 60° C. 
     
     
         5 . The modified starch gel composition according to  claim 1 , wherein the debranching enzyme is a pullulanase. 
     
     
         6 . (canceled) 
     
     
         7 . (canceled) 
     
     
         8 . A method of preparing the modified starch gel according to  claim 1 , which comprises:
 dissolving the starch in water (1:2-1:10 wt/wt) to obtain the starch solution;   adding the debranching enzyme to the starch solution to obtain a mixture (the amount of the debranching enzyme is 0.00001% to 5% of the weight of the starch), and reacting at 40-70° C. for 0.5-5 hours;   heating the mixture to 80° C. or above to inactivate the debranching enzyme; and   cooling the mixture to 40-70° C. to obtain the modified starch gel.   
     
     
         9 . The method of preparing the modified starch gel according to  claim 8 , wherein the starch debranching enzyme is an isoamylase, a pullulanase or a limit dextrinase. 
     
     
         10 . A method for producing a hard empty capsule, which comprises using the modified starch gel according to  claim 1  as a raw material.