WO2019007918A1

WO2019007918A1 - Process for the preparation of a hydrogenated fat composition

Info

Publication number: WO2019007918A1
Application number: PCT/EP2018/067852
Authority: WO
Inventors: Bastiaan Jeroen Victor VERKUIJL
Original assignee: Bunge Loders Croklaan B.V.
Priority date: 2017-07-07
Filing date: 2018-07-02
Publication date: 2019-01-10
Also published as: CN110914395B; EP3649219B1; EP3649219A1; ES2928748T3; CN110914395A; PL3649219T3; DK3649219T3

Abstract

A process for the preparation of a hydrogenated fat composition comprises the steps of: i) providing an unsaturated fat composition comprising unsaturated fatty acids and/or unsaturated fatty acid residues, wherein the unsaturated fat composition comprises polychlorodibenzodioxins (PCDDs) including octachlorodibenzodioxin (OCDD); and ii) contacting the unsaturated fat composition with a catalyst and a hydrogen source at a temperature of about 170°C or lower to at least partially hydrogenate the unsaturated fat composition.

Description

PROCESS FOR THE PREPARATION OF A HYDROGENATED FAT COMPOSITION

This invention relates to a process for the preparation of a hydrogenated fat composition. Vegetable oils are valuable commercial products that are used, for example, in the food and animal feed industry. The oils can be used as such or modified before use. Modification is sometimes necessary or desirable in order to make the vegetable oil more suitable for use in a given application. A vegetable oil of particular interest is palm oil, which is typically obtained from the flesh of the palm fruit (Elaeis guineensis). Palm oil is available in a variety of forms, including crude palm oil, refined palm oil and fractions thereof, such as palm olein and palm stearin.

Crude palm oil contains mainly triglycerides of fatty acids having 12 to 18 carbon atoms, with palmitic acid (C16:0) and oleic acid (C18:1 ) being the predominant acid residues. Generally, palm oil is refined and processed in order to use the glycerides and/or the fatty acids.

Processes for modifying vegetable oils, such as palm oil, on an industrial scale have traditionally involved chemical reactions such as hydrogenation at high temperatures in the presence of a metal catalyst. Hydrogenation increases the level of saturated fatty acids in the oil and so raises the solid fat content at a given temperature.

Vegetable oils, including palm oil, sometimes contain impurities. Some of these impurities can be inadvertently introduced into the oil or generated in the oil itself during the processing. For example, some oils have been found to contain polychlorodibenzodioxins (PCDDs), also known as dibenzo-p-dioxins, in various levels and these compounds are known to have various degrees of toxicity.

V. Berg et a/., The 2005 World Health Organization Reevaluation of Human and Mammalian Toxic Equivalency Factors for Dioxins and Dioxin-Like Compounds, Toxicol. Sci., 93(2), 2006, 223-241 provides an overview of the Toxic Equivalence Factor (TEF) values of various PCDDs and these TEF values are reproduced in Table 1 below.

Table 1

1 ,2,3,7,8-PeCDD 1

1 ,2,3,4,7,8-HxCDD 0.1

1 ,2,3,6,7,8-HxCDD 0.1

1 ,2,3,7,8,9-HxCDD 0.1

1 ,2,3,4,6,7,8-HpCDD 0.01

OCDD 0.0003

Tetrachlorodibenzodioxin (TCDD) and pentachlorodibenzodioxin (PeCDD) both have the highest TEF value of . All three hexachlorodibenzodioxin (HxCDD) compounds have a TEF value of 0.1. Heptachlorodibenzodioxin (HpCDD) has a TEF value of 0.01 and octachlorodibenzodioxin (OCDD) has the lowest TEF value of them all at 0.0003. It is apparent from this table that TCDD and PeCDD are considered to be around 3000 times more toxic than OCDD.

It is believed that OCDD has a lower observed toxicity than lesser chlorinated PCDDs due to the fact that it is relatively insoluble and, therefore, undergoes a much lower ievel of bioaccumulation.

Oils are analysed for their content of potentially toxic substances before being incorporated into, or used as, food products and it is typical to calculate the toxic equivalent factor (TEQ) of such compositions. The TEQ of a composition is calculated by multiplying the mass of each potentially toxic compound by its TEF. in order to lower the TEQ vaiue of oil and fat compositions, it is typical practice to remove PCDDs from oil and fat compositions using adsorbent materials

EP-A-2344614 describes a process for the removal of contaminants, such as heavy metals, polychlorinated biphenyls (PCB), dioxins and flame retardants, from food oils via the use of adsorbent materials. The preferred adsorbent materia! used in the process is activated carbon.

J. Maes et al, Journal of the American Oil Chemists' Society, 82(8), 2005, 593-597 describes a process of using activated carbon to remove dioxins and polychlorinated biphenyls (PCBs) from a fish oil. Both of these documents show that activated carbon is suitable for reducing the amount of PCDDs in oils. However, processing oils with activated carbon is expensive. Furthermore, it is necessary to remove the activated carbon from the oil, which can lead to a lengthy purification procedure.

Therefore, there exists a need to reduce the amount of activated carbon used during the processing of oil and fat compositions, or to avoid the need for using activated carbon altogether, and/or of ensuring that the TEQ value of the processed composition remains within acceptable levels.

According to the invention, there is provided a process for the preparation of a hydrogenated fat composition, comprising the steps of:

i) providing an unsaturated fat composition comprising unsaturated fatty acids and/or unsaturated fatty acid residues, wherein the unsaturated fat composition comprises polychlorodibenzodioxins (PCDDs) including octachlorodibenzodioxin (OCDD); and

ii) contacting the unsaturated fat composition with a catalyst and a hydrogen source at a temperature of about 170°C or lower to at least partially hydrogenate the unsaturated fat composition. It has been found that hydrogenating unsaturated fatty acid compositions at the industry standard temperature of 200°C leads to the conversion of OCDD to its more toxic, less chlorinated, dioxins, which in turn increases the TEQ value of the resulting composition.

It has been surprisingly found that reducing the temperature of the hydrogenation reaction to 170°C or lower leads to an acceptable level of unsaturated fatty acid hydrogenation whilst also preventing, or at least reducing the level of, dechlorination of OCDD to its more toxic less chlorinated equivalents.

Also according to the invention, there is provided a process for preventing, or reducing the level of, dechlorination of OCDD during hydrogenation of an unsaturated fat composition.

Further provided by the invention is a method for maintaining or reducing the TEQ value of a hydrogenated fat composition, as determined according to EN 16215:2012, comprising the steps of:

i) providing an unsaturated fat composition comprising unsaturated fatty acids and/or unsaturated fatty acid residues, wherein the unsaturated fat composition comprises polychlorodibenzodioxins (PCDDs) including octachlorodibenzodioxin (OCDD); and ii) contacting the unsaturated fat composition with a catalyst and a hydrogen source at a temperature of about 170°C or lower to at least partially hydrogenate the unsaturated fat composition,

wherein the TEQ value of the hydrogenated fat composition is within ±60% of the TEQ value of the unsaturated fat composition.

The term "unsaturated fat composition", as used herein, refers to a composition that comprises free fatty acids, glycerides comprising fatty acid residues, or mixtures thereof, and in which at least some of the fatty acids contain unsaturated carbon-carbon double bonds. The fatty acids in glycerides are present as acyl residues bonded to glycerol and may be mono-, di- or triglycerides. The term "fat" does not imply any particular limitation on melting point and encompasses fats and oils.

The term "fatty acid", as used herein, refers to saturated or unsaturated, straight chain carboxylic acids having from 6 to 24 carbon atoms. Unsaturated fatty acids may comprise one, two, or more double bonds, preferably one or two double bonds. "Free" fatty acids are not bonded to glycerol as part of a glyceride molecule. Levels of fatty acids present in compositions can be determined by methods well-known to those skilled in the art, such as GC-FAME analysis according to ISO 15304.

The amount of PCDDs in the compositions, including OCDD, can be measured using any standard method known in the art. Preferably, the amount of PCCDs is measured using high- resolution gas chromatography-mass spectrometry. More preferably, the amount of PCDDs in the compositions is measured according to NEN-EN 16215.

Advantageously, the amount of OCDD in the hydrogenated fat composition after step ii) is within about ±10% of the amount of OCDD in the unsaturated fat composition.

Preferably, the amount of OCDD in the hydrogenated fat composition after step ii) is equal to, or not more than 10% less than, the amount of OCDD in the unsaturated fat composition. Advantageously, the amount of OCDD in the hydrogenated fat composition after step ii) is preferably within about ±5% of (or not more than 5% less than), more preferably within about ±3% of (or not more than 3% less than), the amount of OCDD in the unsaturated fat composition. The percentage amounts are determined based on the concentration of OCDD in the unsaturated fat composition starting material and the concentration in the hydrogenated fat composition directly after step ii) (i.e., before further purification of the hydrogenated fat composition), and are determined by weight in each composition. Advantageously, the amount of 2,3,7,8-tetra chlorodibenzodioxin (TCDD) in the hydrogenated fat composition after step ii) is essentially equal to (i.e., ±10%), or lower than, the amount of TCDD in the unsaturated fat composition. Ideally, the amount of TCDD in the hydrogenated fat composition after step ii) is lower than the amount of TCDD in the unsaturated fat composition. Preferably, the amount of TCDD in the hydrogenated fat composition after step ii) is within about ±8%, such as within about ±5, ±4, ±3 or ±2 % of the amount of TCDD in the unsaturated fat composition, more preferably within about ±1%. The percentages are determined as described above for OCDD.

Conveniently, the amount of 1 ,2,3,7,8-penta chlorodibenzodioxin (PeCDD) in the hydrogenated fat composition after step ii) is essentially equal to (i.e., ±10%), or lower than, the amount of PeCDD in the unsaturated fat composition. Ideally, the amount of PeCDD in the hydrogenated fat composition after step ii) is lower than the amount of PeCDD in the unsaturated fat composition. Preferably, the amount of PeCDD in the hydrogenated fat composition after step ii) is within about ±8%, such as within about ±5%, ±4%, ±3% or ±2 % of the amount of PeCDD in the unsaturated fat composition, more preferably within about ±1%. The percentages are determined as described above for OCDD. Typically, the unsaturated fat composition comprises OCDD in an amount of at least about 5 ppt (parts per trillion), such as at least about 10 ppt, by weight of the unsaturated fat composition. For example, the unsaturated fat composition may comprise OCDD in an amount of from about 5 ppt to about 100 ppt, such as from about 10 ppt to about 80 ppt, or from about 20 ppt to about 50 ppt.

Preferably, the hydrogenated fat composition after step ii) has a toxic equivalent factor (TEQ) value that is essentially equal to, or lower than, the TEQ value of the unsaturated fat composition, as determined according to EN 16215:2012. Unless stated otherwise, the TEQ values of the compositions described herein are determined according to EN 16215:2012 and are based on the concentrations of PCDDs alone. For the avoidance of doubt, the presence of compounds other than PCDDs, including chlorinated dibenzofurans, non-ortho substituted dl-PCBs and mono-ortho substituted dl-PCBs, is not taken into account when calculating the TEQ value of the compositions described herein according to EN 16215:2012. Conveniently, the TEQ value of the hydrogenated fat composition after step ii) is lower than the TEQ value of the unsaturated fat composition. Preferably, the TEQ value of the hydrogenated fat composition after step ii) is within about ±60%, such as within about ±50%, ±40%, ±30%, ±20%, ±10% or ±5% of the TEQ value of the unsaturated fat composition, more preferably within about ±2%.

The TEQ value is calculated based on the total PCDDs in the two compositions, and is usually based on the PCDDs 2,3,7,8-TCDD; 1 ,2,3,7,8-PeCDD; 1 ,2,3,4,7,8-HxCDD; 1 ,2,3,6,7,8- HxCDD; 1 ,2,3,7,8,9-HxCDD; 1 ,2,3,4,6,7,8-HpCDD; and OCDD.

The TEQ value of a composition is calculated based on the following equation:

Where TEQ(pg/g) is the Toxic Equivalent value, (TEF)j is the TEF vaiue of compound i and (concentration)i is the calculated concentration of the compound. Preferably, the unsaturated fat composition is contacted with a catalyst and hydrogen source at a temperature above the melting point of the hydrogenated fat composition. Ideally, the unsaturated fat composition is contacted with a catalyst and a hydrogen source at a temperature of about 150°C or lower, preferably at a temperature of about 140°C or lower, more preferably at a temperature of about 130°C or lower. For example, the unsaturated fat composition may be contacted with a catalyst and a hydrogen source at a temperature of from about 70°C to about 170°C, preferably from about 90°C to about 170°C, for example from about 100°C to about 150°C, more preferably from about 100°C to about 130°C.

Ideally, the catalyst used is selected from the group consisting of palladium, platinum and nickel based catalysts, or mixtures thereof. Preferably, the catalyst is a nickel based catalyst, such as a supported nickel catalyst, more preferably nickel supported on silica. Most preferably, the catalyst is selected from the group consisting of PRICAT 9931 , PRICAT 9932,

Preferably, the hydrogen source is gaseous hydrogen.

Ideally, the unsaturated fat composition is contacted with a catalyst and hydrogen source at a pressure of greater than about 1 bar (100 kPa), such as from about 1 to about 10 bar (about 100 to about 1000 kPa), for example from about 5 to about 10 bar (about 500 to about 1000 kPa), more preferably at a pressure of about 5 bar (about 500 kPa).

Preferably, the unsaturated fat composition is contacted with a catalyst and hydrogen source for a period of from about 5 minutes to about 10 hours, for example from about 30 minutes to about 10 hours, preferably from about 1 to about 10 hours, such as for a period of from about 1 to about 5 hours, more preferably for a period of from about 1 to about 2 hours.

Preferably, the process comprises the further step of filtering the hydrogenated fat composition to remove the catalyst.

Preferably, the process further comprises the step of purifying the hydrogenated fat composition. The composition may be purified by any method known in the art. The term "purifying" is envisaged to encompass any method which increases the concentration of the desired components in the hydrogenated fat composition. Optionally, purifying comprises bleaching. Bleaching may be carried out under conditions known in the art. For example, bleaching may be carried out under any of the conditions disclosed in WO 2012/065790.

Bleaching is preferably carried out in the presence of a bleaching earth.

Preferably, the process is carried out in the absence of the step of contacting the hydrogenated fat composition with an added adsorbing agent, in particular activated carbon, to reduce the content of dioxins. Typically, the unsaturated fat composition comprises free fatty acids, monoacylglycerides, diacylglycerides, triacylglycerides, or mixtures thereof. Preferably, the unsaturated composition comprises at least 50% by weight free fatty acids. More preferably, the unsaturated fat composition comprises free fatty acids or free fatty acid residues derived from vegetable oils, preferably palm, palm kernel, shea, coconut, soybean, rapeseed oil, sunflower or mixtures thereof. Most preferably, the unsaturated fat composition is a palm fatty acid distillate (PFAD).

Preferably, the unsaturated fat composition comprises palmitic acid (C16:0) in an amount of from about 25 wt.% to about 60 wt.%, such as in an amount from about 40 wt.% to about 50 wt.%, more preferably from about 45 wt.% to about 50 wt.%. Stearic acid (C18:0) may preferably be present in the unsaturated fat composition in an amount of less than about 10 wt.%, more preferably from about 1 wt.% to about 5 wt.%. Furthermore, the unsaturated fat composition may preferably comprise from about 20 wt.% to about 50 wt.% oleic acid (C18:1 ), such as from about 30 wt.% to about 40 wt.% oleic acid, more preferably from about 35 wt.% to about 40 wt.% oleic acid. The unsaturated fat composition may preferably comprise less than about 20 wt.% linoleic acid (C18:2), preferably from about 5 wt.% to about 15 wt.% linoleic acid. Preferably, the unsaturated fat composition may comprise from about 1 wt.% to about 5 wt.% of Ci2 to Ci5 fatty acids. The percentages of fatty acids are based on the total Ci₂ to C₂₄ fatty acids present.

The resulting hydrogenated fat composition ideally comprises palmitic acid (C16:0) in an amount of from about 25 wt.% to about 60 wt.%, such as in an amount from about 40 wt.% to about 50 wt.%, more preferably from about 45 wt.% to about 50 wt.%. Stearic acid (C18:0) may be present in the hydrogenated fat composition in an amount from about 30 wt.% to about 60 wt.%, such as in an amount from about 40 wt.% to about 60 wt.%, more preferably from about 40 wt.% to about 55 wt.%. Furthermore, the hydrogenated fat composition may comprise less than about 10 wt.% oleic acid (C18:1), more preferably less than about 7 wt.% oleic acid. The hydrogenated fat composition may also comprise less than about 10 wt.% linoleic acid (C18:2), preferably less than about 5 wt.% linoleic acid, more preferably less than vvi. /o luicio aoiu. 1 1 ic 1 lyui uyci laicu icu ui 1 ιμυοιιιυι ι may i m u ici Cui npi ist; i i ui l l cJDUUi 1 wt.% to about 5 wt.% of C12 to C15 fatty acids. The percentages of fatty acids are based on the total C12 to C24 fatty acids present.

Preferably the unsaturated fat composition has an iodine value of from about 40 to about 60, such as from about 45 to about 55, preferably from about 45 to 50. Ideally, the hydrogenated fat composition has an iodine value of less than about 20, such as less than about 10, preferably less than 7. Iodine value is determined by AOCS Cd 1d-92.

The invention involves an increase in the saturated fatty acid (SAFA) content of the unsaturated fat composition whilst reducing or avoiding the dechlorination of OCDD. Preferably, the saturated fatty acid (SAFA) content of the unsaturated fat composition is up to about 60 wt.%, such as from about 40 to about 55 wt.%, based on the total C12 to C₂₄ fatty acids present.

Hydrogenation in the process of the invention may be partial or complete. In other words, the fatty acids present in the hydrogenated product may be only SAFA or some unsaturated fatty acids may remain. Ideally, the SAFA content of the hydrogenated fat composition is at least about 80 wt.%, such as at least about 85 wt.%, preferably at least about 90 wt.% based on the total C12 to C24 fatty acids present. The monounsaturated fatty acid (MUFA) content of the unsaturated fat composition is preferably in the range of from about 30 to about 50 wt.%, more preferably in the range of about 30 to about 40 wt.% based on the total C12 to C24 fatty acids present. The polyunsaturated fatty acid (PUFA) content of the unsaturated fat composition is preferably from about 1 to about 10 wt.%, more preferably from about 5 to about 10 wt.%, based on the total C12 to C24 fatty acids present.

The MUFA content of the hydrogenated fat composition is ideally up to about 10 wt.%, such as up to about 7 wt.% based on the total C12 to C24 fatty acids present. The polyunsaturated fatty acid (PUFA) content of the hydrogenated fat composition is preferably up to about 5 wt.%, preferably less than about 1 wt.%, based on the total C12 to C24 fatty acids present.

Also provided by the invention is a process for preventing, or reducing the level of, dechlorination of OCDD during hydrogenation of an unsaturated fat composition. Further provided by the invention is a method for maintaining or reducing the TEQ value of a hydrogenated fat composition, as determined according to EN 16215:2012, comprising the steps of:

ii) contacting the unsaturated fat composition with a catalyst and a hydrogen source at a temperature of about 170°C or lower to at least partially hydrogenate the unsaturated fat composition,

The method may comprise any of the steps or conditions described above for the process of the invention, particular aspects of which are repeated below. Preferably, the amount of OCDD in the resulting hydrogenated fat composition after step ii) is essentially equal to, or not more than 10% less than, the amount of OCDD in the unsaturated fat composition. Advantageously, the amount of OCDD in the hydrogenated fat composition after step ii) is preferably within about ±5% of (or not more than 5% less than), more preferably within about ±3% of (or not more than 3% less than), the amount of OCDD in the unsaturated fat composition. Advantageously, the amount of 2,3,7,8-tetra chlorodibenzodioxin (TCDD) in the hydrogenated fat composition after step ii) is essentially equal to (i.e., ±10%), or lower than, the amount of TCDD in the unsaturated fat composition. Ideally, the amount of TCDD in the hydrogenated fat composition after step ii) is lower than the amount of TCDD in the unsaturated fat composition. Preferably, the amount of TCDD in the hydrogenated fat composition after step ii) is within about ±8%, such as within about ±5, ±4, ±3 or ±2 % of the amount of TCDD in the unsaturated fat composition, more preferably within about ±1 %.

Conveniently, the amount of 1 ,2,3,7,8-penta chlorodibenzodioxin (PeCDD) in the hydrogenated fat composition after step ii) is essentially equal to (i.e., ±10%), or lower than, the amount of PeCDD in the unsaturated fat composition. Ideally, the amount of PeCDD in the hydrogenated fat composition after step ii) is lower than the amount of PeCDD in the unsaturated fat composition. Preferably, the amount of PeCDD in the hydrogenated fat υυι ι ιμυΰΐιιυι ι auci οισμ ii y is win in ι auuui υ /ο, suu ι ao vviu in i auuui IJ /O, j.t /o, -J /O I ±.£. /o of the amount of PeCDD in the unsaturated fat composition, more preferably within about ±1%.

Typically, the unsaturated fat composition comprises OCDD in an amount of at least about 5 ppt, such as at least about 10 ppt, by weight of the unsaturated fat composition. For example, the unsaturated fat composition may comprise OCDD in an amount of from about 5 ppt to about 100 ppt, such as from about 10 ppt to about 80 ppt, or from about 20 ppt to about 50 ppt.

Advantageously, the hydrogenated fat composition after step ii) has a toxic equivalent factor (TEQ) value that is essentially equal to, or lower than, the TEQ value of the unsaturated fat composition used in the process of the method, as determined according to EN 16215:2012, Conveniently, the TEQ value of the hydrogenated fat composition after step ii) is lower than the TEQ value of the unsaturated fat composition. Preferably, the TEQ value of the hydrogenated fat composition after step ii) is within about ±60%, such as within about ±50%, ±40%, ±30%, ±20%, ±10% or ±5% of the TEQ value of the unsaturated fat composition, more preferably within about ±2%. Conveniently, the unsaturated fat composition is contacted with a catalyst and a hydrogen source at a temperature of about 150 °C or lower, preferably at a temperature of about 140 °C or lower, more preferably at a temperature of about 130°C or lower. Preferably, the unsaturated fat composition is contacted with a catalyst and a hydrogen source at a temperature of from about 70°C to about 170°C, preferably from about 90°C to about 170°C, for example from about 00°C to about 150°C, more preferably from about 100°C to about 130°C. Advantageously, the method further comprises the step of purifying the hydrogenated fat composition.

Conveniently, the unsaturated fat composition comprises free fatty acids, monoacylglycerides, diacylglycerides, triacylglycerides, or mixtures thereof. Preferably, the unsaturated composition comprises at least 50% by weight free fatty acids.

Preferably, the unsaturated fat composition comprises fatty acids or fatty acid residues derived from vegetable oils, preferably palm, palm kernel, shea, coconut, soybean, rapeseed oil, sunflower or mixtures thereof, preferably wherein the unsaturated fat composition is a palm fatty acid distillate (PFAD).

Advantageously, the unsaturated fat composition has an iodine value of from about 40 to about 60, such as from about 45 to about 55, preferably from about 45 to 50. Conveniently, the hydrogenated fat composition has an iodine value of less than about 20, such as less than about 10, preferably less than 7.

Iodine value is determined by AOCS Cd 1d-92. The listing or discussion of an apparently prior-published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge.

Preferences and options for a given aspect, embodiment, feature or parameter of the invention should, unless the context indicates otherwise, be regarded as having been disclosed in combination with any and all preferences and options for all other aspects, embodiments, features and parameters of the invention. The following non-limiting examples illustrate the invention and do not limit its scope in any way. In the examples and throughout this specification, all percentages, parts and ratios are by weight unless indicated otherwise.

EXAMPLES

Hydrogenation Method Palm fatty acid distillate (PFAD) (2 kg, IOI Loders Croklaan, NL) was added to a 3 liter pressure vessel, equipped with a mechanical stirrer, pressure gauge and electrical heater. A Pricat 9932 nickel catalyst (0.3 wt.%) was added to the vessel. Air was removed from the vessel by vacuum and the reaction mixture was heated (130 to 200°C) and stirred. Once the required temperature was reached, the vacuum was applied again to remove any remaining gas. The stirring was stopped and the vessel was then charged with hydrogen gas to a pressure of 5 bars (500 kPa). The reaction was stirred for 1 to 2 hours. The stirring was then stopped and the remaining hydrogen gas was removed by flushing the vessel with nitrogen gas. The reaction mixture was cooled to 1 0 C, after which Hi-flow was added as a filter aid, and the reaction mixture was filtered to remove the nickel catalyst. The filtered product was heated to -110°C, bleached and filtered again, to give the final hydrogenated-PFAD product.

Example 1

A hydrogenated PFAD composition was prepared as outlined above, but before hydrogenation the PFAD was treated with activated carbon. After hydrogenation, the PFAD was bleached.

Table 2 shows the dioxin content of the fat composition at varying times during the process. Specifically, the dioxin levels are detailed for the PFAD feedstock composition (PFAD), the PFAD composition following treatment with activated carbon (PFAD AC), the PFAD composition following treatment with activated carbon and hydrogenation at 130°C (H[PFAD AC]- 130), and further following bleaching (bH[PFAD AC]-130).

Activated carbon treatment appeared to lower the amount of OCDD and HpCDD slightly. After hydrogenation, OCDD concentrations slightly decreased and HpCDD slightly increased. The bleaching step had little effect on the concentrations of PCDDs. Lower, more potent dioxin concentrations remained substantially unaffected throughout the entire process. Table 2

The fatty acid components of the unsaturated PFAD fatty acid composition and resulting fat composition after treatment with activated carbon and hydrogenation are detailed below in Table 3. Fatty acid content was analysed by GC-FAME analysis according to ISO 15304.

Table 3

Before hydrogenation, the PFAD starting material predominantly comprised palmitic acid and oleic acid. After hydrogenation, palmitic acid content remained largely unaffected, whereas the oleic acid content significantly reduced and the stearic acid content respectively increased. Example 2

A hydrogenated PFAD composition was prepared as outlined above, wherein the PFAD starting material was first hydrogenated at 130°C (H[PFAD]-130), then subsequently bleached (bH[PFAD]-130) and treated with activated carbon (bH[PFAD ACJ-130).

Table 4 shows the dioxin levels of the fat composition at varying times during the process. Hydrogenation at 130°C appeared to have no effect on OCDD concentrations of the fat composition. Concentrations of the most potent dioxins also remained unaffected by the process.

Table 4

The fatty acid components of the fat composition during various stages of treatment are detailed below in Table 5. Fatty acid content was analysed by GC-FAME analysis according to ISO 15304.

Table 5

C18:3 0.4 0.0

C20:0 0.3 0.4

C20:1 0.1 0.0

C22:0 0.0 0.0

SAFA 52.2 99.1

MUFA 38.1 0.8

PUFA 9.6 0.1

Iodine Value 49.7 0.8

The composition of the fat before and after hydrogenation at 130°C is predominantly the same as detailed in Table 2 of Experiment 1. Example 3

The process of Example 2 was repeated with another batch of PFAD starting material.

Table 6 shows the dioxin levels of the fat composition at varying times during the process. The PFAD starting material appears to contain higher concentrations of OCDD compared to the PFAD starting material of Example 2. However, these levels remained within GMP regulations. As with Example 2, hydrogenation at 130°C had little effect on PCDD concentrations overall. Table 6

The fatty acid components of the fat composition during various stages of this treatment are detailed below in Table 7. Fatty acid content was analysed by GC-FAME analysis according to ISO 15304. Table 7

Example 4 - Control This example corresponds to the process of Example 2. However, in this example the hydrogenation step was performed at 200°C (H[PFAD]-200), the product was then subsequently bleached (bH[PFAD]-200) and treated with activated carbon (bH[PFAD AC]- 200).

Table 8 shows the dioxin levels of the fat composition at varying times during the process. Hydrogenation at 200°C resulted in a significant decrease in the concentration of OCDD with a corresponding rise in more toxic PCDD species, especially hepta- and hexa-CDDs. Bleaching after hydrogenation at 200°C decreased the concentration of 1 ,2,3,7,8,9-HxCDD and increased the concentrations of 1 ,2,3,6, 7,8-HxCDD, 1 ,2,3,4,7,8-HxCDD and, more siy I in iudi iLiy, u ic i nui c IUAIL, rouuu,

Table 8

1 ,2,3,6,7,8-HxCDD <0.0500 0.200 <0.250 <0.0500

1 ,2,3,7,8,9-HxCDD <0.0500 0.717 0.265 <0.0500

1 ,2,3,4,6,7,8-HpCDD 1.09 3.28 3.51 1.26

OCDD 16.3 <2.00 <2.00 <2.00

TEQ 0.131 0.235 0.375 0.128

The fatty acid components of the fat composition during various stages of this treatment are detailed below in Table 9. Fatty acid content was analysed by GC-FAME analysis according to ISO 15304.

Table 9

Claims

1. A process for the preparation of a hydrogenated fat composition, comprising the steps of:

ii) contacting the unsaturated fat composition with a catalyst and a hydrogen source at a temperature of about 170°C or lower to at least partially hydrogenate the unsaturated fat composition.

2. The process according to Claim 1 , wherein the amount of OCDD in the hydrogenated fat composition after step ii) is within about ±10% of the amount of OCDD in the unsaturated fat composition.

3. The process according to Claim 1 or 2, wherein the amount of 2,3,7,8-tetra chlorodibenzodioxin (TCDD) in the hydrogenated fat composition after step ii) is essentially equal to (i.e., ±10%), or lower than, the amount of TCDD in the unsaturated fat composition.

4. The process according to any preceding claim, wherein the amount of 1 ,2,3,7, 8-penta chlorodibenzodioxin (PeCDD) in the hydrogenated fat composition after step ii) is essentially equal to (i.e., ±10%), or lower than, the amount of PeCDD in the unsaturated fat composition.

5. The process according to any preceding claim, wherein the unsaturated fat composition comprises OCDD in an amount of at least about 5 ppt, such as at least about 10 ppt, by weight of the unsaturated fat composition, for example, the unsaturated fat composition may comprise OCDD in an amount of from about 5 ppt to about 100 ppt, such as from about 10 ppt to about 80 ppt, more preferably from about 20 ppt to about 50 ppt.

6. The process according to any preceding claim, wherein the hydrogenated fat composition after step ii) has a toxic equivalent factor (TEQ) value that is essentially equal to (i.e. ±60%), or lower than, the TEQ value of the unsaturated fat composition, as determined according to EN 16215:2012.

7. The process according to any preceding claim, wherein the unsaturated fat composition is contacted with a catalyst and a hydrogen source at a temperature of about 150°C or lower, preferably at a temperature of about 140°C or lower, more preferably at a temperature of 125 to 135°C.

8. The process according to anyone of Claims 1 to 6, wherein the unsaturated fat composition is contacted with a catalyst and a hydrogen source at a temperature of from about

70°C to about 170°C, preferably from about 90°C to about 170°C, for example from about 100°C to about 150°C, more preferably from about 100°C to about 130°C.

9. The process according to any preceding claim, wherein the process further comprises the step of purifying the hydrogenated fat composition.

10. The process according to any preceding claim, wherein the unsaturated fat composition comprises free fatty acids, monoacylglycerides, diacylglycerides, triacylglycerides, or mixtures thereof.

11. The process according to any preceding claim, wherein the unsaturated fat composition comprises fatty acids or fatty acid residues derived from vegetable oils, preferably palm, palm kernel, shea, coconut, soybean, rapeseed oil, sunflower or mixtures thereof, preferably wherein the unsaturated fat composition is a palm fatty acid distillate (PFAD).

12. The process according to any preceding claim, wherein the unsaturated fat composition has an iodine value of from about 40 to about 60, such as from about 45 to about 55, preferably from about 45 to 50.

13. The process according to any preceding claim, wherein the hydrogenated fat composition has an iodine value of less than about 20, such as less than about 10, preferably less than 7.

14. Process according to any preceding claim for preventing, or reducing the level of, dechlorination of OCDD during hydrogenation of an unsaturated fat composition.

15. A method for maintaining or reducing the TEQ value of a hydrogenated fat composition, as determined according to EN 16215:2012, comprising the steps of: