A process for a process for a production of fatty acid products for use in animal feed

Abstract

The present invention relates to a method for producing purified soap fractions from crude palm oil, which are suitable for use in animal feed, specifically for livestock such as cows, poultry, and pigs. More particularly, the invention involves a process wherein crude palm oil is reacted with sodium hydroxide (NaOH) or other alkaline earth metals to produce soaps, sodium salts of fatty acids. The soap mixture is then purified to remove the glycerol and produce crude palm free fatty acids. The acids is then split into its high-melting and low-melting fatty acid fractions through a dry fractionation process. The dry fractionation step effectively separates the soap into distinct fractions based on their melting points, resulting in high-quality fatty acid fractions with different properties, which can be optimized for animal nutrition. The use of crude palm oil as a raw material for soap production offers an efficient and sustainable source of fatty acids.

Description

[0001] A process for a process for a production of fatty acid products for use in animal feed

[0002] The present invention relates to a process for a process for a production of fatty acid products for use in animal feed, the process comprising the steps of providing a quantity of crude vegetable oil, particular crude palm oil; extracting free fatty acids from said vegetable oil; and fractionating said fatty acids to form at least a first fraction having a first melting point and a second fraction, having a second melting point, wherein said first melting point is higher than said second melting point.

[0003] During periods of high milk production, conventional cattle feeds generally do not provide enough energy to cattle. It is known that fat is an excellent source of energy and that increasing the levels of fat in cattle feed results in high yields of milk from cattle. Fat compositions that are rich in long chain saturated free fatty acids, especially palmitic acid (C16:0), are particularly preferred as these compositions significantly increase milk production. Furthermore, compositions high in palmitic acid content have been shown to increase weight gain in goats, sheep and pigs and also increase the quality of such meat, for example by increasing the amount of lean meat content.

[0004] However, when the proportion of fat in the diet of cattle exceeds around 5 wt.%, such a feed has a toxic effect on the microorganisms in the rumen of cattle, which severely disrupts their digestive system. This deleterious effect on the digestive system of cattle is particularly true of unsaturated fats.

[0005] Fat compositions that are high in palmitic acid content have a melting point which is higher than the temperature in rumen. Therefore, such fat compositions pass through the rumen without interacting with the digestive system. These compositions are often referred to as "bypass fats" or "protected fats". This is important because the rumen is where most digestion takes place for ruminants like cows, and microbes in the rumen typically break down fats before they can be absorbed in the intestines, where they are more useful for energy. After by-passing the rumen, the fats then enter the small intestine where the large decrease in pH solubilizes the fats allowing them to be absorbed across the small intestine wall.Fat compositions which are derived from palm oil, but are low in palmitic acid content, have melting points lower than the temperature of the rumen. Therefore, in order to avoid the deleterious effects of such fats on the digestive system of cattle, the fatty acids in these compositions are particularly converted to their corresponding calcium salt, which increases the melting point of fat compositions comprising such fatty acids above the temperature of the rumen. Thus, lower molecular weight fat compositions can also be provided as "bypass fats" in the form of their corresponding metal salt, particularly the calcium salt of the corresponding fatty acid.

[0006] Through using such "bypass fat" compositions in cattle feed, the proportion of fat in the diet of cattle may exceed 5 wt.% without having any adverse effects on the microorganisms within the rumen. Thus, this further increases the possibilities of adding fats to animal feed.

[0007] Bypass fats and calcium salts are commonly used in cow feed, particularly for dairy cows, for a variety of important reasons. Both these additives play a crucial role in optimizing the cow's nutrition and improving milk production, body condition, and overall health.

[0008] Bypass fats, designed to pass through the rumen without being broken down by the rumen microbes, increase the energy intake. Cows, especially high-producing dairy cows, require a significant amount of energy to support milk production, especially in the early lactation period. By using bypass fats, farmers can increase the energy density of the cow's diet without overloading the rumen with excess fiber.

[0009] By providing a direct source of fat that bypasses the rumen and is absorbed in the small intestine, bypass fats offer an additional energy source for the cow. This can enhance milk yield and improve milk composition, including higher fat content in milk, which is important for dairy farmers.Bypass fats, especially those that are rumen-protected, are not fermented by the microbes in the rumen. This can reduce the production of methane, known as a greenhouse gas, as a byproduct of ruminal fermentation, which is beneficial from an environmental perspective. Bypass fats contain unsaturated fatty acids that are directly absorbed into the bloodstream through the small intestine. These fatty acids can be utilized for energy, improving the cow's body condition and supporting better reproductive performance.

[0010] Also calcium salts, particularly calcium soaps of fatty acids, are often included in the diet of dairy cows as a form of rumen-protected fat. These calcium salts are typically formed when calcium reacts with fatty acids, particularly calcium stearate and calcium palmitate. These calcium salts of fatty acids are insoluble in the rumen, so they pass through the rumen without being degraded by microbes. Once they reach the small intestine, they are digested and provide a source of high-energy fats. This helps increase the overall energy density of the cow's diet without interfering with the microbial activity in the rumen.

[0011] Calcium salts provide a concentrated source of fatty acids, which are a rich source of energy for cows. These fats are more easily utilized by the cow for energy in the small intestine, allowing for improved milk production, weight gain, and better overall health. The calcium salts of fatty acids are often high in unsaturated fatty acids, which can improve the nutritional profile of the milk produced by the cows. Unsaturated fats are beneficial for the health of the cow and can improve the quality of the milk, particularly in terms of milk fat content.

[0012] By adding calcium salts to the diet, cows can get a more efficient source of fat. Since they are rumen-protected, the cow's digestive system can make use of the fats without overloading the rumen with excess material, which can otherwise lead to bloat or digestive disturbances. Fats, including those from calcium salts, are crucial for reproductive health in dairy cows. Adequate fat intake helps in maintaining the cow'sbody condition score and ensures proper hormone regulation, improving the chances of successful conception and calving intervals.

[0013] For inter alia these reasons, bypass fats and calcium salts are preferably integral to modern livestock nutrition, especially in high-producing dairy cows. They offer a way to optimize energy intake, enhance milk production, and improve overall cow health and performance, all while preventing the negative effects of excessive fermentation in the rumen.

[0014] A process for process for the production of fatty acid products for use in animal feed is for instance known from International patent application WO 2018 / 137938. According to the known production process palm fatty acid distillate (PFAD) is taken as a starting material. PFAD is a processing residue and waste material resulting from physical refining (distilation) of crude palm oil products. Crude palm oil may contain up to 5 wt.% free acids. These free fatty acids are extracted by thermal distillation to deliver PFAD.

[0015] At room temperature PFAD is a light brown semi-solid, melting to a brown liquid on heating. Up to 80 wt.% of PFAD is taken up by free fatty acids (FFA), with palmitic acid and oleic acid being the major components. According to the known process these PFAD free fatty acids are fractionated into a high melting point first fraction, comprising palmitic acid (C16:0) in an amount greater than about 60 wt.%, and a lower melting point second fraction, comprising palmitic acid (C16:0) in an amount from about 20 wt.% to about 55 wt.%. The first fraction may be used directly as bypass fats in animal feed. The second fraction, preferably, is reacted with an alkaline earth metal compound, like calcium or magnesium, to form a fatty acid alkaline earth metal salt.

[0016] A disadvantage of the known process for obtaining these nutritious additives is that by extracting the free acids from crude palm oil by physical distillation also several toxic compounds, particularly dioxins and pesticides used during cultivation of the palm trees, are distilled and contained by the resulting PFAD distillate.It is inter alia an aim of the present invention to offer a process for the production of fatty acid products for use in animal feed that is high in high melting point fatty acids and low in contamination, such as those pesticides and dioxins found in PFAD.

[0017] In order to achieve the above object, a process for the production of fatty acid products for use in animal feed as described in the opening paragraph, according to the invention is characterized in that said extraction comprises exposing said crude vegetable oil to a saponification process to obtain a mixture comprising glycerol and fatty acid metal salts, in that said fatty acid metal salts are hydrolysed to their corresponding fatty acids to form a fatty acid mixture, and in that said fatty acid mixture is fractionated to obtain at least said first fraction and said second fraction.

[0018] In a preferred embodiment the process according to the invention is characterized in that, prior to said saponification process, the crude vegetable oil is washed with water. This will already remove any water soluble toxic contaminants that may be present in the starting material.

[0019] The process step of saponification results in the production of soap and glycerol. In a particular embodiment, the process according to the invention is characterized in that said saponification process comprises exposing said crude vegetable oil to an aqueous alkaline environment, particularly containing an aqueous alkali metal hydroxide solution, more particularly containing aqueous sodium hydroxide or aqueous potassium hydroxide. The soaps will in that case comprise alkali metal salts of the free fatty acids found in the crude vegetable oil, such as particularly palm oil.

[0020] In the case of crude vegetable oil, particularly palm oil, which contains a mix of different fatty acids, the products would primarily be a mixture of different alkali metal salts of those fatty acids as well as glycerol. A further particular embodiment of the process according to the invention is characterized in that said glycerol and said fatty acid metal salts are separated by precipitating said fatty acids from said mixture using filtration, decanting and / or centrifugation. In a further preferred embodiment the processaccording to the invention is characterized in that said mixture is diluted with a solvent to selectively dissolve glycerol, particularly with water. The recovered glycerol may be sold or processed further as a byproduct.

[0021] In order to recover the free fatty acids from their corresponding salt, a particular embodiment of the process according to the invention is characterized in that said fatty acid metal salts are hydrolysed by exposure to an acidic environment, particularly to aqueous hydrochloric acid. This step will neutralize the soaps in the mixture to convert them into the corresponding free fatty acids. This is typically done by adding a strong acid like hydrochloric acid ( H Cl) to the soap, converting the alkali metal salts (soap) into free fatty acids. After neutralization, there will be a mixture of different fatty acids with varying chain lengths, some of which are solid at room temperature and others are liquid.

[0022] To fractionate the obtained mixture into at least said first fraction and said second fraction, a preferred embodiment of the process according to the invention is characterized in that said fatty acid mixture is fractionated by maintaining said mixture at a first temperature, beyond said first melting point, and cooling said mixture to a second temperature, between said first melting point and said second melting point, to selectively solidify said first fraction, followed by removing said first fraction from the mixture by filtration, decanting and / or centrifugation.

[0023] This process may be referred to as dry fractionation and is used to further split the mixture into separate fatty acid fractions based on their different melting points. In this method, the solid and liquid components are separated without the use of solvents or water, unlike other fractionation methods that rely on liquid solvents or heat distillation. The process of dry fractionation involves cooling the mixture of fatty acids, allowing different fatty acids to crystallize at different temperatures, and then physically separating them based on their crystallization behaviour.The fatty acid mixture is cooled gradually to induce crystallization. The temperature is carefully controlled to encourage the solidification of the higher-melting fatty acids first. Different fatty acids have different melting points, and longer-chain fatty acids as well as (multi)saturated fatty acids tend to solidify at higher temperatures than

[0024] shorter-chain and unsaturated ones. The solid fraction may then be separated using any of the above techniques.

[0025] At this instance it is also noted that the term "crystallized" and related terms used herein refer to the solid obtained in general terms and does not necessarily mean that the solid is fully crystalline or solid. For example, the solid may contain some material that is crystalline and some that is not crystalline. Typically, the solid fraction may contain a mixture or an emulsion of compounds.

[0026] If desired the remaining liquid phase of the fatty acid mixture may be used as the second fraction or may be fractionated further to obtain at least one further fraction. To that end, a further particular embodiment of the process according to the invention is characterized in that said fatty acid mixture is further fractionated by cooling said fatty acid mixture to at least one further temperature, between said second melting point and said second temperature, to selectively solidify at least one further fraction, followed by removing said at least one further fraction from the mixture by filtration, decanting and / or centrifugation.

[0027] This solid first fraction may also be referred to as either the crystallized fraction or as the stearine fraction and these three terms are used interchangeably, whereas the remaining liquid fraction may be referred to as the olein fraction and these two terms are also used interchangeably.

[0028] The first and second temperature may be chosen to optimize both fractions as nutritious supplements in animal feed. In this respect, a further embodiment of the process according to the invention is characterized in that said second temperature lies beyond body temperature of the animal, particularly beyond rumen temperature of theanimal. This will create a first fraction of bypass or protected fatty acids only that will be, and remain, in a solid state once digested by the animal.

[0029] In still a further embodiment, the process according to the invention is characterized in that said second temperature is between 20 and 25 degrees Celsius. This will create a first fraction that is mainly crystallized at room temperature while the second fraction will reside at ambient temperature as an olein phase.

[0030] To allow the olein fraction to bypass the rumen of the animal as weel, a further preferred embodiment of the process according to the invention is characterized in that at least said second fraction is reacted with an edible alkaline earth metal compound to convert the fatty acids in said second fraction to a corresponding fatty acid alkaline earth metal salt. Particularly said alkaline earth metal compound may comprise calcium or magnesium, more particularly calcium carbonate or calcium oxide. Reacting calcium oxide (CaO) or an earth mineral such as calcium carbonate (CaCO3) with fatty acids lower than C16:0 forms calcium soaps, which are essentially salts of fatty acids with calcium as the counter-ion. These calcium soaps generally have a higher melting point than the originating fatty acid and accordingly may bypass the rumen in solid form and, as such, serve in feed as a source of energy for the animal.

[0031] Before serving either fraction as a nutritious supplement in animal feed it may be brought in a suitable form or shape. To that end, a further particular embodiment of the process according to the present invention is characterized in that at least one of said fatty acid fractions is brought in powdery or granular form, particularly by spray drying, more particularly by saponification followed by spray drying. The resulting powder or granular material may be mixed with a standard animal feed as an energy supplement.

[0032] In a further particular embodiment, the process according to the invention is characterized in that solid animal feed pellets are provided, and wherein at least one of said fatty acid fractions is used in liquid or liquidized form for coating said feed pellets, followed by drying. In this case the animal feed pallets are enriched by a nutritiouscoating that serves among others as a source of extra energy. Particularly, according to the invention, said first fraction comprises at least 60 wt% C16:0 palmitic acid and the second fraction comprises between 20 wt% and 60 wt% palmitic acid.

[0033] Hereinafter, the invention will be set out in further detail by means of an explanatory embodiment.

[0034] Example

[0035] 1. Saponification:

[0036] In this example the process according to the invention is used on crude palm oil to react with sodium hydroxide (NaOH) to form a soap. To that end a quantity of crude palm oil is brought in a vessel at ambient temperature together with a stoichiometric or slight excess amount of sodium hydroxide.

[0037] Crude palm oil is primarily composed of triglycerides, which are molecules made up of a glycerol (also known as glycerine) backbone attached to three fatty acid chains. When sodium hydroxide reacts with crude palm oil, a chemical reaction called saponification takes place. This dissociates the glycerol backbone from the fatty acid chains, releasing the fatty acid groups. These groups will attach to the sodium ions to create the corresponding fatty acid sodium salts, also referred to as soaps. As the crude oil will contain several different fatty acid chains, so will the reaction product be a mixture of fatty acid soaps of varying chain length and / or saturation. The fatty acids typically contain long carbon chains, and the resulting salts are the soap molecules.

[0038] 2. Separation

[0039] Glycerol is also released in the saponification reaction, which is a byproduct that can be used in various applications. The soap will be cleaned and washed from glycerol. After the saponification reaction has completed, glycerol will be mixed in with the soap and other byproducts. To isolate the glycerol, follow these steps:

[0040] Add Water: Add water to the soap mixture to dissolve both the soap, i.e the sodium salts of fatty acids, and the glycerol. Glycerol is water-soluble, while the soap (especially in the form of sodium salts) will form a separate phase.Heating: Gently heat the soap and water mixture. The glycerol will dissolve more readily in hot water, allowing it to separate from the soap. Heating also helps to soften the soap, making it easier to separate.

[0041] Filtration: Filter the mixture to remove the solid soap. The filtrate will contain dissolved glycerol and any water-soluble impurities, particularly aqeous pesticides and dioxins.

[0042] In some cases, the mixture can be centrifuged. This allows for the separation of the different phases based on density. The glycerol will settle in a different layer than the soap, making it easier to separate them.

[0043] 3. Neutralization

[0044] The resulting soap mixture contains a blend of various fatty acid sodium salts. The next step is to neutralize the soap in order to convert the soaps into the corresponding free fatty acids. To that end, fatty acid metal salts are hydrolysed by exposure to an acidic environment, in this example to aqueous hydrochloric acid. This is typically done by adding a strong acid, like hydrochloric acid (HCI), to the soap mixture, converting the sodium salts into free fatty acids.

[0045] 4. Crystallization

[0046] After neutralization, the mixture is composed of different fatty acids with varying chain lengths, some of which are solid at room temperature, and others are liquid. This fatty acid mixture is brought to an initial first temperature and then gradually cooled to induce crystallization. The temperature is carefully controlled to encourage the solidification of the higher-melting fatty acids first. Different fatty acids have different melting points, and longer-chain fatty acids tend to solidify at higher temperatures than shorter-chain ones.

[0047] As the temperature drops, higher-melting fatty acids, like stearic acid and palmitic acid, will start to crystallize, while the lower-melting fatty acids, like oleic acid and linoleic acid, will remain in liquid form. The crystallization depends on the chain length anddegree of saturation. Saturated fatty acids, like stearic acid, typically crystallize at higher temperatures than unsaturated ones, like oleic acid.

[0048] The solid fraction at animal body temperature, particularly the rumen temperature, typically will consist of rumen-protected fats, also referred to as bypass fats. These may be used directly as a nutritious supplement in animal feed as they will pass the rumen without being digested substantially. Accordingly the initial first temperature may be an elevated temperature well above rumen temperature, like 60 °C, while the mixture is gradually allowed to cool to beyond rumen temperature.

[0049] 5. Fractionating

[0050] After the fatty acids have had time to crystallize, the solid fatty acids (higher-melting point) are separated from the liquid ones (lower-melting point) using any of the following physical methods.

[0051] Filtration: Vacuum filtration or simple filtration may be used to remove the solidified fatty acids from the liquid ones. The filter will allow the liquid fraction to pass through while retaining the solidified fatty acids.

[0052] Decanting: If the solidified fatty acids form a separate layer that can be easily poured off. Decanting can be used to separate the liquid fatty acids from the solid ones.

[0053] 6. Cleaning

[0054] To remove any residual soap or impurities, the separated fatty acids, both solid and liquid, may be washed with small amounts of warm water or a mild solvent to remove traces of remaining sodium salts or other impurities. After washing, the fatty acids are usually dried and purified, depending on the intended use.

[0055] 7. Further fractionating

[0056] If further separation is desired, for example to further purify the solid fatty acids, the fractionation process of steps 4 to 6 may be repeated by cooling the separated liquid fraction again, causing the next fraction of fatty acids to crystallize and separate.Typically, temperatures of around 20-25°C (room temperature) are ideal for the final stage. Again, the cooling is done slowly, so that the fatty acids crystallize gradually. This will deliver a olein fraction that will be liquid at ambient temperature as well as a solid fraction that may liquify when digested by the animal.

[0057] 8. Calcification

[0058] The liquid fatty acids lower than C16:0 are reacted with calcium oxide (CaO) or an earth mineral such as calcium carbonate (CaCO3) to form the corresponding calcium soaps. These are essentially salts of fatty acids with calcium as the counter-ion and generally have a higher melting point. These calcium soaps may also be used as a dietary supplement in animal feed as a source of energy for animals.

[0059] 9. Applying the fatty acids fractions in animal feed

[0060] The first fraction of higher melting point fatty acids typically comprises more than 60 wt.% C16:0 palmitic acid and is typically in a semi-solid or pasty form after fractionation and cooling. This fraction may be further processed into a dietary supplement for animal feed by spray drying. This involves converting the fatty into a fine spray or mist and allowing the material to precipitate in the form of a fine powder or grains. The key to spraying these fatty acids is ensuring they are in a suitable form, either liquid or semi-liquid, before for spraying and to utilize specialized equipment to create a fine mist that is cooled down to deliver in a fine granulated product, particularly a fine powder. This product is directly useful for various purposes, including as a nutritious additive to animal feed.

[0061] The liquid second fraction typically has a content of between 20 and 60 wt.% of C16:0 palmitic acid. This fraction may be used in liquidized or liquid form for encapsulation of standard animal feed pellets. To that end the pellets are coated, for instance by spray coating or submersion, with the liquid fraction, followed by drying. This will boost the nutritious value of the pellets that may further be used in the same way as non-treated animal feed.The obtained bypass fats and calcium salts may be applied as an integral addition to modern livestock nutrition, especially in high-producing dairy animals. They offer a way to optimize energy intake, enhance milk production, and improve overall animal health and performance, all while preventing the negative effects of excessive fermentation in the rumen. The separated high melting point and low melting point fatty acid fractions may be used in animal feed as nutritional additives for dairy cows, swine or poultry, where the fractions are particularly applied in powder or granulate form or as a coating of feed pellets.

[0062] Although the invention has been explained in further detail based on merely a single embodiment of the invention, it will be appreciated that the invention is by no means limited to that embodiment. On the contrary, within the scope of the present invention many further embodiments, variations and modifications are feasible to a skilled person without requiring him or her to exercise any inventive skill. Particularly the fatty acids applied and obtained in the preceding example may be exchanged for any suitable metal salt thereof without departing from the scope of the present invention. Also different salts and acids than those applied in the example may be used to effect saponification followed by hydrolysis, without departing from the scope of the invention.

Claims

Claims:

1. A process for a production of fatty acid products for use in animal feed, the process comprising the steps of:providing a quantity of crude vegetable oil, particularly crude palm oil; extracting free fatty acids from said vegetable oil; andfractionating said fatty acids to form at least a first fraction having a first melting point and a second fraction, having a second melting point, wherein said first melting point is higher than said second melting point,characterized in that said extraction comprises exposing said crude vegetable oil to a saponification process to obtain a mixture comprising glycerol and fatty acid metal salts, in that said fatty acid metal salts are hydrolysed to their corresponding fatty acids to form a fatty acid mixture, and in that said fatty acid mixture is fractionated to obtain at least said first fraction and said second fraction.

2. The process according to claim 1, wherein the crude vegetable oil is washed with water, prior to said saponification process.

3. The process according to claim 1 or 2, wherein said saponification process comprises exposing said crude vegetable oil to an aqueous alkaline environment, particularly containing an aqueous alkali metal hydroxide solution, more particularly containing aqueous sodium hydroxide or aqueous potassium hydroxide.

4. The process according to claim 1, 2 or 3, wherein said glycerol and said fatty acid metal salts are separated by precipitating said fatty acids from said mixture using filtration, decanting and / or centrifugation.

5. The process according to claim 4, wherein said mixture is diluted with a solvent to selectively dissolve glycerol, particularly with water.

6. The process according to anyone of the preceding claims, wherein said fatty acid metal salts are hydrolysed by exposure to an acidic environment, particularly to aqueous hydrochloric acid.

7. The process according to anyone of the preceding claims, wherein said fatty acid mixture is fractionated by maintaining said mixture at a first temperature, beyond said first melting point, and cooling said mixture to a second temperature, between said first melting point and said second melting point, to selectively solidify said first fraction, followed by removing said first fraction from the mixture by filtration, decanting and / or centrifugation.

8. The process according to claim 7, wherein said fatty acid mixture is further fractionated by cooling said fatty acid mixture to at least one further temperature, between said second melting point and said second temperature, to selectively solidify at least one further fraction, followed by removing said at least one further fraction from the mixture by filtration, decanting and / or centrifugation.

9. The process according to claim 7 or 8, wherein said second temperature lies beyond body temperature of the animal, particularly beyond rumen temperature of the animal.

10. The process according to claim 7 or 8, wherein said second temperature is between 20 and 25 degrees Celsius.

11. The process according to anyone of the preceding claims, wherein at least said second fraction is reacted with an edible alkaline earth metal compound to convert the fatty acids in said second fraction to a corresponding fatty acid alkaline earth metal salt.

12. The process according to claim 11, wherein said alkaline earth metal compound comprises calcium or magnesium, more particularly calcium carbonate or calcium oxide.

13. The process according to anyone of the preceding claims, wherein at least one of said fatty acid fractions is brought in powdery or granular form, particularly by spray drying, more particularly by saponification followed by spray drying.

14. The process according to anyone of the preceding claims, wherein solid animal feed pellets are provided, and wherein at least one of said fatty acid fractions is used in liquid or liquidized form for coating said feed pellets, followed by drying.

15. The process according to anyone of the preceding claims, wherein said first fraction comprises at least 60 wt.% C16:0 palmitic acid and the second fraction comprises between 20 wt.% and 60 wt.% palmitic acid.