MXPA99009725A - Antimicrobial combinations of sorbate, natamycin and dialkyl dicarbonate for use in food products - Google Patents

Abstract

Antimicrobial combinations comprising a sorbate preservative, natamycin and a dialkyl dicarbonate at levels below the taste threshold for each of these antimicrobials but such that combination is effective against food spoilage microorganisms. These antimicrobial combinations are useful in treating beverages, especially dilute juice beverages, calcium fortified beverages, beverages containing tea solids, and beverages containing milk solids and proteins, as well as other acidified, high water activity food and beverage products such as cheese, sausage, ready-to-spread frostings, salad dressings, mayonnaise, and the like, that are susceptible to food spoilage microorganisms, including yeasts such as Zygosaccharomyces bailii.

Description

ANTIMICROBIAL COMBINATIONS OF SORBATO, NATAMYCINE AND DIALCYL DICARBONATE FOR USE IN FOODSTUFFS TECHNICAL FIELD This application relates to antimicrobial combinations useful in beverages, especially diluted juice beverages, calcium fortified drinks, beverages containing tea solids and beverages containing milk and protein solids, as well as other food products susceptible to throwing microorganisms. to lose food. In particular, this application relates to synergistic antimicrobial combinations that can be formulated from existing preservatives at below optimal levels in order not to cause taste loss.

BACKGROUND OF THE INVENTION The products for diluted juice drink are well known in the art. An antimicrobial preservative is a component that is convenient to be present in the diluted juice beverages that are intended to be stored without refrigeration (for example, at ambient temperatures). Diluted juice drinks, when exposed to microorganisms that spoil food, can provide an environment conducive to rapid microbial growth. This exposure can, and rarely results from the accidental inoculation of the juice drink diluted with these microorganisms during manufacture or packaging. Microorganisms that spoil food can then rapidly proliferate T by feeding on the nutrients provided by the juice component of the diluted juice drink. The preservatives, such as, for example, sorbates, benzoates, organic acids and combinations thereof have been used in the drinks of diluted juice to provide some degree of microbial inhibition. At effective levels to inhibit microbial growth, some of these preservatives may contribute to the loss of flavor of the diluted juice beverages. For example, accepted levels of use for potassium sorbate may be in the range of about 200 to about 3000 ppm. Normally, potassium sorbate is included in drinks of diluted juice at levels well above the minimum effective to ensure antimicrobial activity. However, at the highest end of this accepted use interval, potassium sorbate may contribute to the loss of flavor of the diluted juice beverages. In addition, potassium sorbate is not effective against certain yeasts that may be present in the beverage processing plants. Zygosaccharomyces bailii is of particular interest. Zygosaccharomyces bailii is a common yeast that spoils food and is extremely resistant to weak acid preservatives, such as, for example, potassium sorbate; tolerating in some cases very excessive concentrations of the preservative in comparison with those "legally permitted." See Cole et al., "Probality of" Growth of the Spoilage Yeast Zygosaccharomyces bailii in a Model Fruit Drink System, "Food Microbiology, 1987, 4, pp. . 115-19. See also Warth, "Transport of Benzoic and Propanoic Acids by Zygosaccharomyces bailii-," Journal of.-General Microbiology, 1989, 135, p. 1383-90. { Zygosaccharomyces bailii is very tolerant to common weak acid type preservatives, including sorbic acids). This yeast can be introduced into the beverage producing plant by means of chemically preserved fruit juice, unpasteurized or recontaminated and then established by itself in various parts of the plant apparatus, leading to further contamination and decomposition. Inhibitors for yeasts and molds, such as natamycin, have been found to be particularly effective against yeasts, such as, for example, Zygos a ccha romyces ba i l i i. See Shirk & Clark, "The Effect of _Pimaricin in Retarding the Spoilage of Fresh Orange Juice," Food Technolgy, 1963, p 108. Natamycin is also effective against a variety of different fungi and saprophytic and parasitic yeasts. See U.S. Patent No. 3,892,850 (Struyk), issued July 1, 1975. However, natamycin, when in solution, is quite unstable. The inactivation of natamycin by light, peroxides or oxygen is carried out at a higher speed in solution or suspension. For example, an aqueous solution of 6 mcg / ml of natamycin becomes microbiologically inactive after twenty-four hours of exposure to light. Natamycin is also sensitive to heavy metals, and can have a loss of up to 75% of its effectiveness in four or five hours in the presence of these heavy metals. In addition, natamycin is not effective against bacteria. See U.S. Patent No. 4,536,494 (Carter), issued August 20, 1985. ~ - Dialkyl dicarbonates have also been used or proposed to be used as inhibitors for yeast in wine, teas ready for drink, fruit juices, plant products, pharmaceuticals, beer and the like. See 37 CFR §172.133. See also, U.S. Patent 3,979,524 (Bayne), issued September 7, 1976 and U.S. Patent No. 2,910,400 (Berhard et al.), Issued October 27, 1959 (also referred to as " esters of pyrocarbonic acid "). Dialkyl dicarbonates provide a very effective initial "kill" of any microorganisms in the already formulated individual strong drink. However, dialkyl dicarbonate is rapidly hydrolyzed by aqueous systems, such as, for example, juice drinks diluted shortly after the addition. As the concentration of the dialkyl dicarbonate decreases, it becomes ineffective in a short time to kill the microorganisms that could have been introduced later during the processing in the drink. See, Ough, "Dimethyldicarbonat and Diethyldicarbonate" An t im i crobi a ls in Foods, 193, Marcel Dekker, pp. 343-368. It has recently been proposed that the use of certain food-grade polyphosphates, especially sodium hexametaphosphate, may improve the potency of preservatives, such as potassium sorbate, when the preservative is used at lower levels in beverages. diluted juice. See, U.S. Patent No. 5,431,940 (Boilers), issued July 11, 1995, which describes the use of polyphosphates, such as, for example, sodium hexametaphosphate, with sorbate preservatives, such as, for example, sorbate. of potassium, in diluted juice drinks that have a relatively low water hardness. However, the addition of these polyphosphates can present problems in calcium-fortified beverages or those containing proteins, especially milk proteins, such as, for example, caseins and albumins. The addition of polyphosphates at levels sufficient to increase the potency of the preservative will also isolate any calcium and milk proteins present and eliminate them by condensation of the resulting complexes. Even when preservatives are included, such as potassium sorbate, juice drinks diluted in any way may require refrigeration to maintain microbial stability. Refrigerated beverages require special handling, especially in terms of shelf space in the warehouse. This also requires more expensive refrigerated rail cars and trucks to transport these drinks to stores. Therefore, it would be convenient to be able to provide diluted juice beverages that: (1) use conservative systems that can be formulated with existing antimicrobials, such as, for example, potassium sorbate; (2) are stable against microbial growth at ambient temperatures, among which yeasts are included, such as, for example, Zygosa ccha romyces ba i l i i; (3) does not have flavor losses contributed by the preservative system; (4) can be fortified with calcium; (5) may include milk solids; (6) do not require special handling, especially refrigeration, during transportation and storage.

DESCRIPTION OF THE INVENTION The present invention relates to antimicrobial combinations useful in the treatment of beverages, especially diluted juice beverages, calcium fortified drinks, beverages containing tea solids, and beverages containing milk solids and proteins, as well as other acidified food and beverage products (ie, with a pH less than about 4.6), with high aqueous activity (i.e., greater than about 0.85 aw), such as, cheese, sausages, ready-to-sprinkle icings, dressings for salad, mayonnaise and the like, which are susceptible to microorganisms that spoil food. The antimicrobial combinations of the present invention comprise natamycin, dialkyl dicarbonate and a sorbate preservative. The food products are treated with these antimicrobial combinations such that natamycin, dialkyl dicarbonate and a sorbate preservative are at levels below the taste threshold for each of these antimicrobials albeit at levels sufficient for the combination to be effective against microorganisms that spoil food. The present invention also relates to a preferred process for treating beverages, usually susceptible to microorganisms that spoil food with these antimicrobial combinations. This process comprises the steps of: (a) forming a beverage concentrate comprising: (1) a concentrate of a beverage usually susceptible to microorganisms that spoil the food; (2) natamycin in an amount sufficient to provide from about 2 to about 10 ppm thereof in a single strong beverage; and (3) a sorbate preservative in an amount sufficient to provide from about 30 to about 300 ppm thereof in a single strong beverage; (b) adding a source of water to the beverage concentrate in an amount sufficient to provide a strong individual beverage; (c) uniformly and substantially disperse a dialkyl dicarbonate in the individual strong drink in an amount sufficient to provide from about 30 to about 150 ppm thereof.

"Beverages, including diluted juice beverages, beverages containing tea solids, and beverages containing milk solids, treated with these antimicrobial combinations, are stable against microbial growth at ambient temperatures and are especially resistant to growth of common yeasts that spoil food, including Zygosaccharomyces bailii Because the various components of the antimicrobial combination are present at levels below their flavor threshold, it does not contribute to the loss of flavor by this antimicrobial combination Beverages treated with this antimicrobial combination can also be formulated with calcium or other nutrient minerals, as well as with milk solids.Drinks, especially diluted juice beverages, treated with this antimicrobial combination do not require refrigeration during transportation. and storage.

DETAILED DESCRIPTION OF THE INVENTION DEFINITIONS In the sense in which it is used herein, "microbial proliferation" means an increase of 100 times or more in the number of microorganisms that spoil the beverages in a beverage after an initial contamination level of approximately 10 cfu. / ml. In the sense in which it is used herein, "exposure time to the environment" means the period of time during which a beverage product at 68 ° F (20 ° C) can effectively resist microbial growth after of a contamination of 10 cfu / ml with the microorganisms that spoil the drinks. In the sense in which it is used in the present, the term "comprising" means various components and processing steps that can be used together in the antimicrobial combinations, products and processes of the present invention. Accordingly, the term "comprising" encompasses the most restrictive terms "consisting essentially of" and "consisting of". All amounts, parts, ratios and percentages are used herein by weight unless otherwise specified.

B. ANTIMICROBIAL COMBINATIONS The antimicrobial combinations useful in the present invention comprise a combination of natamycin, a dialkyl dicarbonate and a sorbate preservative. Each of the components in these antimicrobial combinations are present at levels below the flavor threshold of the respective antimicrobial. This avoids the taste losses that would be caused by the food product treated with these antimicrobial combinations. The levels of these antimicrobials below the taste threshold are also usually below optimal levels, ie, levels below the usually optimal effect range for the determined antimicrobial. However, it has surprisingly been found that the combination of these three components together can be synergistic in such a way that the combination is effective against microbial growth in a variety of food products susceptible to spoilage microorganisms. which include yeasts, such as, for example, Zygosa ccha romyces ba il ii.

To provide resistance to microbial growth, food products are normally treated with: (a) from about 2 to about 10 ppm, preferably from about 2.5 to about 5 ppm of natamycin; (b) from about 30 to about 150 ppm, preferably from about 50 to about 100 ppm of dialkyl dicarbonate; (c) from about 30 to about 300 ppm, preferably from about 50 to about 150 ppm of sorbate preservative. The natamycin suitable for use in the present invention is a known and commercially available yeast and a mold inhibitor which has been used to prevent the growth of yeasts and molds in various food products, such as cheeses, sausages, juices , etc. Natamycin is particularly effective against yeasts, such as, for example, Zygosa ccha romyces ba i l i i. Natamycin is produced by S trep t omyces na ta l in s i s and by S. cha t tan oo gen sisy are often referred to by other names, such as pimaricin, antibiotic A 5283, tenecetin, CL 12625, Mycophyt, Myprozine, Natacyn and Pimafucin, all of which are collectively referred to as "natamycin". "for the purposes of the present invention. Natamycin useful in the present invention also includes any compounds which have practically the same chemical structure as natamycin, for example, compounds produced by chemical synthesis or biotechnology, with the proviso that these compounds have essentially the same properties of mojio inhibition. and leaven. Natamycin is available from several of the companies under various trade names, for example, from Gist-Brocades Food Ingredients, Inc. of King of Prussia, Pennsylvania, under the trade name DELVOCID® and from Cultor Food Science Inc., Roseville, California under the trade name NÁTAMAX®. See, U.S. Patent No. 892,850 (Struyk et al.), Issued July 1, 1975 (incorporated herein by reference), which describes the preparation of natamycin (pimaricin) to the cultivar S trep tomyces na ta l in sis. See also The Merck Index (20th Edition, 1996), page 967, entry 6519, for more details on natamycin and its preparation.

Dialkyl dicarbonates (also referred to as "pyrocarbon acid esters") suitable for use in the present invention have been used or proposed for use as yeast inhibitors in wine, ready-to-drink teas, fruit juices, plant products, pharmaceuticals , beer and the like. See, U.S. Patent No. 3,936,269 (Bayne), issued February 3, 1976 and U.S. Patent No. 3,972,524 (Bayne), issued September 7, 1976. These dialkyl dicarbonates have the following General Formula: wherein Ri and R2 represent the same or a different alkyl group, such as, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, cyclohexyl, etc. See U.S. Patent No. 2,910,400 (Koln-Stammheim et al.), Issued October 27, 1959, which is incorporated by reference. Preferred dialkyl dicarbonate for use in the present invention is dimethyl dicarbonate. See also U.S. Patent No. 4,929,748 (Franklin), issued May 29, 1990; U.S. Patent No. 5,214,185 (Nishihira et al.), issued May 25, 1993; and U.S. Patent No. 5,231,211 (Tang), issued July 27, 1993 (incorporated herein by reference) for methods of producing dialkyl carbonates, including dimethyl dicarbonate. Sorbate preservatives suitable for use in the present invention include sorbic acid, as well as sorbic acid salts, such as calcium sorbate, sodium sorbate, potassium sorbate and mixtures thereof. Potassium sorbate is particularly preferred for use in the present invention, especially for dilute juice beverages and other beverage products that require good water solubility.

C. FOOD PRODUCTS AND BEVERAGES, TREATED WITH ANTIMICROBIAL COMBINATIONS The antimicrobial combinations of the present invention can be used to treat a wide variety of food and beverage products susceptible to spoilage microorganisms. These food products and beverages include dairy products, such as cheese, milk, sour cream, yogurt, butter, margarine, ice cream, food and beverage products that contain dairy or milk solids and proteins, such as salad dressings. , powdered milks, ready-to-sprinkle frosting products, mayonnaise, wines, juices, purées, processed meat products, such as sausages, hot dogs, and fermented manufactured meat products, raw, and other food and beverage products acidified (ie, with a pH of less than about 4.6 ~), high aqueous activity (ie greater than about 0.85 aw). These antimicrobial combinations are particularly useful in beverage products, especially diluted juice beverages, calcium fortified beverages, beverages containing tea solids and beverages containing milk solids and proteins. The diluted juice beverages of the present invention typically comprise from about 0.2 to about 5%, preferably from about 0.5 to about 3%, more preferably from about 0.8 to about 2%, of a beverage emulsion. it may be either a cloudy emulsion or a flavoring emulsion.For turbid emulsions, the haze agent may comprise one or more stabilized fats or oils as an oil in water emulsion using a suitable food grade emulsifier. of a variety of fats or oils as the agent of turbidity, provided that the fat or oil is suitable for use in food and beverages.The fats and oils preferred are those that have been refined, bleached and deodorized to eliminate Taste losses Especially suitable for use as turbidity agents are those fats that are orga nolépticamente neutral. These include fats from the following sources: vegetable fats, such as, for example, soybeans, corn, safflower, sunflower, cottonseed, canola, and rapeseed; fats from nuts, such as coconut, palm and palm kernel; and synthetic fats. See U.S. Patent No. 4,705,691 (Kupper, et al.), Issued November 10, 1987, (incorporated herein by reference) for turbidity agents with suitable grease or oil.

Any suitable food-grade emulsifier which can stabilize the turbidity agent with grease or oil as an oil-in-water emulsion can be used. Suitable emulsifiers include acacia gum, modified food starches (for example, food starches modified with alkenyl succinate), anionic polymers derived from cellulose (for example, carboxymethylcellulose), ghatti gum, modified ghatti gum, xanthan gum, gum tragacanth, guar gum, locust bean gum, pectin and mixtures thereof. See U.S. Patent No. 4,705,691 (Kupper, et al.), Issued November 10, 1987, which is incorporated by reference. Modified starches treated in this manner contain hydrophobic as well as hydrophilic groups, such as for example those described in U.S. Patent No. 2,661,349 (Caldwell et al.) (Incorporated herein by reference), are preferred emulsifiers for use in the present. Starches modified with octenyl succinate (OCS), such as, for example, those described in U.S. Patent No. 3,455,838 (Marotta et al.), And U.S. Patent No. 4,460,617 (Barndt et al.), (Incorporated herein by reference), are especially preferred emulsifiers. The turbidity agent may be combined with a compensating agent to provide a beverage opacifier that gives a total or partial opaque effect to the beverage without separating it or causing it to surface. The beverage opacifier provides the consumer appearance of a beverage containing juice. Any suitable compensation oil can be employed in the beverage opacifier.

Normal compensating oils include brominated vegetable oil, wood resin glycerol ter (ester gum), sucrose acetate isobutyrate (SAIB) and other esters of sucrose, damar gum, rosin, elemi gum, or others known to those skilled in the art. Other suitable compensating agents include liquid polyol polyesters, brominated, which are not digestible. See U.S. Patent No. 4,705,690 (Brand et al.), Issued November 10, 1987, which is incorporated by reference. The turbid / opacifying emulsion is prepared by mixing the turbidity agent with the compensation agent (for the opacifying emulsions), the emulsifier and water. The emulsion normally contains from about 0.1 to about 25% of the haze agent, from about 1. to about 20% by weight of the oily agent (in the case of opacifying emulsions), from about 1 to about 30% of emulsifiers and from about 25 to approximately 97.9% of water, the amount that is necessary. The particle size of the water-insoluble components of the emulsion is reduced by employing a suitable apparatus known in the art. Due to the ability of the emulsifying agents to keep the oil in suspension is proportional to the particle size, emulsions of particles with diameters of about 0.1 to about 3.0 microns are adequate. Preferably, the particles are approximately 2.0 microns in diameter or less. A more preferred emulsion is one in which practically all particles are 1.0 mm in diameter or less. The particle size is reduced by passing the mixture through a homogenizer, colloid mill or a turbine type stirrer. Usually, one or two passes is enough. See U.S. Patent No. 4,705,691 (Kupper, et al.), Issued November 10, 1987, which is incorporated by reference. Flavoring emulsions useful in beverages comprise one or more suitable flavor oils, extracts, oleoresins, essential oils and the like, known in the art to be used as flavorings in beverages. This component may also comprise flavor concentrates, as for example, those derived from the concentration of natural products, such as, for example, fruits. Also, citric oils without terpene and essences can be used here. Examples of suitable flavors include fruit flavors, such as, for example, orange, lemon, lime and the like, flavors with cola extract, tea flavors, coffee flavors, chocolate flavors, dairy flavors and others. These flavors can be derived from natural sources, such as essential oils and extracts, or can be prepared synthetically. The flavoring emulsion usually comprises a mixture of various flavors and can be used in the form of an emulsion, alcohol extract, or dry spray. The flavoring emulsion may also include turbidity agents, with or without compensating agents, as previously described.

See U.S. Patent No. 4,705,691 (Kupper, et al.), Issued November 10, 1987, which is incorporated by reference.

Normally, flavor emulsions are prepared in the same way as turbid / opacifying emulsions by mixing flavor oils (0.001 to 20%) with an emulsifying agent (1 to 30%) and water. (Oily turbidity agents may also be present.) Emulsions of particles with diameters of about 0.1 to about 3.0 microns are adequate. Preferably, the particles are approximately 2.0 microns in diameter or less. More preferably, the particles are approximately 1.0 mie in diameter or less. The emulsifying agent covers the particularized flavor oil to aid in preventing coalescence and in maintaining an appropriate dispersion. The specific viscosity and gravity of the flavoring emulsion are regulated so that they are compatible with the finished beverage. See U.S. Patent No. 4,705,691 (Kupper, et al.), Issued November 10, 1987, which is incorporated by reference.

The diluted juice beverages of the present invention, optionally, but preferably, comprise flavor solids selected from fruit juice, tea solids and mixtures of fruit juice and tea solids. When fruit juice is included, the beverages of the present invention can comprise from 0.1 to about 40%, preferably from 1 to about 20%, more preferably from about 2 to about 10%, even more preferably from about 3 to about 6% fruit juice. (As measured herein, the percentage by weight of fruit juice is based on an individual intensity of 2 ° to 16 ° Brix fruit juice.) The fruit juice can be incorporated into the beverage as a puree, ^ crushed, or as a juice of individual intensity or concentrate. The incorporation of fruit juice as a concentrate with a solids content is especially preferred. (mainly as sugar solids) from about 20 ° to about 80 ° Brix. The fruit juice can be any citrus juice, non-citrus juice or mixture thereof, which are known to be used in drinks of diluted juice. The juice can be derived from apple, cranberry, pear, peach, plum, apricot, peach, grape, cherry, currant, raspberry, wild gooseberry, elderberry, blackberry, blueberry, strawberry, lemon, lime, tangerine, orange, grapefruit, cupuacu, potato, tomato, lettuce, celery, spinach, cabbage, watercress, dandelion, rhubarb, carrot, beet, cucumber, pineapple, coconut, pomegranate, kiwi, mango, papaya, banana, watermelon, tangerine and melon. The preferred juices are derived from apple, pear, lemon, lime, tangerine, grapefruit, cranberry, orange, strawberry, tangerine, grape, kiwi, pineapple, passion fruit, mango, guava, raspberry and cherry. Citrus juices, preferably grapefruit, orange, lemon, lime and tangerine juice juices, as well as juices derived from mango, apple, raaracuyá and guava, as well as mixtures of these juices are more preferred. When tea solids are included, the beverages of the present invention can comprise from about 0.01 to about 1.2%, preferably from about 0.05 to about 0.8% by weight of tea solids. In the sense in which it is used herein, the term "tea solids" means solids extracted from tea materials, including those materials obtained from the Camel lily, among which C is included. sinensi and C. as sa imi ca, for example, freshly harvested tea leaves, fresh green tea leaves, dried immediately after harvest, fresh green tea leaves that have been heat treated before drying to inactivate any enzymes present , unfermented tea, instant green tea and partially fermented tea leaves. The green tea materials are tea leaves, tea plant stems and other plant materials that are related and that do not undergo substantial fermentation to create black teas. You can also use the members of the genus Phyl l an th u s, ca t ech u gambi r and the Uncaria family of tea plants. Mixes of unfermented and partially fermented teas can be used. The tea solids for use in the beverages of the present invention can be obtained by known and conventional tea solids extraction methods. A particularly preferred source of green tea solids can be obtained by the method described in copending US Application Serial No. 08 / 606,907 (Ekanayake et al.), Filed on February 26, 1996, which is incorporated as reference. The tea solids thus obtained will normally comprise "caffeine, theobromine, proteins, amino acids, minerals and carbohydrates." Suitable beverages containing tea solids can be formulated in accordance with U.S. Patent No. 4,946,701 (Tsai et al.) , issued August 7, 1990, which is incorporated by reference, See also U.S. Patent No. 5,427,806 (Ekanayake et al.), issued June 26, 1995, "for adequate sources of green tea solids. for use in the present invention. Beverages, according to the present invention, can also be formulated to contain milk solids. These milk solids can be derived from several sources, including whole milk, skimmed milk, condensed milk, and dried milk powder. In the sense in which it is used herein, the term "milk" will be used to describe an aqueous dispersion of milk solids, such as liquid milk (whole or skim milk) or nonfat dry milk or condensed milk diluted with water. The amount of milk is usually included in the range of from about 5 to about 99.8%, preferably from about 5 to about 75%, most preferably from about 5 to about 40% and even more preferably from about 5 to about 15. %. (The amount of non-fat milk solids that correlates with these milk solids levels is in the range of from about 0.5 to about 8.2%, from about 0.5 to about 6.2%, from about 0.5 to about 3.3% and from about 0.5. to 1.2% of the beverage, respectively.) Drinks according to the present invention, especially the diluted juice drink and the tea solids containing the beverages may comprise thickeners, including xanthan gum, carboxymethylcellulose, propylene glycol alginate, gellan gum, guar gum, pectin, tragacanth gum, acacia gum, locust bean gum, gum arabic, gelatin, as well as mixtures of these thickeners. These thickeners are normally included in the beverages of the present invention at levels of up to about 0.07%, depending on the particular thickener involved and the desired viscosity effects. The beverages of the present invention can, and normally will contain, an effective amount of one or more sweeteners, including carbohydrate sweeteners and natural and / or artificial sweeteners without calories / low calories. The amount of the sweetener used (ie, "effective amount") in the beverages of the present invention usually depends on the particular sweetener used, and the desired sweetness intensity. For sweeteners without calories / low calories, this amount varies depending on the sweetness intensity of the particular sweetener. The beverages of the present invention can be sweetened with any of the carbohydrate sweeteners, preferably mono- and / or di-saccharide sugars. Sugar-sweetened beverages will typically comprise from about 0.1 to about 20%, most preferably from about 6 to about 14% sugar. These sugars can be incorporated into the drinks in solid or liquid form although normally, and preferably, they are incorporated as a syrup., more preferably as a concentrated syrup, such as, for example, high fructose corn syrup. For the purposes of the beverage to be prepared of the present invention, these sugar sweeteners may be provided to some degree by other components of the beverage, such as, for example, the fruit juice component, flavorings, etc.

The preferred sugar sweeteners for use in these beverages are sucrose, fructose, glucose and mixtures thereof. Fructose can be obtained or provided as liquid fructose, high fructose corn syrup, dry fructose or fructose honey, although it is preferably provided as high fructose corn syrup. High fructose corn syrup (HFCS) is commercially available as HFCS-42, HFCS-55 and HFCS-90, comprising 42%, 55% and 90%, respectively, by weight of the sugar solids in the same as fructose. Other naturally occurring sweeteners or their purified extracts, such as, for example, glycyrrhizin, the protein sweetener thaumatin, the Luo Han Guo juice described, for example, in U.S. Patent No. 5,433,965 (Fischer et al. ), issued July 18, 1995 (incorporated herein by reference) and the like may be used in the beverages of the present invention. Suitable calorieless / low calorie sweeteners include saccharin, cyclamates, acesulfam K (Sunette ™), lower alkyl ester sweeteners of L-aspart il-L-phenylalanine (eg, aspartame); L-aspart il-D-alanine amides described in U.S. Patent No. 4,411,925 to Brennan et al .; L-aspart il-D-serine amides described in U.S. Patent No. 4,399,163 to Brennan et al .; sweeteners of L-aspart il-L-1-hydroxymethylalkamide described in U.S. Patent No. 4,338,346 to Brand; L-aspart il-1-hydroxyethyl ialcanoamide sweeteners described in U.S. Patent No. 4,423,029 to Rizzi; and L-aspart il-D-phenylglycine ester and amide sweeteners described in European Patent Application No. 168,112 of J. M. Janusz, published January 15, 1986; and the similar and mixtures thereof. Aspartame is a particularly preferred low-calorie sweetener. The beverages of the present invention may comprise other optional beverage ingredients, including other preservatives (eg, organic acids), dye, etc. These beverages can also be fortified with 0 to approximately 110% of the US daily recommended tolerance (RDA) of vitamins and minerals, provided that these vitamins and minerals do not substantially alter the desired properties of the beverage ( for example, times of exposure to the environment), and that these vitamins and minerals are chemically and physically compatible with the other essential components of the beverage. Especially preferred are vitamin A (eg, vitamin A palmitate), provitamins thereof (eg, β-carotene), vitamin Bl (eg, thiamine HCl) and vitamin C (ie, ascorbic acid), although it is understood that other vitamins can also be used. The minerals that can be included in the beverages of the present invention include calcium, magnesium, zinc, iodine and copper. Any soluble salt of these suitable minerals can be used for inclusion in edible products, for example, calcium carbonate, calcium citrate, calcium alato, calcium citrate malate, calcium gluconate, magnesium citrate, magnesium gluconate. , magnesium sulfate, zinc chloride, zinc sulfate, potassium iodide and cupric sulfate. A preferred source of calcium is a complex with certain organic acids and in particular calcium citrate malate. The preparation of this preferred calcium organic acid complex is described in U.S. Patent No. 4,737,375 (Nakel et al.), Issued April 12, 1988, which is incorporated by reference. The beverages of the present invention typically have a pH of from about 2 to about 4.5, preferably from about 2.7 to about 4.2. This pH range is normal for still drinks. The acidity of the beverage can be adjusted and maintained within the required range by known and conventional methods, such as, for example, the use of food grade acid regulators. Normally, the acidity of the beverage within the aforementioned ranges is a balance between the maximum acidity for microbial inhibition and the optimum acidity for the desired taste and acidity of the beverage. The beverages of the present invention can be prepared by conventional methods to formulate still beverages. Methods for producing diluted juice beverages, for example, are described in U.S. Patent No. 4,737,375 (Nakel et al.), Issued April 12, 1988, which is incorporated herein by reference. Methods for manufacturing beverage products are also described by Woodroof and Phillips, Beveragés: Carbonated &; Noncarbonat ed, AVI Publishing Co. (revised edition 1981); and by Thorner and Herzberg, Non-alcoholic Food Service Beverage Handbook, AVI Publishing Co. (2nd ed., 1978). These methods may include hot-filling operations or aseptic packaging, although these operations are not necessary to achieve either the stability of the beverage or long-term exposure times to the environment. Indeed, the advantage of the synergistic antimicrobial combination of the present invention is that beverages containing this combination can be produced without hot packaging the product.Any method that ensures the antimicrobial combination is incorporated into the food or drink, as such. any microorganisms present are effectively killed or their growth is inhibited in a suitable manner A preferred method for making dilute juice beverages according to the present invention is as follows: the sorbate preservative and the natamycin are added to a concentrate of juice used to formulate the beverage in sufficient quantities to provide the levels indicated above for these antimicrobials in the individual strong diluted juice drink.The juice concentrate with these antimicrobial components is then mixed, stirred "or otherwise combined with a water source in the percentage appropriate for propo Rotate a strong individual diluted juice drink. Once I know. The individual strong diluted juice drink is prepared, the dialkyl dicarbonate is then added and preferably evenly and substantially dispersed in the beverage. Dialkyl dicarbonate provides an effective initial "kill" of any microorganisms in the individual strong drink right after it is formulated. While dialkyl dicarbonate is hydrolyzed with water, the sorbent preservative and natamycin present ensure effective inhibition of microbial growth for a longer time.

E. TEST METHOD: AMBIENT EXPOSURE TIMES / MICROBIAL STABILITY The times of exposure to the environment correspond to the period of time during which a food product, such as a beverage product at 68 ° F (20 ° C) can Effectively resist microbial growth after inoculation of 10 cfu / ml with microorganisms that spoil food. The term "microbial proliferation", in the sense in which it is used herein, means an increase of 100 times or more in the number of microorganisms that spoil food in a food product, after an initial inoculation level. of approximately 10 cfu / ml. The exposure times to the environment for food products can be determined by the following method. The food products are inoculated with mixed groups of preservative-resistant yeasts, which contain at least four separate yeast isolates, including Zygosa ccha romyces ba ilii, and with mixed groups of acid tolerant bacteria, resistant to Conservatives, including the species of Ace toba c ter. All yeasts and bacteria used in the inoculation are previously isolated from canned fruit juice drinks. Inoculated food products are maintained at 68 ° F (20 ° C) for 21 days and cultures are carried out periodically in aerobic plate. Aerobic plaque counts of both yeast and bacterial populations are performed as described in the Compendium of Methods for Microbiological Food Examinations, the American Public Health Association, Washington, DC, (edited by C. Vanderzant and DF Splitt st oesser), the description of which is incorporated herein by reference. These plate counts are then used to identify the degree of microbial proliferation in the inoculated beverage.

EXAMPLES The following are illustrative examples of beverages prepared using the synergistic antimicrobial combination of the present invention.

EXAMPLE 1 A juice / milk drink is prepared from the following ingredients: All the ingredients (for example juice concentrates, milk solids, flavors, sweeteners, thickeners, etc.) are added and mixed well, except for citric acid, potassium sorbate, natamycin and dimethyl dicarbonate, provide the drink. The pH of the beverage is adjusted to 4.1 with citric acid and then the potassium sorbate is added and dissolved in the beverage. A mother solution of natamycin is constituted in water and then added to the beverage. The dimethyl dicarbonate is uniformly dispersed in the beverage before bottling (from the dosing point to the bottling and capped point, the time interval is less than about 2 minutes). The prepared beverage is stable microbially at room temperature for 21 days.

EXAMPLE 2 A diluted juice drink is prepared from the following ingredients: All ingredients (eg juice concentrates, milk solids, flavors, sweeteners, thickeners, etc.) are added and mixed well, except for citric acid, potassium sorbate, natamycin and dimethyl dicarbonate to provide the drink. The pH of the beverage is adjusted to 3.2 with citric acid and then potassium sorbate is added and dissolved in the beverage. A mother solution of natamycin is constituted in water and then added to the beverage. The dimethyl dicarbonate is uniformly dispersed in the beverage before it is bottled (from the dosing point to the bottling and capped point, the time interval is less than about 2 minutes). The prepared beverage is stable microbially at room temperature for 21 days.

EXAMPLE 3 A tea beverage is prepared from the following ingredients: All the ingredients (for example juice concentrates, milk solids, flavors, sweeteners, thickeners, etc.) are added and mixed well, except for citric acid, potassium sorbate, natamycin and dimethyl dicarbonate to provide the tea beverage. The pH of the beverage is adjusted to 4.2 with citric acid and then potassium sorbate is added and dissolved in the beverage. A mother solution of natamycin is constituted in water and then added to the beverage. The dimethyl dicarbonate is dispersed in a uniform manner in the beverage before bottling (from the dosing point to the bottling point and capping, the time interval is less than about 2 minutes). The prepared beverage is stable microbially at room temperature for 21 days.

Claims (12)

1. CLAIMS 1. An antimicrobial combination, the antimicrobial combination characterized in that it comprises: (a) natamycin; (b) dialkyl dicarbonate; (c) a sorbate preservative; (d) wherein the level of each natamycin, dialkyl dicarbonate and a sorbate preservative are below the taste threshold, albeit at a sufficient level such that the combination is effective against microorganisms that spoil the food.
2. 2. The antimicrobial combination according to claim 1, characterized in that the microbial co-assembly comprises: (a) from about 2 to about 10 ppm, preferably from about 2.5 to about 5 ppm of natamycin; (b) from about 30 to about 150 ppm, preferably from about 50 to about 100 ppm of dialkyl dicarbonate; (c) from about 30 to about 300 ppm, preferably from about 50 to about 150 ppm of sorbate.
3. 3. The antimicrobial combination according to claim 1 or 2, characterized in that the dialkyl dicarbonate has the following general formula: wherein Ri and R2 represent the same alkyl group or a different alkyl group selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl and cyclohexyl.
4. 4. The antimicrobial combination according to claims 1, 2 or 3, characterized in that the dialkyl dicarbonate is dimethyl dicarbonate.
5. 5. The antimicrobial combination according to claims 1, 2, 3 or 4, characterized in that the sorbate preservative is selected from the group consisting of sorbic acid, calcium sorbate, sodium sorbate, potassium sorbate and mixtures thereof.
6. 6. A food or beverage product that is usually susceptible to spoilage microorganisms, characterized in that the product is treated with an effective amount of the antimicrobial combination according to claims 1, 2, 3, 4, or 5.
7. 7. The product according to claim 6, characterized in that it is selected from the group consisting of cheese, milk, sour cream, yogurt, butter, margarine, ice cream, salad dressings, milk powders, glaze products ready to sprinkle, mayonnaise, wines, juices, purées and processed meat products.
8. 8. A diluted juice beverage product comprising: (i) from about 0.2 to about 5% of a beverage emulsion; (ii) from 0.1 to about 40%, preferably from about 2% to about 10%, of fruit juice; the improvement is characterized in that it comprises incorporating in the beverage product the antimicrobial combination according to claims 1, 2, 3, 4, or 5.
9. 9. The product according to claims 6, 7 or 8, the product is characterized in that it comprises from about 5 to about 40%, preferably from about 5 to about 15% milk solids.
10. 10. The product according to claims 6, 7, 8 or 9, characterized in that the dialkyl dicarbonate is dimethyl dicarbonate and wherein the sorbate preservative is potassium sorbate.
11. 11. The product according to claims 6, 7, 8, 9 or 10, characterized in that the product further comprises from about 0.01 to about 1.2%, preferably from about 0.05 to about 0.8% green tea solids.
12. 12. A process for treating a beverage that is usually susceptible to spoilage microorganisms, characterized in that it comprises the steps of: (a) forming a beverage concentrate comprising: (i) a concentrate of a usually susceptible beverage to microorganisms that spoil food; (ii) natamycin in an amount sufficient to provide from about 2 to about 10 ppm, preferably from about 2.5 ppm to about 5 ppm thereof in a single strong beverage; and (iii) a sorbate preservative, preferably potassium sorbate, in an amount sufficient to provide from about 30 to about 300 ppm, preferably from about 50 ppm to about 100 ppm, thereof in a single strong beverage; (b) adding a water source to the beverage concentrate in an amount sufficient for < provide a strong individual drink; (c) uniformly and substantially disperse a dialkyl dicarbonate, preferably dimethyl dicarbonate in the individual strong drink in an amount sufficient to provide from about 30 to about 150 ppm, preferably from about 50 ppm to about 100 ppm thereof .