JPS63258813A - Production of fine powdery coated substance of l-ascorbic acid - Google Patents

Abstract

PURPOSE:To effectively and readily obtain the titled coated substance having controlled dissolution rate into water, by making fine powdery L-ascorbic acid (salt) collide with a fine powdery hydrophobic substance at a rotational speed within a specific range to carry out dryblending. CONSTITUTION:Fine powdery L-ascorbic acid or salt thereof (Ca or Na salt) or both are made to collide with a fine powdery hydrophobic substance (e.g. waxes, animal or vegetable fats or oils, fatty acids, natural resins or higher alcohols) under rotational speed condition within the range of 500-10,000r.p.m., preferably 1,000-8,000r.p.m. and dryblended to afford the aimed fine powdery coated L-ascorbic acids having protective films of the hydrophobic substance. The weight ratio of the L-ascorbic acid (salt) to the hydrophobic substance is selected from a wide range of 1:99-97.5:2.5.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides a method for coating fine powder L-ascorbic acid and/or its salts (hereinafter sometimes abbreviated as ascorbic acids or vitamin C) with a hydrophobic substance. In particular, the present invention relates to a method for chemically stabilizing these fine powder ascorbic acids and effectively producing a fine powder vitamin C coating with a controlled dissolution rate in water.

[Conventional technology and its problems]

Ascorbic acids are nutritionally extremely important substances as vitamin C, and a deficiency in the body can lead to so-called scurvy, which causes bleeding from the gums, skin, mucous membranes, etc., and can also cause anemia. , health problems occur.

In addition, ascorbic acids are used as acidulants in the food industry like other organic acids, and furthermore, for example,
It is useful as a reducing agent for modifying flour for confectionery and bread making.

However, ascorbic acids have the fatal drawback of being easily oxidized under slight oxidizing conditions.1 For example, when the temperature rises or the pH of the aqueous solution is alkaline, ascorbic acids may be easily oxidized. It is easily oxidized and decomposed by oxygen and loses its chemical and nutritional properties and functions. Furthermore, ascorbic acids are catalytically oxidized and decomposed when various mineral components such as iron, copper, and zinc coexist. This chemical property is easily oxidized.

This is a fatal drawback when ascorbic acids are used in the food industry or in compound feeds for livestock and fish, especially considering that they are used in fine powder form.

Therefore, it is extremely important to chemically stabilize these individual microparticles with a protective coating.

In addition, in the case of feed, etc., it is preferable that the elution of ascorbic acids from each particle be controlled at an appropriate rate when animals ingest it orally. Coating is widely practiced, and various coating methods have been implemented. Currently, the most widely used methods are pan coating, fluidized bed coating, and spray granulation, but in all of these methods, particles tend to aggregate to form coarse particles.
Therefore, there are significant restrictions on the utilization of the obtained coated particles, and in addition, these methods do not necessarily form a coating in which the core fine-grained ascorbic acids are located in the center, so the elution rate of the coating is limited. was virtually difficult to control.

Therefore, one object of the present invention is to provide a chemically stabilized coating containing fine particles of ascorbic acids as the core. Another object of the present invention is to provide an effective method for forming a protective film on the surface of fine particles of ascorbic acids with a controlled elution rate into water.

[Means for solving problems]

The present inventors have conducted repeated research on a method of coating and protecting fine particles of ascorbic acids with a hydrophobic substance to achieve the above object, and as a result, have developed a coating method that is extremely desirable for practical use.

That is, in the present invention, finely powdered L-ascorbic acid and/or its salts and a finely divided hydrophobic substance are mixed at a concentration of 500 to 1
0. Provided is a method for producing a finely powdered L-ascorbic acid coating, characterized in that dry mixing is carried out by collision at a rotational speed in the range of OOO rpm.

The objects to be coated by the method of the invention include so-called vitamin C, including L-ascorbic acid and its salts, for example calcium and sodium salts being typical salts. Such fine powders, which are conveniently used in the food industry and many other fields of application, are, for example, in the form of fine powders of several μm to several hundred μm.

Also, what is the hydrophobic substance used to coat these?

Any hydrophobic substance may be used as long as it has adhesion to ascorbic acids, is chemically stabilized by coating, and can control the elution rate by suppressing the water elution rate. Examples of such hydrophobic substances include , carnauba wax, rice wax, beeswax.

Waxes such as paraffin wax and synthetic wax; Animal and vegetable oils and fats such as seed, beef tallow, rapeseed oil, rice oil, and their hydrogenated oils; Fatty acids such as stearic acid, valmitic acid, oleic acid, etc.; Shellac, dammaru horse chestnut Natural resins such as fats and the like; higher alcohols such as dodecyl alcohol, palmityl alcohol, stearyl alcohol and the like can be mentioned. These may be used alone or in combination of two or more.
-I can. These coating substances are desirably fine powders smaller than the particle size of the coating core material, and fine powders with a particle size of, for example, about 1 to 30 μm are advantageously used.

The ratio of the fine powder ascorbic acids as the core material and the hydrophobic material used to coat it is determined by taking into consideration chemical stabilization and water elution rate, and also depending on the purpose of use, target of use, and other conditions. For example, the weight ratio of ascorbic acids:hydrophobic substance is 1:99 to 97.
5: A wide range of 2.5 is adopted.

In the method of the present invention, it is important to collide both of the above components at high speed, and to maintain both components in a fluidized bed.
It is especially effective to perform dry mixing under rotation conditions of 500 to 10,000 rpm+.The zero rotation speed (speed) is 50 Or
If it is less than 10 pm, the desired coating cannot be obtained;
．． At OOO rpm or higher, there is a risk that the fine powder of ascorbic acids will be crushed during the collision, which is disadvantageous because the desired coating material cannot be obtained. The preferred rotation speed is 1,
000~8. OOOrpm.

Dry mixing devices that can be advantageously used in the method of the invention are, for example, high-speed fluid mixers, centrifugal mixers, rotating fluidized bed devices, and other hybridization mixers.

The method of the present invention involves introducing predetermined amounts of finely powdered ascorbic acids as a coating core material and a hydrophobic substance to coat the same into a mixing device, and drying while colliding both fine powders at high speed. By mixing, ascorbic acid-coated fine granular material can be effectively produced. This collisional mixing is related to the collision speed, but if the mixing time is too short, the coverage of the hydrophobic substance is incomplete.

It is not industrially advisable to make the length longer than necessary.

Industrially, a mixing time of about 1, for example, 3 to 30 minutes is usually advantageously employed. However, the length of this mixed coating time can be selected to vary the size of the coated particles or to control the elution rate, especially if the particles are physically completely coated with hydrophobes and chemically highly It is also possible to form a fine powder coating of ascorbic acids stabilized by

[Effect]

According to the present invention, it is possible to form a hydrophobic protective film on finely powdered ascorbic acids very effectively and easily, and it is possible to produce a coating whose elution rate into water is controlled.

〔Example〕

Next, the present invention will be explained in more detail with reference to examples.

Example 1 15 g of finely powdered carnauba wax with an average particle size of 15 μm and 3 fine powders of L-ascorbic acid with an average particle size of 75 to 250 μm
5 g was first preblended using a centrifugal rotary mixer (Kaida Seiko Co., Ltd.: Mechano Mill MM-10) at a rotational speed of 100 rpm+a, and then further under a temperature condition of 20°C.

Immobilization when mixing for 60 minutes at a rotation speed of 500 rpm.

Embedding occurred, resulting in a carnauba wax-coated, composite cored coating of finely divided L-7 scorbic acid.

The resulting coating had a uniform carnauba wax coating on the surface of each particle, and substantially all of the coating passed through a 40 mesh sieve.

When this coated material was poured into water at 20° C., L-ascorbic acid was eluted at a fairly constant rate. Its elution is 10
Lasted for more than an hour.

Example 2 First, 15 g of rice wax with an average particle size of 8.6 μm and 35 g of L-ascorbic acid with an average particle size of 75 μm or less were mixed at 200 rpm using the same centrifugal mixer as in Example 1.
After pre-blending for 3 minutes at a rotation speed of p+m, an additional 1
The rotation speed was increased to looorpm and mixing was carried out for 60 minutes at a temperature of 35°C. As a result, immobilization and embedding occurred, and a coating containing composite fine powder L-ascorbic acid as a core was obtained.

When this coating is put into water at 20°C.

L-ascorbic acid was eluted at a fairly constant rate.

The elution lasted for 12 hours.

In addition, the proportions of rice wax and L-ascorbic acid to be mixed were changed to 2.5 g and 7.5 g, respectively.

A coating was prepared in the same manner. However, this coated granule was incompletely coated, and when put into water, approximately 50% of ascorbic acid was eluted in a short period of time.

Example 3 35 g of finely powdered L-ascorbic acid with an average particle size of 75 μm or less and 1.75 g of beeswax were placed in the centrifugal mixer, and first preblended for 5 minutes at a rotation speed of 1100 rpm and a temperature of 60° C. Next, 1 part of finely powdered rice wax with an average particle size of 8.6 μm was added to this.
Add 3.25 g and rotate at 1100 orp at 35°C.
Even stronger immobilization was achieved by mixing for 60 minutes at a temperature of . A multilayer coating was formed by repeated immobilization. All of the resulting coatings passed a 40 mesh sieve.

This coating has L-ascorbic acid as its core.

There are virtually no coating defects, and when it is poured into water at 20°C, L-ascorbic acid is eluted at a constant rate.
The elution lasted for 20 hours.

Example 4 5 g of rice wax with an average particle size of 8.6 μm and a particle size of 75
35 g of L-ascorbic acid with a particle size of ~250 μm was introduced into a 0M dizer (Nara Kikai Seisakusho 12: Ordered Mixture of Hybridization System), a high-speed air flow impact reformer combined with thermal treatment, and pre-incubated for 3 minutes. After blending and adhering the wax to the surface of the L-ascorbic acid particles, further.

Add 10g of rice wax with an average particle size of 100μm,
While dispersing these particles in a fluid state in the air stream.

A high-speed collision was performed for 6 minutes at a rotation speed of 8000 rpm, and Il!
Mechanical thermal energy, mainly force, was applied to the particles to fix the waxes and form a film. A finely powdered coating containing L-ascorbic acid as the core was obtained.

This coating was all fine powder that passed through a 40 mesh sieve and did not need to be ground.

In addition, there are virtually no uncoated L-ascorbic acid particles in this coated material, and when it is poured into water at 20°C, L-ascorbic acid is eluted at an approximately constant rate. Lasted for over 30 hours.

Example 5 15 g of rice wax with an average particle size of 8.6 μm and 35 g of L-calcium ascorbate with a particle size of 75 μm or less were charged into the OM dizer used in Example 4.

After pre-blending for 2 minutes to surface-treat the L-ascorbic acid particles with a hydrophobic wax, the mixture was allowed to collide with each other at high speed for 6 minutes by increasing the rotational speed of the hybridizer to 800° rpm to achieve uniform mixing and, at the same time, A fine powder coating containing calcium L-ascorbate as a core was obtained by immobilization, embedding, film formation, and compositing.

All of this coating is in the form of an extremely fine powder that passes through a 60-mesh sieve, and when it is poured into water at 20°C, there is very little elution of calcium L-ascorbate even after 12 hours have passed. There wasn't.

When this coating was heated to around 80°C, elution of calcium L-ascorbate was observed.

Example 6 Finely powdered carnauba wax tsg with an average particle size of 15 μm
and 35 g of finely powdered sodium L-ascorbate having a particle size of 75 μm or less were charged into the above 0M dizer, and a coating containing sodium L-ascorbate as a core was obtained in the same manner as in Example 5. The resulting coating.

It was a complete coating cored with L-7 sodium scorbate that passed through a 60 mesh sieve.

When the obtained coating is put into water at 20°C, 1
Even after 2 hours had passed, there was almost no elution of sodium L-ascorbate. However, when the system was heated to 80''C, the L-7 sodium scorbate began to elute.

〔Effect of the invention〕

According to the method of the present invention, each particle of finely powdered L-ascorbic acid or its salts is effectively formed with a substantially uniform film of a hydrophobic substance on its surface with each particle as a central core, and chemically Finely powdered L-ascorbic acids stabilized by the following methods can be easily obtained.

In the method of the present invention, there are almost no uncoated particles,
Therefore, by appropriately changing the selection of the hydrophobic substance, the mixing ratio, and the mixing time, the elution rate of fine powder L-ascorbic acid or its salts into water can be selectively formed as desired. Alternatively, it can be converted into physically completely sealed hydrophobic particles.

Furthermore, in the method of the present invention, from several μm to several hundred μ-,
For example, L-
Hydrophobic coatings of ascorbic acid or its salts can be easily produced.

Claims (1)

[Claims] 1. Finely powdered L-ascorbic acid and/or its salts and a finely divided hydrophobic substance are heated at 500 to 10,000 rpm.
A method for producing a finely powdered L-ascorbic acid coating, which comprises dry mixing by collision under rotational speed conditions in the range of . 2. The manufacturing method according to claim 1, wherein the hydrophobic substance is waxes, oils and fats, fatty acids, natural resins, or higher alcohols. 3. The ratio of fine powder L-ascorbic acid and/or its salts to fine powder hydrophobic substance is 1:99 to 97.5:
The manufacturing method according to claim 1, wherein the weight range is 2.5.