Method of reducing acrylamide in coffee extract and a soluble coffee product

Abstract

The present invention provides a method of reducing acrylamide in an aqueous coffee extract, the method comprising: contacting an acrylamide-containing aqueous coffee extract with spent coffee grounds at a temperature of 70 to 120 C. for at least 30 minutes to form an acrylamide-depleted coffee extract.

Claims

1. A method of producing a soluble coffee product, the method comprising: (i) performing an aqueous extraction of roast and ground coffee beans at a temperature of at least 175 C. to provide spent coffee grounds; (ii) providing further roasted and ground coffee beans; (iii) performing an aqueous extraction of the further roasted and ground coffee beans at a temperature of from 175 to 220 C. to obtain an acrylamide-containing aqueous coffee extract; (iv) reducing acrylamide in the acrylamide-containing aqueous coffee extract to obtain an acrylamide-depleted coffee extract by contacting the acrylamide-containing aqueous coffee extract with the spent coffee grounds at a temperature of 70 to 120 C. for at least 30 minutes to obtain an acrylamide-depleted coffee extract; and (v) drying the acrylamide-depleted coffee extract to provide the soluble coffee product.

2. A method according to claim 1, wherein the step of drying is a step of spray-drying or a step of freeze-drying.

3. A method according to claim 1, wherein the step of performing the aqueous extraction of the roasted and ground coffee beans is at the temperature of from 175 to 205 C.

4. A method according to claim 1, wherein, in step (iv), before being contacted with the spent coffee grounds the aqueous coffee extract comprises at least 500 ppb acrylamide.

5. A method according to claim 1, wherein, in step (iv), the acrylamide-depleted coffee extract comprises less than 400 ppb acrylamide.

6. A method according to claim 1, wherein the method in step (iv) reduces the acrylamide levels by at least 30%.

7. A method according to claim 1, wherein, in step (iv), the acrylamide-containing aqueous coffee extract is contacted with the spent coffee grounds at a temperature of from 100 to 120 C.

8. A method according to claim 1, wherein, in step (iv), the acrylamide-containing aqueous coffee extract is contacted with the spent coffee grounds for from 1 to 50 hours.

9. A method according to claim 8, wherein, in step (iv), the acrylamide-containing aqueous coffee extract is contacted with the spent coffee grounds for from 2 to 10 hours.

10. A method according to claim 1, wherein, in step (iv), the acrylamide-containing aqueous coffee extract is passed through the spent coffee grounds in a continuous process.

11. A method according to claim 1, wherein, in step (iv), the acrylamide-containing aqueous coffee extract comprises from 1 to 55 wt % soluble coffee solids.

12. A method according to claim 1, wherein, in step (iv), the spent coffee grounds are provided as a bed of spent coffee grounds.

13. A method according to claim 12, wherein, in step (iv), the bed of spent coffee is held in a sealed pressure chamber.

14. A method according to 1, wherein the step (i) of performing the aqueous extraction of roast and ground coffee beans is performed at the temperature of at least 200 C.

15. A method according to claim 14, wherein the step (i) of performing the aqueous extraction of roast and ground coffee beans is performed at the temperature of 205 to 240 C.

Description

BRIEF DESCRIPTION OF THE FIGURE

(1) The invention will now be described further with reference to the following non-limiting figures, in which:

(2) FIG. 1 shows a configuration for a percolation bed with optional recirculation for contacting aqueous coffee extract with spent coffee grounds; and

(3) FIG. 2 shows a slurry treatment system for contacting aqueous coffee extract with spent coffee grounds.

DETAILED DESCRIPTION

(4) The invention will now be described further with reference to the following non-limiting examples.

(5) Aqueous coffee extracts obtained by a three stage extraction process, including a final aqueous extraction step at around 200 C. were held in contact with spent coffee grounds and their levels of acrylamide were measured before and after treatment. The reduction observed is summarised in the table below. The normalised level is based on the starting level of acrylamide being set to 1.

(6) TABLE-US-00001 Treatment Temperature Holding Normalised ( C.) time (hrs) Acrylamide Level 120 1 0.18 120 3 0.05 70 3 0.58 70 50 0.39 37 400 0.85 37 750 0.85 37 1100 0.68 37 1450 0.52 23 400 0.92 23 750 0.92 23 1100 0.89 23 1450 0.76

(7) As can be seen, acrylamide levels dropped for all tested samples, but only within the range of 70 to 120 C. were the treatment times within commercially viable durations.

(8) Although preferred embodiments of the invention have been described herein in detail, it will be understood by those skilled in the art that variations may be made thereto without departing from the scope of the invention or of the appended claims.