Process for the production of a liquid coffee concentrate
The invention relates to a process for the production of a liquid coffee concentrate that has an improved storage stability at ambient temperature. The process comprises treating a coffee concentrate to a heat treatment and a pH increasing step.
1. A process for the production of a liquid coffee concentrate, the process comprising the steps of:
a) subjecting roasted, ground coffee to one or more extraction steps with water resulting in a coffee extract,
b) subjecting the coffee extract to separation, either by fractionation during said extraction step(s) or by aroma recovery after said extraction step(s) resulting in a high aromatic coffee extract and a low aromatic coffee extract,
c) concentrating the low aromatic coffee extract to a dry matter content of at least 10 wt. % to form a low aromatic coffee concentrate,
d) subjecting at least 25 wt % dry matter of the low aromatic coffee concentrate to a heat treatment of at least 150° C. at a holding time for at most 15 minutes,
e) combining at least the low aromatic coffee concentrate with the high aromatic coffee extract,
whereby after step b) a pH increasing step is carried out,
thereby obtaining a liquid coffee concentrate, wherein the liquid coffee concentrate has a pH of 4.8 to 6.
2. The process according to claim 1 , wherein the heat treatment is conducted at a temperature of at least 150° C. at a holding time of at most 10 minutes.
3. The process according to claim 2 , wherein the heat treatment is conducted from 150° C. to 200° C. at a holding time of 10 minutes to 10 seconds.
4. The process according to claim 3 , wherein the heat treatment is conducted from 150° C. to 180° C. at a holding time of 10 minutes to 10 seconds.
5. The process according to claim 4 , wherein the heat treatment is conducted from 160° C. to 170° C. at a holding time of 5 minutes to 30 seconds.
6. The process according to claim 1 , whereby after step b) and before step e) the low aromatic coffee extract or the low aromatic coffee concentrate which is to be heat treated is subjected to a pH increasing step.
7. The process according to claim 6 , wherein the pH increasing step is carried out between step b) and step c).
8. The process according to claim 1 , wherein the pH increasing step is carried out between step c) and step d).
9. The process according to claim 7 , wherein the pH is raised to a value of 6 to 8.
10. The process according to claim 1 , wherein the pH increasing step is carried out between step d) and step e).
11. The process according to claim 1 , wherein the pH increasing step is carried out after step e).
12. The process according to claim 10 , wherein the pH is raised to a value of 5 to 6.
13. The process according to claim 1 , wherein the pH is raised with an anion exchanger.
14. The process according to claim 1 , wherein the low aromatic coffee extract is concentrated to a dry matter content of 10 to 60% by weight.
15. The process according to claim 1 , wherein at least 50 wt % dry matter of the low aromatic coffee concentrate is subjected to the heat treatment.
16. The process according to claim 1 , wherein the process results in a hydrolysation of at least 120 mmoles acid/kg dry matter solids content in the liquid coffee concentrate.
17. The process according to claim 8 , wherein the pH is raised to a value of 6 to 8.
18. The process according to claim 11 , wherein the pH is raised to a value of 5 to 6.
19. The process according to claim 13 , wherein the pH is raised with an anion exchange column.
20. The process according to claim 1 , wherein the low aromatic coffee extract is concentrated to a dry matter content of 15 to 50% by weight.
21. The process according to claim 1 , wherein the low aromatic coffee extract is concentrated to a dry matter content of 15 to 40% by weight.
22. The process according to claim 1 , wherein at least 75 wt % dry matter of the low aromatic coffee concentrate is subjected to the heat treatment.
23. The process according to claim 1 , wherein all of the low aromatic coffee concentrate is subjected to the heat treatment.
24. The process according to claim 1 , wherein the process results in hydrolysation of at least 150 mmoles acid/kg dry matter solids content in the liquid coffee concentrate.
25. The process according to claim 1 , wherein the process results in hydrolysation of at least 180 mmoles acid/kg dry matter solids content in the liquid coffee concentrate.