Method of preparing acid stable caramel
Class IV caramel color with reduced 4-MeI content is formed by combining carbohydrate with ammonium bisulfite and acid in an amount effective to establish a pH of less than 5. This is heated in a closed reactor vessel and heated to a temperature and for a time effective to provide the desired intensity caramel color. A base is injected into the closed reaction vessel during heating to control the caramelization reaction.
1. A method of forming ammonium bisulfite caramel comprising:
blending a carbohydrate with a catalyst to form a blend said catalyst comprising ammonium bisulfite and optionally an acid, said catalyst having a pH effective to form said blend having an initial pH of less than 5, said blend having a temperature less than 250° F.;
subsequent to establishing said initial pH, heating said blend in a closed reaction vessel to a temperature of at least 250° Fahrenheit; and
maintaining said temperature of said blend to complete caramel formation to form a class IV caramel having a color intensity of at least 0.200 and a 4-Mel content less than 25 ppm.
2. The method claimed in claim 1 wherein said initial pH is established at less than 4.5.
3. The method claimed in claim 2 wherein said initial pH is established by adding an acid selected from the group consisting of phosphoric acid, phosphorous acid, sulfuric acid, sulfurous acid and sodium metabisulfite, and mixtures thereof to said blend.
4. The method claimed in claim 2 wherein base is added to said blend during heating to slow color formation and prevent formation of insoluble caramel.
5. The method claimed in claim 1 wherein said carbohydrate is glucose.
6. The method claimed in claim 5 wherein said glucose is selected from the group consisting of corn syrup and wheat syrup, and mixtures thereof.
7. The method claimed in claim 3 wherein said acid is added to said carbohydrate prior to addition of said ammonium bisulfite.
8. The method claimed in claim 1 wherein said caramel has a 4-Mel content of less than 15 ppm.
9. The method claimed in claim 1 wherein said initial pH is established at from 2-4.
10. The method claimed in claim 6 wherein said acid is selected from the group consisting of phosphorus acid, phosphoric acid sulfurous acid, sulfuric acid, sodium metabisulfite, and mixtures thereof.
11. A method of forming class IV caramel having a color intensity at 610 nm of at least 0.200 and a 4-Mel content less than 20 ppm comprising:
blending glucose with an acid selected from the group consisting of phosphoric acid, phosphorous acid, sulfuric acid, sulfurous acid, and ammonia metabisulfite and mixtures thereof to establish a pH of 2-4;
adding ammonium bisulfite to said glucose in an amount effective to catalyze formation of caramel IV having an intensity of at least 0.200 at 610 nm wherein said pH is maintained between 2-4 at a temperature less than 250° F.; and
subsequently heating said glucose at autogenous pressure to 250° F.-290° F. for a time effective to form said caramel color having a 4-Mel content less than 20 ppm.
12. A method of forming class IV caramel having a color intensity at 610 nm of at least 0.010 and a 4-Mel content less than 5 ppm comprising:
blending glucose with an acid selected from the group consisting of phosphoric acid, phosphorous acid, sulfuric acid, sulfurous acid, sodium metabisulfite, and mixtures thereof to establish a pH of 2-4;
subsequently adding ammonium bisulfite to said glucose in an amount effective to catalyze formation of caramel IV having an intensity of 0.010-0.170 at 610 nm wherein said pH is maintained between 2-4 at a temperature less than 250° F.; and
heating said glucose at autogenous pressure to 250° F.-290° F. for a time effective to form said caramel color having a 4-Mel content less than 10 ppm.
13. The method claimed in claim 1 wherein said ammonium bisulfite has an ammonia content less than 14% by weight and a sulfur dioxide content greater than 46% by weight.