Production of Enzyme-Resistant Starch by Extrusion

Abstract

A process for producing alpha-amylase resistant starch comprises extruding a feed starch at a temperature in the range of about 60-220° C., thereby producing a product alpha-amylase resistant starch. The feed starch can be in the form of an aqueous slurry or paste that has a dry solids concentration of at least about 50% by weight. The process optionally can include the additional step of heating the product starch to a temperature of at least about 90° C. in the presence of moisture, to increase further the alpha-amylase resistance of the product.

1 . A process for producing alpha-amylase resistant starch, comprising extruding a feed starch at a temperature in the range of about 60-220° C., thereby producing a product alpha-amylase resistant starch.  
   
   
       2 . The process of  claim 1 , wherein the feed starch comprises at least about 50% by weight amylose.  
   
   
       3 . The process of  claim 1 , wherein the feed starch comprises at least about 65% by weight amylose.  
   
   
       4 . The process of  claim 1 , wherein the feed starch is dry starch.  
   
   
       5 . The process of  claim 1 , wherein the feed starch is in an aqueous slurry or paste that has a dry solids concentration of at least about 50% by weight.  
   
   
       6 . (canceled)  
   
   
       7 . The process of  claim 1 , wherein the feed starch is in an aqueous slurry or paste that has a dry solids concentration of at least about 60% by weight.  
   
   
       8 . The process of  claim 1 , wherein the feed starch is in an aqueous slurry or paste that has a dry solids concentration of at least about 70% by weight.  
   
   
       9 . The process of  claim 1 , wherein the feed starch is from corn, potato, tapioca, rice, pea, wheat, or a combination of two or more thereof.  
   
   
       10 . The process of  claim 1 , wherein the feed starch is chemically modified starch.  
   
   
       11 . The process of  claim 1 , wherein the extrusion is done in a single-screw for twin-screw extruder.  
   
   
       12 . The process of  claim 1 , wherein the temperature of the feed starch during extrusion is in the range of about 70-145° C.  
   
   
       13 . The process of  claim 1 , wherein the product starch has a total dietary fiber content of at least about 30% by weight.  
   
   
       14 . The process of  claim 1 , further comprising heating the product starch to a temperature of at least about 90° C. in the presence of moisture.  
   
   
       15 . The process of  claim 14 , wherein the product starch is heated to at least about 120° C. at a moisture content of about 15-35% by weight.  
   
   
       16 . The process of  claim 14 , wherein the product starch is heated to at least about 150° C. at a moisture content of about 15-35% by weight.  
   
   
       17 . The process of  claim 14 , wherein the moisture content of the product starch during the heating is about 20-25% by weight.  
   
   
       18 . The process of  claim 12 , wherein the total dietary fiber content of the product starch is increased to at least about 50% by weight by the heating in the presence of moisture.  
   
   
       19 . A starch composition produced by the process of  claim 1 .  
   
   
       20 . The composition of  claim 19 , wherein the feed starch comprises at least about 50% by weight amylose.  
   
   
       21 . The composition of  claim 19 , wherein the feed starch is dry starch.  
   
   
       22 . The composition of  claim 19 , wherein the feed starch is in an aqueous slurry or paste that has a dry solids concentration of at least about 50% by weight.  
   
   
       23 . (canceled)  
   
   
       24 . The composition of  claim 19 , wherein the extrusion is done in a single-screw or twin-screw extruder.  
   
   
       25 . The composition of  claim 19 , wherein the temperature of the feed starch during extrusion is in the range of about 70-145° C.  
   
   
       26 . The composition of  claim 19 , wherein the product starch has a total dietary fiber content of at least about 30% by weight.  
   
   
       27 . (canceled)