NZ741784B2

NZ741784B2 - Oil compositions and methods of making

Info

Publication number: NZ741784B2
Application number: NZ741784A
Authority: NZ
Inventors: Jaroslav Kralovec; Chris Luigart; Mark Oxford; Ralf Proplesch; Suarez Erick Reyes; Alfred Rolle; Michael Lenn Stefanski
Original assignee: Dsm Ip Assets Bv
Filing date: 2016-10-05
Publication date: 2024-01-04

Abstract

The present invention is directed to oil compositions that are enriched in polyunsaturated fatty acids; compositions containing the enriched oil compositions; and methods of making and using the enriched oil compositions. The oil is preferably a microbial or marine oil. More specifically the present invention is directed to a process for separation and concentration of an oil comprising esters of polyunsaturated fatty acids, the process comprising subjecting the oil to at least one distillation step, wherein a first distillation step comprises feeding the oil to at least one apparatus and subjecting the oil to conditions to remove low-boiling compounds in a distillate, and wherein a second distillation step comprises subjecting the oil to conditions to separate at least a portion of one long-chain polyunsaturated fatty acid (LC-PUFA) which is eicosapenaenoic acid (EPA) from at least a portion of a second LC-PUFA which is docosahexaenoic acid (DHA), wherein said at least one apparatus comprises a fractionating column that is attached to a wiped-film evaporator.

Description

OIL COMPOSITIONS AND METHODS OF MAKING CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of the filing date of United States Provisional Patent Application No. 62/237,320 filed October 5, 2015, the disclosure of which is hereby incorporated herein by reference in its entirety.

FIELD OF THE INVENTION Disclosed herein are oil compositions that are enriched in polyunsaturated fatty acids; compositions containing the oil compositions; and methods of making and using the oil compositions. The oil is preferably a microbial or marine oil.

BACKGROUND OF THE INVENTION Fatty acids are classified based on the length and saturation characteristics of the carbon chain. Fatty acids are termed short chain, medium chain, or long chain fatty acids based on the number of carbons present in the chain, are termed saturated fatty acids when no double or triple bonds are present between the carbon atoms, and are termed unsaturated fatty acids when double or triple bonds are present. Unsaturated long chain fatty acids are monounsaturated when only one double or triple bond is present and are polyunsaturated when more than one double or triple bond is present.

Polyunsaturated fatty acids (PUFAs) are classified based on the position of the first double bond from the methyl end of the fatty acid; omega-3 (n-3) fatty acids contain a first double bond at the third carbon counting from the methyl terminal, while omega-6 (n-6) fatty acids contain a first double bond at the sixth carbon. For example, docosahexaenoic acid ("DHA") is an omega-3 long chain polyunsaturated fatty acid (LC-PUFA) with a chain length of 22 carbons and 6 double bonds, often designated as "22:6 n-3." Other omega-3 LC- PUFAs include eicosapentaenoic acid ("EPA"), designated as "20:5 n-3," and omega-3 docosapentaenoic acid ("DPA n-3"), designated as "22:5 n-3." Omega-6 LC-PUFAs include arachidonic acid ("ARA"), designated as "20:4 n-6," and omega-6 docosapentaenoic acid ("DPA n-6"), designated as "22:5 n-6." Omega-3 fatty acids are biologically important molecules that affect cellular physiology due to their presence in cell membranes, regulate production and gene expression of biologically active compounds, and serve as biosynthetic substrates. Roche, H. M., Proc.

Nutr. Soc. 58: 397-401 (1999). DHA, for example, accounts for approximately 15%-20% of the fatty acids making lipids in the human cerebral cortex, 30%-60% of the fatty acids making lipids in the retina, is concentrated in the testes and sperm, and is an important component of breast milk. Bergé, J.P., and Barnathan, G.. Adv. Biochem. Eng. Biotechnol. 96:49-125 (2005). DHA accounts for up to 97% of the omega-3 fatty acids in the brain and up to 93% of the omega-3 fatty acids in the retina. Moreover, DHA is essential for both fetal and infant development as well as maintenance of cognitive functions in adults. Id. Because omega-3 fatty acids are not synthesized de novo in the human body, these fatty acids must be derived from nutritional sources. However, sources of omega-3 fatty acids can vary in the identity and amounts of LC-PUFAs produced. As such, a continuing need exists for omega-3 fatty acid sources having high amounts of LC-PUFAs with desirable LC-PUFA profiles and for oils that contain higher concentrations of LC-PUFAs. Previous concentration methods have been shown to require numerous steps to achieve a desired concentration level, resulting in an inefficient process while often not obtaining the desired LC-PUFA content or profile.

Other known methods are costly and time-consuming. Further, previous concentration methods have not provided a method of separation and concentration in one continuous process that provides a desired LC-PUFA content and profile. The inventors have surprisingly found a method of separation and concentration of oils comprising polyunsaturated fatty acids to produce desirable LC-PUFA profiles having higher concentrations of LC-PUFAs that is less costly and time-consuming than previous methods.

SUMMARY OF THE INVENTION The present invention is directed to an oil comprising an ester fraction, wherein at least about 70% by weight of the fatty acids in the ester fraction is docosahexaenoic acid (DHA) and from about 0.5% to about 5% by weight of the fatty acids in the ester fraction is docosapentaenoic acid n-3 (DPA n-3). In some embodiments, less than about 5% by weight of the fatty acids in the ester fraction is eicosapentaenoic acid (EPA). In some embodiments, from about 0.1% to about 5% by weight of the fatty acids in the ester fraction is EPA. In some embodiments, from about 2% to about 8% by weight of the fatty acids in the ester fraction is DPA n-6. In some embodiments, the ester fraction comprises at least about 70% by weight of the oil.

The present invention is directed to an oil comprising an ester fraction, wherein at least about 70% by weight of the fatty acids in the ester fraction is docosahexaenoic acid (DHA) and from about 3% to about 13% by weight of the fatty acids in the ester fraction is docosapentaenoic acid n-3 (DPA n-3) and docosapentaenoic acid n-6 (DPA n-6). In some embodiments, from about 1% to about 5% by weight of the fatty acids in the ester fraction is DPA n-3. In some embodiments, from about 2% to about 8% by weight of the fatty acids in the ester fraction is DPA n-6. In some embodiments, less than about 5% by weight of the fatty acids in the ester fraction is eicosapentaenoic acid (EPA). In some embodiments, from about 0.1% to about 5% by weight of the fatty acids in the ester fraction is EPA. In some embodiments, the ester fraction comprises at least about 70% by weight of the oil.

The present invention is also directed to an oil comprising an ester fraction, wherein at least about 70% by weight of the fatty acids in the ester fraction is docosahexaenoic acid (DHA) and the amount of DHA in the ester fraction is at least about 65% by weight of the total omega-3 fatty acids in the ester fraction. In one embodiment, at least about 8% by weight of the fatty acids in the ester fraction is EPA. In some embodiments, the amount of EPA in the ester fraction is at least about 2% by weight of the total omega-3 fatty acids in the ester fraction.

The present invention is also directed to an oil comprising an ester fraction, wherein at least about 20% by weight of the fatty acids in the ester fraction is docosahexaenoic acid (DHA) and at least about 20% by weight of the fatty acids in the ester fraction is eicosapentaenoic acid (EPA). In some embodiments, from about 0.1% to about % by weight of the fatty acids in the ester fraction is DPA n-3.

The present invention is also directed to an oil comprising an ester fraction, wherein at least about 30% by weight of the fatty acids in the ester fraction is docosahexaenoic acid (DHA) and at least about 30% by weight of the fatty acids in the ester fraction is eicosapentaenoic acid (EPA). In some embodiments, from about 0.1% to about 5% by weight of the fatty acids in the ester fraction is DPA n-3.

The present invention is also directed to an oil comprising an ester fraction, wherein at least about 65% by weight of the fatty acids in the ester fraction is docosahexaenoic acid (DHA) and at least about 15% by weight of the fatty acids in the ester fraction is eicosapentaenoic acid (EPA). In some embodiments, from about 0.1% to about 5% by weight of the fatty acids in the ester fraction is DPA n-3.

The present invention is also directed to an oil comprising an ester fraction, wherein at least about 50% by weight of the fatty acids in the ester fraction is docosahexaenoic acid (DHA) and at least about 25% by weight of the fatty acids in the ester fraction is eicosapentaenoic acid (EPA). In some embodiments, from about 0.1% to about % by weight of the fatty acids in the ester fraction is DPA n-3.

The present invention is also directed to a process for separation and concentration of an oil comprising esters of polyunsaturated fatty acids, the process comprising subjecting the oil to at least one distillation step, wherein a first distillation step comprises feeding the oil to at least one apparatus and subjecting the oil to conditions to remove low-boiling compounds in a distillate.

In some embodiments, the oil is a microbial or marine oil.

In some embodiments, the oil is a microbial oil produced from a microorganism. In some embodiments, the microorganism is selected from the group comprising microalgae, bacteria, fungi and protists.

The present invention is directed to a food, supplement, or pharmaceutical composition comprising an oil of the invention.

The present invention is further directed to a process for separation and concentration of an oil comprising esters of polyunsaturated fatty acids, the process comprising subjecting the oil to at least one distillation step, wherein a first distillation step comprises feeding the oil to at least one apparatus and subjecting the oil to conditions to remove low-boiling compounds in a distillate, and wherein a second distillation step comprises subjecting the oil to conditions to separate at least a portion of one long-chain polyunsaturated fatty acid (LC-PUFA) which is eicosapenaenoic acid (EPA) from at least a portion of a second LC-PUFA which is docosahexaenoic acid (DHA), wherein said at least one apparatus comprises a fractionating column that is attached to a wiped-film evaporator.

The present invention is further directed to a process for separation and concentration of an oil comprising esters of polyunsaturated fatty acids, the process comprising subjecting the oil to at least two distillation steps, wherein a first distillation step comprises feeding the oil to at least one apparatus and subjecting the oil to conditions to remove low-boiling compounds in a distillate, and wherein a second distillation step comprises subjecting the oil to conditions to separate at least a portion of one long-chain polyunsaturated fatty acid (LC-PUFA) which is eicosapentaenoic acid (EPA) from at least a portion of a second LC-PUFA which is docosahexaenoic acid (DHA), wherein said at least one apparatus in the second distillation step comprises a fractionating column that is attached to a wiped-film evaporator.

The present invention is further directed to a process for separation and concentration of a starting oil comprising esters of polyunsaturated fatty acids, the process comprising subjecting the oil to more than two distillation steps, wherein a first distillation step comprises feeding the oil to at least one apparatus and subjecting the oil to conditions to remove low-boiling compounds in a distillate, and wherein a second distillation step comprises subjecting the oil to conditions to separate at least a portion of one esters of long- chain polyunsaturated fatty acid (LC-PUFA) which is esters of eicosapentaenoic acid (EPA) from at least a portion of a second esters of LC-PUFA which is esters of docosahexaenoic acid (DHA) so providing product oils, wherein said at least one apparatus in the second distillation step comprises a fractionating column that is attached to a wiped film evaporator, wherein the total isomer value of the product oil is less than 2% by weight.

DETAILED DESCRIPTION OF THE INVENTION The features and advantages of the invention may be more readily understood by those of ordinary skill in the art upon reading the following detailed description. It is to be appreciated that certain features of the invention that are, for clarity reasons, described above and below in the context of separate embodiments, may be combined to form sub- combinations thereof.

Embodiments identified herein as exemplary are intended to be illustrative and not limiting.

In this specification and in the claims that follow, reference will be made to a number of terms, which shall be defined to have the following meanings: The use of the terms "a" and "an" and "the" and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein.

Disclosed herein are enriched oil compositions comprising polyunsaturated fatty acids; compositions containing the enriched oil compositions; and methods of making and using the enriched oil compositions.

Polyunsaturated fatty acids (PUFAs) are classified based on the position of the first double bond from the methyl end of the fatty acid; omega-3 (n-3) fatty acids contain a first double bond at the third carbon counting from the methyl end, while omega-6 (n-6) fatty acids contain a first double bond at the sixth carbon. For example, docosahexaenoic acid (DHA) is an omega-3 long chain polyunsaturated fatty acid (LC-PUFA) with a chain length of 22 carbons and 6 double bonds, often designated as "22:6n-3." In one embodiment, the PUFA is selected from an omega-3 fatty acid, an omega-6 fatty acid, and mixtures thereof.

In another embodiment, the PUFA is selected from docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), arachidonic acid (ARA), gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA), stearidonic acid (SDA), and mixtures thereof. In another embodiment, the PUFA is selected from DHA, DPA, EPA, and mixtures thereof. In another embodiment, the PUFA is DHA. In a further embodiment, the PUFA is DPA. In yet a further embodiment, the PUFA is EPA.

In some embodiments, the oil comprises one or more PUFAs. In some embodiments, the oil comprises at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% PUFA. In a preferred embodiment, the PUFA is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the PUFA is the % by weight of the oil. In a more preferred embodiment, the % by weight of the PUFA is the % by weight of the fatty acids in an ester fraction.

In one embodiment, the oil comprises at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98% or at least about 99% by weight DHA. In a preferred embodiment, the DHA is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of DHA is the % by weight of the oil. In a more preferred embodiment, the % by weight of the DHA is the % by weight of the fatty acids in an ester fraction.

In some embodiments, the oil comprises about 3% to about 13%, about 4% to about 12%, about 5% to about 11%, about 6% to about 10%, or about 7% to about 9% DPA n-3 and DPA n-6. In a preferred embodiment, the DPA n-3 and DPA n-6 is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the DPA n-3 and DPA n-6 is the % by weight of the oil. In a more preferred embodiment, the % by weight of the DPA n-3 and the DPA n-6 is the % by weight of the fatty acids in the ester fraction.

In some embodiments, the oil comprises from about 0.5% to about 5%, about 1% to about 5%, or about 3% to about 4% DPA n-3. In a preferred embodiment, the DPA n- 3 is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the DPA n-3 is the % by weight of the oil. In a more preferred embodiment, the % by weight of the DPA n-3 is the % by weight of the fatty acids in an ester fraction.

In some embodiments, the oil comprises about 2% to about 8%, about 3% to about 7%, or about 4% to about 6% DPA n-6. In a preferred embodiment, the DPA n-6 is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the DPA n-6 is the % by weight of the oil. In a more preferred embodiment, the % by weight of the DPA n-6 is the % by weight of the fatty acids in an ester fraction.

In some embodiments, the oil comprises less than about 5%, less than about 4%, less than about 3%, less than about 2.5%, less than about 2%, less than about 2%, less than about 1.5%, less than about 1%, or less than about 0.5% EPA. In a preferred embodiment, the EPA is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the EPA is the % by weight of the oil.

In a more preferred embodiment, the % by weight of the EPA is the % by weight of the fatty acids in an ester fraction.

In some embodiments, the oil comprises from about 0.1% to about 5%, about 0.5% to about 3%, or about 1% to about 2% EPA. In a preferred embodiment, the EPA is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the EPA is the % by weight of the oil. In a more preferred embodiment, the % by weight of the EPA is the % by weight of the fatty acids in an ester fraction.

In some embodiments, the oil comprises less than about 5%, less than about 4%, less than about 3%, less than about 2.5%, less than about 2%, less than about 2%, less than about 1.5%, less than about 1%, or less than about 0.5% ARA. In a preferred embodiment, the ARA is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the ARA is the % by weight of the oil.

In a more preferred embodiment, the % by weight of the ARA is the % by weight of the fatty acids in an ester fraction.

In some embodiments, the oil comprises less than about 5%, less than about 4%, less than about 3%, less than about 2.5%, less than about 2%, less than about 2%, less than about 1.5%, less than about 1%, or less than about 0.5% GLA. In a preferred embodiment, the GLA is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the GLA is the % by weight of the oil.

In a more preferred embodiment, the % by weight of the GLA is the % by weight of the fatty acids in an ester fraction.

In some embodiments, the oil comprises less than about 5%, less than about 4%, less than about 3%, less than about 2.5%, less than about 2%, less than about 2%, less than about 1.5%, less than about 1%, or less than about 0.5% DGLA. In a preferred embodiment, the DGLA is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the DGLA is the % by weight of the oil. In a more preferred embodiment, the % by weight of the DGLA is the % by weight of the fatty acids in an ester fraction.

In some embodiments, the oil comprises less than about 5%, less than about 4%, less than about 3%, less than about 2.5%, less than about 2%, less than about 2%, less than about 1.5%, less than about 1%, or less than about 0.5% SDA. In a preferred embodiment, the SDA is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the SDA is the % by weight of the oil.

In a preferred embodiment, the % by weight of the SDA is the % by weight of the fatty acids in an ester fraction.

In some embodiments, the comprises less than about 5%, less than about 4%, less than about 3%, less than about 2.5%, less than about 2%, less than about 2%, less than about 1.5%, less than about 1%, or less than about 0.5% of a polyunsaturated fatty acid having greater than 22 carbons (very long chain PUFAs). In some embodiments, the very long chain PUFA is 7,10,13,16,19,22,25 octacosaoctaenoic acid (C28:8). In a preferred embodiment, the oil comprises 0% 7,10,13,16,19,22,25 octacosaoctaenoic acid (C28:8). In a preferred embodiment, the very long chain PUFA is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the very long chain PUFA is the % by weight of the oil. In a preferred embodiment, the % by weight of the very long chain PUFA is the % by weight of the fatty acids in an ester fraction.

In one embodiment, the oil comprises at least about 50%, at least about 55%, at least about 60%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98% or at least about 99% EPA. In a preferred embodiment, the EPA is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the EPA is the % by weight of the oil. In a preferred embodiment, the % by weight of the EPA is the % by weight of the fatty acids in an ester fraction.

In some embodiments, the oil comprises less than about 5%, less than about 4%, less than about 3%, less than about 2.5%, less than about 2%, less than about 2%, less than about 1.5%, less than about 1%, or less than about 0.5% DHA. In a preferred embodiment, the DHA is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the DHA is the % by weight of the oil.

In a more preferred embodiment, the % by weight of the DHA is the % by weight of the fatty acids in an ester fraction.

In some embodiments, the oil comprises less than about 5%, less than about 4%, less than about 3%, less than about 2.5%, less than about 2%, less than about 2%, less than about 1.5%, less than about 1%, or less than about 0.5% DPA n-3 and DPA n-6. In a preferred embodiment, the DPA n-3 and DPA n-6 is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the DPA n-3 and DPA n-6 is the % by weight of the oil. In a preferred embodiment, the % by weight of the DPA n-3 and DPA n-6 is the % by weight of the fatty acids in an ester fraction.

In some embodiments, the oil comprises less than about 5%, less than about 4%, less than about 3%, less than about 2.5%, less than about 2%, less than about 2%, less than about 1.5%, less than about 1%, or less than about 0.5% DPA n-3. In a preferred embodiment, the DPA n-3 is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the DPA n-3 is the % by weight of the oil. In a more preferred embodiment, the % by weight of the DPA n-3 is the % by weight of the fatty acids in an ester fraction.

In some embodiments, the oil comprises less than about 5%, less than about 4%, less than about 3%, less than about 2.5%, less than about 2%, less than about 2%, less than about 1.5%, less than about 1%, or less than about 0.5% DPA n-6. In a preferred embodiment, the DPA n-6 is in ester form. In a more preferred embodiment, the ester is an ethyl ester. In a preferred embodiment, the % by weight of the DPA n-6 is the % by weight of the oil. In a preferred embodiment, the % by weight of the DPA n-6 is the % by weight of the fatty acids of the ester fraction.

In some embodiments, the oil comprises an ester fraction wherein at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% by weight of the fatty acids in the ester fraction is docosahexaenoic acid (DHA) and the amount of DHA in the ester fraction is at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90% by weight of the total omega-3 fatty acids in the ester fraction. In some embodiments, at least about 8%, at least about 10%, at least about 15%, at least about 20%, at least about 35%, at least about 40% by weight of the fatty acids in the ester fraction is EPA. In some embodiments, the amount of EPA in the ester fraction is at least about 2%, at least about 3%, at least about 4%, at least about 5%, at least about 10%, at least about 15%, at least about 20%, at least about 25% by weight of the total omega-3 fatty acids in the ester fraction.

In some embodiments, the oil comprises an ester fraction of at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% by weight of the oil. In some embodiments, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98% or at least about 99% by weight of the fatty acids in the ester fraction is DHA. In some embodiments, from about 0.5% to about 5%, about 1% to about 5%, or about 3% to about 4% by weight of the fatty acids in the ester fraction is DPA n-3.

In some embodiments, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98% or at least about 99% by weight of the fatty acids in the ester fraction is DHA and DPA n-3.

In some embodiments, the DHA content of the fatty acids in the ester fraction is at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98% or at least about 99% by weight of the amount of DHA and DPA n-3 content of the fatty acids in the ester fraction.

In some embodiments, the DPA n-3 content of the fatty acids in the ester fraction is from about 0.5% to about 5%, about 1% to about 5%, or about 3% to about 4% of the DHA and DPA n-3 content of the fatty acids in the ester fraction.

In some embodiments, the DHA, DPA n-3 and DPA n-6 content of the fatty acids of the ester fraction is at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98% or at least about 99% of the total amount of fatty acids in the ester fraction.

In some embodiments, the DHA content of the fatty acids in the ester fraction is at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98% or at least about 99% of the DHA, DPA n-3 and DPA n- 6 content of the fatty acids in the ester fraction.

In a preferred embodiment, the ester fraction is an ethyl ester.

In one embodiment, the DHA and EPA content of the fatty acids in the ester fraction is at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98% or at least about 99% of the total amount of fatty acids in the ester fraction. In some embodiments, the DHA content of the fatty acids in the ester fraction is an amount of at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98% or at least about 99% by weight of the total amount of fatty acids in the ester fraction. In some embodiments, the EPA content of the fatty acids in the ester fraction is less than about 5%, less than about 4%, less than about 3%, less than about 2.5%, less than about 2%, less than about 2%, less than about 1.5%, less than about 1%, or less than about 0.5% of the total amount of fatty acids in the ester fraction. In a preferred embodiment, the ester fraction is an ethyl ester.

In one embodiment, the DHA and EPA content of the fatty acids in the ester fraction is at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98% or at least about 99% of the total amount of fatty acids in the ester fraction. In some embodiments, the EPA content of the fatty acids in the ester fraction is an amount of at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98% or at least about 99% by weight of the total amount of fatty acids. In some embodiments, the DHA content of the fatty acids in the ester fraction is less than about 5%, less than about 4%, less than about 3%, less than about 2.5%, less than about 2%, less than about 2%, less than about 1.5%, less than about 1%, or less than about 0.5% if the total amount of fatty acids in the ester fraction. In a preferred embodiment, the ester fraction is an ethyl ester.

In some embodiments, the total isomer value of the oil is less than 5%, less than 4.5%, less than 4%, less than 3.5%, less than 3%, less than 2.5%, less than 2%, less than 1.5%, less than 1%, less than 0.5%, less than 0.1%, or 0%.

In some embodiments, the EPA isomer value of the oil is less than 5%, less than 4.5%, less than 4%, less than 3.5%, less than 3%, less than 2.5%, less than 2%, less than 1.5%, less than 1%, less than 0.5%, less than 0.1%, or 0%.

In some embodiments, the DHA isomer value of the oil is less than 5%, less than 4.5%, less than 4%, less than 3.5%, less than 3%, less than 2.5%, less than 2%, less than 1.5%, less than 1%, less than 0.5%, less than 0.1%, or 0%.

In some embodiments, the amount of DHA in the oil per gram of oil is from about 100 mg to about 300 mg, about 100 mg to about 600 mg, about 100 mg to about 800 mg, about 100 mg to about 900 mg, about 100 mg to about 950-mg, about 800 to about 950 mg, or 0 to about 100 mg.

In some embodiments, the amount of EPA in the oil per gram of oil is from about 100 mg to about 300 mg, about 100 mg to about 600 mg, about 100 mg to about 800 mg, about 100 mg to about 900 mg, about 100 mg to about 950-mg, about 800 to about 950 mg, or 0 to about 100 mg.

In some embodiments, the oil is a microbial or marine oil.

Oil produced by a microorganism or obtained from a microbial cell is referred to as "microbial oil". Oil produced by algae and/or fungi is referred to as an algal and/or a fungal oil, respectively.

As used herein, a "microorganism" refers to organisms such as algae, bacteria, fungi, protist, yeast, and combinations thereof, e.g., unicellular organisms. A microorganism includes but is not limited to, golden algae (e.g., microorganisms of the kingdom Stramenopiles); green algae; diatoms; dinoflagellates (e.g., microorganisms of the order Dinophyceae including members of the genus Crypthecodinium such as, for example, Crypthecodinium cohnii or C. cohnii); microalgae of the order Thraustochytriales; yeast (Ascomycetes or Basidiomycetes); and fungi of the genera Mucor, Mortierella, including but not limited to Mortierella alpina and Mortierella sect. schmuckeri, and Pythium, including but not limited to Pythium insidiosum.

In one embodiment, the microorganisms are from the genus Mortierella, genus Crypthecodinium, genus Thraustochytrium, and mixtures thereof. In a further embodiment, the microorganisms are from Crypthecodinium Cohnii. In a further embodiment, the microorganisms are from Mortierella alpina. In a still further embodiment, the microorganisms are from Schizochytrium sp. In yet an even further embodiment, the microorganisms are selected from Crypthecodinium Cohnii, Mortierella alpina, Schizochytrium sp., and mixtures thereof.

In a still further embodiment, the microorganisms include, but are not limited to, microorganisms belonging to the genus Mortierella, genus Conidiobolus, genus Pythium, genus Phytophthora, genus Penicillium, genus Cladosporium, genus Mucor, genus Fusarium, genus Aspergillus, genus Rhodotorula, genus Entomophthora, genus Echinosporangium, and genus Saprolegnia.

In an even further embodiment, the microorganisms are from microalgae of the order Thraustochytriales, which includes, but is not limited to, the genera Thraustochytrium (species include arudimentale, aureum, benthicola, globosum, kinnei, motivum, multirudimentale, pachydermum, proliferum, roseum, striatum); the genera Schizochytrium (species include aggregatum, limnaceum, mangrovei, minutum, octosporum); the genera Ulkenia (species include amoeboidea, kerguelensis, minuta, profunda, radiate, sailens, sarkariana, schizochytrops, visurgensis, yorkensis); the genera Aurantiacochytrium; the genera Oblongichytrium; the genera Sicyoidochytium; the genera Parientichytrium; the genera Botryochytrium; and combinations thereof. Species described within Ulkenia will be considered to be members of the genus Schizochytrium. In another embodiment, the microorganisms are from the order Thraustochytriales. In yet another embodiment, the microorganisms are from Thraustochytrium. In still a further embodiment, the microorganisms are from Schizochytrium sp.

In certain embodiments, the oil can comprise a marine oil. Examples of suitable fish oils include, but are not limited to, Atlantic fish oil, Pacific fish oil, or Mediterranean fish oil, or any mixture or combination thereof. In more specific examples, a suitable fish oil can be, but is not limited to, pollack oil, bonito oil, pilchard oil, tilapia oil, tuna oil, sea bass oil, halibut oil, spearfish oil, barracuda oil, cod oil, menhaden oil, sardine oil, anchovy oil, capelin oil, herring oil, mackerel oil, salmonid oil, tuna oil, and shark oil, including any mixture or combination thereof. Other marine oils suitable for use herein include, but are not limited to, squid oil, cuttle fish oil, octopus oil, krill oil, seal oil, whale oil, and the like, including any mixture or combination thereof.

In some embodiments, a fatty acid as described herein can be a fatty acid ester or ester. In some embodiments, a fatty acid ester includes an ester of an omega-3 fatty acid, omega-6 fatty acid, and combinations thereof. In some embodiments, the fatty acid ester is a DHA ester, an EPA ester, or a combination thereof. In some embodiments, an oil or fraction thereof as described herein is esterified to produce an oil or fraction thereof comprising fatty acid esters. The term "ester" refers to the replacement of the hydrogen in the carboxylic acid group of the fatty acid molecule with another substituent. Examples of esters include methyl, ethyl, propyl, butyl, pentyl, t-butyl, benzyl, nitrobenzyl, methoxybenzyl, benzhydryl, and trichloroethyl. In some embodiments, the ester is a carboxylic acid protective ester group, esters with aralkyl (e.g., benzyl, phenethyl), esters with lower alkenyl (e.g., allyl, 2-butenyl), esters with lower-alkoxy-lower-alkyl (e.g., methoxymethyl, 2-methoxyethyl, 2-ethoxyethyl), esters with lower-alkanoyloxy-lower-alkyl (e.g., acetoxymethyl, pivaloyloxymethyl, 1- pivaloyloxyethyl), esters with lower-alkoxycarbonyl-lower-alkyl (e.g., methoxycarbonylmethyl, isopropoxycarbonylmethyl), esters with carboxy-lower alkyl (e.g., carboxymethyl), esters with lower-alkoxycarbonyloxy-lower-alkyl (e.g., 1- (ethoxycarbonyloxy)ethyl, 1-(cyclohexyloxycarbonyloxy)ethyl), esters with carbamoyloxy- lower alkyl (e.g., carbamoyloxymethyl), and the like. In some embodiments, the added substituent is a linear or cyclic hydrocarbon group, e.g., a C1-C6 alkyl, C1-C6 cycloalkyl, C1-C6 alkenyl, or C1-C6 aryl ester. In some embodiments, the ester is an alkyl ester, e.g., a methyl ester, ethyl ester or propyl ester. In some embodiments, the ester substituent is added to the free fatty acid molecule when the fatty acid is in a purified or semi-purified state.

Fatty acid esters, in particular polyunsaturated fatty acid esters, can be made in ways that are known to one of ordinary skill in the art.

For example, tri-acyl glycerides, di-acyl glycerides, and /or mono-acyl glycerides that contain fatty acids, particularly poly-unsaturated fatty acids, can be reacted with an alcohol in the presence of an acid or a base to produce esters. The disclosure of U.S.

Patent Application No. 12/163,555, that published as U.S. Patent Application Pre-Grant Publication No. 2009/0023808, is incorporated by reference herein in its entirety.

Alcohols can include, for example, C -C alkyl alcohols, for example, ethanol, methanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n- pentanol, and n-hexanol. The alcohol can be used as the reaction solvent and co-reactant, either alone or with a co-solvent. The amount of the alcohol can range from 25 % to 50 % by weight of the reaction mixture, including all values and subranges therebetween as if explicitly written out. For example, the amount of alcohol in the reaction mixture can be %, 35%, 40% or 45% by weight of the reaction mixture.

The base can be, for example, a metal alkyloxide. Metal alkyloxides include sodium ethoxide, sodium methoxide, sodium n-propoxide, sodium iso-propoxide, sodium n- butoxide, sodium iso-butoxide, sodium sec-butoxide, sodium, tert-butoxide, sodium n- pentoxide, sodium n-hexoxide, lithium ethoxide, lithium methoxide, lithium n-propoxide, lithium iso-propoxide, lithium n-butoxide, lithium iso-butoxide, lithium sec-butoxide, lithium, tert-butoxide, lithium n-pentoxide, lithium n-hexoxide, potassium ethoxide, potassium methoxide, potassium n-propoxide, potassium iso-propoxide, potassium n- butoxide, potassium iso-butoxide, potassium sec-butoxide, potassium, tert-butoxide, potassium n-pentoxide, and /or potassium n-hexoxide.

In some situations, the base can be made by adding sodium metal, potassium metal, or lithium metal to an alcoholic solution.

In some situations, the base can be made by adding a metal hydride, such as lithium hydride, sodium hydride, or potassium hydride, to an alcoholic solution.

The ratio of base to oil, on a weight: weight basis can, for example, range from 1:1 to 1000:1, including all values and subranges therebetween as if explicitly written out.

For example, the ratio of base to oil, on a weight to weight basis, can be 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 20:1, 30:1, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1, 100:1, 200:1, 300:1, 400:1, 500;1, 600:1, 700:1, 800:1, or 900:1.

The esterification reaction can be run at a temperature ranging from 10 C to 100 C, including all values and subranges therebetween as if explicitly written out. For o o o o o o example, the esterification reaction can be run at 20 C, 30 C, 40 C, 50 C, 60 C, 70 C, 80 C, or 90 C.

The esterification reaction can be run open to the atmosphere, or under an inert atmosphere such as nitrogen or argon.

Workup and isolation of the fatty acid esters can be done in ways known to one of ordinary skill, for example, by extraction with an organic solvent and / or water. The organic solvent can be, for example, pentane, hexane, di-ethyl ether, ethyl acetate, or a combination of these. The water can optionally contain other substances such as sodium bicarbonate, sodium carbonate, ammonium chloride and / or dilute mineral acid.

In some embodiments, the oil is transesterified to convert at least part of the ester fraction in the oil to a triglyceride fraction. Transesterification, in particular transesterification of polyunsaturated fatty acid esters, can be made in ways that are known to one of ordinary skill in the art.

In the present invention, any concentrating, reacting, and/or purifying technique can be combined with any other concentrating, reacting, and/or purifying technique to produce microbial oils enriched in: polyunsaturated fatty acids, their esters, their salts, aldehydes thereof and/or alcohols thereof. The enrichment techniques can be used in any order and combination.

In some embodiments, the present invention is a food, supplement, or pharmaceutical composition comprising an oil of the invention. The pharmaceutical composition can contain a pharmaceutically acceptable carrier.

In some embodiments, the composition is a food product. A food product is any food for non-human animal or human consumption, and includes both solid and liquid compositions. A food product can be an additive to animal or human foods. Foods include, but are not limited to, common foods; liquid products, including milks, beverages, therapeutic drinks, and nutritional drinks; functional foods; supplements; nutraceuticals; infant formulas, including formulas for pre-mature infants; foods for pregnant or nursing women; foods for adults; geriatric foods; and animal foods.

In some embodiments, the composition is an animal feed. An "animal" includes non-human organisms belonging to the kingdom Animalia, and includes, without limitation, aquatic animals and terrestrial animals. The term "animal feed" or "animal food" refers to any food intended for non-human animals, whether for fish; commercial fish; ornamental fish; fish larvae; bivalves; mollusks; crustaceans; shellfish; shrimp; larval shrimp; artemia; rotifers; brine shrimp; filter feeders; amphibians; reptiles; mammals; domestic animals; farm animals; zoo animals; sport animals; breeding stock; racing animals; show animals; heirloom animals; rare or endangered animals; companion animals; pet animals such as dogs, cats, guinea pigs, rabbits, rats, mice, or horses; primates such as monkeys (e.g., cebus, rhesus, African green, patas, cynomolgus, and cercopithecus), apes, orangutans, baboons, gibbons, and chimpanzees; canids such as dogs and wolves; felids such as cats, lions, and tigers; equids such as horses, donkeys, and zebras; food animals such as cows, cattle, pigs, and sheep; ungulates such as deer and giraffes; or rodents such as mice, rats, hamsters and guinea pigs; and so on. An animal feed includes, but is not limited to, an aquaculture feed, a domestic animal feed including pet feed, a zoological animal feed, a work animal feed, a livestock feed, and combinations thereof.

In some embodiments, the composition is a feed or feed supplement for any animal whose meat or products are consumed by humans, such as any animal from which meat, eggs, or milk is derived for human consumption. When fed to such animals, nutrients such as LC-PUFAs can be incorporated into the flesh, milk, eggs or other products of such animals to increase their content of these nutrients.

The present invention is also directed to a process for separation and concentration of an oil comprising esters of polyunsaturated fatty acids to produce an oil.

In some embodiments, the process comprises subjecting the oil to at least one distillation step, wherein a first distillation step comprises feeding the oil to at least one apparatus and subjecting the oil to conditions to remove low-boiling compounds in a distillate. In a preferred embodiment, at least a portion of eicosapentaenoic acid (EPA) is removed in the distillate. In some embodiments, at least about 5%, at least about 10%, at least about 15%, at least about 20% of EPA is in the distillate of the first distillation step.

In some embodiments, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75% of one long-chain polyunsaturated fatty acid (LC-PUFA) is separated from a second LC-PUFA in the second distillation step. In a preferred embodiment, one LC-PUFA is EPA. In a preferred embodiment, the second LC-PUFA is DHA. In a more preferred embodiment, one LC-PUFA is EPA and the second LC-PUFA is DHA.

In some embodiments, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75% of one long-chain polyunsaturated fatty acid (LC-PUFA) is separated from a second LC-PUFA in the third distillation step. In a preferred embodiment, one LC-PUFA is EPA. In a preferred embodiment, the second LC-PUFA is DHA. In a more preferred embodiment, one LC-PUFA is EPA and the second LC-PUFA is DHA.

In some embodiments, the process comprises short path distillation, fractional distillation, falling-film evaporator, wiped-film evaporator, or combinations thereof. In a preferred embodiment, the process comprises fractional distillation.

In some embodiments, the apparatus is a fractionating column.

In some embodiments, the column comprises a rectification section. In some embodiments, the column has at least about 1 meter, at least about 2 meter, or at least about 3 meter of structured packing, having at least about 3-4, at least about 4-5, at least about 5-6, at least about 6-7, at least about 7-8, at least about 8-9, at least about 9-10, at least about 10-11, at least about 11-12, or at least about 12-13 theoretical stages.

In some embodiments, the column is attached to a vacuum. In some embodiments, the pressure at the top of the column is less than about 4 mbar, less than about 3.5 mbar, less than about 3 mbar, less than about 2.5 mbar, less than about 2 mbar, or less than about 1.5 mbar. In some embodiments, the pressure drop of the column is less than about 10 mbar, less than about 9 mbar, less than about 8 mbar, less than about 7 mbar, less than about 6 mbar, less than about 5 mbar, less than about 4 mbar, or less than about 3 mbar.

In some embodiments, the apparatus is a fractionating column or short-path distillation. In a preferred embodiment, the fractionating column is attached to a wiped-film evaporator. In some embodiments comprising more than one distillation step, the apparatus of each distillation step may be the same apparatus or may be in series.

In some embodiments, feeding the oil to at least one apparatus comprises a mid-column feed. In some embodiments, feeding the oil to at least one apparatus comprises an evaporator feed.

In a preferred embodiment, the oil subjected to a first distillation step is separated at the residue end and the distillate end in an amount of at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, or at least about 80% by weight. In a preferred embodiment, the oil collected at the residue end comprises at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 85%, or at least about 90% by weight EPA and DHA. In a preferred embodiment, the oil collected at the distillate end comprises at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 85%, or at least about 90% by weight polyunsaturated fatty acids having less than 20 carbons.

In a preferred embodiment, the oil subjected to the second distillation step is separated at the residue end and the distillate end in an amount of at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, or at least about 80% by weight. In a preferred embodiment, the oil collected at the residue end comprises at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 85%, or at least about 90% by weight EPA. In a preferred embodiment, the oil collected at the distillate end comprises at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 85%, or at least about 90% by weight DHA.

In a preferred embodiment, the oil subjected to the third distillation step is separated at the residue end and the distillate end in an amount of at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, or at least about 80% by weight. In a preferred embodiment, the oil collected at the residue end comprises at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 85%, or at least about 90% by weight EPA. In a preferred embodiment, the oil collected at the distillate end comprises at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 85%, or at least about 90% by weight DHA.

In some embodiments, the at least one distillation step comprises heating wherein the temperature is less than about 275 ºC, less than about 250 ºC, less than about 225 ºC, less than about 200 ºC, less than about 190 ºC, less than about 180 ºC, or less than about 170 ºC, from about 100 º C to about 250 ºC, from about 125 º C to 225 ºC, from about 150 º C to 200 ºC, or from about 160 º C to 190 ºC.

In some embodiments, the reflux ratio is less than about 5, less than about 4.5, less than about 4, less than about 3.5, less than about 3, less than about 2.5, less than about 2, less than about 1.5, less than about 1, or less than about 0.5.

The present invention is also directed to an oil produced by any of the processes disclosed herein.

EXAMPLES The following examples are set forth below to illustrate the methods and results according to the disclosed subject matter. These examples are not intended to be inclusive of all aspects of the subject matter disclosed herein, but rather to illustrate representative methods and results. These examples are not intended to exclude equivalents and variations that are apparent to one skilled in the art.

Analytical Methods: Determination of fatty acid compositions was performed using gas chromatograph with a flame ionization detector (GD/FID) according to European Pharmacopoeia method 2.04.29.

Example 1 A crude oil was produced through fermentation of Schizochytrium sp. Table 1 shows the fatty acid profile of the starting oil.

Table 1: Fatty Acid Profile-Starting Oil Fatty Acid Area Percent (%) C14:0 1.3 C16:0 18.3 C18:0 1.1 C18:1 n-9 2.1 C20:4 n-6 1.3 C20:5 n-3 (EPA) 9.5 C22:5 n-6 4.0 C22:5 n-3 1.2 C22:6 n-3 (DHA) 58.1 Transesterification: To convert the starting oil from a triglyceride to an ethyl ester, a one liter round-bottomed flask was charged with 400 g of the dry, crude oil and a solution of sodium ethoxide (3.2 g) dissolved in ethanol (120 g) was added. The mixture was heated to 75°C while stirring under a N atmosphere and then maintained at this temperature for 1 hour. The reaction mixture was allowed to cool to 30°C, transferred to a separatory funnel, and the bottom glycerol layer was drained. The top oil layer was then transferred to a clean 1L round- bottomed flask and a solution of sodium ethoxide (0.32 g) in ethanol (12.0 g) was added. The mixture was again heated to 75°C while stirring under a N atmosphere and then maintained at this temperature for 1 hour. The ethanol was removed using a rotary evaporator, the residue was washed with a citric acid solution (1% w/w) until the pH of the aqueous washing portions was no longer basic, washed with water, and dried under vacuum.

Analytical Methods: Determination of oligomers and lipid class was performed using size exclusion chromatography with refractive index detection (SEC/RI).

Polymer based Tosahaas TSK-GEL were used for gel permeation chromatography. The apparatus was assembled with two TSK-GEL columns + a guard column and equilibrated with tetrahydrofuran (THF) at a flow rate of 0.600 mL/min. The oil samples were dissolved in THF at a concentration of 15 mg/mL and injected into the chromatorgraph in 10.0µL injection volume. Table 2 shows the lipid class profile of the starting oil after transesterification.

Table 2: Lipid Class-Starting Oil Lipid Class % Ethyl Ester 96 Monoglyceride 2.6 Diglyceride 1.2 Triglyceride 0.1 Purification and Concentration, Trial 1: The oil was fractionated via three passes through a short path distillation apparatus using a temperature range from 120ºC to 180ºC and vacuum of approximately 20mtorr. On the first pass, the starting oil was passed through the short path distillation apparatus. The distillate contained 110 mg/g EPA and 322 mg/g DHA (Sample 1D) and the residue contained 70 mg/g EPA and 759 mg/g DHA (Sample 1R). On the second pass, the residue from the first pass was fed through the short path distillation apparatus, resulting in 72 mg/g EPA and 789 mg/g DHA in the distillate (Sample 2D). The residue could not be sampled due to the viscosity (Sample 2R). On the third pass, the distillate from the second pass was fed through the short path distillation apparatus, resulting in 126 mg/g EPA and 715 mg/g DHA in the distillate (Sample 3D) and 43 mg/g EPA and 811 mg/g DHA residue in the residue (Sample 3R). Results are shown in Table 3.

Table 3: Short path Distillation Results, Trial 1 Sample EPA (mg/g) DHA (mg/g) Total Omega-3 (mg/g) Starting oil 87 548 646 First Pass-Distillate 110 322 451 (Sample 1D) First Pass-Residue 70 759 853 (Sample 1R) Second Pass- 72 789 887 Distillate (Sample Second Pass- ---- ---- ---- Residue (Sample Third Pass-Distillate 126 715 868 (Sample 3D) Third Pass-Residue 43 811 877 (Sample 3R) Purification and Concentration, Trial 2: The oil was fractionated via four passes through a short path distillation apparatus using a temperature range from 120ºC to 180ºC and vacuum of approximately 20mtorr. On the first pass, the starting oil was passed through the short path distillation apparatus. The distillate contained 69 mg/g EPA and 154 mg/g DHA (Sample 1D) and the residue contained 94 mg/g EPA and 641 mg/g DHA (Sample 1R). On the second pass, the residue from the first pass was fed through the short path distillation apparatus, resulting in 131 mg/g EPA and 373 mg/g DHA in the distillate (Sample 2D) and 84 mg/g EPA and 717 mg/g DHA in the residue (Sample 2R). On the third pass, the residue from the second pass was fed through the short path distillation apparatus, resulting in 86 mg/g EPA and 742 mg/g DHA in the distillate (Sample 3D). The residue could not be sampled due to the viscosity (Sample 3R). On the fourth pass, the distillate from the third pass was fed through the short path distillation apparatus, resulting in 117 mg/g EPA and 722 mg/g DHA in the distillate (Sample 4D) and 26 mg/g EPA and 785 mg/g DHA in the residue (Sample 4R). Results are shown in Table 4.

Table 4: Short path Distillation Results, Trial 2 Sample EPA (mg/g) DHA (mg/g) Total Omega-3 (mg/g) Starting oil 87 548 646 First Pass-Distillate 69 154 234 (Sample 1D) First Pass-Residue 94 641 758 (Sample 1R) Second Pass-Distillate 131 373 527 (Sample 2D) Second Pass-Residue 84 717 825 (Sample 2R) Third Pass-Distillate 86 742 853 (Sample 3D) Third Pass-Residue ---- ---- ---- (Sample 3R) Fourth Pass-Distillate 117 722 867 (Sample 4D) Fourth Pass-Residue 26 785 832 (Sample 4R) Purification and Concentration, Trial 3: A different starting oil was used for this example than in Trials 1 and 2. The oil was produced through fermentation of Schizochytrium sp. and was subjected to the same transesterification process as above. The oil was fractionated via three passes through a short path distillation apparatus using a temperature range from 120ºC to 180ºC and vacuum of approximately 20mtorr. On the first pass, the starting oil was passed through a short path distillation apparatus. The distillate contained 112 mg/g EPA and 332 mg/g DHA (Sample 1D) and the residue contained 60 mg/g EPA and 733 mg/g DHA (Sample 1R). On the second pass, the residue from the first pass was fed through the short path distillation apparatus, resulting in 76 mg/g EPA and 766 mg/g DHA in the distillate (Sample 2D). The residue could not be sampled due to the viscosity (Sample 2R). On the third pass, the distillate from the second pass was fed through the short path distillation apparatus, resulting in 96 mg/g EPA and 786 mg/g DHA in the distillate (Sample 3D) and 22 mg/g EPA and 805 mg/g DHA residue in the residue (Sample 3R). Results are shown in Table 5.

Table 5: Short path Distillation Results, Trial 3 Sample EPA (mg/g) DHA (mg/g) Total Omega-3 (mg/g) Starting oil 86 525 630 First Pass-Distillate 112 332 462 (Sample 1D) First Pass-Residue 60 733 815 (Sample 1R) Second Pass- 62 766 851 Distillate (Sample Second Pass-Residue ---- ---- ----- (Sample 2R) Third Pass-Distillate 96 786 907 (Sample 3D) Third Pass-Residue 22 805 848 (Sample 3R) Example 2 A crude oil was produced through fermentation of Schizochytrium sp.

Transesterification: A one liter round-bottomed flask was charged with 400 g of the dry, filtered, crude oil and a solution of sodium ethoxide (3.2 g) dissolved in ethanol (120 g) was added. The mixture was heated to 75°C while stirring under a N atmosphere and then maintained at this temperature for 1 hour. The reaction mixture was allowed to cool to °C, transferred to a separatory funnel and the bottom glycerol layer was drained. The top oil layer was then transferred to a clean 1L round- bottomed flask and a solution of sodium hydroxide (0.32 g) in ethanol (12.0 g) was added. The mixture was again heated to 75°C while stirring under a N atmosphere and then maintained at this temperature for 1 hour. The ethanol was removed using a rotary evaporator, washed with a citric acid solution (1% w/w) until the pH of the aqueous washing portions was no longer basic, washed with water, and dried under vacuum.

Purification and Concentration: The oil was fractionated at a temperature not exceeding 210ºC with a pressure drop of the column of 2.3 mbar. The heavy fraction was further refined using short path distillation at a pressure of 0.01 mbar and a temperature of 140°C. The DHA concentrate was isolated in the amount of 225 mg and purity of 890 mg/g.

Example 3 A crude fish oil was subjected to a separation and concentration process.

Transesterification: An esterification reaction between the purified marine oil and ethyl alcohol, using sodium ethoxide as a catalyst, was used to produce a marine oil ethyl ester. Ethanol and sodium ethoxide was added to a purified marine oil that had been heated.

The glycerol was separated from the marine oil. Ethanol and sodium ethoxide was then added again to the marine oil (after removal of the glycerol). The ethyl ester marine oil formed was centrifuged for further glycerol removal. The sodium ethoxide was neutralized by 5% addition by weight of the marine oil of a 9% citric acid solution. The acid wash layer was separated from the ethyl ester marine oil, water was added, and the ethyl ester marine oil was dried.

The ethyl ester marine oils used in Examples 4-9 were prepared as in this Example 3.

Example 4 A crude fish oil was subjected to a separation and concentration process. A falling-film evaporator with a rectification column followed by short path distillation (SPD) was evaluated. The column contained approximately 1 meter of packing having approximately 3-4 theoretical stages. An ethyl ester marine oil was fed through the recycle stream at a temperature of 205ºC. Concentration results are shown in Table 7. Isomer results are shown in Table 8.

Analytical Methods: Isomers and related impurities were measured using gas chromatography. About 25 mg of sample was weighed and dissolved in 25 mL of hexanes.

A silver ion SPE cartridge was mounted on the manifold; the cartridge was conditioned with 4 mL of acetone and equilibrated with 4 mL of hexane. 1 mL of the sample solution was loaded onto the cartridge and pulled through. The cartridge was washed with 6 mL of acetone. Into a new 15 mL test tube, the sample was rinsed from the cartridge with 2 mL of acetone/acetonitrile (3:2). The test tube was removed from the manifold and solvent blown under a nitrogen stream. 1 mL of hexane was added to the test tube. The solution was transferred to a GC vial. An Agilent DB Wax 30m X 0.25mm X 0.25µm column using Helium @ 1 mL/min was used. The injection volume was 1 µL and the detector was FID @ 260ºC. The gradient was 100ºC for 1.0 min, ramp @ 20/min to 210ºC, hold for 40 minutes.

Table 7: Column Followed by Short Path Distillation, 1m packing, EPA/DHA concentration Sample EPA (mg/g) DHA (mg/g) Starting oil 176 85 Column-Distillate 70.7 0.3 Column-Residue 323.4 191.7 SPD-Distillate 378 210.2 SPD-Residue 19.7 21.9 Table 8: Column Followed by Short Path Distillation, 1m packing, Isomers Sample EPA Isomers (%) DHA Isomers (%) Total Isomers (%) Starting oil 0.3 0.8 0.5 Column-Residue 0.4 2.6 2.0 SPD-Distillate 2.6 5.1 3.8 Example 5 A crude fish oil was subjected to a separation and concentration process. A falling-film evaporator with a rectification column followed by a short path distillation was evaluated. The column contained approximately 2 meter of packing and had a mid-column liquid distributor. A marine oil was fed through the recycle stream at a temperature of 170ºC.

Concentration results are shown in Table 9. Isomer results are shown in Table 10.

Table 9: Column Followed by Short Path Distillation, 2m packing, EPA/DHA concentration Sample EPA (mg/g) DHA (mg/g) Starting oil 175.7 85 Column-Distillate 15.0 0.0 Column-Residue 361.1 177.7 SPD-Distillate 382.4 184.2 SPD-Residue 35.5 28.9 Table 10: Column Followed by Short Path Distillation, 2m packing, Isomers Sample EPA Isomers (%) DHA Isomers (%) Total Isomers Starting oil 0.3 0.8 0.5 Column-Distillate 3.7 n/a 3.7 Column-Residue 3.0 6.7 4.9 SPD-Distillate 2.1 5.7 4.1 Example 6 A crude fish oil was subjected to a separation and concentration process. 2 columns in series (each a falling-film evaporator with a rectification column) followed by short path distillation was evaluated. The column-residue sample in Example 4 was fed through a second falling-film evaporator with a rectification column having approximately 2 meter of packing and a mid-column liquid distributor under the same conditions as in Example 4. Concentration results are shown in Table 11. Isomer results are shown in Table Table 11: Column Followed by Short Path Distillation, 2m packing, EPA/DHA concentration Sample EPA (mg/g) DHA (mg/g) Starting oil 175.7 85 Column 1-Distillate 15.0 0.0 Column 1-Residue 361.1 177.7 Column 2-Distillate 653.1 20.8 Column 2-Residue 0.0 145.5 SPD-Distillate 2.1 227.5 SPD-Residue 0.0 10.7 Table 12: Column Followed by Short Path Distillation, 2m packing, Isomers Sample EPA Isomers (%) DHA Isomers (%) Total Isomers (%) Starting oil 0.3 0.8 0.5 Column 1-Distillate 3.7 n/a 3.7 Column 1-Residue 3.0 6.7 4.9 Column 2-Distillate 0.8 3.3 1.1 Column 2-Residue 6.6 24.4 23.6 SPD-Distillate 17.6 29.4 29.2 Example 7 A crude fish oil was subjected to a separation and concentration process. A fractional distillation column with an external condenser followed by short path distillation (SPD) was evaluated. The external condenser was a wiped-film evaporator. The column was packed with 3 meters of packing, having approximately 8-9 theoretical stages of separation with a mid-column feed. Concentration results are shown in Table 13. Isomer results are shown in Table 14.

Table 13: Column followed by Short-Path Distillation, 3m packing, EPA/DHA concentration Sample EPA (mg/g) DHA (mg/g) Starting oil 173 88.2 Column 1- 13 0.0 Distillate Column 1- 402.2 206.2 Residue SPD-Distillate 450.3 228.1 SPD-Residue 56.9 51.7 Table 14: Column followed by Short-Path Distillation, 3m packing, Isomers Sample EPA Isomers (%) DHA Isomers (%) Total Isomers (%) Starting oil 0.9 1.2 1.0 Column 1-Residue 0.6 0.7 0.6 SPD-Distillate 0.5 0.4 0.5 Example 8 A crude fish oil was subjected to a separation and concentration process. A fractional distillation column with an external condenser followed by short path distillation (SPD) was evaluated. The external condenser was a wiped-film evaporator. The column was packed with 3 meters of packing, having approximately 8-9 theoretical stages of separation with an evaporator feed. Concentration results are shown in Table 15. Isomer results are shown in Table 16.

Table 15: Column followed by Short-Path Distillation, 3m packing, EPA/DHA concentration Sample EPA (mg/g) DHA (mg/g) Starting oil 173 88.2 Column 1- 11 0.0 Distillate Column 1- 409 224.3 Residue Table 16: Column followed by Short-Path Distillation, 3m packing, Isomers Sample EPA Isomers (%) DHA Isomers (%) Total Isomers (%) Starting oil 0.9 1.2 1.0 Column 1-Residue 0.3 0.6 0.5 Example 9 A crude fish oil was subjected to a separation and concentration process. A fractional distillation column with an external condenser followed by a second fractional distillation column with an external condenser followed by a short path distillation (SPD) was evaluated. The external condenser was a wiped-film evaporator. Both columns were packed with 2 meters of packing, having approximately 8-9 theoretical stages of separation with mid- column feed. Concentration results are shown in Table 17. Isomer results are shown in Table Table 17: Column followed by Second Column, followed by Short-Path Distillation, 2m packing, EPA/DHA concentration Sample EPA (mg/g) DHA (mg/g) Starting oil 175.2 83.7 Column 1- 15.0 0.0 Distillate Column 1- 402.2 206.2 Residue Column 2-Feed 407 211.1 Column 2- 825.1 0.0 Distillate Column 2- 33 396.6 Residue SPD-Distillate 21.9 493.2 SPD-Residue 0.0 64.4 Table 18: Column followed by Second Column followed by Short-Path Distillation, 2m packing, Isomers Sample EPA Isomers (%) DHA Isomers (%) Total Isomers (%) Column 2-Feed 0.5 0.6 0.6 Column 2-Distillate 0.3 0.0 0.3 Column 2-Distillate 0.8 1.0 1.0 SPD-Distillate 4.4 0.5 0.6 Example 10 Crude fish oils of various concentrations were subjected to a separation and concentration process. The starting oil concentrations listed in Tables 19-21 are representative concentration values based on the type of fish used (for example, 22:08 is a fish containing approximately 20% EPA and 8% DHA). A fractional distillation column with an external condenser followed by a second fractional distillation column with an external condenser followed by a short path distillation (SPD) was evaluated. The external condenser was a wiped-film evaporator. After passing through the first column, the EPA and DHA concentrations in the residue were measured (Table 19). The residue was passed through a second column and the EPA and DHA concentrations in the distillate were measured (Table ). The residue from the second column was passed through a short path distillation column and the EPA and DHA concentrations in the residue were measured (Table 21).

Table 19: First Column, EPA/DHA concentration Sample Starting Starting EPA Starting Residue EPA Residue DHA Material (wt%) DHA (wt%) (wt%) (wt%) 1 22:8 17.5 8.4 39.5-42.8 20.6-21.8 2 22:8 17.5 8.4 40.5-41.5 21.0-21.2 3 18:12 14.3 12.6 29.5-32.4 29.9-31.6 4 18:12 14.3 12.6 30.4-32.6 29.8-30.8 22:8 17.5 8.4 40.6-41.0 21.1 6 12:18 13.9 13.0 28.7-31.7 30.8-32.4 7 12:18 13.9 13.0 28.5-31.8 30.4-32.4 Table 20: Second Column, EPA/DHA concentration, Distillate Sample Starting Starting EPA Starting Distillate EPA Distillate DHA Material (wt%) DHA (wt%) (wt%) (wt%) 1 22:8 40.7 21.1 79.8-82.2 0.0 2 18:12 31.1 30.6 75.5-78.8 0.0-0.04 3 12:18 30.6 31.3 74.4-76.0 0.0 4 12:18 30.6 31.3 73.9-74.6 0.0 22:8 39.9 20.6 75.1-77.8 0.0-0.66 Table 21: Short Path Distillation Column, EPA/DHA concentration, Residue Sample Starting Starting EPA Starting Residue EPA Residue DHA Material (wt%) DHA (wt%) (wt%) (wt%) 1 22:8 1.8 41.0 2.1-2.2 48.5-50.1 2 18:12 0.3 50.0 0.3-0.5 59.6-59.9 3 12:18 0.2 50.7 0.2 60.0 Example 11 Crude fish oil having an EPA:DHA profile of 14.9 wt% EPA and 10.1 wt% DHA was subjected to a separation and concentration process. A fractional distillation column with an external condenser followed by a second fractional distillation column with an external condenser followed by a short path distillation (SPD) was evaluated. The external condenser was a wiped-film evaporator. After passing through the first column, the EPA and DHA concentrations in the distillate and residue were measured (Table 22). The residue was passed through a second column and the EPA and DHA concentrations in the distillate and residue were measured (Table 23). The residue from the second column was passed through a short path distillation column and the EPA and DHA concentrations in the distillate and residue were measured (Table 24). The EPA and DHA concentrations of each sample were measured at different time intervals during the processing.

Table 22: First Column, EPA/DHA concentration Sample Starting Starting Distillate Distillate Residue Residue EPA DHA EPA (wt%) DHA EPA (wt%) DHA (wt%) (wt%) (wt%) (wt%) 1 14.9 10.1 5.8 --- 30.2 27.6 2 14.9 10.1 2.4 --- 33.7 26.0 3 14.9 10.1 1.9 --- 33.9 25.7 4 14.9 10.1 0.2 --- 35.0 24.4 14.9 10.1 0.2 --- 34.8 24.4 Table 23: Second Column, EPA/DHA concentration Sample Feed Feed Distillate Distillate Residue Residue EPA DHA EPA (wt%) DHA EPA (wt%) DHA (wt%) (wt%) (wt%) (wt%) 1 35.6 24.9 61.3 0.1 --- 46.8 2 35.6 24.9 73.9 --- --- 46.2 3 35.6 24.9 73.3 0.3 --- 46.3 4 35.6 24.9 74.0 --- 0.2 46.0 35.6 24.9 76.4 --- 0.3 45.5 6 35.6 24.9 76.7 --- 0.2 45.2 7 35.6 24.9 77.5 --- 0.3 44.2 8 35.6 24.9 77.0 --- 0.3 44.8 Table 24: Short Path Distillation Column, EPA/DHA concentration Sample Feed Feed Distillate Distillate Residue Residue EPA DHA EPA (wt%) DHA EPA (wt%) DHA (wt%) (wt%) (wt%) (wt%) 1 0.2 45.5 0.2 55.9 --- 0.5 2 0.2 45.5 0.2 57.5 --- 1 3 0.2 45.5 0.2 56.5 --- 1.1 4 0.2 45.5 0.2 56.6 --- 2.3 0.2 45.5 0.2 56.7 --- 2.6 6 0.2 45.5 0.2 57 --- 3.3 7 0.2 45.5 0.2 58.4 --- 1.2 Example 12 Crude fish oil was subjected to a separation and concentration process. A fractional distillation column with an external condenser followed by a second fractional distillation column with an external condenser followed by a short path distillation (SPD) was evaluated. The external condenser was a wiped-film evaporator. The levels of isomers were measured in these samples. Results are shown in Table 25.

Table 25: Isomer Results Sample Isomer A Isomer B Isomer C Isomer D + E Total Isomers Starting Oil 0.26 0.07 0.12 0.34 0.79 (18:12 Fish Oil) Distillate, First 0.0 0.0 0.0 0.0 0.0 column Residue, First 0.29 0.12 0.11 0.45 0.96 column Distillate, 0.33 0.16 0.16 0.51 1.16 Second Column (~77 wt% EPA) Distillate, Short- No or trace No or trace No or trace No or trace No or trace Path Distillation Column (~56 wt% DHA) Example 13 A crude oil was produced through fermentation of Schizochytrium sp. The oil was subjected to a transesterification step to produce ethyl esters of polyunsaturated fatty acids.

Purification and Concentration: A fractional distillation column with an external condenser followed by a short path distillation column was evaluated. The external condenser was a wiped-film evaporator. The fatty acid profile of the starting oil is shown in Table 26. The fatty acid profile of the oil produced is shown in Table 27.

Table 26: Fatty acid profile, starting oil Fatty Acid Weight Percent (%) C14:0 1.5 C16:0 22.9 C18:0 1.7 C18:1 n-9 2.1 C20:4 n-6 1.7 C20:5 n-3 (EPA) 19.9 C22:5 n-6 1.9 C22:5 n-3 3.3 C22:6 n-3 (DHA) 41.4 Table 27: Fatty acid profile, oil Fatty Acid Weight Percent (%) C16:0 12.3 C18:0 1.5 C18:1 n-9 1.9 C20:4 n-6 1.8 C20:5 n-3 (EPA) 21.8 C22:5 n-6 2.4 C22:5 n-3 4.1 C22:6 n-3 (DHA) 50.6 Example 14 A crude oil was produced through fermentation of Schizochytrium sp. The oil was subjected to a transesterification step to produce ethyl esters of polyunsaturated fatty acids.

Purification and Concentration: The oil was fractionated via a first pass through a fractional distillation column. The distillate contained 222 mg/g EPA and 218 mg/g DHA (sample 1D). The residue contained 175 mg/g EPA and 611 mg/g DHA (sample 1R). The distillate from this first pass was fractionated via a second pass through a fractional distillation column. The distillate from this was 77 mg/g EPA and 34 mg/g DHA (sample 3D) and the residue from this was 291 mg/g EPA and 331 mg/g DHA (sample 3R). The residue from the first pass was fractionated via a second pass through a fractional distillation column. The distillate from this was 181 mg/g EPA and 624 mg/g DHA (sample 2D) and the residue from this could not be sampled due to viscosity. Sample 2D was passed through a short path distillation apparatus. The distillate from this was 256 mg/g EPA and 559 mg/g DHA (sample 4D) and the residue was 105 mg/g EPA and 697 mg/g DHA (sample 4R). All passes through the fractionation column and/or short path distillation apparatus used a temperature range from 110ºC to 180ºC and vacuum of approximately 20-25mtorr. Results are shown in Table 28.

Table 28: EPA/DHA concentration Sample EPA EPA DHA DHA Total Total (mg/g) (wt%) (mg/g) (wt%) omega-3 omega-3 (mg/g) (wt%) Starting oil 193 19.3 392 39.2 624 62.4 Column 1- 222 22.2 218 21.8 465 46.5 Distillate (Sample 1D) Column 1- 175 17.5 611 61.1 842 84.2 Residue (Sample 1R) Column 2- 181 18.1 624 62.4 864 86.4 Distillate (Sample 2D) Column 2- ---- ---- ---- ---- ---- ---- Residue (Sample 2R) Column 3- 77 7.7 34 3.4 116 11.6 Distillate (Sample 3D) Column 3- 291 29.1 331 33.1 650 65.0 Residue (Sample 3R) SPD- 256 25.6 559 55.9 857 85.7 Distillate (Sample 4D) SPD- 105 10.5 697 69.7 860 86.0 Residue (Sample 4R) Example 15 A crude oil was produced through fermentation of Cryptochodinium cohnii.

The oil was subjected to a transesterification step to produce ethyl esters of polyunsaturated fatty acids.

Purification and Concentration: A fractional distillation column with an external condenser followed by a short path distillation was evaluated. The external condenser was a wiped-film evaporator. The fatty acid profile of the starting oil is shown in Table 29. Two trials were completed. The fatty acid profile of the oils produced are shown in Tables 30 and 31.

Table 29: Fatty acid profile, starting oil Fatty Acid Weight Percent (%) C12:0 5.09 C14:0 9.10 C16:0 6.74 C18:1 n-9 6.42 C20:5 n-3 (EPA) 0.0 C22:5 n-6 0.0 C22:5 n-3 0.87 C22:6 n-3 (DHA) 48.7 Table 30: Fatty acid profile, oil Fatty Acid Weight Percent (%) C12:0 0.0 C14:0 0.0 C16:0 0.0 C18:1 n-9 0.0 C20:5 n-3 (EPA) 0.0 C22:5 n-6 0.0 C22:5 n-3 1.7 C22:6 n-3 (DHA) 96.9 Table 31: Fatty acid profile, oil Fatty Acid Weight Percent (%) C12:0 0.0 C14:0 0.0 C16:0 0.0 C18:1 n-9 0.0 C20:5 n-3 (EPA) 0.0 C22:5 n-6 0.0 C22:5 n-3 1.36 C22:6 n-3 (DHA) 96.6 All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

1. A process for separation and concentration of a starting oil comprising esters of polyunsaturated fatty acids, the process comprising subjecting the oil to more than two distillation steps, wherein a first distillation step comprises feeding the oil to at least one apparatus and subjecting the oil to conditions to remove low-boiling compounds in a distillate, and wherein a second distillation step comprises subjecting the oil to conditions to separate at least a portion of one esters of long-chain polyunsaturated fatty acid (LC-PUFA) which is esters of eicosapentaenoic acid (EPA) from at least a portion of a second esters of LC-PUFA which is esters of docosahexaenoic acid (DHA) so providing product oils, wherein said at least one apparatus in the second distillation step comprises a fractionating column that is attached to a wiped film evaporator, wherein the total isomer value of the product oil is less than 2% by weight.

2. The process of claim 1, wherein a third distillation step comprises subjecting the oil to conditions to separate at least an additional portion of one esters of long-chain polyunsaturated fatty acid (LC-PUFA) from a second esters of LC-PUFA.

3. The process of any one of the preceding claims, wherein any one of the distillation steps comprises short path distillation, fractional distillation, falling film evaporator, wiped film evaporator, or combinations thereof.

4. The process of any one of the preceding claims, wherein the at least one apparatus in the first distillation step is a short path distillation column or a fractionating column.

5. The process of any one of the preceding claims, wherein the apparatus in a second distillation step comprises a short-path distillation column or a fractionating column.

6. The process of any one of the preceding claims, wherein at least a portion of esters of eicosapentaenoic acid (EPA) is removed in the distillate of the first distillation step, preferably wherein at least 5% of esters of EPA is removed in the distillate, more preferably, wherein at least 10% of esters of EPA is removed in the distillate.

7. The process of any one of the preceding claims, wherein at least one esters of LC- PUFA is separated from a second esters of LC-PUFA in an amount of at least about 50%.

8. The process of any one of the preceding claims, wherein the wt% of at least one esters of LC-PUFA is increased in the product oils by at least about 20 wt% as compared to the wt% in the starting oil.

9. The process according to any one of the preceding claims, wherein the product oils comprises at least about 70% of a desired esters of PUFA, preferably, wherein the oil comprises at least about 80% of a desired esters of PUFA, more preferably, wherein the product oils comprises at least about 90% of a desired esters of PUFA.

10. The process according to any one of the preceding claims, wherein the starting oil is a microbial or marine oil.

11. The process according to claim 10, wherein the starting oil is a microbial oil.

12. The process according to claim 11, wherein the starting oil has been produced by a microorganism, wherein the microorganism is selected from the group comprising microalgae, bacteria, fungi and protists.

13. The process according to claim 12, wherein the microorganism is a microalgae.

14. The process according to claim 13, wherein the microalgae is of the genus Cryptochodinium, preferably, wherein the microalgae is of the species Cryptochodinium cohnii.

15. The process according to claim 13, wherein the microalgae is of the genus Thraustochytrium, preferably, wherein the microalgae is of the species Schizochytrium sp.