Low D.E. starch conversion products

Abstract

The present invention provides a process for preparing low D.E. starch hydrolysates and low D.E. starch conversion syrup products which are both liquid and solid. Starch is treated with acid to a D.E. less than 15 and then converted with a bacterial alpha-amylase to a D.E. between 10 and 25. From the resulting hydrolysate product is obtained a non-hazing syrup which is almost completely water-soluble.

We claim: .[.1. A process for preparing a starch hydrolysate having 
     
        greater than 50% thereby obtaining the syrup..]. .[.6.  A process in accordance with claim 5 wherein the starch is corn starch..]. .[.7. A process in accordance with claim 5 wherein the starch is a waxy cereal starch..]. .[.8. A process in accordance with claim 5 wherin the pH during acid hydrolysis is between about 1 and about 3..]. .[.9. A process for preparing low D.E. dry syrup solids comprising (1) preparing a syrup in accordance with the process of claim 5 and then   (2) reducing the moisture content of said syrup to less than 15%..]. .Iadd. 10. A process for preparing a starch hydrolyzate having   (A) a dextrose equivalent value between about 10 and about 25 and   (B) a descriptive ratio greater than 2.0 said descriptive ratio being the quotient obtained by dividing the sum of the percentages of saccharide, dry basis, having a degree of polymerization of 1 to 6 by the dextrose equivalent value, which comprises: (1) subjecting the mixture of starch and water having a solids content of less than about 50% to the hydrolytic action of an acid to attain a dextrose equivalent value between about 5 and about 15, and   (2) subjecting the resulting acid hydrolyzate to sufficient hydrolytic action of bacterial alpha-amylase to increase the dextrose equivalent value by at least 5 to obtain the starch hydrolyzate. .Iaddend..Iadd. 11. A process in accordance with claim 10 wherein the starch is corn starch. .Iaddend..Iadd. 12. A process in accordance with claim 10 wherein the starch is a waxy cereal starch. .Iaddend..Iadd. 13. A process in accordance with claim 10 wherein the acid hydrolysis takes place at a pH between about 1 and about 3. .Iaddend..Iadd. 14. A process for producing a starch hydrolyzate which comprises:     (1) treating a starch water slurry with an acid above the gelatinization temperature of the starch to solubilize and hydrolyze the starch to a dextrose equivalent value no greater than about 15,   (2) treating the acid hydrolyzed starch with bacterial alpha-amylase to obtain a starch hydrolyzate product having a dextrose equivalent no greater than about 25,   (3) stopping the conversion action of the bacterial alpha-amylase, and   
     
     
       (4) recovering the hydrolyzate so produced. .Iaddend..Iadd. 15.  A process in accordance with claim 14, wherein said treatment with bacterial alpha-amylase is conducted at a temperature from about 50° C. to about 95° C. and at a pH of from about 6 to 8. .Iaddend..Iadd. 16. A process in accordance with claim 14, which includes treatment with bacterial alpha-amylase at a temperature from about 60° C. to about 95° C. .Iaddend..Iadd. 17. A process in accordance with claim 14 wherein the starch is solubilized and hydrolyzed with an acid by raising the temperature of the starch slurry to between about 70° C. and about 160° C. at a pH between 1 and 3. .Iaddend..Iadd. 18. A process in accordance with claim 14 wherein the starch is a non-waxy cereal starch. .Iaddend..Iadd. 19. A process in accordance with claim 14 wherein the starch is a waxy cereal starch. .Iaddend..Iadd. 20. A process in accordance with claim 14 wherein the starch is corn starch. .Iaddend..Iadd. 21. A process for producing a starch hydrolyzate which comprises: (1) treating a starch-water slurry with an acid above the gelatinization temperature of the starch to solubilize and hydrolyze the starch to a dextrose equivalent value of about 5,   (2) treating the acid hydrolyzed starch with bacterial alpha-amylase to increase the dextrose equivalent value by at least about 5 and to obtain a starch hydrolyzate product having a dextrose equivalent value in the range of from about 10 to about 25,   (3) stopping the conversion action of the bacterial alpha-amylase, and   
     
     
       (4) recovering the hydrolyzate so produced. .Iaddend..Iadd. 22.  A process in accordance with claim 21 wherein the treatment with bacterial alpha-amylase is carried out at a pH range between about 6 and 8 and at a temperature between about 80° C. and about 92° C. .Iaddend..Iadd. 23. A process for producing a corn starch hydrolyzate which comprises: (1) slurrying corn starch in water to a density between 5° and 30° Baume,   (2) adjusting the pH of the slurry to between about 1 and about 3 with an acid and raising the temperature of the starch slurry to between 70° C. and 160° C. to solubilize and hydrolyze the starch to a dextrose equivalent value not greater than about 15,   (3) adjusting the pH of the acid hydrolyzed starch to between 6 and 8,   (4) treating the acid hydrolyzed starch mixture with bacterial alpha-amylase at a temperature in the range between 50° C. and about 95° C. to increase the dextrose equivalent value by at least about 5,   (5) stopping the conversion action of bacterial alpha-amylase, and   (6) recovering the hydrolyzate so produced. .Iaddend..Iadd. 24. A process for producing a starch hydrolyzate which comprises:   (1) treating a starch-water slurry with an acid above the gelatinization temperature of the starch to solubilize and hydrolyze the starch to a dextrose equivalent value less than about 15,   (2) treating the acid hydrolyzed starch with bacterial alpha-amylase to increase the dextrose equivalent value by at least about 5 and to obtain a starch hydrolyzate product having a dextrose equivalent value in the range of from about 10 to about 25,   (3) stopping the conversion action of the bacterial alpha-amylase, and   (4) recovering the hydrolyzate so produced. .Iaddend..Iadd. 25. A process for producing a starch hydrolyzate which comprises treating an aqueous slurry of starch with an acid at a temperature above 70° C. to liquefy and hydrolyze the starch to a dextrose equivalent of less than about 15, then treating the said hydrolyzed starch with a saccharifying enzyme at a temperature below 95° C. to achieve a hydrolyzate product having a dextrose equivalent value not substantially above about 25, stopping the saccharification reaction and recovering the hydrolyzate so produced. .Iaddend..Iadd. 26. A process for preparing a syrup having   (A) a dextrose equivalent value between about 10 and about 25,   (B) a solids content greater than about 50%, and   (C) a descriptive ratio greater than 2.0, said descriptive ratio being the quotient obtained by dividing the sum of the percentages of saccharides, dry basis, having a degree of polymerization of 1 to 6 by the dextrose equivalent value, which comprises (1) subjecting a mixture of starch and water having a solids content less than about 50% to the hydrolytic action of acid to obtain a hydrolyzate having a dextrose equivalent value between about 5 and about 15,   (2) subjecting the resultant hydrolyzate to the hydrolytic action of bacterial alpha-amylase to increase the dextrose equivalent value by at least 5, and   (3) concentrating the resulting starch hydrolyzate to a solids content greater than 50% thereby obtaining the syrup..Iaddend.