JP5320449B2 - Method for producing thickener - Google Patents

Description

The present invention relates to a method for producing a microbial polysaccharide thickener having excellent emulsification / dispersion stability used for various emulsified products and solid dispersion products and having high viscosity.

  In general, various thickeners are used in emulsified products and dispersion products of fine solids for the purpose of preventing separation of the emulsified system, preventing sedimentation and floating of the solid dispersion, and imparting appropriate viscosity that is easy to handle. Yes. For example, it is good to spread with a low viscosity because it is applied thinly in a lotion or lotion, it has an appropriate viscosity so that it can be applied partially in a cream or serum, and it does not flow down in pack cosmetics or massage cosmetics Various viscosity characteristics are required depending on the purpose of use. In addition, emulsified products and fine solid dispersion type products are made by emulsifying or dispersing water and various oils, higher alcohols, pigments, and other raw materials that are incompatible with each other. However, a thickener is blended to prevent separation.

  Thickeners used in cosmetics include synthetic polymers such as acrylic acid polymers, processed natural products such as carboxymethylcellulose and methylcellulose, plant-derived materials such as carrageenan, guar gum, locust bean gum, gum arabic, and caraya gum. Polysaccharides derived from microorganisms such as polysaccharides and xanthan gum are used. In particular, natural products processed for the purpose of obtaining a high thickening effect in a relatively small amount and microbially produced polysaccharides have been used in many cases. However, microbial-produced polysaccharide thickeners have the disadvantage that their viscosity decreases rapidly as the temperature increases.

  Therefore, a method for improving the viscosity characteristics of microbially produced polysaccharides has been proposed. For example, as a method of obtaining high viscosity by blending a low-concentration thickener, gellan gum, which is a microorganism-derived polysaccharide, and other polysaccharides are blended. A method of increasing viscosity (JP-A-10-215795), a method of obtaining high-viscosity xanthan gum by heat treatment or wet heat treatment of powdered xanthan gum (JP-A-10-33125, JP-A-2000-7705), and the like. is there. However, a sufficiently satisfactory thickener has not yet been obtained, and higher performance is required.

The present inventors improved the above problems, gave high viscosity in a small amount, and as an excellent polysaccharide thickener without a rapid decrease in viscosity due to an increase in temperature, fucose, glucose, glucuronic acid, A thickener was proposed in which a polysaccharide obtained by heat-treating a polysaccharide containing rhamnose as a constituent monosaccharide at 60 to 180 ° C. in an aqueous solution having a pH of 8 or more [ Japanese Patent Application No. 2000-313517 ( JP 2002-121538 A)] .

  However, although production on a flask scale is possible, there is a problem in that when the production is performed on an industrial scale as it is, the viscosity of the thickener obtained by the production lot varies.

  An object of the present invention is to provide a thickener that solves such problems and can be actually produced on an industrial scale and has excellent emulsification / dispersion stability.

In order to solve such problems, the present inventors have conducted extensive research on improving the production method of polysaccharide thickeners on an industrial scale. As a result, specific polysaccharides were heat-treated in an alkaline aqueous solution. Later, by external cooling using a refrigerant in a method without strong shearing force, it has a higher viscosity, and there is no sudden drop in viscosity due to temperature rise, excellent emulsification / dispersion stability, and high viscosity The inventors have found that polysaccharides can be obtained and have completed the present invention.

That is, the invention according to claim 1, fucose, glucose, glucuronic acid, a polysaccharide containing rhamnose as a constituent monosaccharide, 8 in more alkaline aqueous solution pH is, after heat treatment at 60 to 180 ° C., stirring blade While maintaining the slow rotation speed of 2.0 m / s or less at the tip of the tube, it is externally cooled using a refrigerant , or passes under pressure through a coiled tube externally cooled using a refrigerant without applying a shearing force by stirring. And a method for producing a thickener having excellent emulsification / dispersion stability and high viscosity .

Invention, the polysaccharide fucose in a molar ratio according to claim 2: Glucose: glucuronic acid: rhamnose = 1-2: 1-4: 1-2: Production of thickener of claim 1 wherein from 1 to 2 Is the method .

The invention according to claim 3 is the production of the thickener according to claim 1 or 2, wherein the polysaccharide is composed of glucose, glucuronic acid, and rhamnose as a main chain, and fucose is bonded to a side chain. Is the method .

The invention according to claim 4 is the method for producing a thickener according to any one of claims 1 to 3, wherein the polysaccharide is a polysaccharide produced by Alkaline Generus B-16 strain.

The thickener obtained by the method of the present invention shows a high viscosity in a small amount, maintains the viscosity even at a high temperature and for a long time, and is excellent in emulsification / dispersion stability as compared with the conventional thickener. . Therefore, it can be suitably used for thickening, emulsifying and dispersing stabilization of emulsified products such as cosmetics, pharmaceuticals, foods, paints, inks and agricultural chemicals.

The present invention is described in detail below.
This onset Ming, fucose, glucose, glucuronic acid, in polysaccharides the pH is 8 or more alkaline aqueous solution containing rhamnose as a constituent monosaccharide, after heat treatment at 60 to 180 ° C., in a way that does not involve high shear force there are, snake tip speed of the stirring blade was external cooling using a refrigerant without applying a shear force by externally cooling or stirring with a refrigerant while maintaining the following slow speed 2.0 m / s It is a manufacturing method of the thickener formed by passing the inside of a pipe under pressure and cooling . Although polysaccharides subjected to alkaline heat treatment holding a high viscosity at high temperatures, when cooling this, when performing a vigorous stirring in view of enhancing the cooling efficiency, a slowly stirring or The effect of thickening is small and the change in viscosity due to temperature is large compared to the case where it is press-fitted into a helical tube (cooling coil) that is not substantially accompanied by a shearing force due to stirring .

Polysaccharides used in the present invention is a polysaccharide containing fucose, glucose, glucuronic acid, rhamnose as a constituent monosaccharide, repeated preferably glucose as shown in the following formula (1), glucuronic acid, consisting of rhamnose structure Is a polysaccharide having a structure in which one fucose is branched to one glucose.

  The polysaccharide used in the present invention is obtained as a polysaccharide produced by microorganisms. In general, since microorganisms often produce two or more types of polysaccharides, other polysaccharides may be included in the polysaccharide used in the present invention, as long as they do not interfere with the effects of the present invention. It does not prevent the inclusion of polysaccharides.

  Although the microorganisms which produce a polysaccharide are not specifically limited, For example, there exists Alkali-Genes Relasts B-16 strain bacteria (FERM BP-2015).

  Production of the polysaccharide of the present invention is carried out as follows, for example, in the case of Alkaline Genus Lasus B-16 strain bacteria.

  Alkaline Genus rutas B-16 strain bacteria are cultivated by the usual microorganism culture method, for example, monosaccharides such as fructose, glucose and sucrose as a carbon source, natural polymers such as hemicellulose, starch and corn starch, olive oil and the like Use oils as the nitrogen source, inorganic nitrogen sources such as urea, ammonium chloride, ammonium nitrate, and ammonium sulfate; organic nitrogen sources such as tryptone, yeast extract, meat extract, peptone, and malt extract; other potassium phosphates and magnesium sulfate Using a medium supplemented with inorganic salts such as sodium chloride, aeration and stirring liquid culture is performed for 3 to 10 days at an initial pH of 4 to 10 and a culture temperature of 15 to 40 ° C. After culturing, an organic solvent such as acetone, ethanol, isopropyl alcohol or the like that is about twice (volume) or more is added to the culture solution, and the culture product is recovered as an insoluble aggregate.

It has been ascertained that the polysaccharide produced by the bacterium Alkagenes latus B-16 strain contains at least two polysaccharides, one of which is the polysaccharide according to the present invention (1) glucose as shown in, glucuronic acid, a polysaccharide having one fucose branched structure one glucose in the repetitive structure consisting of rhamnose, off the other one, the Ru indicated by the following (2) It is a polysaccharide with a repeating structure comprising course and mannose as constituent monosaccharides [see the Annual Meeting of the Japanese Society of Agricultural Chemistry 1998, page 371. Y. Nohata, J .; Azuma, R.A. Kurane, Carbohydrate Research 293, 213~222 ( 1996) see]

Even if the polysaccharide represented by the above formula (2) is contained in the polysaccharide of the above formula (1), which is a polysaccharide according to the present invention , the effect thereof is not hindered. Therefore, the polysaccharide is represented by the above formula (2). Without removing the polysaccharide, it is possible to use the polysaccharide produced by the alkaline genus Lasus strain B-16.

  When the polysaccharide according to the present invention is subjected to alkaline heat treatment, the pH of the polysaccharide aqueous solution is adjusted to 8 or more, preferably 11 or more, more preferably 12 or more by adding an alkaline substance. Under acidic conditions where the pH of the aqueous solution is less than 7, the polysaccharide molecular chain is severely cleaved, and the thickening effect and emulsifying / dispersing effect intended by the present invention may not be obtained.

  The alkali heat treatment temperature is 60 to 180 ° C, preferably 80 to 160 ° C, more preferably 100 to 140 ° C. If it is less than 60 degreeC, even if it makes heating time long, the thickening effect may not be acquired. Moreover, when it exceeds 180 degreeC, decomposition | disassembly of a polysaccharide may advance excessively and may be unpreferable. As a matter of course, when mass production is performed at a temperature of 100 ° C. or higher, it is necessary to use a heat-resistant container such as a jar fermenter for the heat treatment. The heating time is appropriately determined depending on the pH, processing temperature, and target viscosity characteristics, but is usually 10 to 120 minutes. Moreover, the polysaccharide of predetermined viscosity can also be obtained by sampling on the way and measuring a viscosity.

  In the alkaline heat treatment of the polysaccharide according to the present invention, the aqueous solution concentration of the polysaccharide is 0.01 to 3% by weight, preferably 0.1 to 1% by weight. If the concentration exceeds 3% by weight, the viscosity of the aqueous solution may be high and handling may be poor. Further, a concentration of 0.01% by weight or less is not preferable because the concentration is low and the production efficiency is low.

If the polysaccharide is subjected to an alkali heat treatment, it is subsequently cooled externally using a refrigerant while maintaining the tip speed of the stirring blade at a slow rotational speed of 2.0 m / s or less according to the present invention, or by stirring. A method of cooling while applying pressure through an externally cooled snake tube without applying a shearing force is applied . In concrete terms, while passing a coolant such as water cooling coils jar fermenter vessel, a method of tip speed of the stirring blade is stirred cooled below the slow speed 2.0 m / s, jar fermenter vessel And a method of cooling by press-fitting into a cooling pipe (cooling coil). Cooling in a large jar fermenter container is not preferable because it takes a long time for cooling at a low tip speed and at a low stirring speed, and a polysaccharide having the desired viscosity cannot be obtained. The shape of the stirring blade at the time of stirring and cooling is not particularly limited, and a shape such as a propeller type, a ribbon type, and a blade type is appropriately selected in consideration of a container such as a jar fermenter. Further, the diameter, length, material, and shape of the serpentine tube (cooling coil) used for cooling are not particularly limited, and are appropriately selected in consideration of conditions such as the temperature to reach cooling, the cooling processing amount, and time. It is. Feature of the present invention, the aqueous polysaccharide solution subjected to alkali heat treatment when the external cooling using a refrigerant, without substantial shear forces due to撹拌 coiled or pressed into (cooling coils) within or stirring Ru near the point of cooling by reducing the shear force by like.

  When the tip speed of the stirring blade during stirring cooling exceeds 2.0 m / s, there is little increase in the viscosity of the polysaccharide obtained by the alkali heat treatment, and the viscosity due to temperature is higher than that of the polysaccharide before the alkali heat treatment. In addition to the large change, the change in viscosity with time is also unfavorable. Further, it is not preferable to continue stirring and cooling more than necessary.

  Although the cooling target temperature is not particularly limited, it may be appropriately selected from 40 ° C. to room temperature as a guide.

  When the cooling temperature of the aqueous solution of polysaccharides subjected to the alkali heat treatment reaches 40 ° C. to room temperature, it is neutralized by adding an aqueous solution of inorganic acid (sulfuric acid, hydrochloric acid), and then about 3 times (volume) with stirring. The target thickener is easily isolated by adding an organic solvent such as acetone, ethanol, isopropyl alcohol, etc., precipitating the heat-treated polysaccharide as an aggregate, filtering and drying under reduced pressure.

Polysaccharides subjected to alkaline heat treatment, which has high thickening in small amounts Ri by to external cooling using a refrigerant in a manner that does not involve high shear force, yet emulsion stabilization of the emulsified product, the individual Due to the excellent dispersion stability of dispersed products, it can be applied in a wide range of fields such as cosmetics, pharmaceuticals, foods, paints, inks, and agricultural chemicals.

In addition, the thickener obtained by the method of the present invention does not impede the use of a mixture with other thickeners as long as the effects intended by the present invention are not impaired.

  Since the polysaccharide used in the present invention is an extremely high polymer having a molecular weight of 10 million or more, when it is treated at a high temperature in the form of an alkaline aqueous solution, the molecules become stretched and the viscosity increases. However, if a strong stirring force is applied during cooling to apply a shearing force, the stretched molecular chains are broken by the shearing force, and a change occurs in the three-dimensional structure of a part of the molecule, resulting in a decrease in viscosity and a thickening effect. It is thought that it will disappear.

  Hereinafter, the present invention will be described specifically by way of examples. However, the present invention is not limited to these.

[Cultivation of Alkaline Generus B-16 Bacteria]
Alkaline generators B-16 (FERM BP2015) strain was inoculated into 1 L of a medium consisting of 0.5% meat extract, 1% peptone and 0.3% salt, and cultured with shaking at 30 ° C for 24 hours. A culture medium of 200 L having the following composition was placed in a jar fermenter having a capacity of 300 L and cultured at 30 ° C. for 144 hours with aeration (aeration: 200 L / min, agitation: 250 rpm).

<Composition of culture medium>
Glucose [Reagent manufactured by Wako Pure Chemical Industries, Ltd.] 4.00 kg
Dipotassium hydrogen phosphate [Reagent made by Wako Pure Chemical Industries, Ltd.] 0.40kg
Potassium dihydrogen phosphate [Reagent made by Wako Pure Chemical Industries, Ltd.] 0.20kg
Sodium chloride [Reagent manufactured by Wako Pure Chemical Industries, Ltd.] 0.01kg
Magnesium sulfate [Reagent made by Wako Pure Chemical Industries, Ltd.] 0.02kg
Potassium nitrate [Reagent made by Wako Pure Chemical Industries, Ltd.] 0.10kg
Yeast extract (Oxoid) 0.15kg
The above components were dissolved in ion-exchanged water, adjusted to pH 6.5 with sodium hydroxide and sulfuric acid, and the total amount was 200 liters.

[Preparation of B-16 polysaccharide]
After completion of the culture, about 3 times the volume of isopropyl alcohol was added to the culture and stirred and mixed. The precipitated aggregate was collected by filtration and dried under reduced pressure to obtain B-16 polysaccharide.

[Preparation of polysaccharide-1]
Into a 300 liter container, 199.9 kg of water was added, and with stirring, 100 g of the B-16 polysaccharide obtained by the above method was added and dissolved to prepare 200 kg of a 0.5 wt% aqueous solution. This was adjusted to pH 13 with a 1 mol / L aqueous sodium hydroxide solution, then placed in a 300 liter jar fermenter and allowed to stand overnight at room temperature. After standing, pressure heat treatment was performed at 120 ° C. for 20 minutes, then cooled to 100 ° C., returned to normal pressure, and B-16 polysaccharide subjected to alkali heat treatment was obtained. B-16 polysaccharide treated with alkaline heat treatment obtained by cooling the outside of a stainless steel snake tube (inner diameter 20 mm, length 12.5 m) with cold water at 15 ° C. is passed through the pressure system over 30 minutes and cooled to 30 ° C. And neutralized with 1 mol / L sulfuric acid. After neutralization, about 3 times the volume of isopropyl alcohol was added to the aqueous polysaccharide solution, and the precipitated aggregate was filtered and dried under reduced pressure to obtain polysaccharide-1.

[Production of polysaccharide- 2 ]
In the method for producing an alkali heat-treated polysaccharide-1, the jacket of a 30 liter jar fermenter containing the obtained alkali heat-treated B-16 polysaccharide was cooled through 15 ° C. cold water, and at the same time propeller type stirring Using a stirring device having a blade, the mixture was stirred at a tip speed of 1.88 m / S for 2 hours, cooled to 30 ° C. or lower, and neutralized with 1 mol / L sulfuric acid. After neutralization, about 3 times the volume of isopropyl alcohol was added to the aqueous polysaccharide solution, and the precipitated agglomerate was filtered, dried under reduced pressure, and an alkaline heat-treated polysaccharide- 2 was obtained.
Similarly, polysaccharide- 5 was obtained with a 30 liter jar fermenter under the cooling conditions shown in Table 1.

[Production of Polysaccharide- 3 ]
Into a 300 liter container, 199.9 kg of water was added, and with stirring, 100 g of the B-16 polysaccharide obtained by the above method was added and dissolved to prepare 200 kg of a 0.5 wt% aqueous solution. This was adjusted to pH 13 with a 1 mol / L aqueous sodium hydroxide solution, then placed in a 300 liter jar fermenter and allowed to stand overnight at room temperature. The jar fermenter is heated and subjected to pressure heat treatment at 120 ° C. for 20 minutes, then cooled to 100 ° C. and returned to normal pressure, and then 15 ° C. cold water is passed through the jacket of the jar fermenter at the same time as a propeller type Using a stirrer having a stirring blade, the mixture was stirred at a tip speed of 1.88 m / s for 2 hours and cooled to 30 ° C. or lower. Further, the mixture was neutralized with 1 mol / L sulfuric acid, about 3 times the volume of isopropyl alcohol was added to the aqueous polysaccharide solution, and the precipitated aggregate was filtered and dried under reduced pressure to obtain polysaccharide- 3 . Similarly, polysaccharides 6 , 7 were prepared under the cooling conditions shown in Table 1. Note that polysaccharide- 4 is a B-16 polysaccharide that has not been subjected to alkali treatment.

[Production of polysaccharide- 8 ]
A 0.5 wt% aqueous solution of xanthan gum (trademark, manufactured by Sanki Co., Ltd.) was prepared and used as Thickener- 8 .

[Production of Polysaccharide- 9 ]
In the production method of polysaccharide-1, B-16 polysaccharide was replaced with xanthan gum (trademark, manufactured by Sanki Co., Ltd.) to obtain polysaccharide- 9 .

[Measurement of viscosity of aqueous solution of thickener]
A 200 mL tall beaker was added with 0.2 g thickener and 199.8 g water, and stirred and dispersed with a small homomixer at 8000 rpm for 10 minutes to give a 0.1 wt% aqueous solution. The aqueous solution is attached to each constant temperature water layer at 30 ° C., 50 ° C., and 80 ° C., left to stand for 24 hours, then set to 30 ° C. and measured for viscosity with a B-type rotational viscometer (30 rpm, measured 1 minute after the start of rotation). did. The results are shown in Table 2.

When cooling the B-16 polysaccharide after the alkali heat treatment, the inside of the externally cooled serpentine tube is cooled under pressure without applying a shearing force by stirring , and is cooled under pressure, or the shearing force by stirring is 2 .00m / s following increasing Nebazai prepared by external cooling using a coolant at slow agitation rate, cooling under the condition that the tip speed of agitation exceeds 2.00 m / s, prepared in Comparative example 5 It can be seen that the viscosity is higher than 7 , the viscosity is maintained even at a high temperature, and the change with time is small. In particular, thickener- 1 obtained by a cooling method using a serpentine tube (cooling coil) without shearing force shows higher viscosity than B-16 polysaccharide, and viscosity from low temperature to high temperature range. It can be seen that the change with time is small. In addition, with xanthan gum, no thickening effect was observed even by the same alkali heat treatment and cooling method without stirring.

[Measurement of emulsification and dispersion stability]
A 200 mL tall beaker was added with 96 mg thickener and 159.904 g water, and stirred and dispersed with a small homomixer at 8000 rpm for 20 minutes to obtain a 0.06 wt% aqueous solution. 0.8 g of liquid paraffin was added thereto, and the mixture was stirred and dispersed at 8000 rpm for 10 minutes with a small homomixer. A part of the liquid was taken, and the absorbance at 500 nm was measured. After measuring the absorbance, about 40 mL was taken in two glass sample bottles each having a diameter of 2.5 mm and allowed to stand at 30 ° C. and 50 ° C. Then, after 1 week and 2 months, a sample was taken from the bottom of the sample bottle with a Pasteur pipette, and the absorbance at 500 nm was measured. As shown in the following formula, the ratio of the absorbance immediately after preparing the sample solution: A and the absorbance B of the sample after standing for a predetermined period is evaluated as an emulsification / dispersion stability rate (%), and the higher the ratio, the better. The results are shown in Table 3.
Emulsification / dispersion stabilization rate (%) = {(B) / (A)} × 100

According to the method of the present invention, after the alkali heat treatment polysaccharides, or to cool the inside substantially without no coiled (cooling coil) passed under pressure shearing force by agitation, or a refrigerant in a state shear force is small by stirring increasing Nebazai prepared by external cooling using, it is seen that excellent emulsification and dispersion stabilization properties.

Claims (4)

A polysaccharide containing fucose, glucose, glucuronic acid, and rhamnose as a constituent monosaccharide is heated at 60 to 180 ° C. in an alkaline aqueous solution having a pH of 8 or higher, and then the tip speed of the stirring blade is 2.0 m / s or less. Emulsification, characterized in that it is cooled externally using a refrigerant while maintaining a slow rotation speed, or is cooled by passing through the inside of a serpentine tube externally cooled using a refrigerant without applying a shearing force by stirring. A method for producing a thickener having excellent dispersion stability and high viscosity . The method for producing a thickener according to claim 1, wherein the constituent monosaccharides of the polysaccharide are fucose: glucose: glucuronic acid: rhamnose = 1 to 2: 1 to 4: 1 to 2: 1 to 2 in molar ratio. The method for producing a thickener according to claim 1 or 2, wherein the polysaccharide comprises glucose, glucuronic acid, and rhamnose as a main chain, and further has a structure in which fucose is bound to a side chain. The method for producing a thickening agent according to any one of claims 1 to 3, wherein the polysaccharide is a polysaccharide produced by Alkaligenes relas B-16.