Foaming compositions and methods of making the same

1. A method for preparing a foaming composition comprising:

contacting a continuous flow of a supercritical fluid with a particulate ingredient having a glass transition temperature above ambient temperature at a temperature above the glass transition temperature of the particulate ingredient, wherein the supercritical fluid is carbon dioxide, nitrous oxide, or a halogenated hydrocarbon, wherein the supercritical fluid has a critical temperature of at least about 10° C., and wherein the particulate ingredient comprises a plurality of internal voids;

holding the particulate ingredient at the temperature above the glass transition temperature of the particulate ingredient for a period of time effective to allow transfer of the supercritical fluid into the plurality of internal voids of the particulate ingredient;

reducing the temperature to below the glass transition temperature of the particulate ingredient, thereby entrapping at least a portion of the supercritical fluid in the plurality of internal voids of the particulate ingredient; and

further reducing the temperature to below the critical temperature such that the entrapped supercritical fluid forms a mixture of gas and liquefied gas in the plurality of internal voids of the particulate ingredient.

2. The method of claim 1 further comprising:

raising the temperature of the supercritical fluid to raise the temperature of the particulate ingredient above the glass transition temperature of the particulate ingredient; and

reducing the temperature of the supercritical fluid to reduce the temperature of the particulate ingredient below the glass transition temperature of the particulate ingredient.

3. The method of claim 1 wherein the supercritical fluid has a density in the range of about 0.1 g/cc to about 1.6 g/cc.

4. The method of claim 1 wherein the entrapped mixture of gas and liquefied gas comprises at least about 0.5 weight percent of the foaming composition.

5. The method of claim 1 further comprising:

incorporating at least one additive soluble in the supercritical fluid.

6. The method of claim 1 wherein the particulate ingredient comprises at least one of a substantially carbohydrate-free powder, a substantially protein-free powder, and a soluble coffee powder.

7. The method of claim 1 , wherein the contacting a continuous flow of a supercritical fluid with a particulate ingredient is effective to inhibit particle agglomeration in the particulate ingredient having the mixture of gas and liquefied gas in the plurality of internal voids.

8. A foaming composition comprising:

a particulate ingredient having a glass transition temperature above ambient temperature and having a plurality of internal voids containing a mixture of gas and liquefied gas entrapped in the internal voids.

9. The foaming composition of claim 8 wherein the supercritical fluid has a density in the range of about 0.1 g/cc to about 1.6 g/cc.

10. The foaming composition of claim 8 wherein the entrapped mixture of gas and liquefied gas comprises at least about 0.5 weight percent of the foaming composition.

11. The foaming composition of claim 8 wherein at least one soluble additive is incorporated in the supercritical fluid.

12. The foaming composition of claim 8 wherein the particulate ingredient has a glass transition temperature of at least about 30° C. and comprises at least one of a substantially carbohydrate-free powder, a substantially protein-free powder, and a soluble coffee powder.

13. The foaming composition of claim 8 , wherein the particulate ingredient having been exposed to a continuous flow of the supercritical fluid is effective to inhibit particle agglomeration in the particulate ingredient having the mixture of gas and liquefied gas in the plurality of internal voids.

14. A foaming composition prepared by a method comprising:

contacting a continuous flow of a supercritical fluid with a particulate ingredient having a glass transition temperature above ambient temperature at a temperature above the glass transition temperature of the particulate ingredient, wherein the supercritical fluid is carbon dioxide, nitrous oxide, or a halogenated hydrocarbon, wherein the supercritical fluid has a critical temperature of at least about 10° C., and wherein the particulate ingredient comprises a plurality of internal voids;

holding the particulate ingredient at the temperature above the glass transition temperature of the particulate ingredient for a period of time effective to allow transfer of the supercritical fluid into the plurality of internal voids of the particulate ingredient;

reducing the temperature to below the glass transition temperature of the particulate ingredient, thereby entrapping at least a portion of the supercritical fluid in the plurality of internal voids of the particulate ingredient; and

further reducing the temperature to below the critical temperature such that the entrapped supercritical fluid forms a mixture of gas and liquefied gas in the plurality of internal voids of the particulate ingredient.

15. The foaming composition of claim 14 , wherein the method further comprises:

raising the temperature of the supercritical fluid to raise the temperature of the particulate ingredient above the glass transition temperature of the particulate ingredient; and

reducing the temperature of the supercritical fluid to reduce the temperature of the particulate ingredient below the glass transition temperature of the particulate ingredient.

16. The foaming composition of claim 14 wherein the supercritical fluid has a density in the range of about 0.1 g/cc to about 1.6 g/cc.

17. The foaming composition of claim 14 wherein the entrapped mixture of gas and liquefied gas comprises at least about 0.5 weight percent of the foaming composition.

18. The foaming composition of claim 14 wherein at least one soluble additive is incorporated in the supercritical fluid.

19. The foaming composition of claim 14 wherein the particulate ingredient comprises at least one of a substantially carbohydrate-free powder, a substantially protein-free powder, and a soluble coffee powder.

20. The foaming composition of claim 14 , wherein the contacting a continuous flow of a supercritical fluid with a particulate ingredient is effective to inhibit particle agglomeration in the particulate ingredient having the mixture of gas and liquefied gas in the plurality of internal voids.

21. A method for preparing a foaming composition comprising:

contacting a continuous flow of supercritical carbon dioxide with a particulate ingredient having a glass transition temperature above ambient temperature at a temperature above the glass transition temperature of the particulate ingredient, wherein the particulate ingredient comprises a plurality of internal voids;

holding the particulate ingredient at the temperature above the glass transition temperature of the particulate ingredient for a period of time effective to allow transfer of the supercritical carbon dioxide into the plurality of internal voids of the particulate ingredient;

reducing the temperature to below the glass transition temperature of the particulate ingredient, thereby entrapping at least a portion of the supercritical carbon dioxide in the plurality of internal voids of the particulate ingredient; and

further reducing the temperature to below the critical temperature such that the entrapped supercritical fluid forms a mixture of gas and liquefied gas in the plurality of internal voids of the particulate ingredient.