JP4522064B2 - Method for dry separation of fats and oils - Google Patents

Description

  The present invention relates to a method for dry fractionation of fats and oils containing 60% by weight or more of symmetric triglycerides.

Fats and oils containing a large amount of symmetrical triglycerides such as cacao butter, shea fat, mango kernel oil, monkey fat, iripe fat, and palm oil have been utilized as fats and oils for chocolate and creams taking advantage of their properties.
These fats and oils may be used as they are, but in order to use them as high-quality chocolate fats and oils having high snapping properties and good mouthfeel, for example, by separating solvents using acetone or hexane, symmetrical triglycerides are used. Concentration in the crystal fraction has been conventionally performed.

However, although the symmetric triglyceride is concentrated in the crystal fraction obtained by the solvent fractionation as described above, it is necessary to completely remove the solvent by bleaching and deodorizing treatment, which is expensive and complicated in operation. There was a problem.
Therefore, in recent years, simpler and more economical dry fractionation has been tried as a fractionation method for concentrating symmetric triglycerides.

  This dry fractionation is generally a method of cooling a fractionated raw oil and fat while stirring in a crystallization tank to precipitate crystals, and then obtaining a crystal fraction and a liquid fraction by pressing and / or filtration. In this method, when an oil containing 60% by weight or more of symmetric triglyceride is used, fine crystals are precipitated and the whole is solidified, so that it cannot be separated into a crystal fraction and a liquid fraction. If it is carefully crystallized slowly over a very long time, it can be separated into a crystalline fraction and a liquid fraction, but it is not efficient and the fluidity of the crystallized slurry Therefore, the amount of crystals that can be precipitated is about 30% as the solid fat content, and the yield of the crystal fraction is low compared to the solvent fraction. In addition, crystals precipitated under stirring tend to embrace the liquid fraction, and the purity of the crystal fraction tends to decrease.

  Therefore, as a dry fractionation method for obtaining a crystal fraction with higher yield and higher purity, the seed is added at a temperature 3 to 10 ° C. higher than the solidification temperature and crystallization is continued to some extent. A method of promoting crystallization (for example, refer to Patent Document 1), and a method of crystallization at a relatively fast cooling rate of 0.1 to 2 ° C./min in a temperature range where crystallization starts (for example, 35 to 20 ° C. for palm oil) ( For example, see Patent Document 2). However, when crystallization of the separated raw material fats and oils is allowed to stand in this way, in order to obtain granular crystals that can be squeezed and / or filtered, the crystals that have precipitated during crystallization settle and become non-uniform crystallization state. In many cases, a long crystallization time is required, so that it is not an efficient crystallization method. On the other hand, when the cooling crystallization is advanced rapidly, the crystallization state becomes uniform, but the crystal becomes too fine, and there is a disadvantage that it is difficult to obtain granular crystals that can be pressed and / or filtered.

JP-A-60-101197 Japanese Patent Laid-Open No. 2-80495

  It is an object of the present invention to deposit granular crystals suitable for pressing and / or filtration uniformly and quickly when dry-separating fats and oils containing 60% by weight or more of symmetric triglycerides, and to produce symmetric triglycerides in a high yield. An object of the present invention is to provide a method for dry fractionation of fats and oils to obtain a crystal fraction having a high content.

As a result of intensive studies to achieve the above object, the present inventors have found that by taking a specific temperature condition, granular stable crystals can be deposited uniformly, and the present invention has been achieved. .
That is, the present invention has been made on the basis of the above-mentioned findings, and fats and oils containing 60% by weight or more of symmetric triglycerides are completely dissolved, and this is rapidly cooled and crystallized to −20 ° C. to 20 ° C. by standing. After precipitating the unstable crystal, it is kept for 12 to 94 hours at a temperature 1 to 15 ° C. lower than the melting point of the stable crystal of the oil to precipitate granular stable crystal, which is separated into a crystal fraction and a liquid fraction The present invention provides a method for dry fractionation of fats and oils containing 60% by weight or more of symmetrical triglycerides.

  When dry-separating fats and oils containing 60% by weight or more of symmetric type triglycerides, the completely dissolved oils and fats are rapidly cooled and crystallized by standing to precipitate unstable crystals. By holding at a temperature 1 to 15 ° C. lower than the melting point, it is possible to uniformly and quickly precipitate granular crystals suitable for pressing and / or filtration, and a crystal image having a high content of symmetrical triglyceride useful for fats and oils for chocolate, etc. Minutes can be obtained efficiently at low cost.

Hereinafter, the dry separation method for fats and oils of the present invention will be described in detail.
The symmetric triglyceride here is one in which an unsaturated fatty acid is bonded to the 2-position of the triglyceride and a saturated fatty acid is bonded to the 1,3-position. Examples of the unsaturated fatty acid include oleic acid and linoleic acid, and examples of the saturated fatty acid include palmitic acid, stearic acid, arachidic acid, and behenic acid.

  Examples of the “fat containing 60% by weight or more of symmetric triglyceride” that is a raw material oil for fractionation of the dry fraction of the present invention include cacao butter, monkey fat, iripe fat, mango kernel oil, kokum fat, shea fat, palm oil, and duper. Fats and oils such as fats, mora fats, full wall fats and Chinese tallows, and fractionated fats of these fats and oils can be used, and one or more of these can be used.

  In the dry fractionation method of the present invention, the fractionated raw material fat is first completely heated and dissolved. Specifically, the fractionated raw material fat is preferably dissolved at 40 ° C or higher, more preferably 50 ° C or higher, and most preferably 50 to 70 ° C for 30 minutes or longer. If this heating and dissolution is insufficient, unstable crystals are not precipitated by subsequent rapid crystallization, and fine stable crystals are likely to be precipitated. In that case, the entire fats and oils are uniformly fine in the subsequent aging process. There is a risk that it may become impossible to squeeze and / or filter.

Next, the heated and dissolved fractionated raw material oil and fat is rapidly cooled and crystallized under standing to precipitate unstable crystals. Before the rapid cooling and crystallization, the fractionated raw material oil and fat is subjected to 40 to 50 ° C., particularly 40 to 45 ° C. It is preferable to cool it.
Next, this separated raw material oil and fat is rapidly cooled in a stationary state to precipitate unstable crystals such that the amount of crystals is preferably 40 to 90% by weight, more preferably 50 to 85% by weight as the solid fat content. Let As a cooling method, first, it is rapidly cooled to -20 ° C to 20 ° C, preferably 0 ° C to 15 ° C at a cooling rate of 1 ° C / hour to 70 ° C / hour, preferably 10 ° C / hour to 50 ° C / hour, Thereafter, the temperature may be maintained for 10 minutes to 12 hours, preferably 10 minutes to 5 hours. What is necessary is just to adjust suitably the cooling rate at this time, the temperature to hold | maintain, and time so that the amount of crystals may become the said range. Here, when the amount of crystals is less than 40% by weight as the solid fat content, it may take a long time to obtain granular crystals in the subsequent aging step, and when the amount exceeds 90% by weight, the granular crystals are fine. There is a risk that subsequent compression and / or filtration may become difficult. The solid fat content indicates the ratio of solid fat to the total fat and oil, and can be determined according to the method described in AOCS Official Methods Cd16b-93, for example.

The unstable crystal is preferably an α-form crystal or a β-prime crystal, which will be described later, and the α-form crystal is advantageous in that the precipitation of granular stable crystals becomes rapid in the subsequent aging step. More preferred. Even in the β prime type crystal, it is possible to precipitate a granular stable crystal in the aging process, but a longer aging time is required as compared with the α type crystal.
The unstable crystal here is a crystal that is identified as one of α form, γ form, or β prime form when the crystal is diffracted by X-ray, and the stable crystal is when the crystal is diffracted by X-ray diffraction. , A crystal identified as β form. Specifically, when the short face spacing is measured according to the method described in AOCS Official Methods Cj2-95, it is slightly different depending on the type of oil and fat. Shape, 3.8 angstroms and 4.2 angstroms with characteristic peaks can be identified as β prime, and 4.6 angstroms with characteristic peaks can be identified as β forms. it can.

Next, the fractionated raw material oil and fat on which unstable crystals are precipitated is subjected to an aging step. In this aging step, the temperature is 1 to 15 ° C., preferably 1 to 9 ° C., more preferably 2 to 6 ° C. lower than the melting point of the stable crystals of the fractionated raw oil and fat, preferably 12 to 94 hours, more preferably 20 to 20 ° C. Hold for 80 hours to precipitate granular stable crystals.
The temperature of 1 to 15 ° C. lower than the melting point of the stable crystals of the above-mentioned fractionated raw material oils and fats, and the precipitation of the granular stable crystals is specifically, for example, fractionation where the melting point of the stable crystals is 34 ° C. If it is raw material fats and oils, it will hold | maintain at 19-33 degreeC, Preferably it is 25-33 degreeC, More preferably, it will hold | maintain at 28-32 degreeC. By this aging step, after a part or most of the unstable crystal is dissolved, a granular stable crystal having a stable crystal form is precipitated. In addition, the granular stable crystal is a spherical aggregate crystal of about 50 μm to 2 mm. In addition, the melting point of the stable crystal is the melting point of the crystal that is identified as the β form when the crystal is X-ray diffracted. In the present invention, the stable crystal of the fractionated raw material oil / fat has a melting point of 1 at 26 ° C., which is obtained by sampling the fractionated raw material oil / fat completely dissolved in a capillary having an inner diameter of 1 mm and an outer diameter of 2 mm, and cooling and solidifying at 0 ° C. Except for the weekly stabilization treatment, it can be determined by measuring the rising melting point according to the standard oil analysis method 2.2.4.2-1996.

From the temperature at which the unstable crystals are precipitated, the speed of temperature rise when the temperature is lowered by 1 to 15 ° C. below the melting point of the stable crystals of the fractionated raw material fat is preferably 1 ° C./hour to 70 ° C./hour, More preferably, it is 3 degreeC / hour-60 degreeC / hour.
Moreover, although the preferable amount of crystals after the aging step varies depending on the purpose, it is 30 to 50% by weight, more preferably 35 to 50% by weight as the solid fat content, and it can be easily applied in the subsequent pressing and / or filtration step. This is preferable in that the crystalline fraction and the liquid fraction can be separated.
In the ripening step, it is preferable that the granular crystals are precipitated without stirring and in a state of not flowing as much as possible. In particular, it is preferable to leave it stationary. However, it may be allowed to flow temporarily after the granular crystals are precipitated to some extent, for example, the granular crystals are precipitated and transferred to another container while maintaining fluidity, and further crystallization is continued. Such an operation may be performed.

Next, it is separated into a crystalline fraction and a liquid fraction by pressing and / or filtration. As this separation method, it is preferable to use a compression filtration method such as a filter press. Moreover, although the method currently performed by the normal dry fractionation etc. can be applied to the separation method, since the amount of the crystal fraction is large, the slurry may not show fluidity, and it is inserted into a filter for separation. Sometimes it is better to mix in advance and make it fluid before separation.
Of course, it is possible to further separate the crystal fraction and liquid fraction of the present invention thus obtained.

The content of the symmetrical triglyceride in the crystal fraction obtained by the fractionation method of the present invention is preferably 75 to 99% by weight, more preferably 80 to 95% by weight, and most preferably 85 to 95% by weight.
The content of the symmetric triglyceride in the liquid fraction obtained by the fractionation method of the present invention is preferably 10 to 85% by weight, more preferably 10 to 80% by weight, and most preferably 10 to 75% by weight. .

  Applications of the crystal fraction obtained by the fractionation method of the present invention include adjusting the hardness of chocolate, fats and oils for white chocolate, raw oils and fats for margarine shortening, and the like. The liquid fraction can also be used to adjust the hardness of chocolate, raw oils and fats for margarine and shortening, oils and fats for ice cream, ice coating, and O / W emulsified oils and fats such as whipped cream. is there.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not restrict | limited at all by these Examples.

[Example 1]
2 kg of cocoa butter from Malaysia (containing 87% by weight of symmetric triglyceride, melting point of stable crystal at 34 ° C.) was placed in a 30 × 40 × 5 cm aluminum tray. The tray was placed in an air thermostat, and the cocoa butter was completely dissolved at 50 ° C. over 2 hours, and then allowed to cool to 40 ° C. Subsequently, it was cooled to 5 ° C. at a cooling rate of 11 ° C./1 hour, and kept at 5 ° C. for 15 minutes for crystallization. The solid fat content after crystallization was 78% by weight, and the crystal form was a mixture of α form and β prime form. Subsequently, the temperature was raised to 30 ° C. at a rate of 5 ° C./hour, and then kept at 30 ° C. for 36 hours for aging. The solid fat content after aging was 39% by weight, and the crystal form was β form. The obtained granular crystals were inserted into a filter press with an auger feeder, pressurized from 0.2 MPa to 2 MPa in 0.1 MPa for 10 minutes, further held at 2 MPa for 30 minutes and squeezed and filtered to obtain a cocoa butter crystal Got the minute. This crystal fraction contained 89% by weight of symmetric triglycerides. The yield of this crystal fraction was 59% by weight.

[Comparative Example 1]
2 kg of cocoa butter used in Example 1 was placed in a 30 × 40 × 5 cm aluminum tray. The tray was placed in an air thermostat and the cocoa butter was completely dissolved at 50 ° C. over 2 hours, then cooled to 30 ° C. at a cooling rate of 11 ° C./1 hour, and held at 30 ° C. for 60 hours. Only a few crystals were precipitated at the bottom of the tray, and a crystal fraction that could be squeezed and filtered was not obtained.

[Example 2]
200 g of deacidified and decolorized monkey fat (containing 71% by weight of symmetric triglyceride, melting point of stable crystal at 35 ° C.) was placed in a 12 × 18 × 5 cm stainless steel tray. The tray was placed in an air thermostat, and the monkey fat was completely dissolved at 50 ° C. over 2 hours, and then allowed to cool to 40 ° C. Then, it was cooled to 5 ° C. at a cooling rate of 50 ° C./hour, and kept at 5 ° C. for 1 hour for crystallization. The solid fat content after crystallization was 83% by weight, and the crystal form was α form. Subsequently, the temperature was raised to 31 ° C. at a rate of 5 ° C./hour, and then kept at 31 ° C. for 72 hours for aging. The solid fat content after aging was 46% by weight, and the crystal form was β form. The obtained granular crystals were inserted into a filter press, pressurized from 0.2 MPa to 1 MPa in increments of 0.1 MPa over 20 minutes, further held at 1 Ma for 30 minutes, and squeezed and filtered to obtain a crystalline fraction of monkey fat. It was. This crystal fraction contained 88% by weight of symmetrical triglycerides. The yield of this crystal fraction was 63% by weight.

[Comparative Example 2]
200 g of monkey fat used in Example 2 was placed in a 12 × 18 × 5 cm stainless steel tray. The tray was placed in an air thermostat and the monkey fat was completely dissolved at 50 ° C. over 2 hours, then cooled to 31 ° C. at a cooling rate of 11 ° C./1 hour, and held at 31 ° C. for 68 hours. Crystals precipitated at the bottom and separation of the liquid fraction was observed. These were subjected to pressure filtration in the same manner as in Example 2 to obtain a crystalline fraction of monkey fat. This crystal fraction contained 88% by weight of symmetric triglyceride, but the yield of this crystal fraction was 58% by weight.

[Comparative Example 3]
Crystallization was performed in the same manner as in Comparative Example 2 except that the crystallization temperature in Comparative Example 2 was changed from 31 ° C. to 29 ° C., but the crystals were solidified uniformly, but the crystals were not granular, It was a fine crystal, and press filtration was impossible.

  As can be seen from the above Examples and Comparative Examples, in the fractionation method of Example 1 and Example 2 of the present invention, granular crystals suitable for squeeze filtration are obtained, whereas the yield of the crystal fraction is high. In the fractionation method of Comparative Examples 1 to 3 in which only the cooling step and no aging are performed, it is impossible to obtain crystals (Comparative Example 1) or the yield of the crystal fraction is poor (Comparative Example 2). The crystal fraction does not become granular, and compression filtration becomes impossible (Comparative Example 3).

Claims (1)

  A fat or oil containing 60% by weight or more of symmetric type triglyceride is completely dissolved, and after standing still, it is rapidly cooled to -20 ° C to 20 ° C to precipitate an unstable type crystal. 60% by weight or more of symmetric triglyceride, characterized in that it is kept at a temperature 1 to 15 ° C. lower than the melting point for 12 to 94 hours to precipitate granular stable crystals and separate them into a crystal fraction and a liquid fraction A method for dry separation of contained oils.