Freeze-dried coffee powder and a method for the manufacture thereof

Patent metadata

Field	Value
Publication number	US-11229221-B2
Application number	US-201716096639-A
Country	US
Kind code	B2
Filing date	Apr 27, 2017
Priority date	Apr 27, 2016
Publication date	Jan 25, 2022
Grant date	Jan 25, 2022

Abstract

The present invention provides a method for the manufacture of a freeze-dried coffee powder, the method comprising: providing a coffee extract having from 40 wt % to 55 wt % solids; adding gas to the coffee extract in an amount of from 1 NL/kg to 5 NL/kg of coffee extract, to provide a gas-containing coffee extract at above atmospheric pressure; depressurising the gas-containing coffee extract to form a foamed coffee extract; cooling the foamed coffee extract to below −40° C. without shear, or with low shear, to form a frozen coffee extract, grinding the frozen coffee extract to a powder; and drying the powder, wherein the step of cooling the foamed coffee extract to below −40° C. comprises: (i) cooling the foamed coffee extract to a first temperature; (ii) cooling the foamed coffee extract from the first temperature to a second temperature lower than the first temperature; and (iii) cooling the foamed coffee extract from the second temperature to below −40° C., wherein the first temperature is 1° C. above a freezing point of the foamed coffee extract and wherein the second temperature is 3° C. below the freezing point, wherein step (ii) has a duration of from 5 to 90 minutes, preferably 10 to 60 minutes.

First claim

The invention claimed is:

1. A method for the manufacture of a freeze-dried coffee powder, the method comprising:
providing a coffee extract having from 40 wt % to 55 wt % solids;
adding gas to the coffee extract in an amount of from 1 NL/kg to 5 NL/kg of coffee extract, to provide a gas-containing coffee extract at above atmospheric pressure;
depressurising the gas-containing coffee extract to form a foamed coffee extract;
cooling the foamed coffee extract to below −40° C. without shear, or with low shear, to form a frozen coffee extract,
grinding the frozen coffee extract to a powder; and
drying the powder,
wherein the step of cooling the foamed coffee extract to below −40° C. comprises:
(i) cooling the foamed coffee extract to a first temperature;
(ii) cooling the foamed coffee extract from the first temperature to a second temperature lower than the first temperature; and
(iii) cooling the foamed coffee extract from the second temperature to below −40° C.,

wherein the first temperature is 1° C. above a freezing point of the foamed coffee extract and wherein the second temperature is 3° C. below the freezing point,
wherein step (ii) has a duration of from 5 to 90 minutes.

2. The method according to claim 1 , wherein the coffee extract:
(a) has from 40 to 45 wt % solids and wherein the freezing point is from −5 to −7° C.; or
(b) has from 45 to 50 wt % solids and wherein the freezing point is from −7 to −8° C.; or
(c) has from 50 to 55 wt % solids and wherein the freezing point is from −8 to −10° C.

3. The method according to claim 1 , wherein the coffee extract has from 48 to 51 wt % solids.

4. The method according to claim 1 , wherein the low shear is less than 50 s −1 .

5. The method according to claim 1 , wherein the gas is selected from nitrogen, air, argon, nitrous oxide and carbon dioxide, or a mixture of two or more thereof.

6. The method according to claim 1 , wherein the coffee extract is at a pressure of at least 2 Bar before the gas is added to the coffee extract.

7. The method according to claim 1 , wherein depressurising the gas-containing coffee extract involves reducing the pressure of the coffee extract to 5 Bar or less.

8. The method according to claim 1 , wherein depressurising the gas-containing coffee extract involves spraying the gas-containing coffee extract.

9. The method according to claim 1 , wherein the foamed coffee extract is at atmospheric pressure before the step of cooling and has a density of from 500 to 800 g/l.

10. The method according to claim 1 , wherein the mean rate of cooling in each of steps (i) and (iii) is at least −5° C. per minute.

11. The method according to claim 1 , wherein one or more of the cooling steps (i), (ii) and (iii) are conducted as a continuous process using a conveyor.

12. The method according to claim 1 , wherein one or more of the cooling steps (i), (ii) and (iii) are conducted in a holding vessel or within a pumped cooling system.

13. The method according to claim 1 , wherein step (ii) has a duration of from 5 to 60 minutes.

14. The method according to claim 1 , wherein step (ii) has a duration of from 10 to 30 minutes.

15. The method according to claim 1 , wherein the coffee extract is at a pressure of at least 5 Bar before the gas is added to the coffee extract.

16. The method according to claim 1 , wherein the coffee extract is at a pressure of from 10 to 250 Bar before the gas is added to the coffee extract.

17. The method according to claim 1 , wherein depressurising the gas-containing coffee extract involves reducing the pressure of the coffee extract to atmospheric pressure.

Assignees

• Douwe Egberts Bv

Inventors

• Welsh Joe Christopher
• Jackson Tamsin Mikeala
• Mulvany Jonathan Patrick
• Rees Jack
• Kang Woncheal

Classifications

• A23F5/08

  Methods of grinding coffee (coffee mills A47J42/00) · CPC title

• A23F5/32 Primary

  by lyophilisation · CPC title

• A23F5/26 Primary

  Extraction of water soluble constituents {(A23F5/246 takes precedence)} · CPC title

• A23F5/28 Primary

  Drying or concentrating coffee extract {(A23F5/246 takes precedence)} · CPC title

• A23V2300/14

  Extraction · CPC title