JPH0481431B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a method for modifying lecithin by enzymatic treatment.

(b) Prior Art Lecithin has been widely used as a natural emulsifier in foods, medicines, cosmetics, etc., and various attempts have been made to modify it. In particular, it increases the polarity of lecithin,
Methods for increasing O/W emulsifying ability include a method of blending lecithin with an emulsifier or propylene glycol (Japanese Patent Publication No. 50-30595 and Japanese Patent Publication No. 56-163747), a method of acetylating lecithin (JAOCS, 53 ,
425, (1976)) and a method for hydroxylating fatty acids in lecithin (JAOCS, 53 , 425, (1976)). Also known are methods of hydrolyzing the fatty acid ester moiety of lecithin with an alkali (JAOCS, 53 , 425, (1976)) or an enzyme (USP 3, 652, 397).

(c) Problems to be solved by the invention The conventional method of adding emulsifiers and propylene glycol to lecithin does not essentially modify lecithin, but saves the trouble of adding other emulsifiers at the time of use. It just improves the sex. Furthermore, reactions that acetylate lecithin or hydroxylate fatty acids are unsuitable for use in foods. In addition, side reactions tend to occur, resulting in browning, polymerization, decomposition, and other deterioration in the quality of lecithin. The same applies when hydrolyzing with alkali.

In contrast, enzymatic treatments do not have such drawbacks. However, conventional enzymatic hydrolysis of lecithin has several problems. Normally, it is necessary to control the pH in enzyme reactions, but since the free fatty acids produced by hydrolysis lower the pH of the reaction system, it is necessary to control the pH, especially when using enzymes with an alkaline optimum pH. is difficult. After the reaction, it is necessary to remove the chemicals used for PH control and the fatty acids, and for this purpose, solvent separation is performed. For example, USP3,
652 and 397 propose that after hydrolyzing with an enzyme, water is removed by drying and free fatty acids are removed with an organic solvent such as acetone or inpropyl alcohol. However, the use of solvents is accompanied by various inconveniences in terms of operation and equipment, and there is also the possibility that product safety may become a problem.

The purpose of the present invention is to provide a method for efficiently producing lecithin that is safe enough to be used as a food, has good quality, and has good emulsifying ability, by improving the above-mentioned drawbacks of the method for modifying lecithin by enzyme treatment. There is a particular thing.

(d) Means for Solving the Problems As a result of intensive research, the present inventors have discovered that the above object can be achieved by adding a specific compound during enzyme treatment.

The present invention was completed based on this knowledge, and is a modification of lecithin characterized by adding a compound that reacts with the generated free fatty acids to produce metal soap when lecithin is hydrolyzed with an enzyme. It is a quality law.

The present invention will be explained in detail below.

Lecithin as used in the present invention refers to phospholipids in general, which are usually commercially referred to as lecithin. Examples of such lecithin include animal and plant lecithins such as egg yolk lecithin, soybean lecithin, rapeseed lecithin, safflower lecithin, sunflower lecithin, and string lecithin, but soybean lecithin is advantageous in terms of price, availability, etc. However, there is no significant difference in performance even if other animal and plant lecithins are used as starting materials.

In addition, in the present invention, it is also possible to use ordinary pasty lecithin containing triglycerides or degum oil sludge before dehydration thereof as raw materials. Furthermore, from the viewpoint of emulsifying power, lecithin from which triglycerides have been removed by acetone fractionation or the like, or powdered lecithin from which phosphatidylcholine has been concentrated by solvent or column fractionation is desirable.

As the enzyme used in the present invention, any enzyme capable of hydrolyzing the ester bond of lecithin, that is, lipase, phospholipase A, or B can be used. When considering the stability of the product, phospholipase A ₂ , which hydrolyzes the 2nd position, which has a large amount of unsaturated fatty acids, is desirable. Conversely, if you want to leave unsaturated fatty acids as much as possible and improve their physical properties and physiological activity, use phospholipase.
A ₁ is preferred. In addition, it is also possible to control physical properties by utilizing the substrate specificity of enzymes.

As the compound for making metal soap, for example, hydroxides or oxides of group metals can be used, but calcium hydroxide or calcium oxide is preferably used from the viewpoint of safety and efficiency.

The present invention is carried out as follows. That is, lecithin is emulsified with water and adjusted to the optimum pH for the enzyme using the above-mentioned compound or fatty acid. After that, an enzyme is added to carry out hydrolysis, and the free fatty acids generated at this time are converted into metal soap using the above-mentioned compound, and the pH is always adjusted to the optimum pH for the enzyme. Free fatty acids become water-insoluble metal compounds and are removed from the reaction system. After the reaction, insoluble matter is removed by filtration or centrifugation, and the filtrate is concentrated and dried to obtain the desired enzyme-treated lecithin.

(e) Examples Example 1 10g of commercially available soybean paste lecithin and 100g of warm water
Disperse and homogeneously emulsify using a homomixer. Add calcium hydroxide, adjust the pH to 8.5, add 0.01 g of snake venom phospholipase A ₂ to the emulsifier with stirring, and react at 25° C. for 4 hours. At this time, the PH
Add calcium hydroxide to maintain 8.0-9.0. After filtering the reaction solution through Celite, the filtrate was concentrated.
Dry to obtain 9g of enzyme-treated lecithin. This product has an acid value of 15, an ascent soluble content of 35%, a benzene insoluble content of 2%, and has the ability to form a safe O/W emulsion.

Example 2 10g of Nisshin Oil's powdered soybean lecithin PC-30 was added to water.
Disperse in 100g and homogeneously emulsify with a homomixer.
Add 0.01 g of Mucor lipase to the emulsion while stirring, and react at 35°C for 4 hours. At this time, the PH
Add calcium oxide to maintain the temperature between 6.5 and 7.5. After centrifuging the reaction solution at 10,000 rpm for 30 minutes, the filtrate was concentrated and dried to obtain 8 g of enzyme-treated lecithin. This product has an acid value of 25, an acetone soluble content of 2%, a benzene insoluble content of 1%, and has the ability to form a stable O/W emulsion.

Example 3 Nisshin Oil Concentrated Soybean Phosphatidylcholine PC
-70 Disperse 10g in 100ml of water and homogeneously emulsify with a homomixer. Add calcium oxide to adjust pH
Adjust to 8.0. Add 0.01 g of pancreatic lipase to the emulsion while stirring, and react at 50°C for 3 hours. At this time, calcium oxide is added to maintain the pH between 7.5 and 8.5. After centrifuging the reaction solution at 10,000 rpm for 30 minutes, the filtrate was concentrated and dried to obtain enzyme-treated lecithin 8.
get g. This stuff has an acid value of 20 and an acetone soluble content of 3.
%, benzene insoluble content of 1%, and has the ability to form a stable O/W emulsion.

(f) Effects of the invention According to the method of the present invention, it is safe because it does not use chemicals or solvents that were essential in the conventional modification of lecithin using enzymes, and it is efficient with fewer manufacturing steps. Furthermore, since the free fatty acid is removed from the reaction system as a water-insoluble metal compound and the reaction is irreversible, the enzymatic reaction itself becomes efficient. Since there is no decrease in pH due to free fatty acids, pH control is easy, especially when using enzymes whose optimal pH is alkaline. Furthermore, it is possible to remove free fatty acids without emulsifying ability from the product and produce lysolecithin with increased polarity compared to normal lecithin.
O/W emulsifier for pharmaceuticals, cosmetics, and other industrial uses,
The effects as a dispersant and surfactant are improved compared to conventional ones.

Claims (1)

[Scope of Claims] 1. A method for modifying lecithin, which comprises adding a compound that reacts with the free fatty acid produced to form metal soap when lecithin is hydrolyzed with an enzyme. 2. The method for modifying lecithin according to claim 1, wherein the compound is a hydroxide or oxide of a group metal. 3. The method for modifying lecithin according to claim 1, wherein the compound is calcium hydroxide or calcium oxide. 4. The method for modifying lecithin according to claim 1, which uses lipase, phospholipase A or phospholipase B as the enzyme. 5. The method for modifying lecithin according to claim 4, which uses an enzyme whose optimum pH is alkaline. 6. The method for modifying lecithin according to claim 1, which uses deoiled powdered lecithin as the lecithin. 7. The method for modifying lecithin according to claim 1, which uses lecithin with an increased content of phosphatidylcholine.