AU1159188A - Aerosol products - Google Patents

Description

AEROSOL PRODUCTS

FIELD OF THE INVENTION

This invention relates to a composition for use in forming milk shake type products.

This invention was conceived as a means for preparing a flavoured thickened foamy milk-based drink as an alternative to the traditional milk shake which was formed by blending milk with syrup powdered flavours and ice-cream in a mechanical blender. It is an object of the invention to provide a similar milk drink using an aerosol dispenser.

10

The requirements of a product of this type should include

(i) compatibility with exisiting aerosol packaging types in order to minimise manufacturing cost.

(ii) a shelf life in an unrefrigerated condition of at

15 least twelve months.

(iii)full complicance with food regulations, (iv) consumer acceptable flavours as attractive as possible .

(v) convenience in use.

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(vi) capability of being thickened and frothed in addition to being flavoured.

In order to achieve these objects, it was realised that many constraints existed preventing the formulation of a successful product as discussed below.

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Most flavours have a limited shelf life in solution due to oxidation, microbial attack, enzymatic breakdown, etc .

The product should be of a low viscosity intially, so that it can be ejected rapidly from the aerosol can to

30 provide the necessary mixing action. This is not easily achieved because the product needs to be concentrated and the thickeners and viscosity builders required in the composition are also concentrated. _,. Conventional aerosol cans are. not produced to food quality specifications and the lining systems are not able to hold pressurized, low pH liquids for adequate periods of time. However, most food products are packed in liquids at a low pH in order to avoid microbial spoilage.

The necessity to provide preservation of the product in the absence of low pH compositions must be achieved from the narrow range of food approved added preservatives.

The aerosol propellant is normally restricted to noncondensible gases by food regulations in most countries.

Finally food colours are also affected by some of the above parameters and must be properly regulated.

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From the above it can be seen that a large number of difficulties stand in the way of providing an acceptable aerosol product.

In PCT/AU/85/00135 an aerosol dispensable -. _j- composition is disclosed comprising in combination (i) 0.05 to 5% of a- frothing agent, (ii) 0.05 to 75% of a sweetener,, (iii)0.05 to 10% of a thickener, (iv) 0.01 to 1% of a preservative, and the balance being other excipients, flavours and colourants,

_ώ J propellants and water. High levels of sweetener are exemplified and believed necessary to maintain bacterial control. This document also discloses the need to maintain the pH in the neutral range, however, the systems disclosed _- have failed to eliminate pinhole corrosion within relatively short times e.g. less than six months.

A similar approach is disclosed in U.S. Patent 3,622,354 which relates to a product utilizing high sugar levels to achieve bacterial control and also reveals the use

30 of preservatives at low pH (5-5.5).

In both instances the product produced is not acceptable primarily due to short shelf life and corrosion. Accordingly further investigation has taken place concerning stabilizing such mixtures. SUMMARY OF INVENTION

35

Surprisingly, a particular phosphate buffer system has been discovered which has been found to effectively stabilize the mixture by maintaining pH in the range 8.0 to 8.5.

Accordingly, there is provided an aerosol dispensable composition comprising in combination : (i) 0.05 to 5% w/w of a frothing agent; (ii) 0.05 to 75% w/w of a sweetener; (iii)0.05 to 10% w/w of a thickener; (iv) 0.01 to 1% w/w of a preservative;

(v) 0.1 to 10% w/w a phosphate buffer system adapted to 0 maintain the pH of the compositions in the range 8.0 to 8.5; and the balance being selected from other excipients, flavours and colourants, propellants and water. Preferably, the phosphate buffer system is present in an amount ranging from 0.1-2.5% w/w. The phospate buffer system typically ₅ comprises a mixture of potassium phosphate and sodium phosphate. This system also allows various types of flavour other than chocolate and strawberry to be also practically incorporated. More particularly the buffer system can comprise a mixture of potassium dihydrogen phosphate and _Q disodium hydrogen phosphate, the ratio of KH₂ P0₄ to a₂ HP0₄ being from 1:60 to 1 to 105.

Testing has shown that a composition of the type disclosed in PCT/AU/85/00135 can be stabilized and no corrosion has been detected either at room temperature or c under accelerated high temperature storage conditions. Thus, the product exhibits very long shelf life.

Preferably, the phosphates are blended in the following ratio to maintain the composition pH in the range 8.0-8.5. _Q KH₂ P0₄ pH = 4.62 as 1% aqueous solution.

Na₂ HP0₄ pH = 9.12 as 1% aqueous solution.

KH₂ P0₄ : aHP0₄ : : 1.0 :87.4

The preferred ingredients for the composition of this invention are as follows: 5 A. Frothing agent is selected from emulsifiers of the sorbitol ester, glycerol ester or fatty acid sucrose ester types. Most preferred are glycerol monostearate, sorbitol monostearate which generally produce the best foam with the least affect on flavour. The frothing agent also aids in the stable dispersion of the flavour agents. B. The sweetener may be selected from artificial sweeteners such as saccharine, aspartame, dextrose, fructose or from natural sweeteners such as sucrose. Typically artificial sweeteners are used in the range 0.1 to 5% whilst natural sweeteners are normally in the range 5 to 75%. The most reliable sweetener is sucrose and the level of

10 sweetener required is constrained by adequacy in providing sweetening effect at the lower end of the scale and by viscosity and solubility at the upper end of the concentration range. Excessive levels when combined with other excipients can produce crystalline growth in the _. ,- aerosol cans which results in valve blockages. The most preferred sweetener is sucrose used at a level of between 15% - 75%. Typically, a representative formula is

% Flavour 3.0

20 Sucrose . 61.0 Water 28.99

AZO Red Dye 0.010

Nitrous Oxide 7.0

25 C. Careful selection of the thickener is required because the product is normally used at a dilution of around 10% and with conventional thickeners such as pectin, tragacanth, the ten-fold concentration in the aerosol product would result in a viscosity that was too high to

30 allow proper dispensing from the aerosol can. Thus, preferred thickeners are gums of polysaccharide type particularly those of a grade which undergo interaction with milk to produce a large increase in milk viscosity after contact. A number of the gums tested showed a tendency to ₃₅ age thicken when stored over a period of time. This aging tendency was reduced by addition of water softening components of the phospate type. Preferred thickeners are carragheenan, methylcellulose, hydroxypropylcellulose, and general polysaccharides . An example of thickeners follows:-

% Flavour 3.0

Sucrose 50.0

Water 45.95

Xanthane Gum 1.0

Sodium Hexametaphosphate 0.05 Nitrous Oxide 7.0

D. The colouring agents should be present in the range of 0.01 to 5% preferably 0.01 to 1%. Variation of the other components of the composition tends to produce variable affects on colour. Many colours also increase the corrosivity of the formula to the aerosol container. All approved dystuff are suitable. The preferred colouring agents are azodyes of the ponceau 4R, erythroscine, carmoisine, tartrazine type, brilliant blue F.C.F., Brown HT, allura red and a wide range of natural colouring substances.

E. Typical examples of the buffer system are^' as follows :

Buffer No. 1: Dipotassium Dihydrogen Phosphate 77.2% W/W

Potassium Dihydrogen Phosphate 22.7% W/W pH of above combination in water at 2.2% W/W is 8.0

Buffer No. 2: Potassium Dihydrogen Phosphate 79.0% W/W

Sodium Hydroxide 21.0% W/W pH of above combination in water at 0.7% is 8.1%

Buffer No. 3: Sodium Dihydrogen Phosphate 4.3% W/W

Disodium Hydrogen Phosphate 95.7% pH of above combination in water at 6.8% is 8.0 Each buffer introduces stability and performance to the dispensable composition described. This system ensures microbiostatic, microbiocidal and fungicidal affect and as well reduce corrosion of lacquered tinplate to the point where shelf life if in excess of twelve months at 20° C are now achievable.

F. The balance of the mixture is made up with purified water.

G. The propellant to be used to dispense.the composition from the aerosol can well comprise 2 to 50% by weight and can comprise any food approved propellant.

10 Preferably nitrous oxide, carbon dioxide and octaflurocyclobutane, or propane may be used. However, the most preferred propellant is nitrous oxide in order to achieve the optimum performance required for this particular composition. Due to its non-condensable nature a higher _. _j. pressure can be used to ensure mixing with nitrous oxide than with condensable propellants. In addition, the condensable propellants tend to produce a shaving-cream type foam due to their densities and settle out of the system. Care must be taken if carbon dioxide is used as propellant

20 because it is acidic. However, it could be used where lined aerosol cans are used.

EXAMPLES EXAMPLE 1

COMPONENT % w/w Flavour

25 0.1 3.0

Sodium Benzoate 0.01 - 1.0 Polysaccharide Gum 0.01 - 1.0 Dye Stuff 0.001 - 0.1

Glyceryl Monostearate 0.01 - 1.0

30 Nitrous Oxide 0.5 6.0 Sucrose 20 45 Wate BALANCE

Butylated Hydroxy Anisole 0.001 - 0.5 Disodiu Hydrogen Phosphate 0.01 - 2.0 ₃₅ Potassium Dihydrogen Orthophosphate 0.01 - 0.5 EXAMPLE 2

COMPONENT Flavour 3 .000 Sucrose 50 .000

Sorbitol ester 2 .000 Hydroxy propyl cellulose 0 .080 Buffer No. 1 ( aforestated) 2 .200 Colour 0 .008

Water TO 200%

EXAMPLE 3 Flavour 3. .000 Sucrose 50, .000

Sorbitol ester 1. .000 Hydroxy propyl cellulose 0. .080 Buffer No. 2 ( aforestated) 0. .700 Colour 0. .008

Water TO 100%

EXAMPLE 4 Flavour 3. ,000 Sucrose 50. ,000

Sorbitol ester 1. 000 Hydroxy propyl cellulose 0. 080 Buffer 3 ( aforestated) 6. 800 Colour 0. 008 Water TO 100%

In each of the examples, testing over a prolonged period of months has failed to reveal any corrosion spoilage or bacterial spoilage.

Aerosol Milk shake compositions utilizing the buffer system achieve a long life and permit a wider range of flavours than previously possible.

Claims (14)

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS :

1. An aerosol dispensable composition comprising in combination:

(i) 0.05 to 5% w/w of a frothing agent;

(ii) 0.05 to 75% w/w of a sweetener;

(iii)0.05 to 10% w/w of a thickener;

(iv) 0.01 to 1% w/w of a preservative;

(v) 0.1 to 10% w/w a phosphate buffer system adapted to maintain the pH of the compositions in the range 8.0 to 8.5; and the balance being selected from other excipients, flavours and colourants, propellants and water.

2. The composition according to Claim 1 wherein the phosphate buffer system is present in an amount ranging from 0.1 to 2.5% w/w.

3. The composition according to Claim 1 wherein the phosphate buffer system comprises a mixture of potassium phosphates and sodium phosphates.

4. The composition according to Claim 1 wherein the phosphate buffer system comprises a mixture of disodium hydrogen phosphate and potassium dihydrogen orthophosphate .

5. The composition according to Claim 1 wherein the phosphate buffer system comprises a mixture of potassium dihydrogen phosphate and disodium hydrogen phosphate, the ratio of KH₂ P0₄ to Na₂HP0₄ being from 1:60 to 1 to 105.

6. An aerosol dispensable composition according to Claim 1 wherein the frothing agent is selected from emulsifiers of the sorbitol ester, glycerol ester and fatty acid sucrose ester types.

7. An aerosol dispensable composition according to Claim 1 wherein the frothing agent is glycerol monostearate and/or sorbitol monostearate.

8. An aerosol dispensable composition according to Claim 1 wherein the sweetener is selected from the group of artificial sweeteners including saccharine, aspartame, dextrose and fructose.

9. An aerosol dispensable composition according to Claim 1 wherein the sweetener is an artificial sweetener present in amounts from 0.1 to 5%.

10. An aerosol dispensable composition according to Claim 1 wherein the sweetener is a natural sweetener present in amounts of from 5 to 75%.

11. An aerosol dispensable composition according to Claim 1 wherein the thickener is selected from the group- of gums of the polysaccharide type including carragheenan, methylcellulose, hydroxypropylcellulose and general polysaccharides.

12. An aerosol dispensable composition according to Claim 1 wherein the colourants are present in the range of 0.01 to 5%.

13. An aerosol dispensable composition according to Claim 1 wherein the colourants are selected from the group of asodyes of the ponceau 4R, erythroscine, carmoisine, tartrazine type, brillian blue F.C.F., brown HT and allura red.

14. An aerosol dispensable composition according to Claim 1 wherein the propellant is selected from nitrous oxide, carbon dioxide, octafluorpcyclobutane and propane