Krill oil process
The present invention relates to a process for preparing compositions of high concentrations of omega-3 fatty acids from krill. Furthermore, the invention relates to a composition comprising high concentrations of omega-3 fatty acids, and a lipid fraction from krill comprising high amounts of fatty acids with chain length C14 and C16.
1. A process for preparing a composition comprising a high concentration of omega-3 fatty acids, the process comprising:
a) reducing the water content of a krill raw material;
b) isolating the lipid fraction from the krill raw material to obtain a substantially total lipid fraction
c) subjecting the lipid fraction to an ethylation step to form ethyl esters; and
d) subjecting the lipid fraction to short path distillation or to one or more steps of supercritical fluid extraction, chromatography, or a combination thereof.
2. The process of claim 1 , wherein step a) comprises washing the krill raw material with at least one alcohol chosen from ethanol, methanol, propanol, iso-propanol, and any combination thereof in a weight ratio of krill material:alcohol ranging from 1:0.5 to 1:5; and step b) comprises isolating the lipid fraction from the at least one alcohol.
3. The process of claim 2 , wherein step a) comprises washing the krill raw material with ethanol; and step b) comprises isolating the lipid fraction from the ethanol.
4. The process of claim 1 , further comprising the step:
a-1) extracting the water reduced krill raw material from step a) with CO 2 at supercritical pressure containing at least one alcohol chosen from ethanol, methanol, propanol, iso-propanol, and a combination thereof;
wherein step a-1) is performed after step a) and before step b).
5. The process of claim 2 , wherein the krill raw material is heated to a temperature ranging from 60° C. to 100° C. before washing with the at least one alcohol.
6. The process of claim 5 , wherein the krill raw material is heated to a temperature ranging from 70° C. to 100° C. before washing with the at least one alcohol.
7. The process of claim 6 , wherein the krill raw material is heated to a temperature ranging from 80° C. to 95° C. before washing with the at least one alcohol.
8. The process of claim 1 , wherein the krill raw material is pre-treated by use of microwaves before washing.
9. The process of claim 2 , wherein washing the krill raw material with the at least one alcohol in step a) produces an extract rich in omega-3 fatty acids, and
removing residual alcohol from the krill material in step b) produces an extract low in omega-3 fatty acids.
10. The process of claim 9 , wherein the removal of residual alcohol from the krill material in step b) is carried out by pressing, centrifugation, or a combination thereof.
11. The process of claim 1 , wherein the short path distillation is a one-step or two-step short path distillation.
12. The process of claim 1 , further comprising the step:
e) subjecting the lipid fraction of step d) to mild urea fractionation.
13. The process of claim 12 , wherein the urea to ethyl ester ratio ranges from 0.1 to 1.5.
14. The process of claim 13 , wherein the urea to ethyl ester ratio ranges from 0.5 to 1.0.
15. The process of claim 12 , further comprising the step:
f) subjecting the lipid fraction of step e) to short path distillation.
16. A composition derived from krill comprising at least 75% by weight of at least one of eicopentaenoic acid (EPA) and docosahexaenoic acid (DHA), wherein the omega-3/omega-6 fatty acid ratio is greater than 30.
17. The composition of claim 16 , wherein the composition comprises at least 80% by weight of at least one of EPA and DHA.
18. The composition of claim 16 , wherein the composition comprises at least 90% by weight of omega-3 fatty acids.
19. The composition of claim 17 , wherein the weight ratio of EPA to DHA ranges from 1:2 to 2:1.
20. The composition of claim 16 , wherein the composition comprises a combination of EPA and DHA.
21. The composition of claim 16 , wherein at least one of the EPA and DHA is present in acid or ethyl ester form.
22. The composition of claim 16 , wherein the omega-3/omega-6 fatty acid ratio is greater than 40.
23. The composition of claim 22 , wherein the omega-3/omega-6 fatty acid ratio is greater than 50.
24. The composition of claim 16 , wherein the concentration of the fatty acid C22:5 n-6 is below 0.8% by weight with respect to the total composition weight.
25. A lipid fraction from krill comprising:
greater than 25% by weight of at least one fatty acid with a chain length chosen from C14 and C16, with respect to the total lipid fraction weight; and
greater than 30% by weight of at least one of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) with respect to the total lipid fraction weight.
26. The lipid fraction of claim 25 , comprising greater than 35% by weight of at least one of EPA and DHA with respect to the total lipid fraction weight.
27. The lipid fraction of claim 25 , comprising greater than 40% by weight of at least one of EPA and DHA with respect to the total lipid fraction weight.
28. The lipid fraction of claim 25 , wherein the lipid fraction is substantially free from the fatty acid C22:5 n-6.
29. A krill oil supplement product comprising the lipid fraction of claim 25 .
30. The process of claim 1 , wherein the lipid fraction is used as a start material in further process steps in order to achieve a high concentrate omega-3 acid or ester product.
31. The process of claim 30 , wherein the high concentrate omega-3 acid or ester product is an omega-3 supplement product or a pharmaceutical composition.