WO2006099305A2

WO2006099305A2 - Preservative for food and cosmetic use

Info

Publication number: WO2006099305A2
Application number: PCT/US2006/008916
Authority: WO
Inventors: Damon R. Thibodeaux
Original assignee: Intellectual Concepts, Llc
Priority date: 2005-03-10
Filing date: 2006-03-10
Publication date: 2006-09-21
Also published as: WO2006099305A3

Abstract

Methods and compositions for extending the shelf life of food products and, simultaneously, retaining a non-acidic taste in the final food product are disclosed. For the cosmetic industry, the invention also provides methods and compositions for addressing the significant problem of bacterial contamination in, for example, products such as lipsticks, facial cleansers and base makeup. The composition of the invention is a liquid preservative formulation that includes a antimicrobial agent, preferably a food grade antimicrobial agent, and an amount of glucono-1, 5-lactone (GdL) effective to counteract the basic pH range buffering effect (normally pH 10-11) of the antimicrobials and maintain the pH of the liquid preservative below 7.0.

Description

TITLE OF THE INVENTION PRESERVATIVE FOR FOOD AND COSMETIC USE

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the priority of U.S. Provisional Application No. 60/660,274, filed March 10, 2005, entitled PRESERVATIVE FOR FOOD AND COSMETIC USE, the whole of which is hereby incorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

N/A

BACKGROUND OF THE INVENTION

As the world population increases, the need for a safe and reliable food supply also grows. To meet the increasing demand for a safe food supply, antimicrobial preservatives have been developed and incorporated into many foods . The use of an antimicrobial preservative also increases the shelf life of these foods. However, an unpleasant side effect from the use of most such preservatives is an acidic aftertaste in the final food product .

The use of an acidifier in the common preservative formulations is required due to the nature of the antimicrobial agents used in the formulation. Antimicrobial agents such as potassium sorbate, sodium propionate and the parabens, in solution without acidification, result in a preservative formulation with an alkaline pH, which is ineffective for their activity. When this alkaline preservative formulation is added to the ingredients of a food product, it acts as a buffer and raises the pH of the final product. Even a small rise, however, in the pH value of a food product can render the antimicrobial agents ineffective and decrease the shelf life of the product considerably. Thus, common commercial practice is to add food acids, such as acetic acid, lactic acid or citric acid, to a preservative formulation so as to maintain the pH of the final food product to which the formulation is added within the acidic range. This action, though, simultaneously results in the unfortunate trade-off of the unpleasant acidic aftertaste.

Thus, it would be desirable to have additional antimicrobial preservatives available that would not leave an unpleasant acidic aftertaste upon use. An effective preservative formulation in conjunction with an appropriate pH level should both prevent microbial contamination and extend the shelf life of the food product .

BRIEF SUMMARY OF THE INVENTION

The invention is directed to methods and compositions for extending the shelf life of food products and, simultaneously, retaining a non-acidic taste in the final food product. For the cosmetic industry, the invention also provides methods and compositions for addressing the significant problem of bacterial contamination in, for example, products such as lipsticks, facial cleansers and base makeup. The composition of the invention is a liquid preservative formulation that includes a antimicrobial agent, preferably a food grade antimicrobial agent, and an amount of glucono-1, 5-lactone (GdL) effective to counteract the basic pH range buffering effect (normally pH 10-11) of the antimicrobials and maintain the pH of the liquid preservative below 7.0.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION The present invention eliminates the difficulties encountered in the prior art discussed above. The invention is directed to methods and compositions for extending the shelf life of food products and, simultaneously, retaining a non-acidic taste in the final food product. For the cosmetic industry, the invention also provides methods and compositions for addressing the significant problem of bacterial contamination in, for example, products such as lipsticks, facial cleansers and base makeup .

It has unexpectedly been discovered that the use of glucono- 1,5-lactone, also known as glucono delta lactone (GdL), in a liquid preservative formulation eliminates the acidic taste normally associate with organic acidifiers in a preservative formulation while simultaneously providing the preservative formulation with an improved ability to maintain the desired pH level of the food product to which it is added. If GdL is used as an acidifier in a preservative formulation, a lower pH is obtainable without the harsh tart taste of more common food acids (such as acetic acid, lactic acid or citric acid) . This lower pH

(below 7.0) provides the antimicrobial agents with the effective pH environment for functionality. The presence of GdL ensures a progressive and continuous decrease of the natural pH value of the antimicrobial solution to equilibrium through the slow hydrolysis of GdL to gluconic acid. During its hydrolysis, the initial sweet taste of GdL becomes only slightly acidic, making the final flavor of an aqueous solution of GdL much less tart than that of other acidifiers .

Thus, in one aspect, the invention is directed to a composition and method for simultaneously extending the shelf life of and producing a non-acidic aftertaste in a food product. The composition of the invention is a liquid preservative formulation that includes a antimicrobial agent, preferably a food grade antimicrobial agent, and an amount of glucono-1, 5-lactone (GdL) effective to counteract the basic pH range buffering effect

(normally pH 10-11) of the antimicrobials and maintain the pH of the liquid preservative below 7.0. As a consequence, when the preservative composition according to the invention is added to a food preparation, e.g., the dough for a baked good, the original pH of the dough does not change, and in particular, the pH of the baked good does not rise above 7.0. This capability of GdL permits the food preparation operator to decrease, or even eliminate, the amount the primary acidifier in the food batch formula. Exemplary antimicrobial agents include, e.g., a sorbate salt, a propionate salt, methyl sodium paraben, propyl sodium paraben, a lactic acid salt, natamycin, nisin and epsilon- polylysine . In the method of the invention, this liquid preservative is added to, or used to coat or otherwise become incorporated with, a food product, e.g., during its preparation. In an additional embodiment, a method according to the invention includes the steps of providing an antimicrobial agent, providing glucono-1, 5-lactone as an acidifying agent and adding the antimicrobial agent and the acidifying agent in a preparation stage of said food product, wherein the antimicrobial agent is at a sufficient concentration to function as a preservative and the acidifying agent in combination ^' with other acidifying agents is at a sufficient concentration to maintain the food product in its final stage at a pH below 7.0. Preferably, the concentration of glucono-1, 5- lactone is at least 50% of the total amount of the acidifying agents used. Exemplary food products that can incorporate GdL in the non-liquid state include rice flour and the dough for a tortilla or other baked good.

An effective and low acidic tasting antimicrobial preservative formulation according to the invention can be used at l%-3% of the final batch weight of the food product's preparative stage, depending, e.g., on the final food product's moisture content and/or pH value. For foods such as baked sweet goods, an exemplary liquid preservative according to the invention can consist of GdL (as an antimicrobial agent and an acidifier) and other effective antimicrobial agents at the concentration levels listed in Table 1. One of ordinary skill in the food industry can readily calculate the correct percentage of GdL for a particular formulation using conventional scale-up procedures and as described herein.

Table 1: General formulation for many food products

Pounds per 1000 exact

Product gallon batch % w/w

Potassium Sorbate (Sorbic acid potassium salt) 1000-1300 11-14%

Sodium Propionate (Propionic acid sodium salt) 750-1000 8-10%

Methyl Sodium Paraben 50-100 0.1-1%

Propyl Sodium Paraben 50-100 0.1-1%

Glucono-1 ,5-Lactone 50-100 0.1-1%

Purified Water 6500-7500 70-75%

Total 8400-10,100 100%

Optional ingredients include antioxidants, chelating agents and natural antimicrobial agents such as lactate acid and its salts, and thickeners such as xantham gum as is conventional in the food industry.

Various food products may require an alternate concentration level of one or more ingredients. For instance, it has been shown that, used at 1.0%-3% of the flour weight, an exemplary effective preservative formulation for tortillas shown in Table 2.

Table 2: Preservative formulation for a tortilla dough

Optional ingredients, as for Table 1, also include antioxidants, chelating agents and natural antimicrobial agents, such as a lactate salt, and thickeners such as xantham gum. The preferences of individual manufacturers (e.g., as to the thickness of the preservative formulation) may also influence the ingredients used for a preservative formulation for the same type of product.

Example I: Use of the formulation of the invention in preparation of tortillas

A dry tortilla premix with all preservatives removed was obtained from B.C. William Foods (Dallas, Texas) . To 54.0 grams of the dry tortilla premix was added 800.0 grams of wheat flour, 90.0 grams of all purpose shortening, 2.0 grams of emulsifier, 400.0 grams of wate, and 40 grams (2.97%) of the above preservative formulation. The final pH of a tortilla from this dough after baking was 5.8. At the end of 35 days of storage at room temperature, the tortillas contained no visible mold. In addition, there was no detectable acid flavor in the tortillas after baking.

GdL can also be added as a dry powder ingredient to a food product formula to enhance the acidification contributed by the

GdL-embedded liquid preservative formulation. This is especially important when a food product requires a low acidic environment to prevent microbial growth. Many of the antimicrobials used in a liquid preservative formulation can not be acidified below a pH of 6.0 in aqueous solutions and remain stable. For example, potassium sorbate will begin to precipitate in aqueous solutions below a pH of 6.4. Consequently, a supplemental amount of powdered GdL would be used in conjunction with the GdL-embedded liquid preservative formulation as only a very small weight percentage

(e.g., l%-3%) of the liquid preservative formulation is added to a total batch of a food formula. The liquid preservative formulation can not contribute sufficient acidification capacity to the remaining 97%-99% of ingredient weight to bring the final pH of the food product into a low acidic environment. An example of such food products is shelf-stable ready to eat (RTE) products, which are classified by the FDA as having pH values of 4.5 or lower .

In addition, there are certain product formulations for which one would use a liquid preservative formulation according to the invention that, by the nature of the other ingredients, would provide a pH unfavorable for microbial growth. The need for supplemental acidification will depend upon the manufacture's formula and the length of shelf-life desired. For example, a tortilla dough as described herein can require additional acidification to bring the pH to a desired acidic condition to deter microbial growth. Ingredients such as the flour in the above-described tortilla formulation can buffer a portion of the acidification contributed by the liquid preservative formulation and leave the tortilla with a pH level that is favorable for microbial growth. To bring the pH level of the tortilla to a pH range of 5.5 to 5.8, which is unfavorable for microbial growth, an additional acidifier is needed. Fumaric acid is currently the industry standard for this situation. Unfortunate fumaric acid is widely known for its extreme tart aftertaste in food products . In the method according to the invention, GdL is an excellent replacement for fumaric acid because of its lack of tartness . As discussed above, the liquid preservative will not lower the pH of the tortilla to the desired level alone. In cases such as this, GdL in the powder form should be added directly to the batch formula in an amount sufficient to acidify the tortilla to a 5.5- 5.8 pH. Experimental testing on a small scale, using procedures well-known to those of ordinary skill in the food industry, should be conducted to determine the exact amount of powdered GdL to be added to any food formula. As an example of another area where the invention will be appreciated, the meat and poultry industry is known to be in constant battle with pathogens such as Listeria sp. , Salmonella sp. and Escherichia coli, but they are especially sensitive to lactic acid. The most common lactic acid preservative in the industry today is a combination of potassium lactate and sodium diacetate at a final solution of 57% and 3% respectively. Sodium diacetate, which is nothing more than vinegar, imparts a strong tartness to meat and poultry and is undesirable in some meat and poultry applications, such as ready to eat (RTE) products. The use of a preservative formulation according to the invention, containing GdL in place of, e.g., sodium diacetate, gives a much better flavor profile than prior art formulations and yet the formulation according to the invention remains as powerful an antimicrobial for the industry as any other. An exemplary effective antimicrobial formulation according to the invention for the meat and poultry industry given in Table 3.

It has been shown that an effective preservative coating according to the invention can be applied to the outer layer of fruits and vegetables. Such a formulation would include, but not be limited to, those ingredients shown in Table 4. Table 4.

This formulation produces a "wax-like" coating on the individual fruits or vegetables . Other exemplary ingredients besides polyethylene glycol capable of providing this coating ability to the formulation include the shellac-based and carnauba waxes. Other optional ingredients include those mentioned earlier for other exemplary formulations .

The foregoing descriptions merely explain and illustrate preferred embodiments of the invention and the invention is not limited thereto.

While the present invention has been described in conjunction with a preferred embodiment, one of ordinary skill, after reading the foregoing specification, will be able to effect various changes, substitutions of equivalents, and other alterations to the compositions and methods set forth herein. It is therefore intended that the protection granted by Letters Patent hereon be limited only by the definitions contained in the appended claims and equivalents thereof .

Claims

CLAIMS What is claimed is:

1. A liquid preservative formulation comprising: an antimicrobial agent; and glucono-1, 5-lactone at a sufficient concentration to maintain said liquid preservative below a pH of 7.0.

2. The liquid preservative of claim 1, wherein said antimicrobial agent is food grade.

3. The liquid preservative of claim 1, wherein said antimicrobial agent comprises one or more agents selected from the group consisting of a sorbate salt, a propionate salt, methyl sodium paraben, propyl sodium paraben, a lactic acid salt, natamycin, nisin and epsilon-polylysine.

4. The liquid preservative of claim 1, wherein said glucono- 1, 5-lactone is at a concentration of between 0.1% and 3% in said formulation.

5. A method for simultaneously extending the useful life of and producing a food product without an acidic aftertaste, said method comprising the steps of: providing an antimicrobial agent; providing glucono-1, 5-lactone as an acidifying agent; and adding said antimicrobial agent and said glucono-1, 5-lactone acidifying agent in a preparation stage of said food product, wherein said antimicrobial agent is at a sufficient concentration to have a preservative effect and the total concentration of acidifying agent is at a sufficient concentration to maintain the final stage of said food product below a pH of 7.0.

6. The method of claim 5, wherein the concentration of said glucono-1,5-lactone acidifying agent is at least 50% of the total concentration of acidifying agent in said food product.

7. A method for simultaneously extending the useful life of a meat product without incurring an acidic aftertaste, said method comprising the steps of: providing a meat product; and applying a liquid preservative formulation according to claim 1 to a surface of said meat product.

8. The method of claim 7, wherein said meat product is beef.

9. The method of claim 7, wherein said meat product is chicken.

10. A method for simultaneously extending the useful life of a fruit or vegetable product without incurring an acidic aftertaste, said method comprising the steps of: providing a fruit or vegetable product product; and applying a liquid preservative formulation according to claim 1 to a surface of said fruit or vegetable product.