WO2001030412A1

WO2001030412A1 - Flavor protectant closure liner compositions

Info

Publication number: WO2001030412A1
Application number: PCT/US2000/029622
Authority: WO
Inventors: Fred Teumac
Original assignee: Zapata Technologies Inc.
Priority date: 1999-10-27
Filing date: 2000-10-27
Publication date: 2001-05-03
Also published as: AU8032400A

Abstract

A liner composition for a potable fluid container closure element which includes an unactivated hydrazide for preventing off-flavors due to the presence of aldehydes in the fluid. The unactivated hydrazide is present in an amount sufficient to improve the taste of the potable fluid but in an amount less than 0.1 %. Also, a method of improving the taste of a potable fluid such as bottled water or beer by use of a container and the previously described liner compositions associated therewith.

Description

FLAVOR PROTECTANT CLOSURE LINER COMPOSITIONS

FIELD OF THE INVENTION

The present invention relates to plastic compositions that are intended for use as liners in closures for potable fluid containers such as bottled water and beer. The liner includes very small amounts of an unactivated hydrazide compound to protect against the development during processing of the liner and the container of off-flavor in the potable fluid that would otherwise result from the reaction of oxygen with the plastic liner composition or components thereof.

BACKGROUND OF THE INVENTION

Crown liner technology Current crown liner technology includes the in situ molding of a thermoplastic liner material directly in the crown which will later be used for bottling beer or other beverages. Such liners are primarily made of polyvinyl chloride ("PVC") in the United States and of thermoplastics that do not contain chlorine, such as EVA or polyethylene ("PE") , in Europe and Japan. A conventional apparatus for making lined crowns is the Za-Matic® Model 1400A (available from ZapatA Industries, Inc.) described in U.S. Patents Nos. 3,135,019, 3,360,827, and 3,577,595. The liner compositions may be based upon plastics such as, for instance, PVC, EVA, or PE, and may include those of U.S. Patent No. 3,547,746. PVC compositions with or without additives as stabilizers for imparting certain properties are known in the art. For instance, U.S. Patent No. 4,380,597 discloses a stabilized thermoplastic composition of PVC or mixed polymers that may include ascorbates or gluconates as stabilizer additives. These stabilizers are added not to absorb oxygen from inside packages made of the polymer but to prevent breakdown of the polymer itself. U.S. Patent No. 4,211,681 discloses shaped articles, for instance films or tubes, that include high molecular weight poly (ethylene oxide) polymers with stabilizers of ascorbic acid, 2 , 3-butylhydroxyanisoles, and the like. Japanese Patent Application No. 62-215,101 discloses a deodorizing fiber obtained by treating thermoplastic fibers with inorganic particles of divalent ferrous iron and L-ascorbic acid. U.S. Patent No. 4,278,718 discloses a sealing composition for beverage containers consisting of a vinyl chloride resin, a plasticizer, and a metal oxide.

It is known to use hydrazides such as OBSH as a blowing agent in the liner composition of a closure element of a potable fluid container. Blowing agents are chemicals that are added to plastics or rubbers for generating inert gas upon decomposition, causing the resin to assume a cellular structure. For example, adding 4-4'-oxybis (benzenesulfonyl hydrazide) (^■•OBSH*¹) to the liner of a closure element of a container for bottled beverage and decomposing the OBSH to produce small bubbles (foam) of nitrogen gas which are trapped inside the liner provides a sponginess to the material. When used as a liner of a closure element of the container, an improved seal is achieved.

The liners for most beverage closures are based either on PVC or EVA, although other materials have been used too. For instance, U.S. Patent No. 4,968,514 teaches that polyurethanes can be used to make liners for metal-shelled beer bottle crown caps. These polymer bases can be compounded to give adequate processing properties and product performance, utilizing among other additives heat stabilizers, antioxidants, and lubricants. Naturally occurring fatty acids are often used as lubricants in liner formulations. Fatty acids are separated into individual products and purified by distillation. Because of the wide range of individual acids occurring in nature, a distillation fraction will contain several fatty acids. Some of the impurities contain unsaturation at the 4-, 5-, 6-, 7-, or 8-carbon position. The fatty acids are converted to ester or amide derivatives which likewise contain mid-chain unsaturation. When used as lubricants in liner formulations, the fatty acid derivatives are subject to oxidation at the mid-chain unsaturation by oxygen or other oxidizing agents in the beverage or in the air that is enclosed along with the beverage in the container. Such oxidation results in aldehydes. Some of the compounds with the lowest flavor thresholds are these aldehydes. Such liners, however, are adequate for many beverage products in that their contribution of off- flavor to the beverage is not noticeable. Some beverages, though, — notably, mineral waters — have such delicate bouquets that they cannot tolerate even the relatively slight off-flavors that can be generated with conventional liners. A source of double- bond containing precursors that react with oxygen in bottled water is the polymeric cap liner of the container. Polymeric cap liners typically contain a number of plasticizers, heat stabilizers, lubricants, antioxidants, blowing agents, and pigments, some or all of which contain double bonds that are susceptible to attack by oxygen. For example, the liner formulations for twist-off caps typically comprise oleamide-type lubricants. The double bonds in such oleamides are readily susceptible to attack by oxygen, resulting in off-flavored producing medium-chain-length aldehydes. Also, fatty acids or derivatives of fatty acids of liner compositions react with oxygen to form off-flavored aldehydes. Other compounds often found in polymeric cap liners which are susceptible to attack from oxygen include activated aromatic compounds such as phenols, and other double bond containing compounds such as ketones, amides, erucic acid, etc. The resulting aldehydes are responsible for the fruity tastes and odors often found in bottled water. In order to produce bottled drinking water, it is necessary to disinfect the water so as to remove the microorganisms that would otherwise grow therein. In the past, water was disinfected using chlorine. However, the use of chlorine invariable resulted in the production of trihalomethanes such as chloroform which have been shown to pose a serious health risk. Alternatively, water bottling companies can use ozone as a disinfectant instead of chlorine to kill any microorganisms present in the water itself. Thus, the bottled water usually contains ozone in trace amounts. Typically, ozone is present in an amount of about 0.1 to 0.4 mg/1. These trace amounts kill the microorganisms so that it is not necessary for the water to be pasteurized. In addition, ozone oxidizes many nuisance compounds or contaminants in water supplies.

Drinking water standards in the United States specify that drinking water should not have any smell or taste. As shown by C. Anselme et al. in J. American

Waterworks Association. 80, 45-51 (1988) , the intensity of a fruity off-flavor correlates strongly with the total concentration of aldehydes present in the water.

Ozone also reacts with compounds which contain double bonds, such as alkenes, yielding corresponding aldehydes as the major oxidation product. As noted above, those aldehydes are responsible for the fruity tastes and odors that are found in bottled water.

While one solution to this problem is to remove the compounds that are reactive with oxygen, this solution is not practical since the liner would not possess the desired properties to properly seal the bottle. While the presence of off-flavor substances may be more readily remarked in water than in more strongly flavored beverages such as beer, the presence of such substances can also adversely affect the taste of the more strongly flavored beverages. Accordingly, a need exists for an improved liner which can protect against the development of an off-flavor in bottled water or other fluids.

Oxygen-related problems in beer generally

In packaging oxygen-sensitive materials such as foodstuffs, beverages, and pharmaceuticals, oxygen contamination can be particularly troublesome. Care is generally taken to minimize the introduction of oxygen or to reduce the detrimental or undesirable effects of oxygen on the product. Carbon-carbon double bonds are particularly susceptible to reaction with active oxygen species. Such carbon-carbon bonds are often found in foods and beverages, pharmaceuticals, dyes, photochemicals, adhesives, and polymer precursors. Virtually any product that has complex organic constituents will contain such carbon-carbon double bonds or other oxygen-reactive components, and hence can undergo oxidative reactions. Where the products of the oxidative reactions adversely affect the performance, odor, or flavor of the products, then removing the oxygen which is present (either dissolved in or trapped with the product) , preventing oxygen ingress, and inhibiting the reactions of oxygen will all benefit the product. A number of strategies exist to deal with oxygen as a contaminant. The most basic is simply to remove oxygen from the product by vacuum, by inert gas sparging, or both. Such systems are used in boiler water treatment, in the orange juice and brewing industries, and in modified-atmosphere packaging of food products. This technology, while somewhat equipment intensive, can remove up to 95% of the oxygen present in air from the product or its container prior to or during packaging. However, removal of the remaining oxygen using this approach requires longer times for vacuum treatment and/or sparging and increasingly larger volumes of higher and higher purity inert gas that must not itself be contaminated with trace levels of oxygen. This makes the removal of the last traces of oxygen very expensive. A further disadvantage of these methods is a tendency to remove volatile product components. This is a particular problem with foods and beverages, in which such components are often responsible for much of the aroma and flavor.

In beer, for instance, it has been known since the 1930' s that oxygen in beer adversely affects it flavor and stability. Amounts of oxygen as low as 0.1 to 0.2 ml per 355 ml container will, over time, cause darkening of the beer, an increase in chill-haze values, and significant taste changes. Oxygen's effect on beer is so strongly detrimental that many brewers go to great lengths to remove it from the bottle during the filling process. One usual technique is to remove the air via vacuum from a clean bottle, fill the bottle with carbon dioxide, flow the beer down the bottle wall into the bottle thus displacing the carbon dioxide, and finally squirting a jet of high-pressure deoxygenated water into the bottle to cause the beer to over-foam just as the cap is put on, thereby attempting to displace the remaining headspace gases with the beer's own carbon dioxide. In addition, production lines are run slowly in order to minimize the introduction of air into the headspace just before capping. All of this is expensive, and usually reduces the total oxygen concentration in the headspace to about 200-400 parts per billion. The 200-400 ppb achieved in the packaged product by careful brewers corresponds to approximately 50-100 microliters of oxygen per 355 ml bottle. Even this small quantity of oxygen is still considered to be one of the major limitations on quality and shelf life of beer today. The desired level is as close to zero as possible, but certainly below about 50 ppb.

Prior art oxygen scavenging

None of the above techniques remove or control oxygen that is dissolved in the product or leaked or permeated into the package. Compounds such as sulfur dioxide, trihydroxybutyrophenone, butylated hydroxy toluene, butylated hydroxy anisole, ascorbic acid, isoascorbic acid, and glucose oxidase-catalase have been used in an attempt to reduce the effects of oxygen when it is dissolved in beer. See, for instance, Reinke et al., "Effect of Antioxidants and Oxygen Scavengers on the Shelf-Life of Canned Beer", A.S.B.C. Proceedings. 1963, pp. 175-180; Thomson, "Practical Control of Air in Beer", Brewer's Guild Journal. Vol. 38, No. 451, May 1952, pp. 167-184; von Hodenberg, "Removal of Oxygen from Brewing Liquor", Brauwelt International. Ill, 1988, pp. 243-4. The direct addition of such agents into beer has several disadvantages. Both sulfur dioxide and ascorbates, when added to beer, can result in production o off-flavors, thus negating the intended purpose of the addition. Many studies have been conducted on the effect of such agents on the flavor of beer. See, for instance, Klimowitz et al., "The Impact of Various Antioxidants of Flavor Stability", MBAA Technical Quarterly. Vol. 26, 1989, pp. 70-74; Gray et al. , "Systematic Study of the Influence of Oxidation on Beer Flavor", A.S.B.C.

Proceedings. 1948, pp. 101-112. Also, direct addition of such compounds to a food or beverage requires stating on the label that the product contains the additive — an undesirable matter with today's emphasis on "freshness" and "all natural" products. Attempts have been made to incorporate oxygen scavenging systems in a container crown or closure. For instance, U.S. Patent No. 4,279,350 discloses a closure liner that incorporates a catalyst disposed between an oxygen-permeable barrier and a water-absorbent backing layer. U.K. Patent Application No. 2,040,889 discloses a closure in the form of a stopper molded from ethylene vinyl acetate ("EVA") having a closed-cell foamed core that may contain water and sulfur dioxide to act as an oxygen scavenger and a liquid-impervious skin. European Patent Applications Nos. 328,336 and 328,337 disclose container closure elements, such as caps, removable panels, liners, or sealing compositions that are formed of a polymeric matrix containing an oxygen scavenger therein. U.S. Patent No. 4,287,995 discloses a sealing member for a container that is used to preserve aqueous liquids therein. This sealing member is mounted on the cap or stopper of the container on the portion facing the contents. The sealing member contains an oxygen absorbent that is separated from contacting the contents of the container by a film that has a plurality of fine openings such that it is gas-permeable but water- impermeable at one atmosphere pressure.

U.S. Patent No. 5,143,763 describes an approach that prevents oxygen deterioration in containerized substances that relies on the absorption of oxygen from within the container. This patent does not teach how to prevent the containerized substances from developing off flavor that is due to leaching substances from the liner.

Another approach to reduce or prevent off-flavor in bottled potable fluids is to remove the off-flavor causing compound. Off-flavor causing compounds, such as aldehydes, are often present as a result of compounds present in the container closure or in the potable fluid which become oxidized. U.S. Patent No. 5,633,223 discloses liner compositions for potable fluid container closure elements which include an inorganic sulfite and/or tocopherol compound for preventing off-flavors in the potable fluid due to the presence of aldehydes in the fluid. The inorganic sulfite or tocopherol is used in combination with a second flavor protectant compound which differs from the first flavor protectant compound. The second flavor protectant compound may be a hydrazide compound, an inorganic sulfite, or a tocopherol. U.S. Patent No. 5,863,964 discloses a liner composition for a container closure element for a bottled fluid which includes a hydrazide in combination with a second different flavor protecting compound. The combination of flavor protectant compounds prevents or inhibits the formation of off-flavor causing substances in the liner composition, thus improving the taste of the bottled fluid compared to bottled fluids that do not include the hydrazide and flavor protectant compounds.

W095/16366 discloses a liner composition for a potable fluid container closure which includes a hydrazide in an amount of 0.1 to 1%. For some liner compositions it is difficult to retain these amounts of the hydrazides. Thus, a liner composition for a container closure element for a bottled fluid wherein the liner includes lower but effective amounts of flavor protecting compounds is desirable. The present invention provides such a liner composition.

SUMMARY OF THE INVENTION

The present invention protects containerized beverages such as beer and water from developing off- flavor due to leaching of aldehydes from the crown liner. This invention is directed to a liner composition for a closure element of a container for potable fluids such as water. The liner composition includes a polymer and a hydrazide compound present in a non-decomposed state and in an amount sufficient to at least partially inhibit the formation of off-flavor causing substances in the liner composition, but in an amount of less than 0.1% by weight of the composition. The presence of the non-decomposed hydrazide compound improves the taste of the bottled fluid compared to bottled fluids which include closure elements having liner compositions that do not include the non-decomposed hydrazide therein. The hydrazide compound may be a sulfonyl hydrazide or a carboxylic acid hydrazide. The preferred hydrazide compound is 4,4'- oxybis (benzene sulfonyl hydrazide).

The polymer of the liner composition may be a thermoplastic resin compound selected from the group consisting of a polyolefin, polyvinyl chloride, ethylene- vinyl acetate or a mixture thereof. The liner composition may further include one or more of a plasticizer, a heat stabilizer, a lubricant, a blowing agent or a pigment. The bottled fluid can be beer or water.

Another aspect of the invention relates to a method of improving the taste of a bottled fluid such as water by containing the fluid in a potable fluid container and associating the above liner composition with the container so that the hydrazide compound can react with residual off-flavor compounds in the fluid. The method includes providing, in the liner composition during manufacture thereof, a hydrazide compound in a non-decomposed state and in an amount which is sufficient to prevent or inhibit the formation in the liner composition of off-flavor causing substances, but in an amount of less than 0.1% by weight of the composition. The presence of the non-decomposed hydrazide compound improves the taste of the fluid compared to bottled fluids which are retained by closure elements having liner compositions that do not include the hydrazide compound therein. DETAILED DESCRIPTION OF THE INVENTION

It has been unexpectedly discovered that a liner composition for a potable fluid container closure element comprising an unactivated hydrazide component in an amount less than 0.1% by weight of the composition dramatically protects the flavor of the liquid in contact with the liner composition. Thus, this invention relates in part to container closures for use in combination with means for retaining a water-containing foodstuff, beverage, chemical, or pharmaceutical product, which retaining means has at least one opening therein for filling or dispensing of the product. These container closures include a member for closing the opening of the retaining means and preventing escape of the liquid product when not desired, and a liner or gasket comprising a hydrazide compound in an amount less than 0.1% by weight of the composition being positioned adjacent the closing member. Preferably, the retaining means is a can, jar, or bottle of metal, glass, or plastic construction, and the closing member is a crown or closure.

The polymers

A wide variety of polymers may be used in accordance with the teaching of the present invention. For use in applications such as crown or closure liners, the polymer is preferably a polymeric thermoplastic, such as polyvinyl chloride ("PVC") , ethylvinyl acetate ("EVA") , polyethylene terphthalate ("PET") , polyethylene ("PE") , polypropylene ("PP") , or a polyurethane. U.S. Patent No. 3,547,746 provides much useful disclosure about these and thus is expressly incorporated herein by reference. The PVC resins that are preferred for use as the polymer in the flavor protectant compositions of the invention are set forth in the patent at column 2, lines 35-47. This patent also discloses suitable plasticizer compounds that may be used with the thermoplastic resin along with preferred ranges thereof. In this invention, it is preferred to use an amount of plasticizer ranging from about 60 to 90 parts by weight based on 100 parts by weight of the polymer for crown liners. Depending upon the specific product to be made, the amount of plasticizer can vary from 10 to 120 parts. Specific plasticizers for PVC crown liners are recited in column 5, lines 49-53 of the patent. The polymer should have a rate of water vapor transmission of between 0.05 and 25 g-mm/m²/24 hours at 37.8°C. PVC typically provides a value of 2-12, PE between 0.1 and 1 , and EVA 0.8 to 1.2. These rates are sufficient to enable the water vapor to permeate the polymer to activate the flavor protectant materials therein. The polymer should also be permeable to oxygen and have a permeability rate of between 50 and 2000, and preferably between 100 and 1500 cc-mil/100 square inches/24 hours per atmosphere pressure at 25°C. PVC provides values between 100-1400, PE about 185-500, and EVA about 830-850.

The flavor protectant agent

In the present invention, the liner composition comprises an unactivated hydrazide compound as a flavor protectant agent. The unactivated hydrazide compound is present in an amount sufficient to protect against the development of off-flavor in a potable fluid in the container but in an amount less than 0.1%.

The liner composition is generally made of a material which is permeable to gases and water or water vapor. As noted above, this material would typically be a polymer, such as a thermoplastic resin. Thermoplastic resins of polyolefins such as PE and the like, PVC, EVA, and the like would allow gases such as oxygen or ozone, and water or water vapor to pass into and through the liner. The unactivated hydrazide of the present invention protects against the development of off-flavors which would otherwise result from the formation of aldehydes due to the reaction of oxygen sources present in the potable fluid with prior art liner compositions or components thereof.

The presence of unactivated hydrazide compounds protects the flavor of liquid in contact with the processed polymer even in the presence of standard processing additives. Standard processing additives include stabilizers that raw material manufacturers add to their products to protect them during their own processing, storage, transportation, and as some protection for the consumer. These include BHT, phosphites, bases, free radical blockers, chelators, and additives in polymer compounding to prevent oxidation or heat damage during processing and product fabrication. Without wishing to be bound by theory, it is believed that the unactivated hydrazide compounds function as a flavor protectant by reacting with aldehydes. This happens during the mixing or compounding and subsequent processing of the compound regardless of the presence of other additives.

The preferred hydrazide is a sulfonyl hydrazide such as 4,4 '-oxybis (benzene-sulfonyl hydrazide) ("OBSH") or p- toluene-sulfonyl hydrazide. Carboxylic acid hydrazides can also be used. In the present invention the hydrazides are present in an amount less than 0.1%.

In the present invention, the hydrazide compound is an "unactivated hydrazide," i.e., a hydrazide compound which has not been subjected to a decomposition reaction. This can occur by either adding an amount of a hydrazide compound beyond that which is needed for use as a blowing agent or by processing the liner so as to not decompose the hydrazide compound which is present.

Hydrazides of organic sulfonic acids have been found to be useful in the present invention. Both aliphatic and aromatic sulfonic acids can be used, with one or both -NH₂ groups of the hydrazine molecule being substituted with alkyl or aryl radicals. The most preferred compound is a sulfonyl hydrazide, such as OBSH, since it has FDA approval for applications and articles which come into contact with food or beverages. Other sulfonyl hydrazides such as p-toluene sulfonyl hydrazide can be used, if desired. The useful hydrogens may optionally be substituted by other organic moieties.

Other hydrazides which may be used to reduce the off-flavor of bottled water include carboxylic acid hydrazides of the general structure shown below.

O

t -NH,

where R is hydrogen, a straight chain or branched alkyl or alkenyl group of 1 to 20 carbon atoms, a phenyl group, which is substituted or unsubstituted, or the like.

The only restrictions on the hydrazide compounds for use in the liners of the present invention are that the hydrazide compound be compatible with the material and other components of the liner and that the compound be FDA approved for use in contact with the fluid to be ingested.

Since the liner composition may also include a hydrazide compound for use as a blowing agent, the composition must be formulated so that the amount of hydrazide compound that is decomposed is less than the total amount of hydrazide compound that is added to the liner composition. This is relatively easy to accomplish in the present invention because amounts of hydrazide as low as 0.04 to 0.05 percent by weight can provide flavor protection. This decomposition may be activated by an activator or by heat. In the present invention, an activator for decomposing the hydrazide compound is added in an amount that is less than that necessary to activate the total amount of hydrazide compound in the liner composition. Examples of typical activators include carbonates, glycols, ureas, acids, alkanolamines, and oxidizing agents such as peroxides. In particular, carbonates such as sodium carbonate are preferred activators. The present invention may also include at least one blowing agent other than the unactivated hydrazide compound, if desired.

Manufacture

Preferred uses of the compositions of the invention are as liners or gaskets in crowns or closures for capping beverage bottles. Entire closures may also be made of plastics containing compositions of the invention, for instance all plastic screw-on threaded caps for soft drink bottles, and the like. Another preferred use of the composition of the invention is as a gasket or liner applied to an aluminum or plastic closure or metal crown for plastic or glass bottles.

Conventional bottle closure linings are made of a thermoplastic material, such as PVC or EVA, polyolefins such as PE or PP, or blends thereof. In order to attain the optimum combination of oldability, resilience, sealability, etc., these materials are formulated to include plasticizers, heat stabilizers, lubricants, blowing agents, antioxidants, pigments, and other additives. These additive components are well known to one skilled in the art so that a detailed description is not needed herein. As noted above, PVC liners are well known for use in crowns as described in the production of crowns using the Za-Matic machines. There is also well know technology for making aluminum or plastic closures containing EVA liners. The disclosure of U.S. Patent No. 3,547,746 is likewise useful for its teachings of crown liner manufacturing techniques, and thus is expressly incorporated herein by reference thereto on this point as well. In addition to this crown liner manufacturing method, which is generally used for PVC, EVA, or PE liners, many other devices can apply liners by plastisol spin-lining or various hot molding techniques. The present invention is easily applicable to both gasketing/coating/sealing materials for metal crowns or closures, such as beer bottle crown or soda closure liners, and to containers or closures comprised primarily of plastic materials.

Formulations according to the present invention may be prepared for use in a Za-Matic machine for application as a liner to a beer bottle crown. The PVC resin is placed in a dry mix kettle, and plasticizer is added with continuous heating and mixing. All other additives, including the unactivated hydrazide, are then gradually introduced into the resin to form a dry blend. This dry blend is place into an extruder and pelletized to form the liner compound that is added to the Za-Matic machine to form liners on metal bottle crowns.

U.S. Patent No. 5,202,052 describes this and other liner manufacturing procedures that may be adapted by those skilled in the art to manufacture the liners of the present invention. The unactivated hydrazide may be admixed into the liner composition or can be coated thereon or otherwise associated therewith.

Preferably, the potable fluid container of the present invention contains a potable fluid, most preferably beer or water. Preferably, the potable fluid container has ozone added thereto. In the case of water, the ozone is preferably added in trace amounts, such as from about 0.1 to 0.5 mg/1.

EXAMPLES

The foregoing and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed non-limiting examples of the present invention.

In order to demonstrate that the addition of an unactivated hydrazide in accordance with the present invention permits the formulation of liners that impart less off-flavor to beverages, test samples containing OBSH were prepared and compared to controls containing no OBSH. It is emphasized that the taste of the water, even though it has important commercial consequences, may be regarded as an indicator of the presence in the liners of extractable off-flavor-causing substances.

A fresh control was prepared for each experiment. A panel of trained flavor tasters evaluated the samples along with an outside consultant.

Under exacting conditions, 16 ounce bottles were filled with spring water. Four experimental crown liners were added to each bottle and the bottle closed with an aluminum closure using the same liner. The bottles were pasteurized at 140°F, cooled to 90°F, and stored for 5 days at room temperature. The liners were prepared using commercially available liner compounds. The flavors were evaluated by an eight member panel. Each member of the panel assigned numbers of 0 to 3 to each bottle with a score of 0 being a perfect score. The results were averaged.

Example 1 Liner compositions having varying amounts of OBSH were prepared using Svelon 597L (commercially available from DS Chemie of Bremen Germany) . This proprietary compound is believed to consist of polypropylene or polyethylene and is widely used as a liner for container closures. There was no evidence that OBSH caused this otherwise solid compound to foam.

This example demonstrates that the addition of OBSH dramatically improves the performance of the commercially acceptable compound Svelon 597L.

Example 2

Liner compositions having varying amounts of OBSH were prepared using Oxylon CS 25 (commercially available from DS Chemie of Bremen Germany) . This proprietary compound is probably a blend of butyl rubber and either polyethylene or polypropylene and is widely used as a liner for container closures. There was no evidence that OBSH caused this otherwise solid compound to foam.

The addition of OBSH to this commercial lining compound also significantly improves the flavor properties. Example 3

Liner compositions having varying amounts of OBSH were prepared using Elvax 750, commonly called EVA, (commercially available from DuPont of Delaware) . Elvax 750 is widely employed, either neat or in compounds, as liners or gaskets for food and beverage closures.

A clear improvement in the flavor is again noted. The flavor performance of this successful resin is considered acceptable for many beverage applications. The addition of very small amounts of OBSH would thus raise the level of acceptance to meet the most discriminating requirements.

Claims

THE CLAIMSWhat is claimed is:

1. A closure element for a bottled fluid, which element includes at least one liner composition consisting essentially of a polymer, a hydrazide compound present in a non-decomposed state and in an amount sufficient to at least partially inhibit the formation of off-flavor causing substances in the liner composition but in an amount of less than 0.1% by weight of the composition, thus improving the taste of the bottled fluid compared to bottled fluids which include closure elements having liner compositions that do not include the non-decomposed hydrazide therein.

2. The liner composition of claim 1 wherein the hydrazide compound is a sulfonyl hydrazide.

3. The liner composition of claim 1 wherein the hydrazide compound is 4,4 '-oxybis (benzene sulfonyl hydrazide) .

4. The liner composition of claim 1 wherein the hydrazide compound is a carboxylic acid hydrazide.

5. The liner composition of claim 1 wherein the polymer is a thermoplastic resin compound selected from the group consisting of a polyolefin, polyvinyl chloride, ethylene-vinyl acetate or a mixture thereof.

6. The liner composition of claim 1 further consisting essentially of one or more of a plasticizer, a heat stabilizer, a lubricant, a blowing agent or a pigment, and the bottled fluid is beer or water.

7. A method of improving the taste of a fluid which is retained in a bottle by a closure element that includes a liner composition as a seal, which method comprises providing, in the liner composition during manufacture thereof, a hydrazide compound in a non- decomposed state in an amount which is sufficient to prevent or inhibit the formation in the liner composition of off-flavor causing substances but in an amount less than 0.1% by weight of the composition, thus improving the taste of the fluid compared to bottled fluids which are retained by closure elements having liner compositions that do not include the hydrazide compound therein.

8. The method of claim 7 wherein the hydrazide compound is a sulfonyl hydrazide.

9. The method of claim 7 wherein the hydrazide compound is 4,4 '-oxybis (benzene sulfonyl hydrazide) .

10. The method of claim 7 wherein the hydrazide compound is a carboxylic acid hydrazide.

11. The method of claim 7 wherein the polymer is a thermoplastic resin compound selected from the group consisting of a polyolefin, polyvinyl chloride, ethylene- vinyl acetate or a mixture thereof.

12. The method of claim 7 which further comprises adding to the liner composition during manufacture thereof, one or more of a plasticizer, a heat stabilizer, a lubricant, a blowing agent or a pigment, and the fluid is beer or water.