WO1995005748A1

WO1995005748A1 - Sprayable cookware release composition

Info

Publication number: WO1995005748A1
Application number: PCT/US1994/009219
Authority: WO
Inventors: John Richard Chadwick; Peter Romano, Jr.
Original assignee: American Home Food Products, Inc.
Priority date: 1993-08-24
Filing date: 1994-08-15
Publication date: 1995-03-02
Also published as: KR960703521A; BR9407626A; CO4370086A1; AU7566194A; CA2170254A1

Abstract

Disclosed herein is a vegetable oil composition containing a cookware release agent, such as lecithin, which is suitable for dispensing from an aerosol container. The propellant used comprises nitrous oxide. The spray pattern of such composition is substantially maintained throughout product life. Moreover, the composition provides more servings per container relative to current products and complies with legislation directed to reduced content of volatile organic compounds.

Description

Sprayable cookware release composition

Field of Invention

The present invention relates generally to vegetable oil compositions containing cookware release agents, such as lecithin, which are suitable for dispensing from aerosol containers. More specifically, the present invention relates to such compositions which are dispensed with only minimal change in their spray pattern during the useful life of the product.

The present invention further relates to a method for maintaining the spray pattern of vegetable oil compositions containing cookware release agents, such as lecithin, which are suitable for dispensing from aerosol containers.

The present invention further relates to cookware release compositions which are both dispensable from aerosol containers and possess low levels of volatile organic compounds.

Background of the Invention

Lecithin, when applied to the surface of a mold, utensil or other cooking implement provides an excellent release coating. Therefore, much effort has been expended in recent years in the development of lecithin-containing compositions and methods of their application.

For instance, a solid stick form of a lecithin cookware lubricant is disclosed in U.S. Patent No. 4,023,912. Lecithin cookware lubricants dispensable in convention aerosol containers are disclosed in U.S. Patent Nos. 2,796,363; 3,896,975; 4,073,411 and 4,073,412. Pump sprayable lecithin-containing cookware lubricants are further disclosed in U.S. Patent Nos. 4,155,770 and 4,163,676.

Compositions dispensable through conventional aerosol technology have typically occupied the largest commercial market segment. Propellants used in such products include pressurized chlorofluorocarbons and lower molecular weight alkanes. In view of ecological concerns, the trend in recent legislation has been to limit emissions of halogenated hydrocarbons, such as chlorofluorocarbons which have been shown to damage the ozone layer, and volatile organic compounds, such as lower molecular weight alkanes which contribute to the production of smog. In response to the latter, legislation is being enacted in several states to limit the use of volatile organic compounds ("VOC") such as lower molecular weight alkanes. For instance, California has enacted legislation limiting the VOC content of aerosol food release products to no more than 18 wt. %. Aerosol lecithin-containing cookware compositions having other than chlorofluorocarbon or lower molecular weight alkane propellants are therefore sought.

The use of a compressed gas propellant (specifically nitrogen, carbon dioxide and nitrous oxide) is highly desirable in cooking spray compositions due to the absence of the above mentioned ecological concerns. However, while these propellants do not contribute to the environmental concerns mentioned above, they normally pose other problems when used to propel cooking release spray compositions. Specifically, the spray pattern of these compositions degrades noticeably during their useful lifespan. This degradation is due to the continued decrease in propellant pressure within the aerosol container causing a decrease in the breadth of the spray pattern. Aerosol lecithin-containing cookware compositions exhibiting a decreased tendency for degradation of its spray pattern are therefore also sought. Such compositions are further known to possess a discharge spray which is foamy and/or opaque, rather than a clear discharge which is desirable.

It is therefore an object of the present invention to provide an aerosol lecithin-containing cookware release composition having a propellant comprising other than fluorocarbons or lower molecular weight alkanes.

It is therefore a further object of the present invention to provide such a composition with improved longevity of its spray pattern.

It is therefore a further object of the present invention to provide a spray discharge which is clear and not foamy or opaque as is typical of spray compositions using compressed gases as propellant. It is still another object of the present invention to provide a composition in compliance with VOC legislation now being enacted.

Other objects and advantages of the claimed invention may be seen in the details set forth in the remainder of this specification.

Summary of the Invention

The present invention relates to vegetable oil compositions containing lecithin which are suitable for dispensing from an aerosol container wherein the propellant used therein comprises nitrous oxide and the spray pattern thereof is substantially maintained throughout its useful lifespan.

The present invention further relates to a method for maintaining the spray pattern of vegetable oil compositions containing lecithin which are suitable for dispensing from an aerosol container wherein the propellant used therein comprises nitrous oxide.

The present invention further relates to such compositions which are in compliance with current and expected legislation on their content of volatile organic compounds ("VOC").

Brief Description of the Drawing

Figure 1 is a graphic representation of the comparative results of Example 2.

Detailed Description of the Invention

The present invention relates to vegetable oil compositions containing lecithin which are suitable for dispensing from aerosol containers with only minimal degradation of their spray pattern.

In the practice of the present invention, any of the common food grade vegetable oils can be used, such as soybean oil, olive oil, corn oil, canola oil, etc. As used herein, the term "vegetable oil" refers to those food grade oils of vegetable origin which are liquid at normal use temperatures (65-80°F) as distinguished from fully hydrogenated vegetable fats which are solid at such temperatures. For example, vegetable oils having a viscosity of about 40 to about 300 centipoise are suitable for use herein. The use of canola oil is preferred. The vegetable oil component typically comprises from about 65 % to about 85 % by weight of the total weight of the liquid components. Preferably, it comprises from about 75 % to about 80% on the same basis. Most preferably, it is present in an amount of about 77.5% on such basis.

Cookware release agents useful in the practice of the present invention include lecithin and phosphated monoglycerides and diglycerides. Lecithin is the preferred cookware release agent.

The lecithin component used in the preferred practice of the present invention may comprise standard oil-soluble lecithin, such as that derived from soybeans which typically contains about 50 - 54 wt. % of phosphatides. However, lecithin in a water-dispersible form can be used either instead of or in admixture with the oil-soluble lecithin. Oil-soluble lecithin may further be chemically reacted such as by hydroxylation and/or acylation per the teachings of U.S. Patent No. 3,962,292, for example. Mixtures of oil-soluble lecithin and such chemically reacted lecithins are also within the scope of the present invention. The lecithin component typically comprises from about 2% to about 12% by weight of the total weight of the liquid components. Preferably, it comprises from about 3% to about 6% on the same basis. Most preferably, it is present in an amount of about 4.8% on such basis.

The propellant used in the practice of the present invention is nitrous oxide. The propellant is to be present in an amount ranging from about 2% to about 8.5% by weight, based upon the total weight of the liquid components. Preferably, the propellant is present in an amount ranging from about 3% to about 5% on the same basis. Most preferably, it is present in an amount of about 4.5%, on such basis. Also contemplated in the practice of the present invention is the use of mixtures of nitrous oxide and minor portions of other conventional propellants such as carbon dioxide, nitrogen and lower molecular weight alkanes (and mixtures of such alkanes). The claimed composition may further contain optional ingredients such as preservatives, antioxidants, emulsifying agents, coloring agents, flavoring agents and visually directing aids (as explained below) in minor proportions. Useful preservatives include sodium benzoate, calcium propionate, sorbic acid or salts of sorbic acid such as sodium sorbate and potassium sorbate. Preferred are sodium benzoate in an amount of from about 0.05 to about 0.1 wt. percent and calcium propionate in an amount of from about 0.1 to about 0.3 wt. percent. Antioxidants may include tocopherols which act to prevent rancidity. Visually directing aids include white flour and/or starch, as is disclosed in U.S. Patent No. 4,425,164, the contents of which are hereby incorporated by reference. Such visually directing aids allow the discharged spray to be more readily seen, thereby enabling the user to better direct such discharged spray in the practice of the present invention.

Optional ingredients may also include a solvent to decrease the viscosity of the lecithin/vegetable oil mixture found in the claimed composition. Preferred is the use of ethyl alcohol. The ethyl alcohol, for the purposes of the present invention is ethanol of 190° and 200° proof which conforms with United States Pharmacopoeia (U.S.P.) standards for Alcohol and Dehydrated Alcohol, respectively. The 190° proof to 200° proof ethanols are staple articles of commerce and are available, for instance, from U.S. Industrial Chemical Co. Ethanol of 200 U.S. proof degrees at 60°F has a specific gravity of 0.79365, is 100 percent by weight of ethyl alcohol. Ethanol of 190 U.S. proof degrees at 60 °F has a specific gravity of 0.81582, is 92.423 present by weight of alcohol and contains 7.577 percent by weight of water. The 190° proof ethanol may be made by mixing 95 parts by volume of ethyl alcohol with 6.18 parts by volume of water. As used in the present invention, the ethyl alcohol functions as both a viscosity-lowering solvent and a clarifying agent.

In addition to the use of ethyl alcohol, ethyl alcohol denatured with a GRAS- classified food grade denaturant, as for example S.D.A. 29-3, can be used in the practice of the present invention. S.D.A. 29-3 contains 99% ethyl alcohol and 1 % ethyl acetate as a denaturant. Ethyl acetate is a GRAS denaturant thereby allowing the use of S.D.A. 29-3 in a food grade product such as the claimed composition.

The ethyl alcohol component may be present in amounts ranging from 0 to about 20% by weight, based upon the total weight of the liquid components. Preferably it is present in amounts ranging from about 8 to about 14% by weight, on the same basis. Most preferably, it is present in an amount of about 13.1% by weight, on such basis.

In preparing the claimed composition, a suitable manufacturing procedure is as follows: The lecithin component, which may be preheated to 100°-140°F, is mixed with the vegetable oil component stepwise until a uniform solution is obtained. The ethyl alcohol component, as well as other optional components, may be added separately at this point, or previously introduced in one or both of the other components. Any optional materials which are not soluble in the resultant solution, such as the previously described visual directing aids may be added with agitation continued until a uniform dispersion is obtained. The resulting blend is then filled into the container and a vacuum is drawn to purge air from the container. Alternatively, the propellant may be used to purge air from the headspace. A suitable aerosol valve is then inserted and crimped into place creating an air tight pressure seal. Nitrous oxide is then injected into the container.

With regard to the aerosol containers useful in the practice of the present invention, the ecological benefits of the invention as well as some maintenance of spray pattern can be realized using convention aerosol containers. Also useful in the practice of the present invention are thin-walled aerosol containers such as those disclosed in U.S. Patent No. 5,211,317, the contents of which are hereby incorporated by reference. Valve components such as those manufactured by Summit Packaging Systems and Seaquist Valve Company may be used in the practice of the present invention.

A most preferred embodiment of the present invention has been identified and is described below. Most preferably, the "head space" or space within the aerosol container occupied by the propellant is measured relative to conventional containers so as to occupy from about 15% to about 60% of the volume of the container (when full). The valve assembly through which the lecithin-containing composition is discharged is of the preferred construction: Summit Packaging Systems S-62 toggle or vertical action aerosol valves, having the following general construction: Stem orifice: 0.010" to 0.018", Body orifice: 0.016" to 0.024", Spring: 0.023", Actuator terminal orifice: 0.016" to 0.024". Most preferably the valve system the Summit Packaging Systems S-62 valve, having the following construction: Stem orifice: 0.013", Body orifice: 0.016", Spring: 0.023", Actuator: Toggle T-90 having an insert with a terminal orifice of 0.020", a land dimension of 0.010" and a channel depth of 0.018".

The claimed compositions can be uniformly and effectively applied to surfaces of molds, frying pans, sauce pans, baking pans or other cooking surfaces whether composed of metal, glass or ceramic materials. The thin coating film better permits the cooking of moisture-containing materials such as eggs, pancakes, etc. without grease or fat, and after cooking, these materials will come free from the surface without rubbing or scouring. When fatty foods are cooked on a surface so coated, they will come off readily by soaking in water for several minutes, even when burned crisp or charred. In no case is scrubbing, scouring or the use of brushes, abrasives or scouring powders, soaps or detergents normally required for the cleaning for such utensils. While preferably, the composition should be applied each time the cooking surface is utilized, in many cases the coating will last for several or more cookings without reapplication.

Unexpected in the development of the claimed composition was the maintenance of its spray pattern. While lecithin-containing aerosol-dispensed compositions propelled by compressed gases typically possess a spray pattern characterized by a severe narrowing during use and, in many cases, incomplete evacuation of the composition. The composition of the present invention possesses a clear, uniform spray pattern throughout the evacuation of the composition from the container. This permits use of the claimed composition with its spray pattern substantially maintained through the life of the composition. As used herein, the phase "substantially maintained" as relating to the spray pattern of the composition therefore means minimal change to the clarity and physical diameter of the resultant spray.

Another unexpected result realized in the practice of the present invention is that a higher number of discharges are obtained relative to an equal size container of a conventional cooking spray. Such discharges are known in the art as "servings", each of which is equal to 0.266 grams. Typically, one can obtain from about 525 serving from container of 6.0 ounces net weight. In contrast, a container of equal size containing a conventional spray composition yields about 425 servings.

It is the belief of Applicants that the unexpected properties exhibited by the claimed invention is attributable to the replacement of the current liquified propellant system with a compressed gas. The reason for the increased servings per container is due to the difference in propellant to concentrate ratio between the two systems. The number of servings is determined as follows: the weights of the components which will volatilize when sprayed are totaled and that total is then subtracted from the net contents weight of the container. The remaining mass (lecithin and vegetable oil) is divided by the FDA Serving Size Reference Amount for cooking spray products (0.266g/serving) to determine servings per container. Therefore, a product which uses a hydrocarbon propellant, at about 15% formula weight, will have fewer servings per container when compared to the formula specified in this disclosure; which has approximately 4.5% propellant. Since there is more "measurable" concentrate in the formula of the present invention, the resultant servings per container determination will be higher than the hydrocarbon system, given that the label weights of the two products are identical.

The following Examples are offered for the purpose of illustration only and are not to be construed in any way as a limitation of the invention or its scope. Example 1

A composition made up of the following components: vegetable oil, ethanol, lecithin and propellant was formulated according to the following procedure.

1. The formula amount of Vegetable oil (Canola Salad Oil) was transferred into an appropriate vessel equipped with a variable speed agitator.

2. The required amount of soybean lecithin (heated to 100 - 140F to facilitate transfer) was then added to the batch vessel under moderate non-aerating agitation.

3. While maintaining agitation, the required amount of alcohol was added to the mixture.

4. The batch was allowed to mix until uniform.

The compositions were then charged into conventional aerosol containers having a volume capacity of 473 cc. A vacuum is then drawn to purge air from the container. A suitable aerosol valve is then inserted and crimped into place creating an air tight pressure seal. The containers were then each charged with either a blend of isobutane and propane (60/40 wt. %), nitrous oxide, carbon dioxide, or nitrogen. The total weight of all ingredients was about 280 grams. The spray patterns produced when the containers were full, 50% full and 25% full were then characterized. The results are set forth below in Table I.

Formulation I Formulation II Formulation III Nitrogen 1.50% Carbon Dioxide 4.50% Nitrous Oxide 4.50% Canola Oil 80.49% Canola Oil 77.59% Canola Oil 77.59% Alcohol 13.13% Alcohol 13.13% Alcohol 13.13% Lecithin 4.78% Lecithin 4.78% Lecithin 4.78%

TABLE I

CONTAINER FILL FORMULA 1 FORMULA II FORMULA III (Nitrogen Propellant) (Carbon (Nitrous Oxide Dioxide Propellant) Propellant)

FULL CONTAINER 5.5" (WIDE) 3.5" CONE/ 2.50" SOLID UNEVEN FOAMY CONE CLEAR SPUTTERING APPEARANCE SPRAY- SPRAY ACCEPTABLE

50% FULL 3.5" UNEVEN 2.25" CONE/ 2.25" SOLID

SPRAY/SLIGHTLY COARSE CONE

FOAMY STREAM/ CLEAR SPRAY- FOAMY ACCEPTABLE

25% FULL 2.5" COARSE, 2.0" 2.00" SOLID (NARROW) SPRAY CONE/VERY CONE SLIGHTLY FOAMY COARSE/ CLEAR SPRAY- FOAMY ACCEPTABLE

Table I clearly shows that (a) Formulae I and II provided unacceptable spray qualities even when dispensed from full containers, and (b) their spray quality (pattern) deteriorated during use.

Example 2

The formulations of Example 1 were optimized to each type of propellant used therein. The formulations listed immediately below resulted from such optimization. Formulation I Formulation 11 Formulation III

Nitrogen 1.47% Carbon Dioxide 4.00% Nitrous Oxide 4.50%

Canola Oil 82.47% Canola Oil 80.64% Canola Oil 77.59% (60/40 blend)

Alcohol 11.72% Alcohol 9.60% Alcohol 13.13%

Lecithin 4.34% Lecithin 5.76% Lecithin 4.78%

The spray patterns produced when the containers were full, 50% full and 25% full were then evaluated. The results are set forth in Table II.

TABLE π

CONTAINER FILL FORMULA 1 FORMULA II FORMULA III

FULL CONTAINER 4.00" (WIDE) 3.00 2.50" SOLID CONE (NARROW) CONE CLEAR

SPRAY/SLIGHTY VERY FOAMY SPRAY- FOAMY ACCEPTABLE

50% FULL 3.25" ACCEPTABLE 2.75"- 1 .0" 2.25" SOLID CONE SPRAY/ JET CONE SLIGHTLY FOAMY STREAM/VERY CLEAR SPRAY- FOAMY ACCEPTABLE

25% FULL 2.00" COARSE, 0.50" - 1 .0" 2.00" SOLID (NARROW) SPRAY JET" CONE /MEDIUM FOAMY STREAM/VERY CLEAR SPRAY- FOAMY ACCEPTABLE

The results of Example II are further shown in Figure I.

Claims

1. A vegetable oil composition containing a cookware release agent which is suitable for dispensing from an aerosol container wherein the propellant used therein comprises nitrous oxide and the spray pattern thereof is substantially maintained throughout use of the composition.

2. The composition of Claim 1 wherein the cookware release agent is selected from the group consisting of lecithin, phosphated monoglycerides and phosphated diglycerides.

3. The composition of Claim 1 wherein the cookware release agent is lecithin.

4. The composition of Claim 3 wherein the lecithin is selected from the group consisting of oil-soluble lecithin, water-dispersible lecithin, hydroxylated lecithin and acylated lecithin.

5. The composition of Claim 3 wherein the lecithin is soybean lecithin.

6. The composition of Claim 1 wherein the cookware release agent comprises lecithin and said lecithin is present in such composition in amounts ranging from about 2 wt. % to about 12 wt. %, based upon the total weight of the liquid components of the composition.

7. The composition of Claim 6 wherein said lecithin is present in such composition in amounts ranging from about 3 wt. % to about 6 wt. %, based upon the total weight of the liquid components of the composition. 8. The composition of Claim 6 wherein said lecithin is present in such composition in an amount of about 4.

8 wt. %, based upon the total weight of the liquid components of the composition.

9. The composition of Claim 1 wherein the nitrous oxide is present in such composition in amounts ranging from about 2 wt. % to about 8.5 wt. % , based upon the total weight of the liquid components of the composition.

10. The composition of Claim 1 wherein the nitrous oxide is present in such composition in amounts ranging from about 3 wt. % to about 5 wt. %, based upon the total weight of the liquid components of the composition.

11. The composition of Claim 1 wherein the nitrous oxide is present in such composition in an amount of about 4.5 wt. %, based upon the total weight of the liquid components of the composition.

12. The composition of claim 1 further comprising ethanol, said ethanol being present in an amount from about 8 to about 14 wt. %, based upon the total weight of the liquid components.

13. The composition of claim 12 further comprising ethanol, said ethanol being present in an amount of about 13 wt. %, based upon the total weight of the liquid components.

14. A method for maintaining the spray pattern of vegetable oil composition containing a cookware release agent which is suitable for dispensing from an aerosol container comprising employing as the propellant therein nitrous oxide wherein the nitrous oxide is present in such composition in amounts ranging from about 2 wt. % to about 8.5 wt. %, based upon the total weight of the liquid components of the composition.

15. The method of Claim 14 wherein the cookware release agent is selected from the group consisting of lecithin, phosphated monoglycerides and phosphated diglycerides.

16. The method of Claim 14 wherein the cookware release agent is lecithin.

17. The method of Claim 16 wherein the lecithin is selected from the group consisting of oil-soluble lecithin, water-dispersible lecithin, hydroxylated lecithin and acylated lecithin.

18. The method of Claim 16 wherein the lecithin is soybean lecithin.

19. The method of Claim 14 wherein the cookware release agent comprises lecithin and said lecithin is present in such composition in amounts ranging from about 2 wt. % to about 12 wt. %, based upon the total weight of the liquid components of the composition.

20. The method of Claim 19 wherein said lecithin is present in such composition in amounts ranging from about 3 wt. % to about 6 wt. %, based upon the total weight of the liquid components of the composition.

21. The method of Claim 19 wherein said lecithin is present in such composition in an amount of about 4.8 wt. %, based upon the total weight of the liquid components of the composition.

22. The method of Claim 14 wherein the nitrous oxide is present in such composition in amounts ranging from about 3 wt. % to about 5 wt. % , based upon the total weight of the liquid components of the composition.

23. The method of Claim 14 wherein the nitrous oxide is present in such composition in an amount of about 4.5 wt. %, based upon the total weight of the liquid components of the composition.

24. A method of coating cookware comprising applying to said cookware a thin film of the composition of Claim 1.

25. The vegetable oil composition of claim 1 containing less than about 18 wt. % of volatile organic compounds.

26. The composition of claim 25 having a clear discharge spray.