GB1417177A - Dried coffee extracts and manufacture thereof - Google Patents

Abstract

1417177 Coffee GENERAL FOODS CORP 11 Dec 1972 [17 Dec 1971 14 Aug 1972] 57169/72 Heading A2B Instant coffee comprises a spray-dried coffee extract and a freeze-dried coffee extract blended together and matched in particle size and density, so that the blend does not separate when subjected to vibration such as would be encountered when transported. The spray-dried extract is produced by agglomerating spray-dried particles in point-to-point contact, and has a moisture content of 3.5- 5%. The freeze-dried extract has a moisture content of 1-3%, and the moisture content of the blend as packaged does not exceed 4.5%. The freeze-dried extract has a density of 0.18-0.35 gm/cc and the density of the spray-dried extract is within 25% of this. The strength of the spray-dried agglomerate is such that not more than 20% of fines capable of passing through a U.S. standard 40 mesh screen are generated in packaging. The freeze-dried extract is made from a quality coffee blend high in arabica beans (Milds) e.g. Colombian Medellius, to which flavour enhancers, e.g. mercaptans or diacetyes, may be added. The spray-dried extract may be made from low quality coffee, e.g. Robusta beans, and is ground to particles of between 15 and 200 microns prior to agglomeration. Instead of using different coffee blends to make the spray- and freezedried extracts, the freeze-dried extract may be made from one part of a liquid extract, and the spray-dried extract from the remaining part of the same liquid. Agglomeration of the spray dried particles is by means of steam, hot water spray, or hot coffee extract. An after drier may be used to reduce the moisture content of the agglomerate to below 5%. The density of the freeze-dried extract is adjusted by varying the solids content of the liquid extract, or by a foaming technique. Particle size distribution is adjusted by screen classification so that the major part of the blended mixture consists of particles of between 12 and 40 mesh. Before blending the dried extracts coffee oil may be added to the freeze-dried extract. The colour of the dried extracts may be adjusted by varying the freezing rate, or the degree of roasting. The final blend may include from 5-60% of freezedried extract, depending on the amount of flavour enhancers added. Fines produced in the initial screening of the dried extracts prior to blending may be recycled to the agglomerating apparatus. The blended product is placed in a hermetically sealed package containing less than 4% oxygen. The colours of the spray- and freeze-dried extracts may differ from one another in the final blend. Details of manufacturing conditions, and colour testing procedures are given in the Specification, particularly in the Examples.