JPH0471119B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for separating glycerol esters. More specifically, the present invention relates to a method for separating intermediate melting point glycerol esters from a mixture whose main components are fatty acids and glycerol esters. An industrial method for separating mixtures whose main components are fatty acids and glycerol esters into fatty acids and glycerol esters, such as fats and oils with abnormally high acid values or transesterification products of fatty acids and glycerol esters. Known methods include an alkali deoxidation method and a steam distillation method. The alkaline deoxidation method can be applied when the fatty acid content is relatively low, but cannot be applied when the fatty acid content is high because of the large loss of glycerol esters to the soap mixture foot. Further, in the steam distillation method, transesterification occurs between glycerol esters and/or fatty acids, and the composition of the glycerol esters changes, so that a desirable glycerol ester composition cannot be obtained. Column chromatography is a laboratory method for separating fatty acids and glycerol esters, and with this method, fatty acids and glycerol esters can be separated without changing the composition of the glycerol esters. . However, the process cost of column chromatography is high and it is impossible to apply it industrially. An object of the present invention is to provide a method for separating fatty acids and glycerol esters from a mixture of fatty acids and glycerol esters having a fatty acid content of 20% or more without causing a change in the composition of the glycerol esters. . Another object of the present invention is to provide a method for separating high quality intermediate-melting point glycerol esters from glycerol esters. That is, in the method for separating glycerol esters of the present invention, fatty acids and high melting point glycerol esters are first separated into crystalline parts by solvent fractionation using hexane from a mixture consisting of fatty acids and glycerol esters and having a fatty acid content of 20% or more. Next, a liquid oil substance was added to the obtained filtrate to remove residual fatty acids by alkaline deacidification, and this alkaline deoxidized oil was subjected to solvent fractionation with acetone to separate the intermediate melting point glycerol ester as a crystal part. , the low melting point glycerol ester is separated as a filtrate. The method for separating glycerol esters of the present invention will be described in detail below. In the present invention, fatty acids and high melting point glycerol esters can be more selectively crystallized by using hexane as the solvent for the initial solvent fractionation. As this hexane, n
Examples include -hexane, isohexane, and cyclohexane, and n-hexane and isohexane (mixture) can be used particularly effectively. As the liquid oil substance, oily substances that are liquid at room temperature can be effectively used, but in particular, glycerol esters that are liquid at room temperature, such as soybean oil, corn oil, rapeseed oil, cotton salad oil, palm oil, mahua oil, etc. Fractionated soft part oils such as fat, monkey fat, shea fat, etc. can be used more effectively. In the present invention, acetone used for solvent fractionation of alkaline deoxidized oil can be used easily and effectively, and examples of this acetone include acetone alone, a mixture of acetone and water, a mixture of acetone and alcohol, etc. It will be done. As for the solvent used for solvent fractionation, if the effects are the same, a single solvent is more desirable than a mixed solvent of two or more types in that the recovery system is simplified. The amount of hexane used is preferably 2 to 8 parts by weight, more preferably 3 to 5 parts by weight, per 1 part by weight of the raw material (a mixture whose main components are fatty acids and glycerol esters). The separation temperature at this time varies depending on the type of solvent and the amount used, but in the case of hexane, it ranges from -5℃ to 5℃.
℃ is preferable. Filtrate part 1 obtained by this solvent fractionation
By adding 0.2 to 2 parts by weight of the liquid oil substance based on the weight part, alkaline deoxidation can be effectively carried out. The amount of acetone used is preferably 1 to 10 parts by weight, more preferably 1.5 to 4 parts by weight, per 1 part by weight of the alkaline deoxidized oil. The separation temperature at this time varies depending on the amount of acetone used, but is preferably from -5°C to +2°C. The medium-melting point glycerol ester obtained by the method of the present invention is mainly used as a cocoa butter substitute, but when separating the medium-melting point glycerol ester from a mixture containing a large amount of fatty acids,
The most important thing is to minimize random transesterification between glycerol esters and between glycerol esters and fatty acids. The reason for this is that when a large amount of fatty acids is contained, random transesterification is very likely to occur during the process, resulting in a change in the composition of the glycerol ester and, therefore, a change in physical properties. In the production of ordinary edible fats and oils, compositional changes and changes in physical properties do not affect much, but in the case of production of cocoa butter substitutes or intermediate melting point glycerol esters that are the raw materials for them, one-part composition Products that have undergone changes, that is, changes in physical properties, cannot be used as cocoa butter substitutes or raw materials. The method for separating glycerol esters of the present invention is applied to glycerol esters with a high acid value having a fatty acid content of 20% or more. Such raw materials are first subjected to solvent fractionation using hexane, and in this solvent fractionation, components such as saturated fatty acids, monoglycerides, diglycerides, and high melting point triglycerides are mainly removed as crystalline parts. The fatty acid content of the obtained filtrate is about half of the fatty acid content of the raw material. The remaining fatty acids are mainly unsaturated fatty acids. By adding a liquid oil substance to this filtrate and performing alkaline deoxidation, it is possible to reduce the loss of the intermediate melting point glycerol ester foot. Further, in this alkaline deoxidation, residual monoglycerides and diglycerides are removed. By washing this deoxidized oil with hot water and/or bleaching it as necessary, and further solvent fractionating it with acetone, it is possible to separate and fractionate the intermediate melting point glycerol ester of good quality in the crystalline part. By bleaching and deodorizing the medium-melting point glycerol ester, it can be used as a cocoa butter substitute or a raw material for a cocoa butter substitute. EXAMPLES The present invention will be explained in more detail with reference to Examples below. Comparative Example A A transesterification reaction was performed on 9 parts of stearic acid and 10 parts of monkey fat soft part oil in a hexane solvent using lipase derived from Rhizopus deremer to obtain a reaction oil with an acid value of 97.7 (fatty acid content: 49%). Compositional analysis of the silylated product of this reaction oil by gas chromatography (relative sensitivity not taken into account) revealed that fatty acids were 50.2%;
Diglyceride was 6.1% and triglyceride was 43.4%. 4 parts of hexane was added to 1 part of this reaction oil, heated and dissolved, cooled to 4°C, and filtered into a crystal part and a filtrate part. Yield of filtrate part is 60.7%, acid value 53.2
(Fatty acid content approximately 26.6%). In the compositional analysis of silylated compounds in this filtrate by gas chromatography (relative sensitivity not taken into account), fatty acids
32.4%, diglyceride 6.0%, triglyceride 61.6
It was %. 4 parts of liquid oil was mixed with 6 parts of this filtrate, and alkaline deacidification was performed. Compositional analysis of the silylated product of the deoxidized oil by gas chromatography (relative sensitivity not taken into account) revealed that it contained 0% fatty acids, 6.1% diglycerides, and 93.9% triglycerides.
Mix 1.7 parts of n-hexane with 1 part of this deoxidized oil,
After heating and dissolving, the mixture was cooled and solvent fractionation was carried out at -7°C. The yield of the crystalline part was 31.5%, and when the properties of the obtained crystalline part were examined, it was found to be very suitable as a raw material for a cocoa butter substitute. Example 1 1 part of the deoxidized oil obtained in Comparative Example A was mixed with 2.2 parts of acetone, heated and dissolved, and then subjected to solvent fractionation at 0°C. The yield of the crystalline part was 28.7%, and when the properties of the obtained crystalline part were examined, it was found to be very suitable as a raw material for a cocoa butter substitute. In particular, it was a raw material with good tempering workability for thiyocolate. Comparative Example B 9 parts of stearic acid and 10 parts of palm soft part oil were subjected to a transesterification reaction using lipase derived from Rhizopus delemer in a hexane solvent to obtain a reaction oil with an acid value of 96.2 (fatty acid content: 48%). Compositional analysis of the silylated product of this reaction oil by gas chromatography (relative sensitivity not taken into account) revealed that fatty acids were 57.4%;
Diglyceride was 5.6% and triglyceride was 36.8%. 4 parts of hexane was added to 1 part of this reaction oil, heated and dissolved, and then fractionated at 2°C. The yield of the filtrate part is
61.3%, acid value 58.4 (fatty acid content approximately 29.2%). Compositional analysis of the silylated product in this filtrate by gas chromatography (relative sensitivity not taken into consideration) revealed that it was 33% fatty acids, 6.1% diglycerides, and 60.9% triglycerides. 5 parts of liquid oil was mixed with 5 parts of this filtrate, and alkaline deacidification was performed. Compositional analysis of silylated deacidified oil by gas chromatography (relative sensitivity not taken into consideration) revealed 0% fatty acids, 3.9% diglycerides, and 3.9% triglycerides.
It was 96.1%. Add n-hexane to 1 part of this deoxidized oil.
1.5 parts were mixed, heated and dissolved, then cooled and subjected to solvent fractionation at -7°C. The yield of the crystalline portion was 19.1%, and when the properties of the obtained crystalline portion were examined, it was found to be very suitable as a raw material for a cocoa butter substitute. Comparative Example 1 The reaction oil (acid value 97.7) of the transesterification reaction using lipase in Comparative Example A was deacidified by steam distillation. This method is a deoxidizing method generally called physical refining. This deoxidized oil had an acid value of 12.8. This deoxidized oil was further deoxidized by a conventional alkaline deoxidation method. This alkali-deoxidized oil was subjected to two-stage solvent fractionation to separate the intermediate melting point glycerol ester, but it could not be used as a cocoa butter substitute. Comparative Example 2 The reaction oil (acid value 97.7) from the transesterification reaction using lipase in Comparative Example A was deacidified by a normal alkaline deacidification method, but the neutral oil was not separated from the foots. Comparative Example 3 In the process of Comparative Example A, the reaction oil from the transesterification reaction using lipase was subjected to two-step fractionation using hexane without performing alkaline deacidification. When the properties of the obtained crystalline portion were examined, the fatty acid content was approximately 30%, and it was found that almost no fatty acid had been removed. Comparative Example 4 In the process of Comparative Example A, without performing the final fractionation with n-hexane, the reaction oil of the transesterification reaction using lipase was fractionated with hexane and then deoxidized with alkali. I investigated the properties. This deoxidized oil contained a mixture of medium and low melting point parts and could not be used as a raw material for cocoa butter substitute fat. Comparative Example 5 50 g of the reaction oil obtained in Comparative Example A (acid value: 97.7) for transesterification using lipase is placed in an Erlenmeyer flask, and dissolved in 150 g of acetone as a solvent. Although this solution was cooled to -10°C and ammonia gas was blown into it, crystals derived from the triglyceride and fatty acid contained in the reaction oil were formed, and it was not possible to separate the precipitate of the ammonium salt of the fatty acid. Comparative Example 6 4 parts of acetone was added to 1 part of the reaction oil obtained in Comparative Example A.
After adding 50% of the solution and heating to dissolve, solvent fractionation was carried out at 18°C. The yield of the filtrate was 80% and the acid value was 89.5. 4 parts of liquid oil was mixed with this filtrate portion and alkaline deacidification was performed, but the neutral oil was not separated from the foots. Comparative Example 7 4 parts of hexane was added to 1 part of the reaction oil obtained in Comparative Example A.
After heating and dissolving, the mixture was cooled to 4°C and filtered into a crystal part and a filtrate part. The obtained filtrate was mixed with 2.2 parts of acetone without alkaline deoxidation, heated and dissolved, and then subjected to solvent fractionation at 0°C. The acid value of the obtained crystalline part was 15.
Therefore, it could not be used as a cocoa butter substitute fat. Subsequently, 1.5 parts of liquid oil was added to this and alkaline deoxidation was performed, but a large amount of foots was formed and deoxidation loss was significant, and the yield was only 68% of the crystalline portion before deoxidation. It was low. Comparative Example 8 4 parts of hexane was added to 1 part of the reaction oil obtained in Comparative Example A.
After heating and dissolving, the mixture was cooled to 4°C and filtered into a crystal part and a filtrate part. The solvent in the obtained filtrate was removed by evaporation,
Fatty acids were then removed by steam distillation. This was mixed with 4 parts of acetone, heated and dissolved, and then subjected to solvent fractionation at 0°C, but the resulting crystalline part had a change in the composition of the glycerol ester.
The physical properties were impaired and it could not be used as a cocoa butter substitute. Comparative Example 9 1 part of the reaction oil obtained in Comparative Example A was added with 1.5 parts of liquid oil.
alkaline deoxidation was carried out. However, the amount of foots produced was large and it was not possible to separate the neutral oil from the foots. Comparative Example 10 4 parts of hexane was added to 1 part of the reaction oil obtained in Comparative Example A.
After heating and dissolving, the mixture was cooled to 4°C and filtered into a crystal part and a filtrate part. This filtrate portion was subjected to alkaline deacidification without adding liquid oil, but the neutral oil was not separated from the foots. Production Example Prepared by mixing the oils and fats obtained in Example 1 and Comparative Examples A and B and palm central oil at a certain ratio.
Chiyocolate was produced using a cocoa butter substitute. The results are shown in Table 1.

[Table] Although any oil or fat can be used as a cocoa butter substitute, the oil or fat obtained in Example 1 is particularly superior in workability than the oil or fat obtained in Comparative Examples A and B. it is obvious.

Claims (1)

[Claims] 1. Consists of fatty acids and glycerol esters,
A method for separating medium-melting point glycerol esters from a mixture having a fatty acid content of 20% or more, in which fatty acids and high-melting point glycerol esters are first separated as crystals by solvent fractionation with hexane, and then the obtained A liquid oil substance is added to the resulting filtrate, and residual fatty acids are removed by alkaline deoxidation.The alkaline deoxidized oil is then subjected to solvent fractionation using acetone to convert the medium melting point glycerol ester into the crystalline portion and the low melting point glycerol ester to the filtrate. A method for separating glycerol esters, the method comprising separating glycerol esters as two parts. 2. The method for separating glycerol esters according to claim 1, wherein the liquid oil substance is a liquid glycerol ester.