Low-Carbohydrate Digestible Hydrocolloidal Fiber Compositions

Abstract

A novel low-carbohydrate digestible hydrocolloidal composition is separated from a cereal-based substrate by means of a specific sequence of steps for treating an aqueous slurry of the substrate. These all-natural compositions are low in digestible carbohydrates, principally starches, and rich in soluble fiber, principally β-glucan, as well as proteins. The hydrocolloidal products are recovered in high yields, are smooth in texture, have unexpected thickening properties, have a bland flavor, and are useful for texturizing food, especially bakery products. These hydrocolloidal products can also be used as food ingredients for increasing the nutritional level of foods and supplements.

1 . A thermo-sheared soluble hydrocolloid comprising a ratio of digestible starch to β-glucan soluble fiber in the range of 0.1-2.0. 
     
     
         2 . The soluble hydrocolloid of  claim 1  further characterized by a pasting property wherein an 8% w/w aqueous suspension of said hydrocolloid is characterized by a viscosity greater than 1000 centipoises at 40° C. when initially heated. 
     
     
         3 . The soluble hydrocolloid of  claim 2 , wherein said viscosity is greater than 2000 centipoises at 40° C. when initially heated. 
     
     
         4 . The soluble hydrocolloid of  claim 2 , wherein said viscosity is greater than 2500 centipoises at 40° C. when initially heated. 
     
     
         5 . The soluble hydrocolloid of  claim 2 , wherein said viscosity is approximately 4000 centipoises at 40° C. when initially heated. 
     
     
         6 . The soluble hydrocolloid of  claim 1 , characterized by a gelatinized starch content of less than 30% dwb. 
     
     
         7 . The soluble hydrocolloid of  claim 1 , wherein said β-glucan soluble fiber is selected from the group consisting of oat flour soluble fiber, oat bran soluble fiber and barley flour soluble fiber. 
     
     
         8 . A method for preparing a thermo-sheared soluble hydrocolloid comprising a ratio of digestible starch to β-glucan soluble fiber in the range of 0.1-2.0, wherein said digestible starch is gelatinized and the β-glucan consists essentially of solubilized β-glucan, the method comprising the steps:
 a. subjecting a first aqueous slurry of a cereal substrate to a temperature in the range of about 20-60° C. under conditions of shear sufficient to disrupt the cellular structure of said substrate, thereby yielding a sheared, second aqueous slurry; 
 b. separating the sheared, second aqueous slurry resulting from (a) into a first liquid fraction comprising starch and a first solid fraction comprising fiber; 
 c. separating starch from said first liquid fraction to yield a starch-depleted liquid; 
 d. recombining said starch-depleted liquid with said first solid fraction to yield a third aqueous slurry; and 
 e. recovering said hydrocolloid from said third aqueous slurry. 
 
     
     
         9 . The method of  claim 8 , wherein said separating in step (b) is conducted by wet filtration using a screen pore opening in the range of 0.21-0.025 mm and a force selected from vibrational, centrifugal, and a combination of vibrational and centrifugal. 
     
     
         10 . The method of  claim 8 , wherein said recovering in step (e) comprises subjecting said third aqueous slurry to conditions of shearing at elevated temperature to produce a fourth aqueous slurry and further recovering said hydrocolloid from said fourth aqueous slurry. 
     
     
         11 . The method of  claim 10 , wherein said conditions of shearing and elevated temperature are provide by jet-cooking. 
     
     
         12 . The method of  claim 10 , wherein said elevated temperature is in the-range of 120-150° C. 
     
     
         13 . The method of  claim 10 , wherein said recovering in step (e) further comprises separating said fourth aqueous slurry into a second liquid fraction and a second solid fraction, and recovering said hydrocolloid from said second liquid fraction. 
     
     
         14 . The method of  claim 13 , wherein said separating of said fourth aqueous slurry is by wet filtration using a pore opening between 0.21 and 0.025 mm and a force selected from vibrational, centrifugal, and a combination of vibrational and centrifugal. 
     
     
         15 . The method of  claim 13 , wherein said recovering in step (e) further comprises centrifuging said second liquid fraction into a third liquid fraction and a third solid fraction, and further recovering said hydrocolloid from said third liquid fraction. 
     
     
         16 . The method of  claim 13 , wherein said recovering in step (e) further comprises precipitating said hydrocolloid from said second liquid fraction by means of a hydrophilic liquid precipitation. 
     
     
         17 . The method of  claim 15 , wherein said recovering in step (e) further comprises precipitating said hydrocolloid from said third liquid fraction by means of a hydrophilic liquid precipitation. 
     
     
         18 . The method of  claim 10 , wherein said recovering in step (e) further comprises drying a liquid fraction separated from said fourth aqueous slurry. 
     
     
         19 . The method of  claim 18 , wherein said drying is selected from the group consisting of drum drying and freeze drying. 
     
     
         20 . The method of  claim 8 , wherein said cereal substrate is selected from the group consisting of oat flour, oat bran, barley flour and mixtures thereof. 
     
     
         21 . A product produced by the process of  claim 8 .