JP2006288404A - Method for producing diglyceride - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a diglyceride, by which the highly pure diglyceride can efficiently be produced at a lower cost than those by conventional esterification methods and by conventional glycerolysis methods, while preventing the quality deterioration of an oil, such as coloration, and the loss of fine amounts of active ingredients originated from the oil of raw material. <P>SOLUTION: This method for producing the diglyceride is characterized by comprising the first step reaction for partially hydrolyzing the oil and the second step reaction for adding and esterifying the obtained hydrolysate with glycerol. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing diglycerides in which fats and oils are partially hydrolyzed, and glycerin is added to the decomposed product to perform an esterification reaction.

Diglycerides are used as additives for improving plasticity of oils and fats, or as base materials in the fields of foods, pharmaceuticals, cosmetics and the like. Examples of the method for producing diglyceride include an esterification or transesterification method and a glycerolysis method. As a typical example of the esterification or transesterification method, there is Patent Document 1 (Japanese Patent Publication No. 6-65311). Presence of 1,3-position selective lipase in which fatty acid or a lower alcohol ester thereof and glycerin are immobilized It has been shown that diglycerides are obtained by reacting under the above conditions and removing water or lower alcohol produced by the reaction out of the system under reduced pressure. As described above, the esterification or transesterification method is a production method in which a fatty acid or a lower alcohol ester thereof and glycerin are converted into partial glycerides by a one-stage reaction. I can't say that. In addition, when fats and oils are used as raw materials, the steam decomposition reaction of fats and oils is generally carried out under conditions of 50 to 60 kg / cm ² and 250 to 260 ° C. However, the decomposition products are intensely colored and require a distillation treatment. When the distillation treatment is performed, when vegetable oil or the like is used as a raw material, the yield is reduced by about 10%, and active ingredients such as plant sterols present in the vegetable oil are lost as a distillation residue. Furthermore, Patent Document 2 (Japanese Patent Publication No. 6-65310) is given as a representative example of the glycerolysis reaction performed using fats and oils as a raw material. According to this, diglycerides are obtained by performing alcohol group exchange reaction between fats and oils and glycerin in the presence of 1,3-position selective lipase immobilized. However, this method requires 10 hours or more to complete the reaction, and is not satisfactory in industrial productivity.
Japanese Patent Publication No. 6-65311 Japanese Examined Patent Publication No. 6-65310

  Prior art methods for producing diglycerides are not satisfactory in industrial productivity.

  The present inventors have studied a method for producing diglycerides efficiently and with high purity using relatively inexpensive oils and fats as raw materials, and completed the present invention.

  That is, the present invention is a method for producing diglyceride characterized in that it comprises a first stage reaction in which a partial hydrolysis reaction of fats and oils and a second stage reaction in which glycerin is added to the obtained decomposition product to perform esterification. is there.

  Hereinafter, the present invention will be described in detail. In the present invention, first, the first stage reaction mainly including the 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 and oils having a saturated or unsaturated fatty acid group having 4 to 22 carbon atoms, or mixed fats and oils thereof. For example, rapeseed oil, soybean oil, cottonseed oil, olive oil, corn oil, coconut oil, beef tallow, lard, fish oil and the like can be used.

  The method for partially hydrolyzing fats and oils is not particularly limited, and based on a conventionally known method, water is preferably added in an amount of 20 to 180 parts by weight with respect to 100 parts by weight of fats and oils, and partial hydrolysis may be performed. Specific methods include a method using an enzyme and a method using a steam decomposition method. When partial hydrolysis is performed by an enzymatic method, it is preferably performed under a temperature condition of 20 to 70 ° C. The enzyme can be used as an immobilized enzyme, an intracellular enzyme, or a free enzyme that is not immobilized. Examples of the apparatus to be used include a stirring tank, a fixed bed, a fluidized tank, or a combination of these, and batch, continuous or semi-continuous reactions can be performed. On the other hand, when partial hydrolysis is performed by the steam cracking method, it is desirable to carry out the reaction at a temperature of 190 to 240 ° C, preferably 200 to 235 ° C. Examples of the apparatus to be used include an autoclave and a continuous cracking tower, and batch, continuous or semi-continuous reactions can be performed. In the present invention, since the final purpose is to 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 amount of fatty acid is 67 to 96% by weight, preferably 75 to 93% by weight. Reaction time can be shortened by performing esterification of the 2nd step in the state where the partial glyceride remained. The cracked oil obtained by the first stage partial hydrolysis reaction is preferably less colored, and specifically has a hue showing 40R or less, preferably 30 or less as 10R + Y (Red value × 10 + Yellow value) of the Robibond method. It is desirable that

  After completion of 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 can be used for the second stage esterification reaction after removing water. it can. Moreover, you may use for an esterification reaction of a 2nd stage as it is, without isolate | separating an oil phase and an aqueous phase. The partially decomposed product is preferably used for the esterification reaction in the second stage without being subjected to a distillation treatment. In addition, you may perform processing, such as hardening and a fractionation aiming at hardness adjustment, in the range without the loss of a trace component.

  In the present invention, since the esterification reaction is performed without performing a distillation treatment after the partial hydrolysis reaction of fats and oils, when vegetable oil is used as a raw material, the plant sterol present in the vegetable oil is allowed to remain in the final diglyceride product. Has the advantage of being able to

  In the second stage esterification reaction, esterification is performed by adding glycerin 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. Perform the reaction. This reaction is preferably performed in the presence of an enzyme having ester activity such as lipase or esterase, and more preferably in the presence of immobilized or selective 1,3-position lipase in the cell. Known methods for immobilization are described in, for example, “Immobilized Enzyme” edited by Ichiro Chibata, published by Kodansha, pages 9-85 and “Immobilized Biocatalyst” edited by Ichiro Chibata, published by Kodansha, pages 12-101. It is preferable to immobilize it on an ion exchange resin. Examples of the 1,3-position selective lipase used for immobilization include lipases derived from microorganisms such as Rhizopus genus, Aspergillus genus, Mucor genus, and pancreatic lipase. For example, Rhizopus delemar, Rhizopus japonicus, Rhizopus niveus, Aspergillus niger, Mucor javanicmie, Mucor javanicus, Mucor javanicus Lipases originating from such as can be used. As a commercially available immobilized 1,3-position selective lipase, there is a product name “Lipozyme IM” manufactured by Novo Nordisk Bioindustry. The 1,3-position selective lipase in the microbial cell is a product obtained by adsorbing or binding the 1,3-position selective lipase to the microbial cell body. As a commercial product, there is a trade name “Olipase” manufactured by Nagase Sangyo Co., Ltd.

  The reaction is carried out in a system in which no water is added other than the water contained in the lipase preparation, the partially decomposed product obtained in the first stage reaction, and glycerin, and no organic solvent such as hexane is added. In order to accelerate the esterification reaction, it is preferable to remove as much water as possible from the raw materials and reaction product water out of the reaction system. For example, in addition to dehydration by reduced pressure, a dry inert gas is passed through the reaction vessel. Although dehydration using a water absorbing material such as molecular sieves can be considered, a vacuum dehydration method with less contamination of the reaction system is preferred. Examples of the apparatus to be used include a stirring tank, a fixed bed, a fluidized tank, or a combination of these, and batch, continuous or semi-continuous reactions can be performed.

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

Example 1
In an autoclave having a capacity of 2 liters, 857 g of rapeseed white squeezed oil and 343 g of water were mixed and hydrolyzed with stirring at 200 ° C. for 10 hours. After completion of the reaction, the mixture was cooled and the oil phase and the aqueous phase were separated by centrifugation. Next, “Llipase A-10, manufactured by Nagase Sangyo Co., Ltd.”, which is a 1,3-position selective lipase originating from Rhizopus japonicus, was immobilized by the immobilization method described in Example 1 of JP-A-1-174384. , 34 g of immobilized lipase obtained by immobilization on a commercially available anion exchange resin (trade name Duolite A-568, manufactured by Diamond Shamrock), 4 g of oil phase 300 g and glycerin 39 g obtained by the first stage reaction The mixture was mixed in a mouth flask (fatty acid group / glycerin group = 2), and the reaction was carried out for 4 hours while the system was decompressed to 5 mmHg while stirring at 40 ° C. Thereafter, the lipase preparation was filtered off from the reaction product. A sample of the first-stage reaction product and the second-stage reaction product was partially taken and subjected to alkali titration to determine the amount of fatty acid. The sample was trimethylsilylated and the composition of triglyceride, diglyceride and monoglyceride was determined by gas chromatography. The results are shown in Table 1.

Example 2
In an autoclave having a capacity of 2 liters, 857 g of rapeseed white oil and 343 g of water were mixed and hydrolyzed with stirring at 220 ° C. for 5 hours. After completion of the reaction, the mixture was cooled and the oil phase and the aqueous phase were separated by centrifugation. Next, 45 g of the same immobilized lipase used in Example 1, 400 g of the oil phase obtained in the first stage reaction and 51 g of glycerin were mixed in a four-necked flask (fatty acid group / glycerin group = 2), While stirring at 40 ° C., the reaction was carried out for 4 hours in a state where the pressure in the system was reduced to 5 mmHg. Thereafter, the lipase preparation was filtered off from the reaction product. The composition of the reaction product was determined by the same operation as in Example 1 below. The results are shown in Table 1.

Comparative Example 1
In an autoclave having a capacity of 2 liters, 857 g of rapeseed white squeezed oil and 343 g of water were mixed and hydrolyzed with stirring at 250 ° C. for 4 hours. After completion of the reaction, the mixture was cooled and the oil phase and the aqueous phase were separated by centrifugation. Next, 35 g of the same immobilized lipase used in Example 1, 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). While stirring at 40 ° C., the reaction was carried out for 4 hours in a state where the pressure in the system was reduced to 5 mmHg. Thereafter, the lipase preparation was filtered off from the reaction product. The oil phase obtained by the first stage reaction was distilled under conditions of 160 to 250 ° C. and 1 mmHg or less to obtain fatty acids. The yield of fatty acid was 89%. 300 g of this 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. The results are shown in Table 1.

Example 3
Non-selective lipase (“Lipase OF”, manufactured by Meika Sangyo Sangyo) 5 g and soy white squeezed oil 1000 g were mixed in a four-necked flask and hydrolyzed for 1 hour with stirring at 40 ° C. After completion of the reaction, the oil phase and the aqueous phase were separated by centrifugation. Next, 34 g of the same immobilized lipase used in Example 1, 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). The composition of the reaction product was determined by the same operation as in Example 1 below. The results are shown in Table 1.

Comparative Example 2
In Example 3, the reaction was performed under the same conditions as in Example 3 except that 500 g of water was changed to 100 g of water. The results are shown in Table 1.

Further, the hues of the first-stage partial hydrolysates of Examples 1 to 3 and Comparative Example 1 were measured by the Robibond 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 molecular distillation treatment to obtain a composition rich in diglycerides, and then subjected to decolorization treatment which is a normal oil refining 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. The results are shown in Table 2. As shown in Table 2, the composition obtained in the second stage reaction without distilling the first stage partial hydrolyzate of Comparative Example 1 has a hue (10R + Y) even after decolorization treatment. It was 31 and coloring was not able to be reduced and it was exhibiting brown.
(Quantification of plant sterols)
To 1 g of the oily composition obtained in each step, 10 ml of 1N KOH ethanol solution was added, and after saponification decomposition at 80 ° C. for 1 hour, 15 ml of distilled water was added. Further, 10 ml of n-hexane and 1 ml of a solution of cholesterol dissolved in n-hexane at a concentration of 10 mg / ml as an internal standard were added and mixed, and then the hexane layer was sampled, desolvated, trimethylsilylated, and subjected to gas chromatography. And analyzed. The amount of plant sterol was calculated from the area ratio of cholesterol and plant sterol. In addition, although the normal plant sterol coexists with the ester body of the free sterol and the fatty acid, since this analysis method is saponified and decomposed, the free sterol is quantified.

Claims (6)

A process for producing a diglyceride characterized by comprising a first stage reaction in which a partial hydrolysis reaction of fats and oils and a second stage reaction in which glycerin is added to the obtained decomposition product for esterification. Diglyceride purity is obtained by performing partial hydrolysis of fats and oils as the first stage reaction until the amount of decomposed fatty acid reaches 67 to 96% by weight, and adding glycerin to the degradation product obtained as the second stage reaction and performing esterification reaction. A method for producing diglyceride, characterized in that high-purity diglyceride having [diglyceride weight% / (diglyceride weight% + triglyceride weight%) × 100] of 80% or more is obtained. The manufacturing method of the diglyceride of Claim 1 or 2 which performs the partial hydrolysis of the 1st step on the conditions which suppress the coloring of a decomposition product. The method for producing a diglyceride according to any one of claims 1 to 3, wherein the first stage partial hydrolysis is carried out at 190 to 240 ° C by a steam cracking method. The method for producing a diglyceride according to any one of claims 1 to 3, wherein the first-stage partial hydrolysis is performed in the presence of an enzyme. The method for producing a diglyceride according to any one of claims 1 to 5, wherein the second stage esterification is carried out in the presence of an immobilized enzyme or an intracellular enzyme.