EP1587376A1

EP1587376A1 - Use of granular cold-swelling starches in cosmetic emulsions and method for the production of starches that are adequate for said use

Info

Publication number: EP1587376A1
Application number: EP04705407A
Authority: EP
Inventors: Rolf Stute; Dietrich Knorr
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-01-29
Filing date: 2004-01-27
Publication date: 2005-10-26
Also published as: DE10303472A1; WO2004066752A1

Abstract

The invention relates to the use of granular cold-swelling starches in cosmetic emulsions, said starches being produced by means of high pressure treatment. Also disclosed are the cosmetic emulsions obtained in said manner and a method for producing dry starches that are adequate for said use.

Description

Use of granular cold-swelling starches in cosmetic emulsions and process for the preparation of starches suitable for this use

The invention relates to the use of granular cold-swelling starches produced by high-pressure treatment in cosmetic emulsions and the cosmetic emulsions thus obtained, and to a process for producing dry starches suitable for this use.

While the starches which can be isolated from various plants, e.g. Only swell potato, wheat or corn starch when heated in aqueous liquids (this process is known as "gelatinizing"), and only then, depending on the concentration, form more or less viscous pastes or solid gels can swell starches swell to a multiple of their volume without heating.

Swelling starches have already gelatinized and are produced by drying the pastes obtained by heating the native starches.

The most commonly used and oldest method is roller drying, in which a starch slurry or a starch paste made in an upstream cooker is applied as a thin film to a hot, rotating roller, dried and stripped with a knife at the end of the rotation as a dried film. The film thus obtained is then reduced to the desired particle size. Granular, cold-swelling starches occupy a special position among the swelling starches (known as GCWS "granular cold swelling starches"). Because, while in the other processes for the production of swelling starches, the starch grains stick together when heated by the strong swelling and by the simultaneous escape of amylose from the starch grain and, moreover, are also mechanically destroyed during drum drying, the production of GCWS- Although the starch grains also gelatinized and thus swell cold, the grain shape, on the other hand, remains completely or at least largely preserved, depending on the manufacturing process. A newer method of producing swelling starches is extrusion. The starch granules are also destroyed here, in this case additionally by the particularly high shear forces in the extruder.

GCWS starches were first produced by gelatinization in alcohol / water mixtures. The alcohol concentration is chosen so high (over 80%) that swelling cannot take place, but there is still enough water to then achieve complete gelatinization at temperatures significantly above the gelatinization temperature in water, i.e. a complete loss of the birefringence typical of native starches. This manufacturing method is described for example in US-3583874A and EP 110549A. Since the removal of the alcohol, which is very firmly bound to the starch, causes problems and is reflected in the production costs, this production process has only become established to a limited extent, although starches produced afterwards are on the market.

Another method that is generally suitable for producing swelling starches is spray drying. For a long time, it has not been able to assert itself against the significantly more cost-effective drum drying because here too the destruction of the starch grains could not be prevented and no advantages in product properties justifying the higher costs could be achieved. In recent years, however, the spray drying technique has been improved so that the starch granules only gelatinize at or shortly after they emerge from the nozzle and are largely preserved as individual granules and thus now GCWS starches instead of products that are only analogous to the known source starches can be obtained. These GCWS starches do not contain alcohol, not even in trace amounts.

It is known that starches gelatinize under high pressure (over 330 MPa), ie lose their birefringence. A number of strengths swell comparatively little and the soft pastes produced in this way contain round starch particles similar to fat droplets. According to DE 19616210, these pastes can be used as a fat substitute in food emulsions.

A high-pressure treatment which is suitable for the purposes of the present invention is understood to mean that at a pressure of more than 350 MPa, preferably more than 400 MPa. The optimum minimum pressure is different for different types of starch, for example 500 MPa for corn and wheat starches, and about 800 MPa for potato starches.

The high pressure treatment is generally carried out at a temperature of -5 to + 45 ° C, preferably -2 to + 30 ° C.

The high-pressure treatment is preferably carried out in a medium of high starch concentration, for example in 10-50%, preferably 15-35%, aqueous suspension.

Suitable starches are in particular cereal starches and legume starches, preferably wheat starch, corn starch, tapioca starch or pea starch.

Surprisingly, it was found that the starch pastes produced by the known high-pressure treatment can be dried without problems by conventional methods, such as freeze or spray drying, and that the gelatinized starch granules, in contrast to those obtained by other known methods, do not stick to one another and thus consist of individual starch granules Powder can be obtained. Drying is also particularly cost-effective since, due to the high starch concentration of 25% and above, which can only be used for high-pressure gelatinization, the amount of water to be evaporated is lower.

It is particularly advantageous to add a compound or emulsifier which forms with amylose complexes during the high pressure treatment of the starch suspension. Suitable compounds of this type are the polyoxyethylene derivatives of sorbitan esters known as emulsifiers, for example Tween 60, monoglycerides, sucrose monoesters, nitearyl fumarate, Na stearoyl 2-lactylate and, above all, the complexing agents known from use in the baking industry. These compounds can be used in an amount of 1-6% by weight, preferably 1.5-4% by weight, based on the amount of starch. With increasing content of such compounds, the starch pastes obtained show a softer consistency, decreasing water absorption capacity, decreasing viscosity and increasing shear stability. In this way, tailor-made products can be produced with the properties desired for use in emulsions.

The high-pressure treatment can thus be used to produce GCWS starches in a simple manner and without special measures to prevent the starch granules from sticking together, which starches can be used particularly advantageously in cosmetic emulsions.

The GCWS starches produced in this way not only have the following advantages over the traditional swelling starches, but also over the previously known GCWS starches:

1. rapid and complete dispersibility in aqueous media (no clumping);

2. a significantly lower water binding compared to the known cold swelling starches. For this reason, the GCWS starches according to the invention can in turn be used to produce pastes with a high starch concentration of over 25%, which has not been achievable with the usual swelling starches, and yet have a soft paste consistency (according to literature data, starch 38 (1998) 40-44, the upper limit is with the usual swelling strengths at 8-10%);

3. Their properties for use in cosmetic emulsions can be improved in a simple manner if compounds which form complexes with amylose are added during high-pressure gelatinization. The starch particles produced in this way have a particularly low water binding.

4. Since this manufacturing process can also be used with aqueous solutions of any kind, starch powders can also be produced in this way which contain substances previously dissolved in the aqueous solution, e.g. Active ingredients or flavors bound to the starch granules.

The starches produced according to the invention, like the pastes in this regard, are not only suitable for the complete or partial replacement of fat in cosmetic emulsions, but also change their properties in an advantageous manner: 1. If the physical properties (viscosity, etc.) are largely retained, the so-called sensory properties change above all, an oily skin feeling in the direction of a smooth, silky and dry skin feeling.

2. Since more than 50% of the fat contained in emulsions can be replaced by starch, such creams do not contain excess fat, but only the fat required to care for the skin. There is therefore no excess fat application. The skin stays smooth and quickly absorbs both fat and moisture. You can touch everything immediately after application and there is no danger of not staining your clothes with fat or starch.

3. The proportion of skin care ingredients can also be limited in this way to the proportion necessary for care.

4. Since the starch, like the lipophilic portions of an emulsion, remains completely on the skin (or in the wrinkles of the skin), the products according to the invention also have the function of creams and powders.

5. The starch particles remaining on the skin represent an effective moisture regulation system because of their low water content compared to the known GCWS starches, but high water content compared to fat droplets and the higher water binding capacity.

Such systems are therefore also suitable, for example, for a cream that prevents sweating of the hands when putting on rubber gloves.

6. Via the starch remaining on the skin, components of a formulation that are complex or adsorptively bound to the starch can be fixed on the skin. This applies not only to skin-care components, but especially to fragrances and aromas, which may be released after a delay.

7. In systems which contain fat droplets and starch particles next to one another, water and fat-soluble ingredients can be used particularly advantageously at the same time.

The invention thus also includes cosmetic emulsions, such as skin creams or body emulsions for the care and / or moisture regulation of the skin, which contain a granular, pre-gelatinized starch produced by high-pressure treatment. Their starch content is generally 10-45% by weight, preferably 15-35% by weight. Such cosmetic products can have a water content of 50-90% by weight, preferably 60-85% by weight. The following examples explain the preparation of the GCWS starches according to the invention (Examples 1-3) and show how they are suitable for the preparation of creams which are completely new in their composition and properties (Examples 4,5).

example 1

A suspension of 1 part by weight of wheat starch and 3 parts by weight of water is exposed to a pressure of 550 MPa at room temperature for 15 min and the paste thus obtained a) spray-dried, alternatively b) freeze-dried with subsequent comminution. The powders obtained in this way consist of individual starch particles and are readily dispersible in water. The suspensions or pastes obtained depending on the concentration likewise consist of individual starch particles similar to fat droplets. The water absorption is 3.63 g / g or 4.17 g / g.

Example 2

A GCWS corn starch obtained in the same way from corn starch by high-pressure gelatinization and subsequent freeze-drying also consists of individual grains. The water absorption is also very low and is only 3.83 g / g compared to two known GCWS starches (Ultratex 2, 13.70 g / g; and Ultratex 1100, 12.95 g / g) produced by spray drying and one GCWS starch (8.94 g / g) produced by gelatinization in alcohol / water.

Example 3

Instead of water, starch pastes are prepared with a 0.5, 1.0 and 2% aqueous solution of Tween 60 under the conditions described in Example 1. Based on the starch used, this corresponds to a Tween 60 content of 1.5, 3.0 and 6.0%. These strengths also consist of individual grains.

The pastes obtained in this way show a softer consistency with increasing Tween 60 content, measured with the Stable Micro Systems-Texture Expert. Tween 60 content [%] force after 30 mm penetration depth g]

0.5 786

1,400

2 275

The GCWS starches obtained after spray drying are again well dispersible.

The water absorption capacity of these starches is 4.8; 3.7 and 3.3 g / g compared to

5.8 g / g of a starch made without the addition of Tween 60.

16.7% pastes produced by dispersing in water (10 g starch + 50 g water) have a decreasing viscosity with increasing Tween 60 content and an increasing shear stability in the same direction (determined as a viscosity drop after 15 min

Stir at 25 ° C).

Tween 60 content [%] viscosity [mPas] after

0 min 15 min

0 500 380

0.5 160 140

1.0 113 95

2.0 20 20

Example 4

20 g GCWS-H D wheat starch (obtained by freeze-drying after gelatinization in 1.9% Tween 60 solution) is stirred into 40 g of a commercial body milk (water in oil emulsion) and then 60, 40 and 40 ml of water added with gentle stirring. While adding water without starch leads to immediate segregation, the emulsion remains stable in the presence of GCWS-HD starch despite the addition of water.

The appearance remains intense white and shiny. The application to the skin is pleasant, with a very smooth skin feeling. The hands don't get greasy. Surprisingly, the starch remains completely on the skin and, in contrast to the known starch powders, can no longer be recognized as starch on the skin. Example 5

102.3 g of starch paste (obtained by high-pressure gelatinization of 50 g of wheat starch in 150 ml of 2% Tween 60 solution) are mixed with 99.7 g of commercial body milk with gentle stirring. The water content increases from about 60% to 70%. The starch content i. TS is about 35%. When the amount of starch paste is doubled, the water content increases to about 72% and the starch content to about 52%. The fact that in both cases, in contrast to the pure addition of water, there is no segregation, as in Example 4, proves the stabilizing effect of the starch portion. The properties largely correspond to the cream in Example 4.

Example 6

75 g of starch paste (as in Example 5) are mixed with 75 g of a starch paste (oil in water emulsion) with gentle stirring. The water content increases from about 60% to 70%. The starch content i. TS is about 35%. Appearance and creamy consistency remain unchanged. The application to the skin is pleasant, less greasy with a very smooth skin feeling. The addition of water up to about 80% leads to a steady decrease in the consistency of this oil in water emulsion.

With 150 g of starch paste instead of 75 g, a starch content of about 52%. i. TS reached. Despite the very high starch content, the appearance and creamy consistency remain largely unchanged. The application to the skin is still pleasant, less greasy and very smooth. The addition of water up to about 80% in turn leads to a steady decrease in the consistency.

Claims

claims

1) Use of granular, pre-gelatinized starch produced by high pressure treatment in cosmetic emulsions.

2) Use according to claim 1 to improve or modify the sensory properties of the cosmetic products.

3) Use according to claim 1 for the production of cosmetic products with a high water content.

4) Cosmetic emulsion containing a granular pre-gelatinized starch produced by high pressure treatment.

5) Cosmetic emulsion according to claim 4 containing 10-45% by weight, preferably 15-35% by weight of a granular pre-gelatinized starch produced by high pressure treatment.

6) Cosmetic emulsion according to claim 4 or 5 containing 50-90 wt%, preferably 60-85 wt% water.

7) Process for producing a starch suitable for use according to one of claims 1 to 3 by non-thermal gelatinization of a starch suspension at high hydrostatic pressure, characterized in that the granular, pre-gelatinized starch thus obtained is dried after the high-pressure treatment.

8) Method according to claim 7, characterized in that the drying is carried out by spray drying, vacuum drying or freeze drying.

9) Method according to claim 7 or 8, characterized in that the starch is a wheat, corn or legume starch 10) Method according to one of claims 7 to 9, characterized in that a compound forming amylose complexes is added to the starch suspension before the high pressure treatment.

11) Method according to one of claims 7 to 10, characterized in that the starch suspension before the high pressure treatment cosmetic active ingredients and / or flavorings are added.