JPS6323736A - Preparation of microcapsule containing fats of highly unsaturated fatty acid - Google Patents

Abstract

PURPOSE:To prepare microcapsules of high film stability and free from deterioration of quality during storage by mixing hardened oil such as soybean oil with highly unsaturated fatty acid, raising its melting point and effecting microencapsulation. CONSTITUTION:Fats and oils containing highly unsaturated fatty acid such as refined fish oil or the like are microencapsulated with film forming substances such as gelatine - acacia gum and the like by composite coacervation method. At that time, 10-20% of hardened oil such as ultra hardened soybean oil against fats and oils containing highly unsaturated fatty acid or the like is added and mixed to make the melting point of mixed fats and oils in the range of at least 25 deg.C. To the microcapsulated matter, powders such as powdered milk and the like are added, frozen and dried. Capsules with encapsulated fats and oils containing highly unsaturated fatty acid thus prepared are in the form of fine particles with stabilized films and free of elution of fats and oils. Also, as formaldehyde need not be used as film hardening agent, it can be used as raw material for food and medicine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing microcapsules having an internal phase of oil containing highly unsaturated fatty acids and a coating of gelatin-gum arabic or the like.

[Conventional technology]

Recent studies have revealed that oils and fats containing highly unsaturated fatty acids such as lylunic acid, eicosapencitric acid, and docosahexaenoic acid are effective in preventing adult diseases such as thrombosis and myocardial infarction. However, these highly unsaturated fatty acids are highly susceptible to oxidation, so their use in food products is limited. It is used in the form of gelatin and soft capsules to maintain quality, but due to its shape, it cannot be added to general foods and is only used as a health food.

In order to use highly unsaturated fatty acids as food raw materials, they must be stabilized in the form of fine particles. Therefore, a complex coacervation method has conventionally been adopted as one of the methods, and a known example thereof is a coacervation method using gelatin and gum arabic. This method produces microcapsules containing highly unsaturated fatty acids, but unless the gelatin film is insolubilized by treating it with a chemical such as formaldehyde, there is a risk that the capsules will stick to each other during the drying process. Therefore, since formaldehyde is used in this case, there is a disadvantage that the product is not suitable for human consumption.

Other methods for producing microcapsules using this coacervation method include a method in which the produced microcapsules are taken out of an aqueous solution, coated with powder and dried (Japanese Patent Application Laid-Open No. 59-36540), and a method in which edible oils and fats are mixed with gelatin-Arabic. A method of coating with rubber, further covering it with a film consisting of a thermocoagulable protein, a non-thermocoagulable lid substance, and a polysaccharide, and then heating it above the freezing point of the thermocoagulable protein used (Japanese Patent Application Laid-Open No. 15733/1986) No., Japanese Patent Publication No. 61-851
No. 67), a method of coating edible oils and fats with gelatin-agar, etc. (Japanese Patent Application Laid-open No. 78351/1983), but these methods cannot be applied to fine microcapsules emulsified in a homomixer or homogenizer. It has drawbacks such as being difficult, and because the melting point of the edible fats and oils in the internal phase is low, the formed film may be broken and the edible fats and oils may be eluted.

[Problem that the invention seeks to solve]

As mentioned above, the conventional microencapsulation method for fats and oils uses formaldehyde to insolubilize the film, making it unsuitable for human consumption, and the film ruptures, making it easy for oils and fats in the internal phase to leach out. The inventors conducted extensive research to develop a method for producing microcapsules encapsulating highly unsaturated fatty acid-containing oils and fats that do not have these drawbacks. As a result of mixing highly unsaturated fatty acids with hydrogenated oil such as extremely hydrogenated soybean oil to raise their melting point and performing microencapsulation, the stability of the microcapsule film is increased, resulting in quality deterioration during storage. The present inventors have discovered that microcapsules can be obtained that do not cause this phenomenon, and have completed the present invention.

[Means for solving problems]

In the present invention, when microcapsulating highly unsaturated fatty acid-containing fats and oils with a film-forming substance by complex coacervation, hydrogenated oil is added and mixed to the highly unsaturated fatty acid-containing fats and oils, and the melting point of the mixed fats and oils is raised to 25°C. This is a method for producing microcapsules encapsulating highly unsaturated fatty acid-containing oils and fats, characterized by the above range.

Suitable hydrogenated oils for the present invention are extremely hardened oils, preferably extremely hardened soybean oil, but also extremely hardened whale oil,
Beef tallow, etc. can also be used. This extremely hardened soybean oil has a melting point of 60°C.
The above are preferred, and the amount used is preferably 10 to 20% based on the highly unsaturated fatty acid-containing fats and oils. If the amount added is less than 10%, the melting point of the mixed fat or oil will not exceed 25° C., while if it exceeds 20%, it will coagulate during work, resulting in poor workability. Incidentally, when 30% of extremely hardened soybean oil is added, the mixed fat and oil solidifies at room temperature.

The melting point of the mixed fat of highly unsaturated fatty acid-containing fat and hardened oil is preferably 25°C or higher at room temperature when microencapsulated to prevent the capsule film from being damaged and the oil leaching out. The upper limit is 40°C. The reason for this is as follows.

That is, the temperature of the solution of the film-forming substance in the microencapsulation process is 50°C, and the mixed fat and oil of the internal phase substance is added thereto and emulsified at 40 to 50°C, and then 40°C hot water is added to form a coacervate. Since it is generated and microencapsulated, it is necessary to liquefy it with a mixed fat and oil in the working process, and for this purpose, the melting point of the mixed fat and oil is preferably 40°C or lower.

As highly unsaturated fatty acid-containing fats and oils, refined fish oil, concentrated fish oil, evening primrose oil, linseed oil, safflower oil, etc. are used.

As the film-forming substance, gelatin-gum arabic or one using CMC, sodium alginate, or agar instead of gum arabic is used. The mixing ratio of the highly unsaturated fatty acid-containing oil and fat and the film-forming substance is not particularly limited. However, for example, it is preferable to mix 8 parts each of gelatin and gum arabic as film-forming substances to 100 parts of oil or fat.

In the present invention, the remicroencapsulated product by the coacervation method is further added with powder such as powdered milk and freeze-dried to improve storage stability.

Experimental Example 1 100g of purified fish oil (melting point O~1℃) was mixed with 80g of a 10% acid-treated gelatin solution (50℃) and 80g of a 10% gum arabic solution (50℃), and the pH was adjusted with a 10% acetic acid solution.
Add to the mixture prepared in Steps 4 and 2 and stir vigorously to emulsify using a homomixer. Next, add 260 g of water at 40°C to dilute. By this operation, a film of gelatin and gum arabic is formed around the oil droplets of 0.5 to 5 μm. Next, the solution was cooled to about 5 to 10°C while stirring to solidify and stabilize the oil droplets and film, and then a 2.5% sodium bicarbonate solution whose addition ratio had been confirmed in advance was added to adjust the pH. The isoelectric point of acid-treated gelatin is raised to 8.5 to strengthen the film. This was centrifuged or filtered to collect the precipitate (paste) of microcapsules, and 5 to 10
After adding and mixing 150g of 25% skim milk powder solution at ℃,
Freeze dry.

1 part of the powder obtained in this way was mixed with 9 parts of milk powder with a fat content of 25%, and the mixture was placed in a can purged with nitrogen (residual oxygen: 1 part).
~3%). 20℃, 30℃ and 40℃
The oils and fats contained were stored in the same room, and changes in peroxide value (hereinafter abbreviated as POV) and flavor were examined. The fat and oil content of the mixture was 29.2%, and its inner product, fish oil, was 6.7%. The results are shown in Table 1.

The mixture obtained by this method has PO due to oxidation of fats and oils during storage.
There was almost no increase in ■, but a raw, fishy odor was observed. That is, it is considered that some of the oil contained in the microcapsules obtained by this method was eluted due to breakage of the capsule membrane.

Very fine (0.5 to several μ) microcapsules obtained by the coacervation method are processed without impairing the sealing properties of the film.
The following experiments were further conducted to examine various drying methods.

Experimental Example 2 90g of refined fish oil (melting point 0°C to 1'C) was heated and melted and extremely hardened soybean oil was added and mixed to make a mixed fat (melting point 35°C).
℃). This mixed oil was mixed with 80 g of 10% acid-treated gelatin solution (50°C) and 80 g of 10% gum arabic solution (50°C), and the pH was adjusted to 4 with 10% acetic acid solution.
, Add to the mixture prepared in step 2 and emulsify by stirring vigorously with a homomixer. Next, add 26 .Og of water at 40°C to dilute. By this operation, a film of gelatin and gum arabic is formed around the oil droplets of 0.5 to 5 μm. Next, while stirring the solution, cool it to about 5-10℃ to solidify and stabilize the oil droplets and film. Next, add a 2.5% sodium bicarbonate solution whose addition ratio has been confirmed in advance to adjust the pH.
The isoelectric point of acid-treated gelatin is raised to 8.5 to strengthen the film. This was centrifuged or filtered to collect the microcapsule precipitate (paste), which was prepared in advance.
After adding and mixing 150 g of a 25% skim milk powder solution at ~10°C, the mixture was freeze-dried to obtain a powder containing approximately 60% purified fish oil.

1 part of the powder obtained in this way was mixed with 9 parts of milk powder with a fat content of 25%, and this mixture was placed in a nitrogen-substituted can (residual enzyme 1 part).
~3%). 20℃, 30℃ and 40℃
The samples were stored at The oil content in the mixture was 29.2%, and the inner fish oil content was 6.0%. The results are shown in Table 1. With this method, the stability of the microcapsule film during the manufacturing process was good, and there was almost no deterioration in quality during storage of the mixture.

(Margins below this page) [Example] Example 1 Extremely hardened soybean oil heated and melted in 90 g of refined fish oil was
A mixed fat and oil (melting point: 35°C) was prepared by addition and mixing. This mixed fat and oil was mixed with 80 g (5 g) of 10% acid-treated gelatin solution.
0°C) and 80g of 10% gum arabic solution (50°C) were added to the solution, which was adjusted to pH 4.2 with 10% acetic acid solution, stirred vigorously with a homomixer to emulsify, and then 260g of water at 40°C was added to this. Added and diluted.

Next, the solution was cooled to about 5° C. while stirring, and a 2.5% sodium bicarbonate solution whose addition ratio had been confirmed in advance was added to raise the pF to the isoelectric point of acid-treated gelatin, 8.5. This was centrifuged to collect the microcapsule precipitate (paste). 130 g of a 25% skim milk powder solution prepared in advance at 5 to 10°C was added to the microcapsule precipitate, mixed, and then freeze-dried. The freeze-dried product was pulverized to obtain approximately 150 g of powder (containing 60% purified fish oil).

150g of this powder is combined with 1350g of milk powder with a fat content of 25%.
This mixture was purged with nitrogen in a can (residual oxygen 1
~3%) and stored at 30°C for 3 months.
It had the same good flavor as immediately after filling.

Example 2 In Example 1, agar was used instead of gum arabic, and microencapsulation was performed in the same manner. 3
The flavor after storage at 0°C for 3 months was as good as in Example 1.

Example 3 In Example 1, sodium alginate (manufactured by Kibun Food Chemifa: N5PL low viscosity product) was used instead of gum arabic.
Using the same amount of 0.5% aqueous solution, microencapsulation was carried out in the same manner. The flavor after storage at 30° C. for 3 months was as good as in Example 1.

〔Effect of the invention〕

According to the production method of the present invention, the obtained highly unsaturated fatty acid-containing fat-filled capsules have a stable film in the form of fine particles of 0.5 to several microns, and there is no elution of fats and oils, and formaldehyde as a film hardening agent is not used. Since it is not used, it can be used as a food raw material or a pharmaceutical raw material.

Claims (7)

[Claims] (1) When microcapsulating highly unsaturated fatty acid-containing fats and oils with a film-forming substance by complex coacervation, hydrogenated oil is added to and mixed with the highly unsaturated fatty acid-containing fats and oils so that the melting point of the mixed fats and oils is 25°C or higher. A method for producing microcapsules encapsulating highly unsaturated fatty acid-containing oils and fats. (2) The method for producing microcapsules encapsulating highly unsaturated fatty acid-containing fats and oils according to claim 1, wherein the hardened oil is an extremely hardened oil. (3) The microcapsules encapsulating highly unsaturated fatty acid-containing fats and oils according to claim 1, characterized in that the amount of extremely hardened oil added is 10 to 20% based on the highly unsaturated fatty acid-containing fats and oils. Manufacturing method. (4) The method for producing microcapsules encapsulating highly unsaturated fatty acid-containing fats and oils according to claim 1, wherein the extremely hardened oil is extremely hardened soybean oil. (5) Encapsulation of highly unsaturated fatty acid-containing fats and oils according to claim 1, wherein the highly unsaturated fatty acid-containing fats and oils are refined fish oil, concentrated fish oil, evening primrose oil, linseed oil, and safflower oil. Method for manufacturing microcapsules. (6) Highly unsaturated according to claim 1, characterized in that the film-forming substance is one using CMC, sodium alginate, or agar instead of gelatin-gum arabic or gum arabic. A method for producing microcapsules encapsulating fatty acid-containing oils and fats. (7) Microcapsules encapsulating highly unsaturated fatty acid-containing fats and oils according to claim 1, which are microcapsulated and then freeze-dried by adding powder such as powdered milk to improve storage stability. Manufacturing method.