Porphyran particles, method for producing the same, and cosmetics

Abstract

To realize particles having excellent feel properties with a water-soluble material having excellent biodegradability.SOLUTION: Porphyran particles of the present invention are mainly composed of porphyran, which is a trans-polysaccharide having galactose molecules as structural units. The average particle size is less than 0.5 to 20 μm and the protein content is less than 100 ppm. In addition, the method for producing porphyran particles of the present invention comprises: preparing a dispersion of porphyran having a protein content of less than 100 ppm; and spray-drying and granulating the dispersion to obtain porphyran particle powders.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to Porphyran particles formed by aggregation of Porphyran having good biodegradability, and in particular to spherical Porphyran particles and cosmetics containing the same. [Background technology]

[0002] Currently, petroleum-derived synthetic polymers (plastics) are used in a variety of industries. Many synthetic polymers were developed with long-term stability in mind, and therefore do not decompose in the natural environment. This has led to a variety of environmental problems. For example, plastic products that have been released into the aquatic environment accumulate over long periods of time, causing significant harm to the ecosystems of oceans and lakes. In addition, microplastics, tiny pieces of plastic measuring less than 5 mm in length down to the nano-level, have become a major problem in recent years. Examples of microplastics include fine particles found in cosmetics, small clumps of plastic resin before processing, and larger products that break down into smaller pieces as they float in the ocean.

[0003] In recent years, plastic particles (e.g., polyethylene particles) of several hundred micrometers in size have been blended into cosmetics to improve their texture characteristics. Because plastic particles have a low true specific gravity, they are difficult to remove at sewage treatment plants and are prone to flow into rivers, oceans, ponds, and other areas. Furthermore, because plastic particles tend to adsorb chemicals such as pesticides, there is a risk that they may have an adverse effect on the human body due to bioaccumulation. This issue has been pointed out by the United Nations Environment Programme and other organizations, and various countries and industry groups are considering regulating them.

[0004] Furthermore, interest in natural and organic cosmetics is growing, and guidelines for labeling the natural / organic index for cosmetics (ISO 16128) have been established. According to these guidelines, the ingredients in a product are classified into, for example, natural ingredients, naturally derived ingredients, and non-natural ingredients, and an index is calculated based on the content of each ingredient. In the future, as indexes will be displayed on products in accordance with these guidelines, naturally derived ingredients and even more natural ingredients will be required.

[0005] Given this background, biodegradable plastics, which are decomposed into water and carbon dioxide by microorganisms in the natural environment and integrated into the natural carbon cycle, have attracted attention. Cellulose particles, a natural plant-derived raw material, do not float on water even when released into the environment and have good biodegradability, reducing the risk of environmental problems. Powdered cellulose particles with strength and disintegrability suitable for scrubbing agents are known, using cellulose obtained by a process that does not involve intentional chemical modification (see, for example, Patent Document 1). It is also known that type I crystalline cellulose particles are produced by granulating and drying cellulose dispersed in an organic solvent using a spray-drying method (see, for example, Patent Document 2). It is also known that the use of spherical composite particles containing type I crystalline cellulose and silica allows the production of cosmetics that combine tactile properties with environmental friendliness (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-88873 [Patent Document 2] Japanese Patent Application Publication No. 2-84401 [Patent Document 3] WO2019 / 189692 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the cellulose in the patent document is a trans-polysaccharide composed of glucose molecules and is insoluble in water. Therefore, cellulose is considered to be poorly degradable in nature. Therefore, the object of the present invention is to realize particles that provide excellent tactile properties using a water-soluble material with excellent biodegradability. [Means for solving the problem]

[0008] In the present invention, particles that provide good tactile properties are realized using porphyran. Porphyran is a type of trans-polysaccharide composed of galactose molecules, with some of the hydroxyl groups substituted with sulfate groups. Therefore, it is said to have high water solubility and high biodegradability. Cosmetics containing particles formed from such porphyran are less likely to cause environmental problems and can provide tactile properties similar to those of conventional plastic beads. The porphyran particles of the present invention are formed by aggregation of porphyran, a trans-polysaccharide composed of galactose molecules. The porphyran particles have an average particle size of 0.5 to less than 20 μm and a protein content of less than 100 ppm.

[0009] The method for producing Porphyran particles according to the present invention comprises the steps of preparing a dispersion of Porphyran having a protein content of less than 100 ppm, and spray-drying the dispersion to granulate the dispersion and obtain a powder of Porphyran particles.

[0010] Cosmetics can be prepared by blending any of the Porphyran particles described above with cosmetic ingredients. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an SEM photograph showing the appearance of the porphyran particles of Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0012] The Porphyran particles according to the present invention are formed by aggregation of Porphyran, a "trans-polysaccharide composed of galactose molecules," and have an average particle diameter d of 0.5 μm or more but less than 20 μm and a protein content of less than 100 ppm. The average particle diameter d affects the tactile properties of cosmetics. If the particle diameter is less than 0.5 μm, tactile properties such as rolling feel, duration of rolling feel, and uniform spreadability are significantly reduced. On the other hand, if the particle diameter exceeds 20 μm, the cosmetic product will feel rough and the soft and moist feel will be reduced. The average particle diameter d is preferably 1 to 20 μm, and optimally 1 to 15 μm.

[0013] Seaweed, the raw material for Porphyran, is rich in protein. It has been pointed out that even nori, a typical processed food, can occasionally cause food allergies. There are also concerns about unknown health hazards, such as food-dependent exercise-induced allergies caused by hydrolyzed wheat. For this reason, it is desirable to reduce the protein content by purifying the raw materials in advance. Therefore, the protein content in Porphyran particles is kept below 100 ppm. Less than 10 ppm is even more preferable. The protein content can be determined using the Kjeldahl method.

[0014] Furthermore, seaweed has the property of absorbing arsenic. For this reason, Porphyran is said to contain tens to hundreds of ppm of arsenic. Therefore, in consideration of safety, it is preferable to purify the porphyran before granulation to remove (reduce) the arsenic in advance. The arsenic content in Porphyran particles is preferably less than 5 ppm. If the arsenic content is 5 ppm or more, it may not be permitted to be incorporated into cosmetics.

[0015] The sphericity of the Porphyran particles is preferably 0.85 or more. Cosmetics containing particles with a sphericity of less than 0.85 do not provide good rolling properties. A sphericity of 0.90 or more is particularly preferred.

[0016] Porphyran is known to have moisturizing power equivalent to that of hyaluronic acid. After leaving Porphyran particles standing for 12 hours under conditions of 40°C / 90% RH, it is preferable that the moisture retention capacity is 30% or more. When blended into cosmetics, it can prevent external irritation and dryness. In particular, a moisture retention capacity of 50% or more is preferable.

[0017] Here, the Porphyran content in the Porphyran particles is preferably 90% or more. 95% or more, more than 99%, and substantially 100% are particularly preferred. The higher the content, the higher the natural index according to the aforementioned guidelines. The Porphyran content (Porphyran content per solid content) can be measured by the phenol-sulfuric acid method and calculated from the concentration obtained using a calibration curve previously prepared using galactose.

[0018] Next, a method for producing the porphyran particles will be described.

[0019] First, a dispersion of porphyran is prepared. Porphyran is found in large amounts in seaweed and can be obtained by a known method of extraction by hot water treatment (for example, JP 2005-120193 A). Alternatively, commercially available porphyran powder (manufactured by MMO Co., Ltd.) or porphyran extract (manufactured by Shirako Co., Ltd.) may be used. When using porphyran powder, it is dispersed in warm water at a temperature of 70°C or higher but lower than 90°C. Dispersion is further promoted by irradiating with ultrasonic waves. A uniform dispersion can be obtained by further adjusting the pH to 8 or higher but lower than 10 using any aqueous alkaline solution. The solids concentration of this dispersion is adjusted to a range of 1 to 7% to obtain a dispersion with an appropriate viscosity.

[0020] If the temperature of the hot water in which the Porphyran powder is dispersed is less than 70°C, the Porphyran powder is likely to be insufficiently dispersed. As a result, the particles are unlikely to become spherical during spray drying, resulting in low sphericity. Increasing the temperature of the hot water to 90°C or higher does not promote dispersion of the Porphyran powder, is economically unprofitable, and has no particular advantage. Furthermore, dispersion is also insufficient if ultrasonic irradiation is not performed. If the pH is adjusted using an alkaline aqueous solution to less than 8, dispersion is also insufficient. Increasing the pH to 10 or higher does not further promote dispersion, is economically unprofitable, and has no particular advantage. If the solids concentration exceeds 7%, the viscosity usually increases, making it difficult to form spherical droplets during spray drying, and the sphericity of the particles is likely to decrease. Furthermore, the droplets tend to become larger during spray drying, resulting in an increased particle size. If the concentration is less than 1%, it is economically unprofitable and has no particular advantage. Water is the preferred solvent for the dispersion.

[0021] Next, the dispersion of Porphyran powder is subjected to an enzyme treatment using protease or the like, a solvent extraction treatment using acetone or the like, or an organic acid treatment using malic acid or the like. This reduces the protein content, making it possible to reduce the residual protein content to less than 100 ppm. These reduction treatments may also be combined.

[0022] Furthermore, it is preferable to reduce the arsenic contained in the dispersion. Although the arsenic can be reduced to some extent by washing in the above-mentioned protein reduction treatment, it is difficult to reduce the arsenic to less than 5 ppm. Therefore, by using a strongly acidic cation exchange resin, arsenic can be removed from the dispersion to less than 5 ppm. This arsenic reduction treatment may be performed before the protein reduction treatment.

[0023] Next, the Porphyran dispersion with reduced residual protein is granulated by spray drying using a spray dryer. Protein and arsenic reduction treatments are performed prior to granulation. Porphyran particles are produced by spraying into a hot air stream at a rate of 1 to 3 liters / minute. Spraying can be performed using an atomizer, a two-fluid nozzle, or the like. The hot air preferably has an inlet temperature of 70 to 200°C and an outlet temperature of 40 to 60°C. If the inlet temperature is less than 70°C, the solids contained in the dispersion are not dried sufficiently, resulting in adhesion to the inside of the device. If the temperature exceeds 200°C, the Porphyran may decompose. If the outlet temperature is less than 40°C, the solids are not dried sufficiently, resulting in adhesion to the inside of the device. A more preferred inlet temperature is 130 to 190°C. In the case of a two-fluid nozzle, the spray air pressure for generating spray droplets can be adjusted within the range of 0.05 to 0.60 MPa depending on the desired particle size. If the atomizing air pressure is less than 0.05 MPa, it is difficult to obtain uniformly sprayed droplets, and some droplets become too large to dry in the hot air stream and adhere to the inside of the device. Exceeding 0.60 MPa does not further improve the atomization quality and provides no particular advantage. When using an atomizer, the rotation speed can be adjusted within the range of 3,000 to 30,000 rpm depending on the desired particle size. If the rotation speed is less than 3,000 rpm, it is difficult to obtain uniformly sprayed droplets, and some droplets become too large to dry in the hot air stream and adhere to the inside of the device. Exceeding 30,000 rpm does not further improve the atomization quality and provides no particular advantage.

[0024] <Cosmetics> Cosmetics can be obtained by blending the above-mentioned Porphyran particles with various cosmetic ingredients. Such cosmetics can simultaneously provide the same rolling feel, long-lasting rolling feel, and uniform spreadability as silica particles, as well as the same soft and moist feel as plastic beads. In other words, they can satisfy the typical tactile properties required of a cosmetic feel-improving agent.

[0025] Specific examples of cosmetics are listed by classification in Table 1. These cosmetics can be produced by conventional methods. Cosmetics are used in various forms, such as powder, cake, pencil, stick, cream, gel, mousse, liquid, and cream.

[0026] Representative classifications and ingredients of various cosmetic ingredients are shown in Table 2. Furthermore, cosmetic ingredients listed in the Quasi-drug Ingredients Standards 2006 (published by Yakuji Nipposha Co., Ltd., June 16, 2006) and the International Cosmetic Ingredient Dictionary and Handbook (published by The Cosmetic, Toiletry, and Fragrance Association, Eleventh Edition 2006) may also be blended.

[0027] [Table 1]

[0028] [Table 2] [Example]

[0029] Examples of the present invention will be specifically described below.

[0030] [Example 1] 300 g of porphyran powder (MMO) was suspended in 5700 g of purified water. 30 g of protease (Novozymes Flavorzyme 1000 L) was added to the suspension and stirred at 25°C for 19 hours. The suspension was filtered through a quantitative filter paper (Advantec Toyo No. 2) using a Buchner funnel (Sekiya Rika Glass Instruments 3.2 L). The filtrate was then repeatedly washed with purified water until the conductivity of the filtrate reached 1 mS / m or less to remove the protease. The cake-like substance obtained by this protein removal process was dried at 60°C for 12 hours. 250 g of porphyran powder with a protein content reduced to 87 ppm was obtained.

[0031] Next, 150 g of this porphyran powder was suspended in 2850 g of pure water. This suspension was passed through a column packed with 200 mL of cation exchange resin (SK1BH, manufactured by Mitsubishi Chemical Corporation) to reduce the arsenic content. 300 g of the resulting porphyran suspension was taken, heated to 80°C, and held for 30 minutes. It was then subjected to ultrasonic irradiation at 100% output for 3 minutes using a horn-type ultrasonic disperser (SONOPLUS HD2070, manufactured by BANDELIN). It was then cooled to 23°C, and the pH was adjusted to 9.1 by adding a 1% aqueous NH3 solution. This resulted in a porphyran dispersion with a solids concentration of 5%.

[0032] This Porphyran dispersion was spray-dried to obtain a powder of Porphyran particles. In this example, the dispersion was supplied at a rate of 1 liter / minute into a hot air stream with an inlet temperature of 160°C. Spraying was performed using an atomizer, with the rotation speed set to 27,000 rpm. In this example, the outlet temperature was measured to be 55°C. An SEM photograph of the obtained Porphyran particles is shown in Figure 1.

[0033] The spraying conditions for the Porphyran particles are shown in Table 3. The physical properties of the Porphyran particle powder were measured by the following method, and the results are shown in Table 4. The same applies to the Examples and Comparative Examples described later.

[0034] (1) Average particle diameter The particle size distribution of the porphyran particles was measured by laser diffraction. Here, the particle size distribution was measured using an LA-950v2 manufactured by Horiba, Ltd. The median value was calculated from the obtained particle size distribution and used as the average particle size.

[0035] (2) Sphericity The particles were photographed at magnifications of 2000 to 250,000 times using a transmission electron microscope (Hitachi, H-8000) to obtain a projection image. From the projection image, 50 particles were randomly selected, and the maximum diameter D L and the minor axis D perpendicular to this S Measure the ratio (D S / D L The average value of these was taken as the sphericity.

[0036] (3) Arsenic content Approximately 1 g of porphyran particle powder was placed on a platinum dish, 5 ml of nitric acid and 10 ml of hydrofluoric acid were added, and the mixture was heated on a sand bath. After drying, a small amount of water and 50 ml of nitric acid were added to dissolve the mixture in a 100 ml measuring flask, and water was added to make a 100 ml solution. Five 10 ml aliquots were then taken from this 100 ml solution. The arsenic content was measured using an ICP plasma emission spectrometer (SII, SPS5520) by the standard addition method.

[0037] (4) Protein content The protein content was determined by the Kjeldahl method. Specifically, the porphyran particle powder was thermally decomposed with sulfuric acid, and the nitrogen in the sample was converted to ammonium sulfate. Next, the decomposition solution was made alkaline, and the liberated ammonia was distilled, and the amount of N was measured by titration. The protein content was determined by multiplying this amount of N by 6.25.

[0038] (5) Moisture retention amount Porphyran powder was placed in a porcelain crucible that had been previously heated at 500°C for 1 hour to remove adsorbed moisture, and then exposed to 40°C and 90% RH for 12 hours. It was then dried at 105°C for 2 hours, and the weight loss was measured. The weight loss (wt%) was taken as the moisture content of the porphyran particles.

[0039] [Example 2] A powder of porphyran particles was obtained in the same manner as in Example 1, except that the rotation speed of the atomizer was set to 20,000 rpm.

[0040] [Example 3] A two-fluid nozzle was used to spray the porphyran dispersion at a spray air pressure of 0.4 MPa. At this time, the porphyran dispersion was supplied at a rate of 2 liters / minute into a hot air stream with an inlet temperature of 190° C. A powder of porphyran particles was obtained in the same manner as in Example 1.

[0041] [Example 4] The spray air pressure was set to 0.5 MPa, and the porphyran dispersion was supplied at a rate of 1 liter / minute into a hot air stream having an inlet temperature of 160° C. Except for this, a powder of porphyran particles was obtained in the same manner as in Example 3.

[0042] [Comparative Example 1] A powder of porphyran particles was obtained in the same manner as in Example 1, except that the rotation speed of the atomizer was set to 5000 rpm.

[0043] Comparative Example 2 In this comparative example, a powder of Porphyran particles was obtained in the same manner as in Example 1, except that the protein reduction treatment was not performed. That is, 150 g of Porphyran powder (manufactured by MMO) was suspended in 2850 g of pure water, and the arsenic reduction treatment was performed. After this, a powder of Porphyran particles was prepared in the same manner as in Example 1.

[0044] [Table 3]

[0045] [Table 4]

[0046] <Tactile properties of Porphyran particle powder> Next, the tactile properties of the powders obtained in each Example and Comparative Example were evaluated. A sensory test was conducted for each powder by 20 expert panelists, who interviewed them regarding seven evaluation items: smooth feel, moist feel, rolling feel, uniform spreadability, adhesion to the skin, duration of the rolling feel, and soft feel. The evaluation scores of each panelist based on evaluation criteria (a) were totaled, and the tactile properties were evaluated based on evaluation criteria (b). The results are shown in Table 5. Evaluation criteria (a) 5 points: Very good. 4 points: Excellent. 3 points: Average. 2 points: Inferior. 1 point: Very poor. Evaluation Criteria (b) ◎: Total score is 80 points or more ○: Total score is between 60 and 80 points △: Total score is between 40 and 60 points ▲: Total score is between 20 and 40 points ×: Total points are less than 20 points

[0047] [Table 5]

[0048] <Usage of powder foundation> Powder foundations were prepared using the Porphyran particle powder in the blending ratios (wt%) shown in Table 6. Specifically, the powder obtained in each example was used as component (1), and was placed in a mixer along with components (2) to (9) and stirred until uniformly mixed. Next, cosmetic components (10) to (12) were added to the mixer and stirred until uniformly mixed. The resulting cake-like substance was crushed, and approximately 12 g of it was removed and placed in a 46 mm x 54 mm x 4 mm metal dish for press molding. Sensory tests were conducted on the powder foundations obtained in this manner by 20 expert panelists. Interviews were conducted regarding six evaluation criteria: uniform spread, moist feeling, and smoothness during application to the skin, and the uniformity, moist feeling, and softness of the cosmetic film after application. Each panelist's scores based on the aforementioned evaluation criteria (a) were totaled, and the feel of the foundation when used was evaluated based on the aforementioned evaluation criteria (b). The results are shown in Table 7.

[0049] [Table 6]

[0050] [Table 7]

Claims

1. The porphyran particles are formed by the aggregation of porphyran, a trans-type polysaccharide composed of galactose molecules, and are characterized by having an average particle size of 0.5 to less than 20 μm and a protein content of less than 100 ppm.

2. 2. The porphyran particles according to claim 1, which have a sphericity of 0.85 or more.

3. 3. The Porphyran particles according to claim 1, wherein the arsenic content is less than 5 ppm.

4. 4. The Porphyran particles according to claim 1, which have a water retention of 30% or more when left at 40° C. / 90% RH for 12 hours.

5. 5. The Porphyran particles according to claim 1, wherein the Porphyran content in the Porphyran particles is 90% or more.

6. A cosmetic preparation containing the porphyran particles described in any one of claims 1 to 5.

Images