JPH0971594A - Process for producing fatty acid ester of sugar or sugar alcohol by enzymatic method - Google Patents

Abstract

(57) [Abstract] [Problem] Industrially extremely simple and useful, which does not cause coloration by heating and can be used as a food additive and can obtain a fatty acid ester of sugar or sugar alcohol with a good yield in good yield. Provided is a method for producing a fatty acid ester of sugar or sugar alcohol. A method for producing a fatty acid ester of a sugar or a sugar alcohol, which comprises reacting a sugar or a sugar alcohol with a fatty acid in the presence of a hydrolase capable of degrading fats and oils, wherein the reaction system is inert to the reaction system. A method for producing a fatty acid ester of sugar or sugar alcohol, which comprises controlling the amount of water in the reaction system by aerating a different gas.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention resides in a method for producing a fatty acid ester of sugar or sugar alcohol. More specifically, it lies in a method of producing a fatty acid ester of sugar or sugar alcohol suitable for food additives and the like by carrying out a reaction under a solvent-free and mild condition by the catalytic action of an enzyme.

[0002]

BACKGROUND ART As a method for producing a fatty acid ester of sugar or sugar alcohol, there is a chemical synthesis method in which a sugar or sugar alcohol and a fatty acid or a derivative thereof (eg lower alcohol ester etc.) are reacted in the presence of an acid or an alkali. It is commonly done. However, this method involves a reaction at a high temperature of 100 to 250 ° C., so that there is a problem that a by-product or a target product is colored. As a method for solving such a problem, a method using an enzyme such as lipase having a hydrolyzing ability for fats and oils has been proposed (eg, JP-A-61-26).
No. 8192, No. 62-58992, No. 62-
195292, Japanese Patent Publication No. 63-14948, etc.).

However, there are various problems in industrially carrying out the production method using these enzymes. For example, in Japanese Examined Patent Publication No. 63-14948, sorbitol or sorbitan and a higher fatty acid are incubated in an aqueous solution system in the presence of a hydrolase having a lipase activity to obtain a sorbitan fatty acid ester. However, in this production method, since the reaction system contains a large amount of water as is clear from the description of the examples of the publication, the equilibrium does not shift to the synthesis side and the reaction yield is not sufficient.

On the other hand, Japanese Patent Laid-Open Nos. 62-58992 and 62-195292 disclose methods for performing an esterification reaction under reduced pressure. Generally, in the enzymatic reaction, the reaction rate decreases even if too much water is removed from the reaction system, or conversely a large amount of water is present. Therefore, it is possible to control the water content in the reaction system to a much lower range than before. Was needed.
However, rapid detection and control of the water content in the reaction system are essential for industrial production, but control in a reduced pressure reaction system is extremely difficult, so it is extremely difficult to keep the productivity of the target product constant. It was very difficult.

Further, a method has been proposed in which an enzyme reaction is carried out in the presence of an organic solvent to adjust the water content in the reaction system. However, the organic solvent often reduces the activity of the enzyme, and the ester which is a product. Since the compounds are often used as food additives, a production method that does not use an organic solvent has been desired because of a problem such as an organic solvent remaining in a product.

[0006]

As described above, there have been proposed a number of methods for producing a fatty acid ester by reacting a sugar or sugar alcohol with a fatty acid using an enzyme as a catalyst, but the reaction yield is low and the reaction is low. Since there are problems such as difficulty in controlling the water content in the system and residual organic solvent, there are still no satisfactory ones. The present invention is free from coloring by heating,
Can also be used as a food additive, very good quality fatty acid ester of sugar or sugar alcohol can be obtained in good yield,
It is intended to provide a method for producing a fatty acid ester of sugar or sugar alcohol which is extremely simple and useful industrially.

[0007]

As a result of intensive studies, the present inventors have found a method for producing a fatty acid ester of sugar or sugar alcohol by an enzymatic method which is excellent in operability as an industrial process. That is, the present invention is a method for producing a fatty acid ester of a sugar or sugar alcohol, which comprises reacting a sugar or sugar alcohol with a fatty acid in the presence of a hydrolase capable of degrading fats and oils. A method for producing a fatty acid ester of sugar or sugar alcohol is characterized in that the amount of water in the reaction system is controlled by aeration of an inert gas. Particularly, the method for producing a fatty acid ester of sugar or sugar alcohol according to claim 1, wherein the gas inert to the reaction system is air or nitrogen.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. Sugar or Sugar Alcohol In the present invention, any sugar or sugar alcohol can be used. Specific examples of the sugar include monosaccharides such as xylose, glucose and fructose, disaccharides such as maltose, trehalose, lactose and sucrose, and trisaccharides such as maltotriose. Examples of sugar alcohols include erythritol, xylitol, sorbitol, maltitol and the like, and usually have 4 to 12 carbon atoms.
Use the one.

Fatty Acid The fatty acid used in the present invention usually has 6 to 22 carbon atoms.
It is a saturated or unsaturated fatty acid. Specific examples thereof include caproic acid, capric acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and erucic acid. The fatty acids may be used alone or as a mixture of two or more, depending on the composition required for the ester obtained by the method of the present invention. Since fatty acids obtained from natural fats and oils are usually a mixture, they are often used as a mixture unless it is necessary to use a single product.

Hydrolyzing enzymes capable of degrading fats and oils As the hydrolyzing enzymes capable of degrading fats and oils used in the present invention, various ones derived from animals and microorganisms are known and are commercially available. Any of these can be used. For example Candida cy
lindra-cea, Aspergillus ni
ger, Mucor miehei, Rhizopus
delemer, Pseudomonas frag
i, a lipase obtained from Geotrichum candidum, etc., Baci-lus subtili
Examples thereof include those derived from microorganisms such as protease obtained from s, and those derived from animals such as lipase obtained from porcine pancreas. The enzyme is usually 1000 to 1,000,000 units (U) per 100 g of the fatty acid which is the reaction raw material.
It is preferable to add a certain amount. The unit as used herein is measured by the method described in Japanese Industrial Standard K0601 "Method for measuring activity of industrial lipase". That is, 1 unit represents the amount of enzyme that liberates 1 μmol of fatty acid per minute from the substrate (olive oil) under defined conditions. An emulsion system in which polyvinyl alcohol (PVA) and the like coexist in the reaction system for activity measurement, and PVA
There are two types of non-emulsifying systems in which a substrate and an enzyme are brought into contact with each other by stirring without adding such a substance, and these are selected depending on the type of enzyme. For example, Candida cylin-d
racea, Aspergillus niger, P
It is common to use an emulsified system in Seudomonas fragi and the like, and a non-emulsified system in the case of Geotricum candidum.

Aeration of inert gas The inert gas used in the present invention may be a gas inert to the reaction system of sugar or sugar alcohol and fatty acid in the presence of a hydrolase capable of degrading fats and oils. Any air may be used, but typically air or nitrogen is typically used. Further, as the inert gas to be ventilated into the reaction system, a dry one is usually used, but a gas humidified by a humidifier is used,
The amount of water in the reaction system may be adjusted. At this time, it is necessary to control the reaction solution temperature, reactor pressure, and aeration gas humidity so that the water content in the system does not deviate from the water content range suitable for the enzyme type and substrate type.

Any method may be used as a method for aeration as long as the reaction system and the inert gas come into sufficient contact with each other, but a method of bubbling the inert gas from below the liquid surface of the reaction solution in the reactor is particularly preferable. The gas permeation amount of the gas inert to the reaction system with respect to the reaction solution is usually 0.01 to 10 vvm, preferably 0.1 to 5 vvm, and more preferably 0.2 to 3 vvm. If the aeration amount exceeds 10 vvm, for example, in the case of bubbling, it is disadvantageous because the reaction container needs an excessive size relative to the reaction solution, and if it is less than 0.01 vvm, the esterification reaction rate decreases. The desired effect cannot be obtained. The term "vvm" as used herein means the volume of aeration gas (under 1 atm) for 1 minute per unit volume of the reaction solution.

Reaction conditions The temperature of the esterification reaction is preferably the optimum temperature of the enzyme used. For example, Candida cylind
In the case of an enzyme derived from racea or Aspergillus ni-ger, around 40 ° C., Pseudomonas
It is preferable to carry out the reaction at about 65 ° C. with the enzyme derived from fragi. The enzyme can also be used as an immobilized enzyme, and if the thermostability of the enzyme is improved by immobilization,
The reaction can be carried out at a temperature higher than the optimum temperature of the enzyme.

As a method of immobilization, a known method such as a carrier binding method such as physically adsorbing on an inert carrier such as Celite, or an encapsulation method in which an enzyme is wrapped in a lattice such as polyacrylamide is used. I can. Furthermore,
The esterification reaction temperature is preferably such that the fatty acid used is liquid, that is, the melting point of the fatty acid or higher. When the melting point of the fatty acid exceeds the optimum range of the enzyme, it is necessary to use an enzyme whose heat resistance is improved by immobilization or the like. Further, the melting point of the fatty acid may be lowered by slightly mixing another fatty acid.

Prior to the esterification reaction, it is preferable that the sugar or sugar alcohol and the fatty acid are thoroughly mixed and subjected to the reaction as a homogeneous mixture. When a fatty acid that is solid at room temperature is used, it is preferable that the fatty acid is dissolved by heating and used as a liquid for the reaction. The molar ratio of sugar or sugar alcohol and fatty acid may be appropriately determined depending on the desired composition of the product, but usually the reaction raw materials are kept in a fluid state such as a liquid,
In addition, in order to promote the reaction of sugar or sugar alcohol, it is preferable to use fatty acid in an equimolar amount or more with respect to sugar or sugar alcohol.

Further, in the present invention, it is preferable that sugar or sugar alcohol is mixed with a fatty acid as an aqueous solution, particularly as an aqueous solution having a saturated concentration. Usually, an enzyme and optionally water are added to a mixture of a sugar or sugar alcohol aqueous solution and a fatty acid, and the mixture is maintained at a predetermined temperature with stirring, and a gas inert to the reaction system (usually air or nitrogen). The esterification reaction is carried out while aerating.

The reaction pressure is arbitrary, but reaction at atmospheric pressure which does not require a special reactor is preferable. The reaction time is arbitrary, but is usually several hours to several tens hours. After completion of the reaction, the reaction mixture can be separated and purified by a conventional method to obtain the produced ester. As the separation and purification method, for example, the mixture after the reaction is subjected to liquid-liquid extraction with an organic solvent such as isobutyl alcohol and an alkaline aqueous solution, the ester is extracted into the organic solvent phase, and the unreacted sugar or sugar alcohol and fatty acid are extracted into the aqueous phase. To separate. Then, the organic solvent can be removed from the organic solvent phase to obtain the ester.

[0018]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. (Example 1) According to the composition shown in Table 1, sugar or sugar alcohol, fatty acid and degrading enzyme were put in a reactor equipped with a stirrer,
While bubbling air through these reaction solutions under the condition of 0.3 vvm, the reaction was continued at 1 atm 40 ° C. for 12 hours. On the way, the humidity of the air to be ventilated was controlled from 1 hour after the reaction was started, and the water content in the reaction solution was adjusted to 1,500 ± 2.
It was set to 00 ppm.

After completion of the reaction, 90 g of the obtained crude product was extracted with a 1: 1 (volume ratio) mixture of isobutyl alcohol and 0.1N-sodium hydroxide aqueous solution to recover an isobutyl alcohol phase containing an ester. . This was concentrated to obtain 50 g of a pale yellow paste-like ester mixture, and the reaction yield based on the mass of sugar or sugar alcohol and fatty acid was 54%. The weight composition of the obtained ester mixture was analyzed by gel permeation chromatography using the following adjustment method and analysis conditions. Monoester was about 40% by weight, diester was about 50% by weight and triester was about 10% by weight. % By weight.

<Sample preparation method> The ester mixture was added with tetrahydrofuran (hereinafter referred to as THF) to a concentration of 0.1 to 0.1.
Dissolves in 0.5% by weight. <Analysis conditions> Device: LC-6A (manufactured by Shimadzu Corporation) Column: TSKgel G2500HXL (7.8 mm ID x
30cm) x 2 and TSKguard column (6.0mmID x 4cm) Eluent: THF Flow rate 0.5ml / min Injection volume: Ester mixture 0.1-0.5wt% TH
F solution 100 μl Temperature: 40 ° C Detector: Differential refractometer

Example 2 According to the composition shown in Table 1, sugar or sugar alcohol, fatty acid and degrading enzyme were placed in a reactor equipped with a stirrer, and nitrogen was bubbled through these reaction solutions under the condition of 1.2 vvm. While ventilating, the reaction was continued at 1 atm 60 ° C. for 12 hours. 115 g of the crude product was mixed with methyl ethyl ketone and 0.1N-aqueous sodium hydroxide solution 1:
The mixture was extracted with 1 mixture to recover a methyl ethyl ketone phase containing an ester. This was concentrated to obtain 60 g of a white paste-like ester mixture. The reaction yield and the weight composition of the ester were analyzed in the same manner as in Example 1, and are shown in Table 1.

(Comparative Example 1) The reaction was carried out for 24 hours in the same manner as in Example 1 except that no aeration was performed. Although the water content was 7.5% by weight at the initial stage of the reaction, the water content increased as a reaction by-product as the reaction progressed. 90 g of the crude product was post-treated in the same manner as in Example 2 to obtain 17 g of a white paste-like ester mixture. The reaction yield and the weight composition of the ester were analyzed in the same manner as in the example and were as shown in Table 1.

[0023]

[Table 1]

[0024]

EFFECTS OF THE INVENTION According to the present invention, a fatty acid ester of sugar or sugar alcohol can be obtained without coloring due to heating, with extremely good quality and in good yield, and an industrially simple and useful production method can be provided. In addition, since the reaction container does not need to have a reduced pressure specification, the equipment cost can be significantly reduced.

Claims (2)

[Claims] 1. A method for producing a fatty acid ester of a sugar or a sugar alcohol, which comprises reacting a sugar or a sugar alcohol with a fatty acid in the presence of a hydrolase capable of degrading fats and oils. A method for producing a fatty acid ester of sugar or sugar alcohol, which comprises controlling the amount of water in the reaction system by aeration of an active gas. 2. The method for producing a fatty acid ester of sugar or sugar alcohol according to claim 1, wherein the gas inert to the reaction system is air or nitrogen.