JPH11123097A - Production of diglyceride - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a diglyceride efficiently which is used as an additive and the like for improving plasticity of fat, by partial hydrolysis of fat (1st stage) followed by addition of glycerol to the obtained product to esterify (2nd stage). SOLUTION: The diglyceride is obtained inexpensively and efficiently by carrying out partial hydrolysis of fat by the steam decomposition at 190-240 deg.C or in the presence of an enzyme giving 67-96 wt.% of fatty acid as a product (1st stage) followed by addition of glycerol to the obtained product to carry out esterification in the presence of an immobilized enzyme or intracellular enzyme (2nd stage). The obtained diglyceride has a 'diglyceride purity' [diglyceride wt.%/(diglyceride wt.% + triglyceride wt.%)×100] of 80% or higher and is useful as an additive and the like for improving plasticity of fat, or a base for food, medicine, cosmetic, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing diglycerides by subjecting a fat or oil to partial hydrolysis and adding glycerin to the decomposed product to carry out an esterification reaction.

[0002]

2. Description of the Related Art Diglycerides are used as additives for improving the plasticity of fats and oils, or as base materials in the fields of foods, pharmaceuticals, cosmetics and the like.
Examples of the method for producing diglycerides include an esterification or transesterification method and a glycerolysis method. As a typical example of the esterification or transesterification method, there is Japanese Patent Publication No. 6-65311 in which a fatty acid or a lower alcohol ester thereof and glycerin are immobilized.
It has been shown that a diglyceride is obtained by reacting in the presence of a 1,3-position selective lipase and removing water or a lower alcohol produced by the reaction out of the system under reduced pressure. Thus, the esterification or transesterification method,
This is a production method in which a fatty acid or a lower alcohol ester thereof and glycerin are converted into partial glycerides in a one-step reaction, but each raw material is expensive and cannot be said to be satisfactory in terms of cost. When fats and oils are used as raw materials, generally, the steam decomposition reaction of fats and oils is usually 50 to 60 kg / cm ² , 250 to 260 ° C.
However, the decomposition product is strongly colored and requires a distillation treatment. When the distillation treatment is performed, the yield is reduced by about 10% when vegetable oil or the like is used as a raw material, and the active components such as plant sterols present in the vegetable oil are lost as distillation residues. Furthermore, in the glycerolysis reaction using fats and oils as a raw material, Japanese Patent Publication No. 6-65310 can be mentioned as a representative example. According to this, it has been shown that an alcohol group exchange reaction between oil and fat and glycerin is performed in the presence of immobilized 1,3-position selective lipase to obtain diglyceride. However, this method requires more than 10 hours to complete the reaction, and is not satisfactory in industrial productivity.

[0003]

Means for Solving the Problems The present inventors have studied a method for producing diglyceride efficiently and with high purity by using relatively inexpensive fats and oils as raw materials, and completed the present invention. That is, the present invention relates to a process for producing diglyceride, comprising a first-stage reaction in which a partial hydrolysis reaction of fats and oils is performed, and a second-stage reaction in which glycerin is added to the obtained decomposition product to perform esterification. is there.

[0004]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, first, a first-stage reaction mainly involving a partial hydrolysis reaction of fats and oils is performed. Examples of the fats and oils used in the present invention include general vegetable and animal fats or processed fats or oils having a saturated or unsaturated fatty acid group having 4 to 22 carbon atoms, or a mixed fat or oil thereof. For example,
Rapeseed oil, soybean oil, cottonseed oil, olive oil, corn oil, coconut oil, tallow, lard, fish oil and the like can be used.

There is no particular limitation on the method of partially hydrolyzing fats and oils, and water may be added preferably in an amount of 20 to 180 parts by weight to 100 parts by weight of fats and oils to perform partial hydrolysis based on a conventionally known method. Specific methods include a method using an enzyme for decomposition and a method using a steam decomposition method. When performing partial hydrolysis by an enzymatic method, preferably 20 to 70 ° C.
Under the following temperature conditions. Enzyme forms can be used as immobilized enzymes, intracellular enzymes, or unimmobilized free enzymes. Examples of an apparatus to be used include a stirring tank, a fixed bed, a fluidized tank or a combination thereof, and a batch, continuous or semi-continuous reaction can be performed. on the other hand,
When partial hydrolysis is performed by the steam decomposition method, 190 to 24
It is desirable to carry out the reaction at a temperature of 0 ° C, preferably 200 to 235 ° C. Examples of an apparatus to be used include an autoclave and a continuous decomposition tower, which can perform batch, continuous, or semi-continuous reaction. In the present invention, since the purpose is to finally obtain diglyceride, it is not necessary to decompose 100% in the first-stage hydrolysis of fats and oils, and partial glycerides and triglycerides may be present. It is preferable to operate so that the fatty acid content is 67 to 96% by weight, preferably 75 to 93% by weight. The reaction time can be shortened by performing the second-stage esterification in a state where the partial glyceride remains. The decomposed oil obtained by the first-stage partial hydrolysis reaction preferably has less coloring, and specifically, 10R + Y (Red value × 10 + Yellow) of the Lovibond method.
It is desirable that the hue has a value of 40 or less, preferably 30 or less.

After the completion of the partial hydrolysis, the oil phase and the aqueous phase are separated by a method such as centrifugation, and the glycerin distributed in the aqueous phase is used for the second-stage esterification reaction after removing water. You can also. Further, the oil phase and the aqueous phase may be used as they are in the second-stage esterification reaction without being separated. The partially decomposed product is preferably used in the second-stage esterification reaction without being subjected to a distillation treatment. Incidentally, treatments such as hardening and separation for the purpose of adjusting the hardness may be performed within a range in which a trace component is not lost.

[0007] In the present invention, since the esterification reaction is carried out without performing the distillation treatment after the partial hydrolysis reaction of fats and oils, when vegetable oil is used as a raw material, plant sterols present in the vegetable oil are converted into a final diglyceride product. It has the advantage of being able to remain.

In the second-stage esterification reaction, glycerin is added to the partially decomposed product obtained in the first-stage reaction so that the ratio of fatty acid groups to 1 mol of glycerin groups is 0.8 to 2.5 mol. To carry out an esterification reaction. The reaction is
It is preferably carried out in the presence of an enzyme having ester activity such as lipase or esterase, more preferably in the presence of immobilized or 1,3-position selective lipase in the cells. Known methods for immobilization are described, for example, in "Immobilized Enzymes" edited by Ichiro Chibatake, Kodansha, pp. 9-85 and "Immobilized Biocatalysts" edited by Ichiro Chibatake, Kodansha, pp. 12-101. Therefore, it is preferable to immobilize on an ion exchange resin. Rhizops (Rhizop) is one of the 1,3-selective lipases used for immobilization.
lipase, pancreatic lipase and the like derived from microorganisms such as genus us), Aspergillus and Mucor. For example, Rhizopus del
emar), Rhizopus japonicu
s), lipases derived from Rhizopus niveus, Aspergillus niger, Mucor javanicus, Mucor miehei and the like can be used. As a commercially available immobilized 1,3-position selective lipase, there is a trade name "Lipozyme IM" manufactured by Novo Nordisk Bioindustry. The intracellular 1,3-position selective lipase is obtained by adsorbing or binding the 1,3-position selective lipase to microbial cells, and a commercially available product is "Olipase" manufactured by Nagase & Co., Ltd.

In the reaction, no water is added except for the lipase preparation, the partially decomposed product obtained in the first-stage reaction, and the water contained in glycerin and the like, and no organic solvent such as hexane is added. Do with. In order to promote the esterification reaction, it is preferable to remove water and reaction product water from the raw material as much as possible out of the reaction system.
Dehydration using a water-absorbing material such as molecular sieves or ventilation of a dry inert gas into the reaction vessel is considered.
A vacuum dehydration method that causes less contamination of the reaction system is preferable. Examples of an apparatus to be used include a stirring tank, a fixed bed, a fluidized tank or a combination thereof, and a batch, continuous or semi-continuous reaction can be performed.

[0010] The reaction product obtained in the second-stage esterification reaction is separated from a lipase preparation, and unreacted fatty acids and monoglycerides are removed by conventional or well-known separation / purification means alone or in combination as appropriate. High-purity diglyceride can be obtained with good yield. In particular, if a molecular distillation treatment is performed, a fatty acid and a monoglyceride are separated as a fraction, and a composition rich in diglycerides containing a part of triglycerides as a residue can be obtained. Therefore, in this method, as the definition of diglyceride purity, the diglyceride concentration after molecular distillation is assumed,
[Diglyceride weight% / (diglyceride weight% + triglyceride weight%) × 100] was employed. According to the present invention, highly pure diglyceride of 80% or more can be obtained. The separated lipase preparation can be used repeatedly for the reaction.

[0011]

【Example】

Example 1 rapeseed white oil 857 g in a 2 liter autoclave
And 343 g of water were mixed and hydrolyzed for 10 hours while stirring at 200 ° C. After the reaction was completed, the reaction mixture was cooled and centrifuged to separate an oil phase and an aqueous phase. Next, Rhizops Japonicas (Rhiz
Opus japonicus) is a 1,3-position selective lipase "Lilipase A-10, manufactured by Nagase & Co., Ltd."
Lipase obtained by immobilization on a commercially available anion exchange resin (trade name: Duolite A-568, manufactured by Diamond Shamrock Co., Ltd.) by the immobilization method described in Example 1 of the publication
34 g, 300 g of the oil phase obtained in the first-stage reaction and 39 g of glycerin were mixed in a four-necked flask (fatty acid group / glycerin group = 2), and the pressure in the system was reduced to 5 mmHg while stirring at 40 ° C. For 4 hours. Thereafter, the lipase preparation was separated from the reaction product by filtration. Samples of the first-stage reaction product and the second-stage reaction product were partially taken and subjected to alkali titration to determine the amount of fatty acid. Further, the samples were trimethylsilylated and the compositions of triglyceride, diglyceride and monoglyceride were determined by gas chromatography. Table 1 shows the results.

Example 2 Rapeseed white oil 857 g in an autoclave having a capacity of 2 liters
And 343 g of water were mixed and hydrolyzed for 5 hours while stirring at 220 ° C. After the reaction was completed, the reaction mixture was cooled and centrifuged to separate an oil phase and an aqueous phase. Next, 45 g of the same immobilized lipase as used in Example 1 and 400 g of the oil phase obtained in the first-stage reaction
Then, 51 g of glycerin and 51 g of glycerin were mixed in a four-necked flask (fatty acid group / glycerin group = 2), and a reaction was carried out for 4 hours while stirring at 40 ° C. while reducing the pressure of the system to 5 mmHg. Thereafter, the lipase preparation was separated from the reaction product by filtration. Example 1 below
The composition of the reaction product was determined by the same operation as described above. Table 1 shows the results.

Comparative Example 1 rapeseed rapeseed oil 857 g in a 2 liter autoclave
And 343 g of water were mixed and hydrolyzed for 4 hours while stirring at 250 ° C. After the reaction was completed, the reaction mixture was cooled and centrifuged to separate an oil phase and an aqueous phase. Next, 35 g of the same immobilized lipase as used in Example 1 and 300 g of the oil phase obtained in the first-stage reaction
And 48 g of glycerin were mixed in a four-necked flask (fatty acid group / glycerin group = 2), and a reaction was carried out for 4 hours while stirring at 40 ° C. while reducing the pressure of the system to 5 mmHg. Thereafter, the lipase preparation was separated from the reaction product by filtration. The oil phase obtained in the first-stage reaction was distilled at 160 to 250 ° C. and 1 mmHg or less to obtain a fatty acid. The yield of fatty acids was 89%. 300 g of the distilled fatty acid, 49 g of glycerin and 35 g of the same immobilized lipase used in Example 1 were mixed in a four-necked flask, and the composition of the reaction product was determined by the same operation as in Example 1 below. Table 1 shows the results.

Example 3 Non-selective lipase ("Lipase O") was added to 1000 g of soybean white squeezed oil.
F ", manufactured by Meito Sangyo Co., Ltd.) and 500 g of water were mixed in a four-necked flask and hydrolyzed for 1 hour while stirring at 40 ° C. After the reaction, the oil phase and the aqueous phase were separated by centrifugation. Next, the same immobilized lipase as used in Example 1
34 g, 300 g of the oil phase obtained in the first stage reaction and 38 g of glycerin were mixed in a four-necked flask (fatty acid group / glycerin group = 2), and the composition of the reaction product was obtained by the same operation as in Example 1 below. I asked. Table 1 shows the results.

Comparative Example 2 A reaction was carried out under the same conditions as in Example 3 except that 500 g of water was changed to 100 g of water. Table 1 shows the results.

[0016]

[Table 1]

The first to third embodiments and the first comparative example
The hue of the partial hydrolyzate at the stage was measured by the Lovibond method, and quantified by 10R + Y (Red × 10 times + Yellow) value. The larger the value, the more intense the coloring. Further, the reactants in the second stage of Examples 1 to 3 and Comparative Example 1 were subjected to a molecular distillation treatment to obtain a composition rich in diglycerides, and then subjected to a decolorizing treatment, which is a usual fat and oil purification treatment. The hue of the composition thus obtained was measured, and the amount of plant sterol in the composition was measured by the following method. Table 2 shows the results. As shown in Table 2, the composition obtained by distilling the first-stage partial hydrolyzate of Comparative Example 1 and used in the second-stage reaction had a hue (10R + Y) even after decolorization treatment. 31
And the coloring could not be reduced, and the color was brown. (Quantification of plant sterol) To 1 g of the oily composition obtained in each step, 10 ml of 1N KOH ethanol solution was added, and
After 1 hour of saponification decomposition at 15 ° C., 15 ml of distilled water was added.
Further, 10 ml of n-hexane and cholesterol as an internal standard
After adding and mixing 1 ml of a solution of n-hexane at a concentration of 10 mg / ml, the hexane layer was sampled, desolventized, trimethylsilylated, and analyzed by gas chromatography. The amount of plant sterol was calculated from the area ratio between cholesterol and plant sterol. In addition, although the ester form of a free sterol and a fatty acid coexists in a normal plant sterol, the free sterol is quantified because the present analysis method is decomposed by saponification.

[0018]

[Table 2]

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naoto Yamada Kao Corporation Research Lab.

Claims (6)

[Claims] 1. A process for producing diglycerides, comprising a first-stage reaction in which a partial hydrolysis reaction of fats and oils is carried out, and a second-stage reaction in which glycerin is added to the obtained decomposed product to carry out esterification. 2. In the first step, partial hydrolysis of fats and oils is performed until the amount of decomposed fatty acids becomes 67 to 96% by weight, and glycerin is added to the decomposed product obtained in the second step to carry out the esterification reaction. A process for producing a diglyceride, characterized in that a high purity diglyceride having a diglyceride purity [diglyceride weight% / (diglyceride weight% + triglyceride weight%) × 100] of 80% or more is obtained by performing the method. 3. The process for producing diglyceride according to claim 1, wherein the first-stage partial hydrolysis is carried out under conditions that suppress coloring of the decomposed product. 4. The process for producing diglyceride according to claim 1, wherein the first-stage partial hydrolysis is carried out at 190 to 240 ° C. by a steam decomposition method. 5. The method for producing diglyceride according to claim 1, wherein the first-stage partial hydrolysis is performed in the presence of an enzyme. 6. The method for producing diglyceride according to claim 1, wherein the second step of esterification is carried out in the presence of an immobilized enzyme or an intracellular enzyme.