Foaming Coffee Composition

Abstract

A foaming freeze-dried instant coffee composition comprising particles having a bulk density of from 0.19 to 0.25 g/cm 3 and a closed pore volume of at least 0.05 ml/g, said particles comprising a freeze-dried instant coffee matrix having entrapped therein particles of a foamable component having closed pores containing a gas.

1 . A foaming instant coffee composition comprising particles having a bulk density of from 0.16 to 0.30 g/cm 3 , said particles comprising a continuous phase comprising an instant coffee matrix and a non-continuous phase comprising particles of a foamable component containing a gas. 
   
   
       2 . A composition according to  claim 1  wherein the particles have a continuous phase comprising a freeze dried instant coffee matrix having entrapped therein a non-continuous phase comprising the particles of a foamable component. 
   
   
       3 . A composition according to  claim 1  wherein the particles have a continuous phase comprising agglomerated instant coffee particles and a non-continuous phase comprising particles of the foamable component. 
   
   
       4 . A composition according to  claim 1  wherein the composition particles have a closed pore volume of at least 0.10 cm 3 /g. 
   
   
       5 . A composition according to  claim 1  wherein the foamable component comprises a spray-dried carbohydrate-based powder or a spray-dried instant coffee powder. 
   
   
       6 . A composition according to  claim 1  wherein the instant coffee matrix also comprises a sugar and/or whitener. 
   
   
       7 . A composition according to  claim 1  which comprises from 10 to 50 wt % of the foamable component relative to the total weight of the composition. 
   
   
       8 . A composition according to  claim 1  wherein the foamable component contains closed pores containing entrapped gas under superatmospheric pressure or comprises a condensed liquid or supercritical fluid. 
   
   
       9 . A composition according to  claim 1  wherein the foamable component is a gas-containing clathrate. 
   
   
       10 . A process for preparing a composition as defined in  claim 1  which comprises:
 i. mixing the particles of a foamable component with an aqueous coffee extract to form a coffee mixture;   ii. before the particles of the foamable component have dissolved, freezing the coffee mixture;   iii. granulating the frozen coffee mixture; and   iv. forming the freeze-dried coffee composition by removing water by sublimation.   
   
   
       11 . A process according to  claim 10  wherein the particles of the foamable component are cooled to 5° C. or less prior to mixing with the aqueous coffee extract. 
   
   
       12 . A process according to  claim 11  wherein the particles of the foamable component are cooled in liquid nitrogen. 
   
   
       13 . A process according to  claim 12  wherein the aqueous coffee extract has a coffee solids content of at least 40 wt %. 
   
   
       14 . A process according to  claim 13  wherein the aqueous coffee extract is cooled to 0° C. or less prior to mixing with the particle of the foamable component. 
   
   
       15 . A process according to  claim 14  wherein the particles of the foamable component are mixed with the aqueous coffee extract for 2 minutes or less prior to freezing. 
   
   
       16 . A process for preparing a composition as defined in  claim 1  which comprises:
 i. mixing the particles of a foamable component with instant coffee particles;   ii. agglomerating the instant coffee particles with water to form agglomerated particles having a continuous phase comprising instant coffee particles and a non-continuous phase comprising particles of a foamable component; and   iii. drying the agglomerated particles.   
   
   
       17 . A process according to  claim 16  wherein the water is in the form of steam. 
   
   
       18 . A process according to  claim 17  wherein the mixture of particles is allowed to fall through a grid and is impinged by a flow of steam. 
   
   
       19 . A process according to  claim 18  wherein the agglomerated particles are dried by having a temperature of greater than 100° C. 
   
   
       20 . A process for preparing a coffee drink, which comprises adding hot water to a composition as defined in  claim 1 .