Prevention of MCPD formation in triacylglyceride oils

Abstract

(a) removing insoluble components in the liquid raw triacylglyceride oil by (i) applying centrifugal force to the triacylglyceride oil while maintaining the triacylglyceride oil above its melting temperature; and / or (ii) concentrating the triacylglyceride oil by allowing the insoluble components to settle by gravity while maintaining the triacylglyceride oil above its melting temperature, (b) separating the triacylglyceride oil from the insoluble components, (c) optionally applying an additional purification step, and (d) applying a heat treatment to the triacylglyceride oil. Also provided is a clarified triacylglyceride oil obtainable by the method of the present invention.

Description

Detailed Description of the Invention

[0001] [Technical field] The present invention relates to oil purification, in particular to the mechanical purification of triacylglyceride oils to reduce or completely remove monochloropropanediol esters (MCPDEs) from the refined oil.

[0002] [Background technology] 3-Halogen-1,2-propanediols, especially 3-monochloro-1,2-propanediol (3-MCPD), are known contaminants in food (Food Addit. Contam. (2006) 23:1290-1298). For example, various studies have shown that 3-MCPD can be carcinogenic to rats when administered in high doses (Evaluation of Certain Food Additives and Contaminants, World Health Organisation, Geneva, Switzerland (1993) 267-285; lnt. J. Toxicol. (1998) 17:47).

[0003] 3-MCPD was originally discovered in acid hydrolyzed vegetable proteins (acid-HVP; Z. Lebensm.-Unters. Forsch. (1978) 167:241-244). More recently, refined edible oils have been found to contain 3-MCPD in the fatty acid ester form, but in very small amounts of free 3-MCPD (Food Addit. Contam. (2006) 23:1290-1298). The European Food Safety Authority (EFSA) recommends that 3-MCPD esters be treated equivalently to free 3-MCPD from a toxicity standpoint (European Food Safety Authority (2008)).

[0004] It has been reported that chlorination of acylglycerides can occur at very high temperatures, for example during the final step of the oil refining process, i.e., deodorization, where the oil can be heated up to 260-270° C. under vacuum (3-7 mbar). This can result in the formation of fatty acid esters of MCPD.

[0005] There are limited means for efficient reduction of MCPD esters, posing a challenge to the vegetable oil refining industry. Currently, to ensure full compliance with EFSA's recommendations, the presence of 3-MCPD in essential oils is carefully monitored, and oils with 3-MCPD content above a certain threshold are discarded.

[0006] Because 3-MCPD can occur in many commercially important refined oils, such as vegetable oils, there is a particular need for improved methods of removing and / or avoiding the production of such contaminants during oil refining.

[0007] [Summary of the Invention] The present inventors have devised a method by which the formation of MCPD and MCPD esters (MCPDE, including mono- and diesters) during the process of oil refining can be substantially reduced or prevented.

[0008] The principle of this method is to utilize a mechanical process based on gravity and / or centrifugal force that allows the physical separation of insoluble chlorine or chloride-containing substances from the oil to be purified. As a result, the insoluble chlorine or chloride-containing substances that potentially serve as chlorine sources are concentrated in the sedimentation fraction of the oil and can therefore be separated from the oil to be refined. The method of the present invention can be applied to unrefined or partially refined triacylglycerol (also called triacylglyceride) oils, including but not limited to palm oil, palm stearin, palm olein, and their various fractions, palm kernel oil, coconut oil, sunflower oil, high oleic sunflower oil, and their variants, canola / rapeseed oil, soybean oil, fish oil, algae oil, cocoa butter, and any mixture / blend thereof.

[0009] Mechanical treatment may include centrifugation and / or sedimentation, either before, during, or after any other clarification, refining, or deodorization steps.

[0010] Once the potential chlorine sources are removed, they are no longer available for the formation of chlorinated compounds such as MCPD, MCPD monoesters, and MCPD diesters during the heating step of oil refining, thereby resulting in a product oil with reduced chlorine-bearing materials, which can be subjected to various refining procedures such as thermal treatment and deodorization with the goal of producing a refined oil with reduced or no MCPD and MCPDEs.

[0011] A further advantage of the method of the present invention is that it allows the use of lower temperatures in the deodorization of oil, i.e. 1) Reducing the formation of trans fatty acids (the formation of trans fats at high temperatures is reported in Baley's industrial oil and fat products; Sixth Edition; Volume 5 Edible Oil and Fat Products: Processing Technologies; Chapter 8 Deodorization; section 3. Refined oil quality, subsection 3.2 Fat isomerization and degradation products).

[0012] 2) reduce the formation of glycidyl esters (see overview of GE removal methods in “Glycidyl fatty acid esters in refined edible oils: a review on formation, occurrence, analysis, and elimination methods” in Comprehensive Reviews in Food Science and Food Safety; vol. 16, 263-281; ​​2017).

[0013] Thus, in one aspect, the present invention provides a method for preventing or reducing the formation of monochloropropanediol (MCPD) or monochloropropanediol esters (MCPDE) in a triacylglyceride oil, comprising: (a) Removing insoluble components from a liquid raw triacylglyceride oil, 1. by subjecting the raw triacylglyceride oil to centrifugal force while maintaining the raw triacylglyceride oil above its melting temperature; and / or 2. Concentrating the triacylglyceride oil by maintaining it above its melting temperature while allowing the insoluble components to settle by gravity; (b) separating the triacylglyceride oil from the insoluble components; (c) optionally applying one or more processes selected from physical refining, chemical refining, degumming, neutralization, interesterification, bleaching, winterization or fractionation, in any combination; (d) applying a heat treatment to the triacylglyceride oil.

[0014] In some embodiments, insoluble components include, for example, particulates, separated droplets, emulsions, suspensions, and sediments.

[0015] In another embodiment, the thermal treatment is deodorization (steam distillation or short path distillation).

[0016] In another embodiment, the heat treatment is carried out in a closed vessel.

[0017] In one embodiment, the heat treatment application step removes unwanted components, which may be color pigments, free fatty acids, monoglycerides, trace contaminants and / or odors.

[0018] In some embodiments, prior to step (a), the starting triacylglyceride oil is melted by heating above its melting temperature.

[0019] Thus, in one aspect, the present invention provides a method for preventing or reducing the formation of monochloropropanediol (MCPD) or monochloropropanediol esters (MCPDE) in a triacylglyceride oil, comprising: (e) melting the feed triacylglyceride oil by heating above its melting temperature; (f) removing insoluble components from the liquid triacylglyceride oil; 1. by subjecting the triacylglyceride oil to centrifugal force while maintaining the triacylglyceride oil above its melting temperature; and / or 2. Concentrating the triacylglyceride oil by maintaining it above its melting temperature while allowing the insoluble components to settle by gravity; (g) separating the triacylglyceride oil from the insoluble components; (h) optionally applying one or more processes selected from physical refining, chemical refining, degumming, neutralization, interesterification, bleaching, winterization or fractionation, in any combination; (i) applying a heat treatment to the triacylglyceride oil.

[0020] In some embodiments, insoluble components include, for example, particulates, separated droplets, emulsions, suspensions, and sediments.

[0021] In one embodiment, the present invention provides a method for preventing or reducing the formation of monochloropropanediol (MCPD).

[0022] In one embodiment, the present invention provides a method for preventing or reducing the formation of monochloropropanediol esters (MCPDEs).

[0023] In one embodiment, in step (a) or (f), centrifugal force is applied to the triacylglyceride oil while maintaining the triacylglyceride oil above its melting temperature.

[0024] In one embodiment, in step (a) or (f), the triacylglyceride oil is maintained above its melting temperature while the insoluble components are allowed to settle by gravity.

[0025] In one embodiment, step (a2) is performed and then step (a1) is performed.

[0026] In one embodiment, step (a1) is performed and then step (a2) is performed.

[0027] In one embodiment, step (f2) is performed and then step (f1) is performed.

[0028] In one embodiment, step (f1) is performed and then step (f2) is performed.

[0029] In one embodiment, applying a heat treatment comprises exposing the oil to a temperature in the range of 150-300°C, more usually in the range of 160-290°C or 160-240°C, preferably for at least 30 minutes.

[0030] In one embodiment, the starting triacylglyceride oil is palm oil and the heat treatment step comprises exposing the oil to a temperature in the range of 160-290°C.

[0031] In one embodiment, the starting triacylglyceride oil is sunflower oil and the heat treatment step comprises exposing the oil to a temperature in the range of 160-240°C.

[0032] In another embodiment, the thermal treatment is deodorization (steam distillation or short path distillation).

[0033] In another embodiment, the heat treatment is carried out in a closed vessel.

[0034] In one embodiment, the heat treatment application step removes unwanted components, which may be color pigments, free fatty acids, monoglycerides, trace contaminants and / or odors.

[0035] In one embodiment, the amount of monochloropropanediol (MCPD) or monochloropropanediol esters (MCPDE) in the heat treated oil of step (d) or step (i) is measured.

[0036] In one embodiment, the amount of monochloropropanediol (MCPD) or monochloropropanediol esters (MCPDE) in the heat treated oil of step (d) or step (i) is measured directly by LC-MS.

[0037] In one embodiment, the amount of MCPDE in the thermally treated oil of step (d) or step (i) is reduced by at least 2-fold as measured by direct LC-MS.

[0038] In one embodiment, the feed triacylglyceride oil in step (a) or step (e) is a crude triacylglyceride oil.

[0039] In one embodiment, the starting triacylglyceride oil is not degummed prior to step (a) or step (e). In one embodiment, the starting triacylglyceride oil is not decolorized prior to step (a) or step (e). In one embodiment, the starting triacylglyceride oil is not fractionated prior to step (a) or step (e).

[0040] In a preferred embodiment, the starting triacylglyceride oil is not deodorized prior to step (a) or step (e).

[0041] In one embodiment, the feed triacylglyceride oil is subjected to a pre-wash prior to step (a) or step (e). In one embodiment, the feed triacylglyceride oil is subjected to a pre-refining prior to step (a) or step (e). In one embodiment, the feed triacylglyceride oil is subjected to fractionation prior to step (a) or step (e). In one embodiment, the feed triacylglyceride oil is subjected to hydrogenation prior to step (a) or step (e). In one embodiment, the feed triacylglyceride oil is subjected to interesterification prior to step (a) or step (e).

[0042] In one embodiment, the source triacylglyceride oil is a vegetable oil, an animal oil, a fish oil, or an algae oil.

[0043] In one embodiment, the starting triacylglyceride oil is crude palm oil and the process is applied starting from step (e).

[0044] In one embodiment, the starting triacylglyceride oil is a crude seed oil and the method is applied starting from step (a). For example, the crude seed oil can be sunflower oil, canola / rapeseed oil, corn oil.

[0045] In a preferred embodiment, the starting triacylglyceride oil is a vegetable oil, preferably the vegetable oil is selected from the group consisting of palm oil, sunflower oil, corn oil, canola oil, soybean oil, coconut oil, palm kernel oil, and cocoa butter. In one embodiment, the starting triacylglyceride oil is palm oil. In one embodiment, the triacylglycerol oil is sunflower oil or a high oleic variant thereof.

[0046] In one embodiment, the starting triacylglyceride oil has a free fatty acid content of 0.5-25% (wt / wt%), or a free fatty acid content of 1-12% (wt / wt%), or a free fatty acid content of 3-7% (wt / wt%).

[0047] In another embodiment, the starting triacylglyceride oil has a free fatty acid content of at least 0.5% (w / w), preferably 1% (w / w), more preferably 3% (w / w).In another embodiment, the starting triacylglyceride oil has a free fatty acid content of less than 25% (w / w), preferably less than 15% (w / w), more preferably less than 10% (w / w).

[0048] In one embodiment, the starting triacylglyceride oil is not mixed with any alkali, such as sodium hydroxide or potassium hydroxide, or with any products that contain sodium hydroxide or potassium hydroxide, such as caustic soda, caustic potash, etc. In another embodiment, the starting triacylglyceride oil is not mixed with any ammonium hydroxide or any ammonium salts.

[0049] In one embodiment, the starting triacylglyceride oil is not mixed with salts, such as sodium, potassium, or ammonium salts. Examples of sodium salts include sodium chloride, sodium hypochlorite, sodium carbonate, sodium formate, sodium citrate, and sodium phosphate.

[0050] In another embodiment, the starting triacylglyceride oil has a soap content of less than 1000 ppm. In another embodiment, the starting triacylglyceride oil has a soap content of less than 20 ppm. In another embodiment, the starting triacylglyceride oil is soap-free.

[0051] In one embodiment, the raw triacylglyceride oil has not been acidified or subjected to acid degumming.

[0052] In another embodiment, the starting triacylglyceride oil is not mixed with acids less than 195 Da. In a preferred embodiment, the starting triacylglyceride oil is not mixed with acids less than 195 Da that have an anhydrous form.

[0053] In another embodiment, the starting triacylglyceride oil does not contain more than 0.01% of acids less than 195 Da. In another embodiment, the starting triacylglyceride oil does not contain more than 0.01% of acids having an anhydrous form less than 195 Da.

[0054] In another embodiment, the starting triacylglyceride oil does not contain more than 0.01% of acids having a logP<1. In another embodiment, the starting triacylglyceride oil does not contain more than 0.01% of acids having an acidity pKa1<5.

[0055] In another embodiment, the raw triacylglyceride oil is substantially free of any one of phosphoric acid, citric acid, sodium hydroxide, potassium hydroxide, boric acid, hypochloric acid, and hydrochloric acid. As used herein, sodium hydroxide may refer to caustic soda or alkali, and potassium hydroxide may refer to alkali potash.

[0056] In another embodiment, the starting triacylglyceride oil is substantially free of any one of phosphoric acid, citric acid, sodium chloride, sodium carbonate, sodium hydroxide, potassium hydroxide, phosphates, polyphosphates, acetic acid, acetic anhydride, calcium sulfate, calcium carbonate, sodium sulfate, boric acid, hypochlorous acid, hydrochloric acid, and tannic acid.

[0057] In another embodiment, the starting triacylglyceride oil is substantially free of any added ionic, cationic, and anionic surfactants, hi another embodiment, the starting triacylglyceride oil is substantially free of any emulsifiers, such as sorbitan esters or polyglycerol esters.

[0058] In another embodiment, the starting triacylglyceride oil is substantially free of any additives listed in Bailey's Industrial Oil and Fat Products-6th edition, page 2236 in Chapter Emulsifiers for the food industry-Table 4, page 262, such as sucrose, glycol, propylene glycol, and / or lactylic acid.

[0059] In one embodiment, the raw triacylglyceride oil has not been subjected to water degumming or wet degumming.

[0060] In another embodiment, the starting triacylglyceride oil has a moisture content of less than 1%, or less than 0.5%, or less than 0.3%, and in one embodiment, the starting triacylglyceride oil has a moisture content of less than 1%, or less than 0.5%, or less than 0.3%.

[0061] In a preferred embodiment, the starting triacylglyceride oil is not mixed with any water and has a moisture content of less than 0.5%.

[0062] In another embodiment, the starting triacylglyceride oil does not contain added water.

[0063] In one embodiment, the starting triacylglyceride oil has a bleaching clay content of less than 0.01%. In another embodiment, the starting triacylglyceride oil is not mixed with bleaching clay. In another embodiment, the starting triacylglyceride oil is free of bleaching clay.

[0064] In one embodiment, the starting triacylglyceride oil is not bleached. In another embodiment, the starting triacylglyceride oil is not degummed. In another embodiment, the starting triacylglyceride oil is not neutralized.

[0065] In another embodiment, the starting triacylglyceride oil does not contain added crystallization agents, such as solvents. Such solvents may include hexane, acetone, and detergents as described in [The Lipid Handbook-Third Edition; edited by Frank D. Gunstone; Chapter 4.4.2.] and [Bailey's Industrial Oil and Fat Products-6th edition, Chapter 12] or sorbitan esters or polyglycerol fatty acid esters as described in [Omar et al Journal of Oil Palm Research Vol.27(2)June 2015 p.97-106]. The starting triacylglyceride oil may be crude palm oil.

[0066] In another embodiment, the starting triacylglyceride oil is not winterized.

[0067] In another embodiment, the starting triacylglyceride oil does not contain added substances, such as degumming agents, neutralizing agents, additives, solvents, salts, seeding agents, acids, bases, or buffers.

[0068] In another embodiment, the starting triacylglyceride oil is crude palm oil and does not contain added substances such as degumming agents, neutralizing agents, additives, solvents, salts, seeding agents, acids, bases, or buffers.

[0069] In one embodiment, the raw triacylglyceride oil is centrifuged directly after melting, without additional cooling or gentle agitation.

[0070] In one embodiment, the starting triacylglyceride oil has a crystallized triacylglycerol content of less than 10% (w / w). In another embodiment, the starting triacylglyceride oil has a crystallized triacylglycerol content of less than 5% (w / w). In one embodiment, the starting triacylglyceride oil has a crystallized triacylglycerol content of less than 2% (w / w). In one embodiment, the starting triacylglyceride oil has a crystallized triacylglycerol content of less than 0.5% (w / w).

[0071] As used herein, crystallized triacylglycerol refers to solid triacylglycerol or the solid portion of fat. The solid fat content of fats and oils can be determined by pulsed nuclear magnetic resonance [Bailey's Industrial Oil and Fat Products-6th edition, page 175 Chapter 5.2.1.].

[0072] In another embodiment, the starting triacylglyceride oil has not been cooled below 20°C, 15°C, or 10°C.

[0073] In one embodiment, centrifugation is carried out at a relative centrifugal force of more than 100 g, or more than 200 g, or more than 1000 g, or more than 2000 g, or more than 5000 g, or more than 10000 g.

[0074] In another embodiment, centrifugation is carried out at a relative centrifugal force of less than 15000 g, or less than 10000 g, or less than 5000 g, or less than 2000 g, or less than 1000 g, or less than 200 g.

[0075] In one embodiment, the method further comprises one or more of the following steps following step (d) or step (i):

[0076] (j) one or more processes selected from the group consisting of physical or chemical refining, degumming, neutralization, and decolorization; (k) optionally deodorizing the product of step (j), preferably wherein the deodorization is vacuum steam deodorization; and (l) optionally, fractionating the product of step (j) and step (k).

[0077] In another aspect, there is provided a clarified triacylglyceride oil obtainable by the process of the present invention.

[0078] In one embodiment, as a result of purification, chlorine or chloride bearing substances in the range of 600-800 m / z are preferably reduced by at least 2-fold in the purified triacylglyceride oil compared to the starting unpurified triacylglyceride oil, as evidenced by their LC-MS signals.

[0079] In one embodiment, the amount of monochloropropanediol esters (MCPDEs) in the heat-treated clarified oil is reduced by 2-fold compared to the heat-treated unclarified oil, as measured by direct LC-MS.

[0080] In one embodiment, the amount of monochloropropanediol esters (MCPDEs) in the heat-treated clarified, sediment-free upper phase oil is at least 30% lower compared to the heat-treated, sediment-containing lower phase oil, as measured by direct LC-MS.

[0081] In one embodiment, the amount of monochloropropanediol esters (MCPDEs) in the heat-treated clarified, sediment-free upper phase oil is at least two-fold, preferably five-fold, greater than that of the heat-treated, sediment-containing lower phase oil, as measured by direct LC-MS.

[0082] In one embodiment, the amount of monochloropropanediol (MCPD) in the heat treated clarified oil is reduced by a factor of two as compared to the heat treated unclarified oil as measured by direct LC-MS.

[0083] In one embodiment, the amount of monochloropropanediol (MCPD) in the heat-treated clarified, sediment-free upper phase oil is at least 30% lower as compared to the heat-treated, sediment-containing lower phase oil, as measured by direct LC-MS.

[0084] In one embodiment, the amount of monochloropropanediol (MCPD) in the heat-treated clarified, sediment-free upper phase oil is at least two-fold, preferably five-fold, as compared to the heat-treated, sediment-containing lower phase oil, as measured by direct LC-MS.

[0085] There is also provided a clarified triacylglyceride oil according to the present invention for use in making a food product.

[0086] Food products produced by using the clarified triacylglyceride oil according to the present invention are also provided. [Brief description of the drawings]

[0087] [Figure 1] 1 shows the beneficial effect of centrifugation-based reduction of dipalmitoyl-MCPD, PP-MCPD. [Diagram 2] 1 shows the beneficial effect of centrifugation-based reduction of palmitoyl-oleyl-MCPD. [Diagram 3] 1 shows the beneficial effect of centrifugation-based reduction of Dioleyl-MCPD. [Figure 4]1 shows the beneficial effect of centrifugation-based reduction of oleyl-linoleyl-MCPD. [Diagram 5] 1 shows the beneficial effect of centrifugation-based reduction of Dioleyl-MCPD. [Figure 6] 1 shows the beneficial effect of centrifugation-based reduction of oleyl-linoleyl-MCPD. [Figure 7] 1 shows the beneficial effect of centrifugation-based reduction of dilinoleyl-MCPD. [Figure 8] 1 shows the beneficial effect of centrifugation on MCPDE concentrations observed in heated "crude industrially produced palm oil." [Figure 9] MCPDE observed in heated bottom and top phases of "industrially produced crude corn oil" after extended settling. [Figure 10] MCPDE observed in heated lower and upper phases of "industrially produced crude sunflower oil" after prolonged settling. [Figure 11] MCPDE observed in heated lower and upper phases of "cold pressed crude canola oil" after short-term settling. [Figure 12] MCPDE observed in heated bottom and top phases of “industrially produced crude soybean oil” after prolonged settling. [Figure 13] MCPDE observed in heated lower and upper phases of “solvent extracted crude sunflower oil” after extended settling. [Figure 14] MCPDE observed in the heated lower and upper phases of “industrially produced palm oil” after centrifugation. [Figure 15]The enrichment effect of centrifugation-based reduction at two different relative centrifugal forces is shown. At 15000g, the bottom 10% of the centrifuged oil produces an approximately 12-fold higher MCPDE concentration compared to the top 10%. In contrast, at 4000g, the enrichment efficiency is weaker and the difference in MCPD concentration observed between the bottom and top 10% drops by a factor of 6. (PP-dipalmitoyl-MCPD, PO-palmitoyl-oleyl-MCPD, PL-palmitoyl-linoleyl-MCPD, OO-dioleyl-MCPD, OL-oleyl-linoleyl-MCPD) [Figure 16] The thickening effect of centrifugation is shown for degummed palm oil. These results are also shown after the degumming process. Adding centrifugation as described herein has a thickening effect, showing about twice as much MCPDE in the bottom 10% of the centrifuged oil compared to the top 10%. (PP-dipalmitoyl-MCPD, PO-palmitoyl-oleyl-MCPD, PL-palmitoyl-linoleyl-MCPD, OO-dioleyl-MCPD, OL-oleyl-linoleyl-MCPD)

[0088] [Mode for carrying out the invention] As used herein, the terms "comprising," "comprises," and "comprised of" are synonymous with "including" or "includes" and are inclusive or open-ended and do not exclude additional, unrecited members, elements, or steps. The terms "comprising," "comprises," and "comprised of" also include the terms "consisting of," "containing," or "contains."

[0089] purification Purification is particularly suitable for removing from the raw triacylglyceride oil insoluble fractions of oil that may contain chlorine / chloride-bearing contaminants (substances that may act as a chlorine source necessary for the formation of monochloropropanediol (MCPD) or monochloropropanediol esters (MCPDE)). Raw triacylglyceride oil as used herein throughout this specification is taken to mean the triacylglyceride oil immediately before being subjected to step (a) or step (e) of the process of the present invention.

[0090] The method of the present invention involves subjecting the raw triacylglyceride oil to a treatment to physically remove the insoluble fraction of the oil containing chloride / chlorine-bearing substances that may be active sources of chlorine during oil refining from the raw oil (e.g., crude oil). This treatment may be based on centrifugation or sedimentation, as centrifugal force or gravity allows fine particles, separated droplets, and sediment to be concentrated in the narrow space of a storage vessel, and then the pure oil of the upper phase can be removed.

[0091] 3-Halogen-1,2-propanediols, especially 3-monochloro-1,2-propanediol (3-MCPD), are known contaminants in food (Food Addit. Contam. (2006) 23:1290-1298). For example, various studies have shown that 3-MCPD can be carcinogenic to rats when administered in high doses (Evaluation of Certain Food Additives and Contaminants, World Health Organisation, Geneva, Switzerland (1993) 267-285; lnt. J. Toxicol. (1998) 17:47). However, it has also been found that refined edible oils may contain 3-MCPD in its fatty acid ester form, while free 3-MCPD may only be present in very small amounts (Food Addit. Contam. (2006) 23:1290-1298). The European Food Safety Authority (EFSA) recommends that, from a toxicity standpoint, 3-MCPD esters be treated equally to free 3-MCPD (European Food Safety Authority (2008)).

[0092] It is well known that dehalogenation reactions can occur during thermal processes. For example, it has been shown that chlorine leaves behind its chemical moiety as hydrogen chloride (gas) when abundant and sufficient activation energy is input during deodorization of vegetable oils at high temperatures (e.g., up to 270°C). The inventors believe that hydrogen chloride can be generated during oil refining from chlorine-containing compounds that are inherently present in the feedstock, e.g., plant material, of the triacylglyceride oil refining process.

[0093] In fact, it has been suggested that the MCPD formation reaction increases exponentially (above 150°C) and is completed in a short time.

[0094] Without wishing to be bound by theory, it has been suggested that mechanistically, MCPD diesters may be formed during oil refining via protonation of the terminal ester groups of triacylglycerides (TAGs), which represent approximately 88%-95% of the total glycerides in most vegetable oils, i.e., by interaction with hydrogen chloride generated during oil refining. The oxonium cations formed can then undergo intramolecular rearrangement followed by nucleophilic displacement of chloride ions to release free fatty acids and MCPD diesters.

[0095] Once removed through the use of the method of the present invention, the potential chlorine source is no longer available for the formation of chlorinated compounds such as MCPD esters during the heating step of oil refining, thereby resulting in a purified product oil that produces reduced amounts of monochloropropanediol (MCPD) or monochloropropanediol esters (MCPDE) when subjected to various refining steps involving thermal treatment, e.g., deodorization, compared to unpurified refined triacylglyceride oil.

[0096] In another embodiment, the amount of monochloropropanediol esters (MCPDEs) is reduced by at least 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 99% in the clarified and thermally treated triacylglyceride oil compared to the raw triacylglyceride oil.

[0097] Refined oils produced using the methods of the present invention may contain, for example, less than 3 ppm, less than 1 ppm, less than 0.5 ppm, or preferably less than 0.3 ppm MCPDE.

[0098] In another embodiment, the amount of monochloropropanediol (MCPD) is reduced by at least 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 99% in the clarified and thermally treated triacylglyceride oil compared to the raw triacylglyceride oil.

[0099] Refined oils produced using the methods of the present invention may contain, for example, less than 3 ppm, less than 1 ppm, less than 0.5 ppm, or preferably less than 0.3 ppm MCPD.

[0100] The amount of MCPDE can be easily analyzed using protocols well known in the art. For example, as shown in this example, a liquid chromatography / mass spectrometry (LC / MS)-based approach is suitable for analyzing the concentration of MCPDE.

[0101] In one embodiment, the feed triacylglyceride oil input in step (a) or step (e) of the process of the present invention is a crude triacylglyceride oil.

[0102] As used herein, the term "crude oil" may refer to unrefined oil. For example, in some embodiments, the raw triacylglyceride oil input in step (a) or step (e) of the method of the present invention has not been refined, degummed, bleached, and / or fractionated. In a preferred embodiment, the raw triacylglyceride oil has not been deodorized before step (a) or step (e).

[0103] In some embodiments, the starting triacylglyceride oil is subjected to a pre-treatment, such as pre-washing, prior to step (a) or step (e). However, any process performed on the starting triacylglyceride oil prior to step (a) or step (e) preferably does not include heating the triacylglyceride oil to a temperature greater than 100° C., 150° C., 200° C., or 250° C. In some embodiments, the triacylglyceride oil is subjected to pre-refining, fractionation, hydrogenation, and / or transesterification prior to step (a) or step (e).

[0104] Triacylglyceride Oil The term "triacylglyceride" can be used interchangeably with "triacylglycerol" and "triglyceride." In these compounds, each of the three hydroxyl groups of glycerol is esterified with a fatty acid. Oils that can be purified using the methods of the present invention include triacylglycerides, including vegetable oils, animal oils, fish oils, algae oils, and combinations thereof.

[0105] In a preferred embodiment, the starting triacylglyceride oil is a vegetable oil, such as sunflower oil, corn oil, canola oil, soybean oil, coconut oil, palm oil, palm kernel oil, and cocoa butter.

[0106] In another embodiment, the starting triacylglyceride oil is palm oil or a fractionated palm oil, such as palm olein, palm stearin, or a mid fraction.

[0107] In a preferred embodiment, the source triacylglyceride oil is a crude vegetable oil.

[0108] In another preferred embodiment, the starting triacylglyceride oil is crude palm oil or a fractionated crude palm oil such as crude palm olein, crude palm stearin, crude mid-fraction.

[0109] In one embodiment, the vegetable oil is crude palm oil. In one embodiment, the vegetable oil is crude corn oil. In one embodiment, the vegetable oil is crude sunflower oil. In one embodiment, the vegetable oil is crude cold pressed canola oil. In one embodiment, the vegetable oil is crude soybean oil.

[0110] In a preferred embodiment, the vegetable oil is at least partially solvent extracted. Preferably, the solvent is a mixture of 2-propanol and n-hexane.

[0111] In one embodiment, the vegetable oil is solvent extracted crude sunflower seed oil.

[0112] In one embodiment, the vegetable oil is solvent extracted crude canola seed oil.

[0113] Crude triacylglyceride oil In the case of palm oil, crude oil can be produced from different parts of the palm fruit, for example from the flesh of the fruit known as the mesocarp, and also from the seed or kernel of the fruit. Extraction of crude palm oil (CPO) from the crushed fruit can be carried out, for example, at temperatures ranging from 90 to 140°C.

[0114] In other cases, for example, crude sunflower oil is produced by pressing, by solvent extraction or a combination thereof, as described, for example, in Gotor & Rhazi in Oilseeds & fats Crops and lipids 2016 (DOI: 10.1051 / ocl / 2016007).

[0115] refined oil As used herein, the term "refined" may refer to oil that has been subjected to a process that improves the quality of the oil, including heat treatment. The heat treatment may be a deodorization process that includes steam distillation or short path distillation. Such heat treatment may be applied in the range of 150-300°C, more commonly in the range of 160-260°C or 160-240°C.

[0116] Heat Treatment As used herein, the term "thermal treatment" may refer to exposing the oil to temperatures in the range of 150-300° C., more commonly in the range of 160-260° C. or 160-240° C. Thermal treatment may be applied in a closed vessel or ampoule, or in combination with vacuum and / or steam, as occurs during industrial settings (steam distillation or short path distillation) during deodorization.

[0117] Chlorine and Chlorides Chlorine is a chemical element with the symbol Cl and atomic number 17. Chlorine can be found in a wide variety of substances in both ionic (e.g., sodium chloride) and covalent (e.g., polyvinyl chloride) forms. Thus, the terms "chlorine" and "chloride" both refer to substances that contain the element chlorine in various forms.

[0118] As used herein, the terms "chlorine-containing," "chloride-containing," "organochlorine," and "chlorine donor" all refer to substances that contain the element chlorine in any form, whether ionic, polar covalent, or covalent.

[0119] Chlorine or chloride bearing substances As used herein, the term "chlorine or chloride bearing material" refers to a material that contains the element chlorine in any form, whether ionic, polar covalent, or covalent.

[0120] Chlorine Donor As used herein, the term "chlorine donor" refers to a substance that contains elemental chlorine in any form and can release chlorine in any form, such as, but not limited to, hydrochloric acid, hypochlorite, and chloride anion.

[0121] Acidity and pH In chemistry, pH is a measure used to describe how acidic or basic an aqueous solution is. Similarly, as used herein, the terms "pH" and "acidity" refer to the free acid content in an oil sample. For example, when an oil is mixed with phosphoric acid, it can be considered to lower its pH. Similarly, the neutralization step of adding sodium hydroxide to an oil can be considered to raise the pH of the oil.

[0122] Melting Temperature As used herein, the term "melting temperature" may refer to the temperature at which a solid changes state from solid to liquid at a pressure of 100 kPa. For example, the melting temperature may be the temperature at which a solid changes state from solid to liquid when heated at 2°C / min at a pressure of 100 kPa.

[0123] One of ordinary skill in the art can readily select an appropriate method for identifying the melting temperature of a triacylglyceride oil.

[0124] For example, an apparatus for melting temperature analysis may consist of a heating block or an oil bath with a transparent window (e.g., a Thiele tube) and a magnifying glass. A solid sample may be placed in a thin glass tube, which is placed in the heating block or immersed in an oil bath and then gradually heated. The melting of the solid can be observed and the associated melting temperature recorded.

[0125] For fats and oils containing highly complex triacylglycerol compositions, the slip melting point method is a commonly used standard (AOCS Official method Cc3-25).

[0126] Centrifugation As used herein, the term "centrifugation" may refer to the rapid spinning of a container containing oil as its contents to apply centrifugal force to the container and its contents.

[0127] In addition to reducing the formation of MPCDE, further advantages of the centrifugation step described herein include:

[0128] 1) The centrifugation step allows for improved removal of residual water from the oil, avoiding the need for further vacuum drying, a common practice in the industry today, resulting in energy and cost savings.

[0129] 2) The centrifugation step allows for improved removal of residual solids from the oil prior to the degumming step, thus allowing the production of better quality gums with less solids.

[0130] 3) The centrifugation step allows for improved removal of inorganic sediments, allowing for the use of less clay in the decolorization process, reducing costs and waste in the decolorization process.

[0131] In one embodiment, the centrifugation is carried out at an elevated temperature where the oil is in a liquid state, which can be 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 100°C or more for palm oil, 50°C, 60°C, 80°C, 100°C or more for palm stearin, 15°C, 20°C or more for palm olein, and 5°C or more for seed oils including sunflower oil, canola / rapeseed oil, corn oil.

[0132] In a preferred embodiment, the temperature may be between 30° C. and 80° C., preferably between 35° C. and 70° C. for palm oil. In a preferred embodiment, the temperature may be between 5° C. and 20° C. for sunflower oil. In a preferred embodiment, the centrifugation speed is at least 15,000 g for 15 minutes.

[0133] Sedimentation The term "settling" or "settling" as used herein refers to placing an oil container in a motionless or substantially motionless environment, preferably avoiding disturbance for a period of time which may be at least 4 hours, 6 hours, 1 day, 2 days, 1 week, or 1 month.

[0134] In one embodiment, the oil container is stabilized in a stationary, motionless environment, avoiding disturbance for a period of at least 5 months, for example, for crude sunflower oil or crude soybean oil, In one embodiment, the crude oil is heated to at least 60° C. prior to settling.

[0135] In one embodiment, the oil container is stabilized in a stationary, motionless environment, avoiding disturbance for a period of at least 4 days, for example for cold-pressed crude canola oil.

[0136] Soap As used herein, the term "soap" can refer to a variety of cleaning and lubricating products made from materials having surfactant properties.

[0137] In the context of vegetable oil refining and in the present context, the term "soap" is used to denote alkali carboxylates, which are salts of fatty acids formed by negatively charged deprotonated fatty acids and positively charged counterions, such as sodium or potassium cations. [Bailey's Industrial Oil and Fat Products-6th edition, page 3084-Soap raw materials and their processing page 105; Wikipedia] As is well known in the literature on the practice of alkaline refining, free fatty acids react with alkali, such as sodium or potassium hydroxide, to form such soaps. [The Lipid Handbook-Third Edition; edited by Frank D. Gunstone; pages 178, 191]

[0138] Further refinement Because the insoluble oil components along with their chlorine donor materials are depleted by the process of the present invention, heating during any subsequent refining process will not result in significant production of undesirable chlorinated compounds such as MCPDE.

[0139] In one embodiment, the method further comprises one or more processes selected from the group consisting of physical or chemical refining, degumming, neutralization, and decolorization following step (d) or step (i).

[0140] In one embodiment, the method further comprises deodorization following step (d) or step (i), preferably the deodorization is vacuum steam deodorization.

[0141] In one embodiment, the method further comprises fractionation following step (d) or step (i).

[0142] Processes for refining, degumming, bleaching, deodorizing and fractionating are well known in the art.

[0143] By way of example, the refining of vegetable oils, such as vegetable oils, typically consists of physical or chemical refining.

[0144] In an effort to improve sustainability, oil refineries have modified vegetable oil processing lines over the past few decades to minimize energy consumption (economizers) and reduce waste, however the steps in these two refining processes have remained essentially unchanged.

[0145] Physical refining is essentially a shortened form of chemical refining and was introduced in 1973 as the preferred method of palm oil refining. It can be a three-step sequential operation in which the incoming oil is pretreated with acid (degummed), washed by passing it through an adsorptive bleaching clay, and then steam distilled. This process allows for subsequent deacidification, deodorization, and destruction of carotenoids that are inherent to palm oil (i.e., this crude oil is deep red in color, unlike other vegetable oils). Given the lack of a neutralization step in physical refining, the refined bleached (RB) oil produced from physical refineries has approximately the same free fatty acid (FFA) concentration as that found in the crude oil.

[0146] Neutralized bleached (NB) and RB palm oil from the chemical refinery are comparable in all other respects to those before deodorization.

[0147] The operation of the thermal decolorization unit is the main source of losses in the oil refining process, resulting in a 20-40% reduction in the oil volume after filtration. The process typically lasts for about 30-45 minutes and is typically carried out at temperatures of 95-110 °C and under a vacuum of 27-33 mbar.

[0148] The thermally bleached oil may then be rerouted to a line to a degasser that aids in the removal of dissolved gases and moisture before being sent to a deodorization tower.

[0149] The bleaching process may involve heating the oil and washing the oil by passing it through an adsorbent bleaching clay.

[0150] The deodorization step may include steam distillation.

[0151] It is understood that a person skilled in the art can combine all features of the invention disclosed herein without departing from the scope of the invention disclosed.

[0152] Preferred features and embodiments of the present invention will now be described by way of non-limiting examples.

[0153] The practice of the present invention will employ, unless otherwise indicated, conventional techniques of chemistry, biochemistry, molecular biology, microbiology, and immunology which are within the capabilities of those skilled in the art and are explained in the literature. For example, Sambrook, J., Fritsch, EFand Maniatis, T. (1989) Molecular Cloning: A Laboratory Manual, 2nd Edition, Cold Spring Harbor Laboratory Press; Ausubel, FMet al. (1995 and periodic supplements) Current Protocols in Molecular Biology, Ch. 9, 13 and 16, John Wiley & Sons; Kahn, A. (1996) DNA Isolation and Sequencing: Essential Techniques, John Wiley & Sons; Polak, JMand McGee, J.O'D. (1990) In Situ Hybridization: Principles and Practice, Oxford University Press; Gait, MJ (1984) Oligonucleotide Synthesis: A Practical Approach, IRL Press and Lilley, DMand. Dahlberg, J.E. (1992) Methods in Enzymology: DNA Structures. See Part A: Synthesis and Physical Analysis of DNA, Academic Press. Each of these general texts is incorporated herein by reference.

[0154] [Example] Analytical procedures used in the examples Sample preparation The oil samples were serially diluted before injection.

[0155] 1) First, 100 μL of each sample was transferred to a vial and 900 μL of a mixture of n-hexane:acetone (1:1 volume / volume) was added. The samples were vortexed for 5-10 seconds.

[0156] 2) In a second step, 50 μL of this solution was further diluted by mixing with 950 μL of acetone, and the resulting solution was vortexed for 5-10 seconds.

[0157] 3) 100 μL of this latter solution was mixed with 90 μL of methanol and 10 μL of the internal standard mixture solution. (The internal standard mixture solution contained the following stable isotope-labeled compounds dissolved in methanol at a concentration of 2 ng / μL: 1-oleoyl, 2-linoleoyl, 3-chloropropanediol- 2 H 5 (OL), 1-2-dipalmitoyl 3-chloropropanediol- 2 H 5 (PP), 1-palmitoyl 2-oleoyl 3-chloropropanediol- 2 H 5 (PO), 1-palmitoyl 2-linoleoyl 3-chloropropanediol- 2 H 5 (PL), 1-2-dilinoleoyl 3-chloropropanediol- 2 H 5 (LL)), 1-2-oleoyl 3-chloropropanediol- 2 H 5 (O.O.)

[0158] LC conditions Ultra-performance liquid chromatography was performed using either a Thermo UltiMate 3000 system or a Waters Acquity H-class system equipped with a silica-based octadecyl phase (Waters Acquity HSS C18, 1.7 μm; 2.1×150 mm). The solvent gradients applied are summarized in Table 3.

[0159] [Table 1]

[0160] MS conditions The monitoring of monochloropropanediol (MCPD) esters was carried out using Thermo Fisher high-resolution mass spectrometers (Q Exactive Hybrid Quadrupole-Orbitrap, Orbitrap Fusion™ Lumos™ Tribrid™ and Orbitrap Elite Hybrid). These platforms enabled highly selective mass analysis with a working mass accuracy of approximately 2 ppm. MCPD esters were analyzed in ESI positive ion mode (ESI + The MCPD precursor ion observed under these conditions was [MH] - However, the monitored MCPD ester ion was [M+NH 4 ] + and [M+Na] + It was an adduct.

[0161] Interpretation of data Relative quantification of MCPDE was first performed by calculating [M+NH 4 ] + and [M+Na] + Ion chromatograms of the adducts were extracted at a mass window of 10 ppm at each m / z value, and then integrated the resulting peak areas at the corresponding chromatographic retention times. Abbreviations for the monitored MPCDEs are as follows: PP: dipalmitoyl MCPD ester; PO: palmitoyl-oleyl MCPD ester; OO: dioleyl MCPD ester; OL: oleyl-linoleyl MPCD ester; LL: dilinoyl MPCD ester; PL: palmitoyl-linoleyl MPCD ester.

[0162] In all experiments, the peak area of ​​the most abundant MPCDE detected in the control sample was set to 100%, and the results found in the mitigated samples were expressed as relative % compared to the non-mitigated control sample.

[0163] Sample ampoule heat treatment Thermal treatment of the crude oil samples was carried out in sealed glass ampoules under nitrogen in a Thermo Scientific Heraeus oven (series 6100) at 230 °C for 2 h. Glass ampoules were prepared from glass Pasteur pipettes by flushing with nitrogen and sealing them using a Bunsen gas burner. These conditions were chosen to replicate the thermal conditions used during the deodorization of edible oils.

[0164] Example 1 Solvent Extracted Crude Palm Oil Production of solvent extracted crude palm oil 1.8 kg of frozen whole, intact palm fruit was thawed at room temperature. The kernel was manually removed from the fruit using a scalpel. 4 L of extraction solution was prepared by mixing 2 L of 2-propanol and 2 L of n-hexane. 1.4 kg of palm pulp including pulp and skin was mixed, strained and homogenized with 2 L of extraction solution using a commercial immersion blender mixer (Bamix Gastro 200). The resulting slurry was mixed with the remaining 2 L of extraction solution using a polytron (Kinematica Polytron PT 10 35 GT) and further homogenized. The resulting slurry solution was aliquoted into 1 L polypropylene tubes (Sorvall 1000 mL) and centrifuged at 4000 g for 15 min at 30° C. in a Thermo Scientific Heraeus Cryofuge 8500i centrifuge. The organic phase was filtered through a paper filter (Whatman 595 1 / 2) and combined. The organic solvent was then evaporated from the oil using a Buchi Rotavapor R-300 system (B-300 heating bath, I-300 vacuum controller, V-300 pump, and P-314 recirculating chiller operated at 4° C.) at 60° C. The vacuum was adjusted stepwise until 10 mbar was reached to avoid boiling of the sample.

[0165] To prevent the formation of MPCDE during heat treatment, different batches of crude palm oil were subjected to centrifugation.

[0166] Centrifugation of solvent extracted crude palm oil 1 L of crude palm oil prepared as above was melted by heating to 80°C in a water bath. The oil was homogenized by manual shaking. A 40 mL aliquot was transferred to a 50 mL Falcon test tube. The test tube was placed in an Eppendorf 5810 centrifuge preheated to 40°C and centrifuged at 15000g for 15 min at 40°C.

[0167] To reproduce the thermal conditions used during edible oil deodorization, the oil obtained after treatment by centrifugation and the raw material (without centrifugation) were subjected to the above heat treatment. The obtained samples were analyzed for their MPCDE content by LC-MS. The beneficial effect of centrifugation-based reduction is shown in Figure 1 (dipalmitoyl-MCPD, PP-MCPD), in Figure 2 (palmitoyl-oleyl-MCPD, PO-MCPD), in Figure 3 (dioleyl-MCPD, OO-MCPD) and in Figure 4 (oleyl-linoleyl-MCPD, OL-MCPD).

[0168] Example 2 Solvent Extracted Crude Sunflower Oil Production of solvent extracted crude sunflower seed oil. 1.2 kg sunflower seeds were ground and homogenized with 1.5 L of extraction solution (2-propanol: n-hexane, 1:1 vol / vol) using a commercial immersion blender mixer (Bamix Gastro 200). The homogenate was further mixed with 1.5 L of extraction solution and further homogenized using a polytron (Kinematica Polytron PT 10 35 GT). The resulting slurry was aliquoted into 1 L polypropylene tubes (Sorvall 1000 mL) and centrifuged at 4000 g for 15 min at 22° C. in a Thermo Scientific Heraeus Cryofuge 8500i centrifuge. The organic phase was filtered through a filter paper (Whatman 595 1 / 2) and combined. The organic solvent was then evaporated from the oil using a Buchi Rotavapor R-300 system (B-300 heating bath, I-300 vacuum controller, V-300 pump, and P-314 recirculating chiller operated at 4° C.) at 60° C. The vacuum was adjusted stepwise until 10 mbar was reached to avoid boiling of the sample.

[0169] To prevent the formation of MCPDEs during thermal treatment, the solvent extracted crude sunflower oil (produced as described above) was subjected to centrifugation.

[0170] Centrifugation of solvent extracted crude sunflower oil. 1 L of crude sunflower oil prepared as above was homogenized by manual shaking. Aliquots of 40 mL were transferred to 50 mL Falcon tubes. The tubes were placed in an Eppendorf 5810 centrifuge and centrifuged at 15000 g for 15 min at 23 °C.

[0171] To replicate the thermal conditions used during edible oil deodorization, the oil obtained after treatment by centrifugation and the raw material (without centrifugation) were subjected to the above thermal treatment in triplicate. The obtained samples were analyzed for their MPCDE content by LC-MS. The beneficial effect of centrifugation-based reduction is shown in Figure 5 (dipalmitoyl-MCPD, PP-MCPD), in Figure 6 (palmitoyl-oleyl-MCPD, PO-MCPD), and in Figure 7 (oleyl-linoleyl-MCPD, OL-MCPD).

[0172] Overall, the data show substantial reductions in monochloropropanediol ester (MCPDE) concentrations after reduction in each experiment for crude sunflower oil and crude palm oil compared to concentrations observed in the untreated condition.

[0173] Example 3 Industrially produced crude palm oil Industrially produced crude palm oil was purchased from Nutriswiss (Lyss, Switzerland). The oil was subjected to a reduction test by centrifugation.

[0174] 1 L of crude palm oil was melted by heating to 80°C in a water bath. The oil was homogenized by manual shaking. A 40 mL aliquot was transferred to a 50 mL Falcon test tube. The tube was placed in an Eppendorf 5810 centrifuge preheated to 40°C and centrifuged at 15000g for 15 min at 40°C.

[0175] To simulate the formation of MCPDE, the obtained samples were heat treated in ampoules and analyzed by LC-MS for MCPDE content accordingly. The benefit of centrifugation on the obtained MCPDE concentration is shown in Figure 8.

[0176] Example 4 Long-term settling of industrially produced crude corn oil. Industrially produced crude corn oil was purchased from VFI GmbH (Wels, Austria).

[0177] The crude oil was first heated in a 2 L Pyrex bottle at 60° C. in a water bath, homogenized by vigorous manual shaking, and then left on the bench at room temperature without any disturbance for 5 months.

[0178] After a 5 month period, 40 mL aliquots were taken from the top and bottom phases and designated "top phase" and "bottom phase", respectively.

[0179] To simulate the formation of MCPDE, the obtained samples were heat treated in ampoules and analyzed by LC-MS for MCPDE content accordingly. The benefit of prolonged sedimentation on the obtained MCPDE concentration is shown in Figure 9.

[0180] Example 5 Long-term settling of industrially produced crude sunflower oil. Industrially produced crude bio-sunflower oil was purchased from VFI GmbH (Wels, Austria).

[0181] The crude oil was first heated in a 2 L Pyrex bottle at 60° C. in a water bath, homogenized by vigorous manual shaking, and then left on the bench at room temperature without any disturbance for 5 months.

[0182] After a 5 month period, 40 mL aliquots were taken from the top and bottom phases and designated "top phase" and "bottom phase", respectively.

[0183] To simulate the formation of MCPDE, the obtained samples were heat treated in ampoules and analyzed by LC-MS for MCPDE content accordingly. The benefit of prolonged sedimentation on the obtained MCPDE concentration is shown in Figure 10.

[0184] Example 6 Short-term settling of cold-pressed crude canola oil. 7.9 kg of canola seeds were pressed using a domestic electric oil press (OP 700, Rommelsbacher, Germany) to obtain about 2.4 kg of pressed oil and about 5.5 kg of remaining solid residue (cake). The pressed oil was then filtered through filter paper (Whatman 595 1 / 2) in an oven at 65°C.

[0185] The 2 L of crude oil was then left on the bench at room temperature undisturbed for 4 days to allow for settling.

[0186] After a 4 day period, 20 mL aliquots were taken from both the top and bottom phases and designated "top phase" and "bottom phase", respectively.

[0187] To simulate the formation of MCPDE, the obtained samples were heat treated in ampoules and analyzed by LC-MS for MCPDE content accordingly. The benefit of short-term precipitation on the obtained MCPDE concentration is shown in Figure 11.

[0188] Example 7 Long-term settling of industrially produced crude soybean oil. Industrially produced crude bio-soybean oil was purchased from VFI GmbH (Wels, Austria).

[0189] The crude oil was first heated in a 2 L Pyrex bottle at 60° C. in a water bath, homogenized by vigorous manual shaking, and then left on the bench at room temperature without any disturbance for 5 months.

[0190] After a 5 month period, 40 mL aliquots were taken from the top and bottom phases and designated "top phase" and "bottom phase", respectively.

[0191] To simulate the formation of MCPDE, the obtained samples were heat treated in ampoules and analyzed by LC-MS for MCPDE content accordingly. The benefit of prolonged sedimentation on the obtained MCPDE concentration is shown in Figure 12.

[0192] Example 8 Long-term settling of solvent extracted crude sunflower oil. The production of solvent extracted crude sunflower seed oil is described above.

[0193] 1 L of this crude oil was subjected to a long term settling test by leaving it on the bench at room temperature without any disturbance for 5 months.

[0194] After a 5 month period, 40 mL aliquots were taken from the top and bottom phases and designated "top phase" and "bottom phase", respectively.

[0195] To simulate the formation of MCPDE, the obtained samples were heat treated in ampoules and analyzed by LC-MS for MCPDE content accordingly. The benefit of prolonged sedimentation on the obtained MCPDE concentration is shown in Figure 13.

[0196] Example 9 Industrially produced crude palm oil was purchased from Nutriswiss (Lyss, Switzerland). The oil was subjected to a reduction test by centrifugation.

[0197] 1 L of crude palm oil was melted by heating to 40°C in a water bath. The oil was homogenized by manual shaking. A 30 mL aliquot was transferred to a 50 mL Falcon test tube. The tube was placed in an Eppendorf 5810 centrifuge preheated to 40°C and centrifuged at 15000g for 15 min at 40°C.

[0198] To simulate the formation of MCPDE, the obtained samples were heat treated in ampoules and analyzed by LC-MS for MCPDE content accordingly. The benefit of centrifugation on the obtained MCPDE concentration is shown in Figure 14.

[0199] Example 10 Industrially produced crude palm oil was purchased from Nutriswiss (Lyss, Switzerland). The same batch of crude oil was subjected to reduction tests by two different centrifugation experiments.

[0200] Crude palm oil was melted by heating in a water bath to 80° C. The oil was homogenized by manual shaking.

[0201] One aliquot of oil was transferred to a 40 mL Falcon tube and centrifuged at 15000 g for 15 min at 40°C in an Eppendorf 5810 centrifuge preheated to 40°C.

[0202] The other aliquot was transferred to a 1 L reservoir and centrifuged at 4000 g for 15 min at 40°C in a Thermo Scientific Heraeus Cryofuge 8500i centrifuge preheated to 40°C.

[0203] After centrifugation, the upper 10% (v / v%) and lower 10% (v / v%) phases were separated in different test tubes. These aliquots, corresponding to the clarified oil (upper 10%) and the sediment-enriched oil (lower 10%), were then heat-treated in ampoules to simulate the formation of MCPDE and analyzed by LC-MS for MCPDE content accordingly. The concentration effect of centrifugation on the obtained MCPDE concentration is shown in FIG. 15.

[0204] Example 11 Industrially produced crude palm oil was purchased from Nutriswiss (Lyss, Switzerland). The crude oil was first heated at 80° C. and then centrifuged at 15'000 g for 15 min at 40° C. The lower 10% v / v liquid phase, rich in sediment, was used for degumming.

[0205] Degumming of the oil was performed by first heating the oil to 80°C and adding 0.02% phosphoric acid 85% (vol / vol). The mixture was then sheared at 1000 rpm for 2 minutes using a shear mixer (Silverson L5M-A) while maintaining the crude oil at 85°C. The mixture was then mixed with 2% (vol / vol) Milli-Q water and again sheared at 1000 rpm for 2 minutes. To separate the oil from the gum, the mixture was centrifuged at 3'000g for 5 minutes at 40°C and the top 95% liquid phase was further used as degummed oil.

[0206] Centrifugation-based reduction was applied to this degummed oil by centrifugation at 15000 g for 15 min at 40° C. in a 40° C. pre-heated Eppendorf 5810 centrifuge.

[0207] After centrifugation, the upper 10% (vol / vol%) and lower 10% (vol / vol%) phases were separated in different test tubes. These aliquots, corresponding to clarified degummed oil (upper 10%) and sediment-enriched degummed oil (lower 10%), were then heat-treated in ampoules to simulate the formation of MCPDE and analyzed by LC-MS for MCPDE content accordingly. The concentration effect of centrifugation on the obtained MCPDE concentration is shown in FIG. 16.

[0208] All publications mentioned in the above specification are incorporated herein by reference. Various modifications and alterations of the methods, uses and products disclosed in the present invention will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. Although the present invention has been disclosed in connection with certain preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the disclosed modes for carrying out the invention that are obvious to those skilled in the art are intended to be within the scope of the following claims.

Claims

1. 1. A method for preventing or reducing the formation of monochloropropanediol (MCPD) or monochloropropanediol esters (MCPDE) in a triacylglyceride oil, comprising: (a) Removing insoluble components from a liquid raw triacylglyceride oil; a(i) by subjecting the feed triacylglyceride oil to centrifugal force while maintaining the feed triacylglyceride oil above its melting temperature; and / or a(ii) concentrating the feed triacylglyceride oil by allowing the insoluble components to settle by gravity while maintaining the feed triacylglyceride oil above its melting temperature; (b) separating the triacylglyceride oil from the insoluble components; (c) optionally applying one or more processes selected from physical refining, chemical refining, degumming, neutralization, interesterification, bleaching, winterization or fractionation, in any combination; (d) applying a heat treatment to the triacylglyceride oil, The raw triacylglyceride oil is a vegetable oil, The method, wherein the raw triacylglyceride oil is not mixed with any of acid, alkali, or water.

2. 2. The method of claim 1, wherein prior to step (a), the starting triacylglyceride oil is melted by heating above its melting temperature.

3. 3. The method of claim 1 or 2, wherein in step (a), centrifugal force is applied to the triacylglyceride oil while maintaining the triacylglyceride oil above its melting temperature.

4. 4. The method according to any one of claims 1 to 3, wherein the starting triacylglyceride oil has a free fatty acid content of at least 0.5 (w / w%).

5. The method according to any one of claims 1 to 4, wherein the centrifugation is carried out at a relative centrifugal force of more than 200 g.

6. 3. The method of claim 1 or 2, wherein in step (a), the insoluble components are allowed to settle by gravity while the triacylglyceride oil is maintained above its melting temperature.

7. The method of any one of claims 1 to 6, wherein step a(ii) is carried out and then step a(i) is carried out.

8. The method of any one of claims 1 to 6, wherein step a(i) is carried out and then step a(ii) is carried out.

9. 9. The method of any one of claims 1 to 8, wherein the source triacylglyceride oil is selected from the group consisting of palm oil, sunflower oil, corn oil, canola oil, soybean oil, coconut oil, palm kernel oil, and cocoa butter.

10. 10. The method of claim 9, wherein the starting triacylglyceride oil is palm oil or a fraction obtained from palm oil.

11. 10. The method of claim 9, wherein the starting triacylglyceride oil is sunflower oil or a high oleic variant thereof.

12. 12. The method of any one of claims 1 to 11, wherein the starting triacylglyceride oil has a water content of less than 1%.

13. 13. The method of any one of claims 1 to 12, wherein the starting triacylglyceride oil does not contain added crystallization agents.

14. 14. The method according to any one of claims 1 to 13, wherein the starting triacylglyceride oil has a crystallized triacylglycerol content of less than 10% (w / w%).

15. 15. The method of any one of claims 1 to 14, wherein the starting triacylglyceride oil has a soap content of less than 1000 ppm.

16. 16. The method of any one of claims 1 to 15, wherein the starting triacylglyceride oil is not mixed with salt.

17. 17. The method according to any one of claims 1 to 16, wherein the starting triacylglyceride oil does not contain any added ionic, cationic, or anionic surfactants and / or additives.

18. 18. The method of any one of claims 1 to 17, wherein the starting triacylglyceride oil has a bleaching clay content of less than 0.01%.

19. 19. The method of any one of claims 1 to 18, wherein the starting triacylglyceride oil is not cooled below 20°C.

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