JPH04275339A - Production of spherical particle of water soluble protein - Google Patents

Abstract

PURPOSE:To readily produce spherical particles of a water-soluble protein having desired particle size by emulsifying an aqueous solution of water-soluble protein into an organic solvent being specific value or below in solubility to water and distilling water content from the emulsion. CONSTITUTION:(B) An aqueous solution of water-soluble protein (e.g. gelatin, collagen or casein), preferably having about 1-50wt.% concentration is added to (A) an organic solvent (e.g. 1-pentanol, alkylphenol or toluene) being <=10g/100g water, preferably <=5g/100g water in solubility to water at 20 deg.C, preferably at a ratio in which the component B is 5-70wt.% and the component A is the residual amount and as necessary a surfactant (e.g. sorbitan monopalmitate) is further added thereto in an amount of 0.1-20 wt.% based on the component A and the mixture is emulsified at 0-100 deg.C using a homogenizer, etc. Water content is distilled out by heating from the resultant emulsion to afford a dispersing element in the organic solvent of spherical particles of the water-soluble protein. The organic solvent is removed from the dispersing element and the remainder is dried to provide the objective globular particles of water soluble protein.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing spherical particles of water-soluble proteins.

0002

[Prior Art] Water-soluble proteins, as natural polymer compounds derived from living organisms, are used in foods, cosmetics, medicine, textile processing, and polymer processing due to their high safety and unique texture that cannot be obtained with synthetic polymers. It is used in fields such as

[0003] Powders of water-soluble proteins with various particle sizes are commercially available and are used depending on the purpose.These powders are manufactured by reprecipitation or pulverization, is adjusted by reprecipitation conditions, pulverization conditions, classification, etc.

[0004] Since water-soluble protein powder is produced by reprecipitation or pulverization, its shape is amorphous fragments. Due to this shape, the desired performance may not be fully exhibited depending on the application, the bulk density is high, so storage efficiency is poor, and flowability may be deteriorated due to agglomeration of the powder.

For example, when a water-soluble protein powder such as gelatin is used by dispersing it in a polymer compound or liquid, the dispersibility is poor and the dispersibility is poor because the shape is irregularly shaped. It was difficult to obtain a dispersion.

In order to solve these problems, attempts have been made to granulate fragmented powders. for example,
JP-A-1-245074 discloses a method of granulating finely powdered gelatin to improve its dispersibility.

[0007]

[Problems to be Solved by the Invention] However, the particles obtained by granulation are not spherical, and the effect of improving the particle shape is not sufficiently obtained.

The object of the present invention is to provide spherical particles of water-soluble protein.

[0009]

[Means for Solving the Problems] As a result of repeated studies on a method for producing spherical particles of water-soluble protein, the present inventors emulsified an aqueous solution of water-soluble protein in an organic solvent, and extracted water from this emulsion. We have discovered that spherical particles of water-soluble protein can be obtained by distilling off.

[0010] That is, the present invention emulsifies an aqueous solution of a water-soluble protein in an organic solvent having a solubility in water of 10 g/100 g of water or less at 20°C, and distills water off from this emulsion. This is a method for producing spherical particles of a protein.

The water-soluble protein used in the present invention is not particularly limited, and examples thereof include glue, gelatin, collagen, casein, sodium salt of casein, albumin, peptone, and proteose.

The water-soluble protein aqueous solution used in the present invention is prepared by dissolving the water-soluble protein in water or warm water to obtain an aqueous solution,
The concentration is not particularly limited, but is preferably from 1 to 50% by weight from the viewpoint of operability, processing efficiency, and economy.

The organic solvent used in the present invention has a solubility in water of 10 g/100 g of water or less, preferably 5 g/100 g of water or less at 20°C. If the solubility exceeds 10 g/100 g of water, the organic solvent dissolved in the water layer in which the water-soluble protein is dissolved will precipitate the water-soluble protein during the emulsification operation, making it impossible to obtain spherical particles.

The organic solvents used in the present invention include pentane, hexane, heptane, octane, decane, tridecane, pentadecane, octadecane, liquid paraffin,
Examples include hydrocarbons such as cyclohexane, benzene, toluene, xylene, alkylbenzene, and naphthalene, alcohols such as 1-pentanol, hexanol, cyclohexanol, octanol, decanol, and tetradecanol, and phenols such as alkylphenol.

[0015] In addition, aliphatic carboxylic acid esters, aromatic carboxylic acid esters, phosphoric esters, carbonic esters, aliphatic ethers, aromatic ethers, gasoline, mineral spirits, kerosene, light oil, polyalkylene glycols, halogenated Hydrocarbons, fluorocarbon solvents, etc.2
It can be used if its solubility in water at 0° C. is 10 g/100 g of water or less.

Emulsification is carried out using an emulsifying machine such as a homogenizer between an aqueous solution of a water-soluble protein and an organic solvent. At this time, the ratio of the aqueous solution of water-soluble protein to the organic solvent is not particularly limited, but from the viewpoint of operability and economic efficiency, the ratio is 5 to 70% by weight.
It is preferable that the amount of the water-soluble protein be the aqueous solution amount, and the remainder be the organic solvent.

The emulsification operation is carried out by mechanical stirring and mixing using an emulsifying machine or the like, but emulsification may also be carried out by adding a surfactant. Addition of an appropriate surfactant facilitates the emulsification operation, and emulsification can also be performed by stirring and mixing using a turbine blade or the like. Furthermore, the addition of a surfactant makes the aqueous solution droplets in the emulsion uniform and small, making it possible to obtain spherical particles with uniform particle diameters.

Examples of such surfactants include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants as long as the continuous phase is an organic solvent phase. Any of these can be used, and polymeric surfactants can also be used.

The amount of the surfactant to be added is not particularly limited, but from the economic point of view, it is preferably 0.1 to 20% by weight based on the organic solvent.

Examples of surfactants include fatty acid salts, alkyl sulfates, alkyl ether sulfates, dialkyl sulfosuccinates, alkylbenzene sulfonates, acylmethyl taurine, amide ether sulfates, alkyl sarcosinates, α-sulfo fatty acid ester salts, and maleic anhydride. Anionic surfactants such as salts of copolymers of and unsaturated monomers, cationic surfactants such as alkylamine salts, alkylimidazoline salts, quaternary ammonium salts, dimethylalkylbetaine, alkylglycine, amidobetaine Zwitterionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene polyoxypropylene block copolymer, polyoxyethylene Examples include nonionic surfactants such as oxyethylene alkylamine, fatty acid alkanolamide, glycerol fatty acid ester, and polyglycerin fatty acid ester.

[0021] In addition, polyvinyl alcohol,
An emulsion stabilizer such as carboxymethylcellulose may also be added.

[0022] The emulsification operation is usually carried out at a temperature of 0 to 100°C using an emulsifier or a stirrer. Water is distilled off from the obtained emulsion by heating, and if necessary, the pressure is reduced. The boiling point of the organic solvent is sufficiently higher than the boiling point of water, and
When water and its organic solvent are not azeotropic, water is distilled off to obtain an organic solvent dispersion of water-soluble protein. However, if the boiling point of the organic solvent is lower than water or not sufficiently higher than water, or if water and organic solvent are azeotropic, the organic solvent will also be distilled off at the same time as the water, so only the distilled water will be separated. It is desirable to remove the organic solvent and reflux the organic solvent into the emulsion, or to sequentially add the same amount of organic solvent as the distilled organic solvent to the emulsion. Furthermore, it is desirable to continue stirring even during the operation of distilling off water.

As water is distilled off from the water-soluble protein aqueous solution droplets in the emulsion, the concentration of the water-soluble protein in the spherical aqueous solution drops increases, and when the water distillation is completed, the emulsion changes to It changes to a dispersion state in which spherical particles of water-soluble protein are dispersed in an organic solvent.

The spherical particles of water-soluble protein obtained by the present invention can be prepared as an organic solvent dispersion, or after the organic solvent has been removed by filtration and drying, if necessary, the water-soluble protein spherical particles can be washed with a low boiling point organic solvent, etc., and then dried. It is provided as a powder of spherical particles.

The spherical particles of water-soluble protein obtained by the present invention are determined by the concentration of the water-soluble protein in the aqueous solution, the amount of the water-soluble protein aqueous solution in the emulsion, the operating conditions of the emulsifier, the type of organic solvent, and the amount of surfactant. It is possible to adjust the particle size of the spherical particles obtained by appropriate selection in the range of several tens of nanometers to several hundred micrometers.

[0026]

Effects of the Invention: By the method of the present invention, spherical particles of water-soluble protein can be prepared, and the particle size can be easily adjusted. It becomes possible to provide particles. Furthermore, because of the spherical shape, it is also possible to prepare a dispersion of highly concentrated water-soluble proteins.

[0027]

[Examples] The present invention will be specifically explained below using examples.

Example 1 500 g of toluene (solubility: insoluble) and surfactant sorbitan monopalmitate 5 were placed in a 1 liter four-necked flask equipped with a stirrer with turbine blades and a condenser with a hanging water pipe.
After adding 0g and stirring at 25℃ for 30 minutes to dissolve,
While stirring at 300 rpm, add 50 g of 10% by weight aqueous gelatin (manufactured by Katayama Chemical Industry Co., Ltd., reagent) solution,
Emulsification was performed by mixing for a minute. After that, 300rpm
While stirring continuously, the mixture was heated at 110° C. for 4 hours using an oil bath to distill off water. During this time, toluene was refluxed while removing distilled water using a water suspension pipe. After cooling to room temperature, stirring was stopped, and toluene was removed from the gelatin precipitate by decantation, the gelatin precipitate was washed five times with 50 ml of acetone each.

The gelatin powder obtained by drying was photographed using an electron microscope, and its shape was observed and the average particle size was determined. As a result, it was found to be spherical with an average particle size of 31 μm. The average particle diameter was determined by measuring the particle diameters of 30 particles from electron micrographs. This electron micrograph is shown in FIG.

Example 2 500 g of 1-pentanol (solubility: 2.21 g/100 g of water) and 50 g of a 5% by weight aqueous gelatin solution were placed in a 1 liter beaker, and a T. K
．． AUTO HOMO MIXER TYPE
Attach an emulsifying blade to M, 25°C, 5000 rpm.
Emulsification was performed by mixing for 15 minutes. Transfer this emulsion to a 1-liter eggplant-shaped flask, and while rotating at 150 rpm with an evaporator, maintain the temperature at 80°C and 20 mmHg.
Water was distilled off for 12 hours under the conditions of 1-
A pentanol dispersion was obtained. The obtained 1-pentanol dispersion of gelatin was filtered with a membrane filter, washed five times with 50 ml of acetone each, and then prepared in Example 1.
When the shape and average particle size were determined using the same method as above, it was found to be spherical with an average particle size of 7 μm.

Example 3 In the same manner as in Example 1, toluene (solubility: insoluble) 40
0 g of surfactant sodium di-2-ethylhexyl sulfosuccinate, and 50 g of a 10% by weight aqueous gelatin solution. The gelatin powder obtained was spherical in shape and had an average particle size of 20 μm.

Example 4 In the same manner as in Example 1, 1-octanol (solubility: 0
．． 04g/100g of water) and 30g of surfactant polyoxyethylene (6 mol) nonylphenyl ether,
The test was carried out using 100 g of a 5% by weight aqueous solution of casein sodium salt (manufactured by Katayama Chemical Industry Co., Ltd., reagent). The obtained casein sodium salt powder had a spherical shape and an average particle size of 25 μm.

Comparative Example 1 The same method as in Example 1 was carried out, except that ethylene glycol (soluble in water at any ratio) was used instead of toluene.
Gummy precipitates of gelatin were formed during emulsification, and spherical particles could not be obtained.

Comparative Example 2 In the same manner as in Example 1, tert-amyl alcohol (solubility: 12.5 g/100 g of water) was used instead of toluene.
00g, surfactant sodium di-2-ethylhexyl sulfosuccinate 20g, and 5% by weight aqueous gelatin solution 150g. The shape of the gelatin powder obtained was an amorphous lump, and the average particle diameter was unmeasurable.

Comparative Example 3 Commercial product of gelatin powder (G-22 manufactured by Nitta Gelatin Co., Ltd.)
In case 28), the particle shape was amorphous and fragmentary. This electron micrograph is shown in FIG.

[0036]

[Brief explanation of the drawing]

FIG. 1 is an electron micrograph of gelatin powder obtained in Example 1. The magnification is 200x, and the length scale is shown at the bottom right.

FIG. 2 is an electron micrograph of a commercially available gelatin powder (G-2228, manufactured by Nitta Gelatin Co., Ltd.) of Comparative Example 3. The magnification is 150x, and the length scale is shown at the bottom right.

Claims (1)

[Claims] Claim 1: Solubility in water at 20°C is 10g
/A method for producing spherical particles of water-soluble protein, which comprises emulsifying an aqueous solution of water-soluble protein in an organic solvent containing 100 g or less of water, and distilling water off from the emulsion.