Vegetable oil comprising a polyunsaturated fatty acid having at least 20 carbon atoms

Abstract

The present invention describes a vegetable oil comprising a polyunsatured fatty acid having at least 20 carbon atoms (LC-PUFA), which oil has (a) an anisidine value (AnV) of less than 25; (b) a peroxide value (POV) of less than 10; (c) a triglyceride content of greater than 90%; and/or (d) an Oil Stability Index (OSI) of greater than 5 hours at 80 C.

Claims

1. A process for obtaining a polyunsaturated fatty acid having at least 20 carbon atoms (LC-PUFA) or an oil comprising a LC-PUFA from seeds, said process comprising: (A) (i) obtaining seeds comprising a LC-PUFA and/or an oil comprising a LC-PUFA, (ii) drying the seeds at a temperature of below 40 C. to thereby reduce moisture content of the seeds after drying as compared to the moisture content of the seeds prior to drying, (v) subjecting the seeds to a heating protocol by sequentially: (v1) rapidly heating the seeds such that the temperature passes from 40 to 100 C. in less than one minute, (v2) further heating the seeds to a temperature between 120 C. and 160 C.; (v3) maintaining the seeds at the temperature between 120 C. and 160 C. for a period of less than 8 minutes, and thereafter (v4) rapidly cooling the seeds to a temperature of 40 C. in less than 60 minutes, and one or more of (iii), (iv) or (vi) (iii) storing the seeds, (iv) grinding and/or flaking the seeds, or (vi) pressing the seeds such as to expel a fraction of oil; and (B) obtaining the LC-PUFA or oil comprising the LC-PUFA from the seeds, optionally by extraction with a solvent.

2. The process according to claim 1, wherein in one or more of (i) to (vi): less than 5% of the seeds are total damaged seeds; less than 2% of the seeds are distinctly green seeds; and/or less than 0.1% of the seeds are heated seeds, as determined in accordance with the Official Grain Grading Guide. 2001 of the Canadian Grain Commission.

3. The process according to claim 1, wherein (ii) comprises drying the seeds at a temperature of below 30 C.

4. The process according to claim 1, wherein (ii) comprises drying the seeds using a fluid bed dryer.

5. The process according to claim 1, wherein (ii) comprises drying the seeds using conditioned air having a dew point of <15 C.

6. The process according to claim 1, wherein (ii) comprises drying the seeds, resulting in a moisture content between 6 and 12 wt. %.

7. The process according to claim 1, wherein (iii) comprises storing the seeds at a temperature of below 10 C.

8. The process according to claim 1, wherein in (v1) the temperature passes from 40 to 70 C. in less than 1 minute.

9. The process according to claim 1, wherein in (v3) the temperature is maintained between 120-160 C. for less than 5 minutes.

10. The process according to claim 1, wherein (vi) comprises pressing the seeds to expel oil using a screw press which is cooled.

11. The process according to claim 1, wherein (vi) comprises pressing the seeds to expel the oil, resulting in a pressed oil and a press cake, and wherein step (B) comprises obtaining oil from the press cake by solvent extraction.

12. The process according to claim 1, wherein the seeds are obtained from a transgenic plant.

13. The process according to claim 1, wherein the process further comprises purifying the oil.

14. The process according to claim 13, wherein said purifying comprises deodorizing the oil at a temperature of below 200 C.

15. The process according to claim 1, wherein the LC-PUFA is defined as in any one of claims 6 to 8 is an -3 or -6 PUFA.

16. The process according to claim 1, further comprising: (C) purifying the oil comprising the LC-PUFA to obtain a purified vegetable oil comprising LC-PUFA which has: (a) an anisidine value (AnV) of less than 25, (b) a peroxide value (POV) of less than 10, (c) a triglyceride content of greater than 90%, and/or (d) an Oil Stability Index (OSI) of greater than 5 hours at 80 C.

Description

EXAMPLES

(1) Seeds containing 19% Arachidonic acid (with respect to total fatty acids) are obtained from transgenic Brassica plants that are transformed using the procedures described in WO2008009600.

(2) The seeds have the following specifications (determined in accordance with the Official Grain Grading Guide, 2001 of the Canadian Grain Commission): distinctly green <2%, total damaged <5%.

(3) The seeds, having a moisture content of 17 wt. %, are dried using a fluid bed drier. The bed temperature is 28 C. Conditioned air is used having a dew point of 10 C. The dried seeds have a moisture content of 8.5 wt. %.

(4) Prior to further processing the dried seeds are stored at a temperature of minus 20 C.

(5) After storage (3 months), the seeds are flaked using a conventional flaking process.

(6) The flakes are subsequently heated to reach a temperature of 130 C. in 20 seconds using superheated steam. The flakes are maintained at this temperature for 1 minute, and cooled to 40 C. in 30 minutes.

(7) Following the heat treatment, the flakes are fed to a cooled expeller to obtain a pressed oil. The biomass exiting the expeller is extracted using hexane (ratio hexane:biomass=5:1) in a submerged counter-current extractor at a temperature of 40 C. The hexane is evaporated, yielding a hexane-extracted oil. The pressed oil and hexane-extracted oil are combined resulting in a crude oil.

(8) The crude oil is purified using degumming (acid treatment), alkali purifying (neutralization), and bleaching using standard techniques. After bleaching the oil is steam deodorized under vacuum at a temperature of 180 C.

(9) The characteristics of the crude and refined oil are given in the table below.

(10) TABLE-US-00001 EXAMPLE REFERENCE EXPERIMENT Crude oil Refined oil Crude oil Refined oil Anisidine 20 9 55 27 POV 5 <1 11 <1 Triglyceride 95% 97% 86% 88% content OSI at 80 C. >10 hrs >10 hrs 2 hrs 4 hrs

REFERENCE EXPERIMENT

(11) Seeds as described in example 1 are treated as follows to recover the oil.

(12) The seeds, having a moisture content of 17 wt. % are dried using a vertical open-flame grain dryer at a temperature of 70 C. resulting in a moisture content of 8.5 wt. %. Prior to further processing the dried seeds are stored at ambient temperature.

(13) After storage (3 months), the seeds are flaked using a conventional flaking process.

(14) After flaking the seeds are steamed at a temperature of 100 C. for 30 minutes.

(15) Following the heat treatment, the flakes are fed to an expeller to obtain a pressed oil. The biomass exiting the expeller is extracted using hexane (ratio hexane:biomass=5:1) in a submerged counter-current extractor at a temperature of 40 C. The hexane is evaporated, yielding a hexane-extracted oil. The pressed oil and hexane-extracted oil are combined resulting in a crude oil.

(16) The crude oil is purified using degumming (acid treatment), alkali purifying (neutralization), and bleaching using standard techniques. After bleaching the oil is steam deodorized under vacuum at a temperature of 180 C.

(17) .sup.1H-NMR (to Determine Triglyceride Content)

(18) About 12 mg of an oil sample is weighted accurately into a glass vial and about 12 mg p-nitrotoluene is weighted accurately on top. The sample is dissolved in CDCl.sub.3 and .sup.1H-NMR spectrum were recorded on a Bruker Avance III 600, equipped with a cryoprobe, operating at a proton frequency of 600 MHz and at a probe temperature of 300 K. The spectrum for quantification was recorded with a 60-90 excitation pulse using standard quantitative parameters with a relaxation delay of 30 s.