JPH1029909A - Sericin peptide solution and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sericin peptide solution which can be readily and inexpensively produced and has high safety and provide its production. SOLUTION: Water or an aqueous electrolyte solution is electrolyzed in a ionic water generator to prepare ionic water. This ionic water is used to hydrolyze the sericin in cocoon threads to prepare an aqueous solution containing sericin peptide. The ionic water may be acidic or alkaline either. The cocoon threads may be raw silk, cocoon fluffs or cut cocoons.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sericin peptide solution used for, for example, cosmetics, pharmaceuticals, foodstuffs, fiber modifiers, and the like, and a method for producing the same.

[0002]

2. Description of the Related Art A cocoon thread spitting out from a spinneret has a structure in which two fibers of fibroin, a kind of protein, are covered with a layer of sericin, another protein. Of these, sericin is usually 20 to 3 cocoons.
It accounts for 0% by weight, but most of it is removed during the refining performed during the production process of silk thread and silk cloth, so that fibroin appears on the surface, giving it a silky soft texture and elegant luster. It is well-known that it will take effect.

[0003] Sericin contains serine, which is an important amino acid as a raw material for cosmetics, at a high rate of about 30% by weight, and is also rich in aspartic acid, glutamic acid, glycine, alanine, and tyrosine. And has high utility value as a raw material for cosmetics, pharmaceuticals, foodstuffs, etc., as a modifier for fibers and fabrics, and as a surface coating agent for leather.

[0004] Then, the sericin of the cocoon thread is partially hydrolyzed and eluted with an aqueous alkaline solution such as caustic soda, sodium carbonate, sodium silicate or an aqueous solution of a surfactant, and then eluted.
It has been conventionally attempted to purify this solution to obtain a highly pure sericin peptide (hydrolyzate) solution.

[0005]

However, in the above-mentioned prior art, there is a technical difficulty in removing necessary and sufficient alkaline agents and surfactants from a solution obtained by hydrolyzing sericin. This involves a complicated processing step, which causes a problem that the production cost of the sericin peptide solution becomes extremely high.

When an aqueous alkaline solution is used for the hydrolysis, the resulting solution exhibits extremely strong alkalinity. For example, a neutralizing agent such as hydrochloric acid or sulfuric acid is added to neutralize the solution and then neutralize. It is necessary to remove the resulting salt,
At this time, the alkali agent or the neutralizing agent may not remain in the solution without being completely neutralized, and the generated salt may remain in the solution.On the other hand, the aqueous solution of the surfactant was used for the hydrolysis. In some cases, the surfactant may remain in the solution, and in such a case, there is a risk that the sericin peptide solution emits a strong off-flavor and irritates the skin. Therefore, the sericin peptide solution obtained by the prior art is particularly suitable for cosmetics,
Care must be taken when using it as a raw material for pharmaceuticals and foodstuffs.

Incidentally, it is conceivable to hydrolyze sericin only with hot water without using an alkali agent or a surfactant. In this case, a highly safe sericin peptide solution can be obtained. The extraction efficiency of sericin is greatly reduced as compared with the case where an activator is used, and the amount of sericin peptide obtained from a certain amount of cocoon thread is reduced, thereby increasing the production cost of the sericin peptide solution.

The present invention has been made in view of the above-mentioned problems, and has as its object to provide a sericin peptide solution which can be easily and inexpensively produced, and which is highly safe, and a method for producing the same.

[0009]

In order to achieve the above object, a sericin peptide solution according to the present invention is characterized in that a sericin peptide is dissolved in ionic water.

The method for producing a sericin peptide solution according to the present invention is characterized in that water or an aqueous electrolyte solution is electrolyzed to generate ionic water, and the cocoon thread sericin is hydrolyzed using the ionized water. Things.

The ionic water used for hydrolyzing sericin may be acidic ionic water or alkaline ionic water.

The "cocoon thread" used in the present invention may be in any state as long as sericin of the cocoon thread can be hydrolyzed with ion water. Therefore, in addition to the cocoons forming the cocoons themselves, raw silks (which are aggregates of cocoons) formed by pulling a plurality of cocoons together while pulling them together into one, and wastes produced during sericulture and silk production. Scraps collectively referred to as “sub-silk” such as cocoons, cut cocoons, raw hides (kibiso), and fluff (kebabs) are also included in the “cocoon thread” of the present invention.

[0013] In particular, among the above, "fluff" is a thread that is spit out first to form a scaffold for fixing the cocoon when the silkworm makes the cocoon, and contains about 50% by weight of sericin in total. . Therefore, the sericin content is 20 to 30% by weight.
It is possible to extract about twice the amount of sericin from the same amount of thread as that of ordinary cocoon thread, and since fluff cannot be made into raw thread, it has low general utility value and low price. Therefore, if fluff is used as a raw material, the production cost of the sericin peptide solution of the present invention can be further reduced.

[0014] The "cut cocoon" of the above refers to a cocoon after the pupa is cut out of the cocoon to be used as a silkworm seed. Cut cocoons are inexpensive because cocoons are cut and cannot be used as raw materials for raw silk.Moreover, since dirt and contaminants found in other sub-silk are relatively small, they are used as raw materials for the sericin peptide solution of the present invention. It can be used very suitably.

[0015]

Embodiments of the present invention will be described below. First, ionic water is generated by the ionic water generator.
FIG. 1 shows a schematic configuration of a general ionic water generator. In the drawing, reference numeral 1 denotes a DC power supply, 2 denotes an anode connected to the positive side of the DC power supply 1, and 3 denotes a negative side of the DC power supply 1. The connected cathode 4 is a microporous diaphragm dividing the inside of the electrolytic cell 5 into the anode 2 side and the cathode 3 side, and 6 is water contained in the electrolytic cell 5. In addition, a corrosion-resistant electrode made of carbon or platinum is used for the anode 2 and the cathode 3.

When a DC voltage is applied between the anode 2 and the cathode 3 in such an apparatus, water 6 is applied on the anode 2 side of the diaphragm 4.
Is oxidized by the following reaction to generate oxygen gas and hydrogen ions, thereby generating acidic ionized water. ^{_{2H 2 O → 4H + + O}} 2 ↑ + 4e -

On the cathode 3 side of the diaphragm 4, the water 6 is reduced by the following reaction to generate hydrogen gas and hydroxide ions, thereby generating alkaline ionized water. 2H ₂ O + 2e ⁻ → 2OH ⁻ + H ₂ ↑

In order to increase the electric conductivity between the anode 2 and the cathode 3 to improve the efficiency of generating ionic water, an aqueous electrolyte solution may be used instead of the water 6. In this case, the aqueous electrolyte solution is not particularly limited, but it is preferable to use a saline solution because it is inexpensive, easily available, neutral, easy to handle, and safe.

Next, the cocoon thread is immersed in either the acidic ionic water or the alkaline ionic water generated as described above. As a result, sericin covering the cocoon fibroin is dissolved in the ionic water and hydrolyzed,
The peptide bond of sericin is partially cleaved to obtain a sericin peptide solution in which sericin peptide having a smaller molecular weight than sericin is dissolved in ionic water.

In the above, regarding the ionic water obtained by the ionic water generator, acidic ionic water has been conventionally used as an astringent in cosmetics, while alkaline ionic water is effective for excess gastric acid, antacid and chronic diarrhea. It is safe for the human body because it has been conventionally consumed. Also, when using an aqueous electrolyte solution, a small amount of electrolyte will be contained in the ionic water,
If a harmless electrolyte such as salt is used as the electrolyte, the safety of the ionized water will not be impaired.

[0021] Sericin is hydrolyzed using such safe ionic water. Conventionally, a strong alkaline agent, a neutralizing agent or a salt is used in the solution as in the case of using an aqueous alkali solution for the hydrolysis. And the surfactant does not remain in the solution as in the case of using a surfactant aqueous solution for hydrolysis, so that the sericin peptide solution is extremely safe. Therefore, there is no danger that the sericin peptide solution emits a strong off-flavor or irritates the skin, and the sericin peptide solution can be safely used as a raw material for cosmetics, medicines, and foods.

Further, since a difficult and complicated treatment step for removing an alkaline agent or a surfactant from a solution as in the prior art is not required, the production of a sericin peptide solution becomes extremely easy. The solubility of sericin is higher than in the case of hydrolysis alone, the extraction efficiency is improved, and the amount of sericin peptide that can be recovered from a certain amount of cocoon thread is increased. It is possible to lower it.

The difference between the case of using acidic ionized water and the case of using alkaline ionized water for hydrolyzing sericin is as follows. That is, the pH of the acidic ion water obtained by electrolyzing water or the aqueous electrolyte solution is at most about 2 to 3, and the pH of the sericin peptide solution obtained by hydrolyzing the sericin of the cocoon thread with this acidic ion water is approximately 4 or less. It becomes weak acid of about 5 or so.

Incidentally, human skin usually has a pH of 4.5 to 4.5.
Since the composition is maintained at a weak acidity of about 6.5, it is desirable that the cosmetics such as lotions and creams used for the skin are also weakly acidic. Therefore, the sericin peptide solution produced using acidic ionized water is suitable for use as a skin cosmetic as it is or as a raw material for a cosmetic. However, while the solution is stored for a long period of time, a small amount of aggregates or precipitates (so-called “ori”) may occur.

On the other hand, alkaline ionized water obtained by electrolyzing water or an aqueous electrolyte solution has a pH of about 11 to 12, and a sericin peptide solution obtained by hydrolyzing sericin in cocoon filaments with this alkaline ionized water has a pH of 8 or more.
It becomes slightly alkaline. Therefore, in the case of skin cosmetics, it is desirable to adjust the pH to about 5 to 7 by adding a pH adjuster. As the pH adjuster, a weak acid harmless to the human body such as acetic acid or citric acid can be used.

When acidic ionized water is used, the obtained sericin peptide solution may be slightly turbid and appear white, whereas when alkaline ionized water is used, sericin peptide solution is generally used. The solution becomes highly transparent, and even if stored for a long time
Rarely occurs. Therefore, for example, when used as a fiber modifier to increase the moisture absorption and release properties of the fabric by being applied to a fabric made of a chemical fiber such as polyester or nylon, the adhesiveness to the fiber is not impaired by the dirt, and is extremely good. The result is obtained.

The sericin peptide solution of the present invention may optionally contain a preservative such as ethanol or paraben or other chemicals, in addition to the above-mentioned pH adjuster. In addition to using the sericin peptide solution as a liquid, it is also conceivable to use the solution in a dried and powdered state.

[0028]

【Example】

(Example 1) 0.107% saline was used as an ion water generator "JED-007" manufactured by Hirata Corporation.
Electrolysis was carried out using a mold, and acidic ionized water having a pH of 2.57 was taken out.

On the other hand, 30 g of fluff (cocoon thread) was immersed in hot water of about 90 ° C. for 2 minutes to remove dirt and dust adhering thereto, and then taken out of the hot water and drained.

Then, while heating 1000 ml of the acidic ionized water and maintaining the temperature at about 90 ° C., the entire amount of the fluff is immersed in the ionized water for 40 minutes to hydrolyze the sericin of the fluff and then taken out. , Pore size 0.21
The mixture was filtered through a 0.65 μm filter to remove a small amount of contaminants.
ml was obtained.

This sericin peptide solution was a white liquid with a slightly peculiar odor, and its pH was 5.0. The sericin peptide solution was analyzed by the Kjeldahl method to determine the nitrogen content based on the sericin peptide. As a result, 0.08 g of nitrogen was contained per 100 g of the solution as total nitrogen.

Further, the sericin peptide solution was analyzed by an automatic amino acid analysis method, and the content of each amino acid constituting the sericin peptide was examined. The results shown in Table 1 were obtained.

[0033]

[Table 1]

When the above-mentioned sericin peptide solution was applied to the skin as it was, very good results were obtained as skin cosmetics, for example, the skin was smooth and smooth, and a moist feeling was produced.

After washing the hair with a commercially available shampoo,
When the sericin peptide solution was applied to the hair,
The hair had a moist feeling and luster. Further, when the surface of the hair was examined with an electron microscope, it was found that the scale-like cuticle was in a clean and smooth state. On the other hand, when the hair was washed only with the same shampoo as described above, the hair had a slight puffiness. When the surface of the hair was examined with an electron microscope, it was found that the edge of each cuticle had a saw-toothed shape.

(Comparative Example) As in Example 1, the fluff 3
0 g was immersed in hot water of about 90 ° C. for 2 minutes to remove attached dirt and dust, then taken out of the hot water and drained. Then, while heating 1000 ml of pure water and keeping the temperature at about 90 ° C., the entire amount of the fluff is immersed in the pure water for 40 minutes to hydrolyze sericin to form a sericin peptide, and then taken out. The contaminants were removed by filtration with the same filter as above to obtain about 1000 ml of a sericin peptide solution.

The sericin peptide solution was analyzed by the Kjeldahl method in the same manner as described above to determine the nitrogen content based on the sericin peptide. The result was 0.02 g per 100 g of solution as total nitrogen. From this, pH 2.57
It was found that the use of acidic ionized water significantly improved the sericin extraction efficiency as compared with the case of using pure water (hot water) alone.

When the solution was filtered, the entire amount of the sericin peptide solution could be easily filtered in Example 1, whereas the filter was clogged in this comparative example.
It took a considerable amount of time to filter a total of about 1000 ml of the sericin peptide solution. This is presumably because, in comparison with Example 1, the peptide bond was less likely to be cleaved during hydrolysis in the comparative example, the molecular weight of the sericin peptide was increased, and the sericin peptide solution slightly gelled and became viscous.

Example 2 A 0.107% saline solution was electrolyzed with the same ionized water generator as in Example 1 to obtain a pH of 1
1.8 alkaline ionized water was taken out.

On the other hand, 30 g of cut cocoons (cocoon thread) were immersed in hot water of about 90 ° C. for 2 minutes to remove attached dirt and dust, and then taken out of the hot water and drained.

Next, the alkaline ionized water 1000
The whole amount of the cut cocoon was immersed in this ion water while heating the ml to about 95 ° C. Then, when the ionized water was evaporated and reduced, sericin in the cut cocoon was hydrolyzed for about 2 hours while replenishing the same amount of alkaline ionized water.

Then, after the cut cocoon was pulled up, the obtained sericin peptide solution was filtered with the same filter as in Example 1. The sericin peptide solution is an almost colorless liquid having higher transparency than that of Example 1, and its pH is 8.
It was 0. The sericin peptide solution was analyzed by the Kjeldahl method to determine the nitrogen content based on the sericin peptide.
It contained 077 g of nitrogen.

[0043]

As described above, according to the present invention,
Since sericin in the cocoon thread is hydrolyzed by using acidic ionized water or alkaline ionized water which is safe for the human body, an extremely safe sericin peptide solution can be obtained. Also,
A sericin peptide solution can be produced extremely easily and inexpensively without requiring a technically difficult and complicated processing step for removing an alkali agent, a surfactant and the like from a solution as in the prior art.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an ion water generation device.

[Explanation of symbols]

 1 DC power supply 2 Anode 3 Cathode 6 Water

Claims (4)

[Claims] 1. A sericin peptide solution comprising a sericin peptide dissolved in ionized water. 2. A method for producing a sericin peptide solution, comprising the steps of: electrolyzing water or an aqueous electrolyte solution to generate ionic water; and using the ionic water to hydrolyze sericin in a cocoon thread. 3. The method for producing a sericin peptide solution according to claim 2, wherein the ionic water used for hydrolyzing sericin is acidic ionic water. 4. The method for producing a sericin peptide solution according to claim 2, wherein the ionic water used for hydrolyzing sericin is alkaline ionic water.