GB874481A - Coffee bean products and methods for producing such products - Google Patents

Abstract

874,481. Coffee extracts. BONATTO, M. Oct. 1, 1957 [Oct. 4, 1956], No. 30691/57. Class 129. A liquid or solid water-soluble coffee extract comprises a portion of an extract from fully roasted coffee beans and a portion of an extract from preconditioned unroasted coffee beans in which the aromas have been developed by reaction, below roasting temperature, with oxygen, air or mixtures thereof. The extract may be made by separately grinding, extracting, filtering and concentrating the preconditioned beans and roasted beans separately, treating the concentrate from the preconditioned beans with oxygen, air or a mixture thereof at a temperature below roasting temperature and mixing the two concentrates, In modifications, either the ground roasted and ground preconditioned beans are mixed before extraction and the extract concentrated and subjected to the treatment with oxygen, air or a mixture thereof, or the two concentrates are combined and then the mixed concentrate is subjected to this treatment. Preconditioning consists of heating the green coffee beans for a time at a temperature below roasting temperature until there is a slight odour of roasted coffee and a slight swelling of the beans. The beans are then rapidly unloaded from the roaster and rapidly cooled by ventilation or quenching. For example, the green coffee beans are heated until all moisture has been driven out and the temperature has reached 200-212‹ F., after which the temperature is raised to 300-310‹ F. for a short time and then more heat is applied until the beans swell slightly and there is an odour of roasted coffee. Green coffee beans are roasted, step I, Fig. 1, and then ground, extracted with water, filtered and concentrated. With an efficient counter-current extraction operation, the extract may be sufficiently concentrated to eliminate step III. Steps I and IV can be combined, the step IV beans being removed and then roasting of the step I beans being completed. The beans are then ground, extracted in an aqueous medium, step V, and concentrated, step VI. The concentrate is then treated with oxygen, air or mixtures thereof, step VII at temperatures lower than coffee bean roasting temperatures, e.g. as low as room temperature. At above 212‹ F., sufficient pressure would be used to prevent the water from boiling away. The extract from step VII is mixed with that from step III, e.g. in a ratio of two parts to one. The resulting extract may have hydrogen gas bubbled through it at a temperature of around 212 F. followed by further treatment with oxygen. In a modification, the beans of steps I and IV may be ground, mixed and then extracted, filtered and concentrated as in steps V and V1 and treated with hydrogen and then oxygen as in step VII. In a further modification, the extracts from steps V1 and III can be combined and the extract treated in accordance with step VII. It may be treated with hydrogen first if desired and the extract contains 50 to 75% solids. Step VII may be carried out in an apparatus as shown in Fig. 2, the concentrated extract of step VI being introduced through inlet 1 until the tank of the apparatus, which contains a driven stirrer, is filled, after which oxygen is introduced through inlet 3 and sprayer 4. Steam is introduced at 6 into jacket 7 to maintain the desired temperature. At the finish of the operation, cold water is introduced into the jacket 7 through inlet 10 and discharged through outlet 6. Vent valve 11 is opened and the product is discharged through valve 12. In a further apparatus, Fig. 3 (not shown), step VII may be carried out continuously. Examples are given using different types of coffee beans.