CONTROLLING PRODUCTION OF H2S IN BEVERAGES FOR PACKING IN ALUMINUM CONTAINING PACKAGES

Abstract

Packaging a fermented beverage in an aluminum-bearing or containing vessel includes controlling a concentration of sulfur dioxide within the fermented beverage. The concentration of the sulfur dioxide is decreased by subjecting the fermented beverage to a chemical process in batch or in-line and prior to filling the vessel or after filling the vessel.

Claims

1-46. (canceled)

47. A method of packaging a fermented beverage in an aluminum-bearing container comprising the step of: decreasing a concentration of sulfur dioxide in the fermented beverage.

48. The method of claim 47 wherein the step of decreasing the concentration of the sulfur dioxide in the fermented beverage is accomplished by a step of subjecting the fermented beverage to a chemical process

49. The method of claim 48 wherein the step of decreasing the concentration of sulfur dioxide is performed prior to a step of introducing the fermented beverage into the aluminum-bearing container.

50. The method of claim 48 wherein the step of decreasing the concentration of sulfur dioxide is performed after the step of introducing the fermented beverage into the aluminum-bearing container.

51. The method of claim 48 wherein the chemical process is a batch process.

52. The method of claim 48 wherein the chemical process is performed in-line to a fluid flow of the fermented beverage.

53. The method of claim 48 wherein the chemical process comprises micro-oxygenation.

54. The method of claim 48 wherein the chemical process comprises an addition of hydrogen peroxide to the fermented beverage.

55. The method of claim 48 wherein the chemical process comprises exposing the fermented beverage to an aldehyde-containing material.

56. The method of claim 48 wherein the chemical process comprises introducing the fermented beverage into the aluminum-bearing container wherein the aluminum-bearing container comprises an aldehyde-containing material on an interior surface thereof in contact with the fermented beverage.

57. The method of claim 48 wherein the chemical process comprises adding an antioxidant to the fermented beverage.

58. The method of claim 57 wherein the antioxidant comprises one or more phenolics.

59. The method of claim 58 wherein the one or more phenolics is resveratrol.

60. The method of claim 48 wherein the chemical process comprises adding an aldehyde to the fermented beverage.

61. The method of claim 60 wherein the aldehyde comprises acetaldehyde.

62. The method of claim 48 wherein the chemical process includes the step of oxidizing ethanol to form acetaldehyde, which is then bound by SO.sub.2.

63. The method of claim 48 wherein the chemical process comprises increasing a pH of the fermented beverage to decrease a concentration of molecular sulfur dioxide and increase aluminum passivation/resistance to corrosion to decrease hydrogen sulfide formation in the fermented beverage exposed to an aluminum in the aluminum-bearing container.

64. The method of claim 47 wherein a concentration of molecular sulfur dioxide is less than 0.4 mg/L.

65. The method of claim 47 further comprising the step of increasing a pH of the fermented beverage.

66. The method of claim 47 wherein a pH of the fermented beverage is greater than or equal to 3.5 wherein an amount of molecular sulfur dioxide is decreased and a chemical solution of a system defined by the fermented beverage within an aluminum-bearing container is altered wherein the pH is such that an aluminum of aluminum-bearing container is at least partially passivated and not prone to corrosion.

67. The method of claim 47 comprising exposing the fermented beverage to oxygen wherein the oxygen reacts with ethanol and oxidizes ethanol to form acetaldehyde and wherein the acetaldehyde further reacts with sulfur dioxide.

68. The method of claim 67 wherein the oxygen consumes a quantity of the sulfur dioxide greater than a quantity of the oxygen added to the fermented beverage.

69. The method of claim 68 wherein a concentration of oxygen added to the fermented beverage is greater than a concentration of sulfur dioxide within the fermented beverage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings in which:

[0017] FIG. 1 is a perspective view of an aluminum-bearing container filled with a fermented beverage; and

[0018] FIG. 2 is a cross-sectional view of the aluminum-bearing container of FIG. 1.

DETAILED DESCRIPTION

[0019] While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.

[0020] The inventors believe that an acidic beverage containing sulfur dioxide (SO.sub.2) containing beverages in the presence of metallic aluminum (container body and lid, foil, liner) produces hydrogen sulfide (H.sub.2S), which is objectionable to consumers of the beverages. The methods described herein are aimed at decreasing or eliminating this process, preserving the beverage, and improving consumer acceptance.

[0021] The present invention addresses the problem of sulfide production in acidic, SO.sub.2-containing beverages, such as fermented wines and ciders in aluminum containing packages.

[0022] The mechanism of the problem was discovered to be acid protons and naturally occurring or added sulfur dioxide permeating a barrier coating on the aluminum such as in a can body, or a plastic-foil laminate such as a roll on a pilfer-proof (ROPP) closure cap liner or bag-in-box pouch or paper, or cardboard carton. The protons cause corrosion of the aluminum solid, Al (s), to aluminum (III), an oxidation state 3+ (Al.sup.3+), which generates electrons that chemically reduce the SO.sub.2 to H.sub.2S, which is responsible for rotten egg type aromas. An aspect of the present invention is associated with understanding this mechanism and limiting the undesirable reaction through the limit or control of SO.sub.2.

[0023] Generally, the invention includes lowering molecular SO.sub.2 via various means: decreasing SO.sub.2 use/free SO.sub.2 additions; increasing beverage pH which decreases concentration of molecular SO.sub.2; adding hydrogen peroxide H.sub.2O.sub.2 which oxidizes SO.sub.2 to sulfurous acid (H.sub.2SO.sub.4):

SO.sub.2+H.sub.2O.sub.2.fwdarw.H.sub.2SO.sub.4;

and using micro-oxygenation, or otherwise adding oxygen (O.sub.2) to decrease SO.sub.2 (usually through oxidizing ethanol to form acetaldehyde, which is then bound by SO.sub.2); using/adding phenolics and aldehydes, e.g. additives and/or container coating types to lower SO.sub.2; and adding antioxidant to lower SO.sub.2 to potentially permit less use of SO.sub.2 for a similar antioxidant purpose. SO.sub.2 added to wine, either as dissolved SO.sub.2 gas, or as various salts such as potassium metabisulfite (K.sub.2S.sub.2O.sub.5) or sodium bisulfite (N.sub.2S.sub.2O.sub.5), dissociates into SO.sub.2. This is molecular SO.sub.2. HSO.sub.3— (bisulfite), and SO.sub.3(2-) (sulfite), these species comprise the free SO.sub.2, and the amounts of each are dependent on the pH. Each of these species are reactive to specific chemistries. If reacted/bound, they become bound SO.sub.2. Total SO.sub.2 is the sum of free species and bound SO.sub.2.

[0024] Acetaldehyde (CH.sub.3—CHO) concentration in a newly fermented wine is typically less than 75 mg/L.

CH.sub.3—CHO+HSO.sub.3.sup.−.fwdarw.CH.sub.3—CHOH—SO.sub.3.sup.−

Each milligram of acetaldehyde will bind with 1.45 milligrams of SO.sub.2 to form acetaldehyde-alpha-hydroxy sulphonate.

[0025] Adding aldehydes in a coating could actively bind SO.sub.2 that permeates the coating.

[0026] Phenolics are different than aldehydes and tend to act as antioxidants. Its inclusion is believed to permit a winemaker to use less SO.sub.2 for the same or similar effect.

[0027] In one embodiment, a beverage 22 is treated prior to packaging in an aluminum vessel 10 to decrease concentration of SO.sub.2. The treatment comprises micro-oxygenation and/or addition of hydrogen peroxide (H.sub.2O.sub.2) in an in-line or batch process prior to seaming a can end 14 to a filled can body 18.

[0028] In one embodiment, the beverage 22 is treated to decrease concentration of SO.sub.2 during or in packaging through micro-oxygenation and/or addition of hydrogen peroxide either in-line to the aluminum container 10 or as a batch process just prior to filling and seaming a can end 14 to the aluminum can body 18.

[0029] In one embodiment, the beverage 22 is treated while within an aluminum-bearing container body 18 by introducing aldehyde containing coating materials 26 to the can body 18 interior surface 30 prior to filling.

[0030] In one embodiment, a pH of a fermented beverage 22 is increased pH >3.5 to decrease an amount of molecular SO.sub.2 as well as shift a chemical solution of a system defined by the fermented beverage within an aluminum-bearing container 10 wherein the pH is such that the aluminum of the aluminum-bearing container 10 is at least partially passivated and not prone to corrosion.

[0031] The pH is increased in order to decrease the molecular SO.sub.2 concentration, but it does not necessarily have to be greater than or equal to pH 3.5. Any pH increase will decrease existing molecular SO.sub.2 concentration and likely improve passivity of the Al. A pH of 3.5 or above is the preferred pH.

[0032] In one embodiment, the concentration of molecular sulfur dioxide is less than 0.4 mg/L.

[0033] It is believed that decreasing sulfur dioxide concentration and/or increasing pH of the fermented beverage decreases molecular sulfur dioxide, while increasing pH decreases molecular sulfur dioxide and increases aluminum passivation/resistance to corrosion. All of which combine to decrease hydrogen sulfide formation in sulfur dioxide-containing products exposed to aluminum.

[0034] Each of these embodiments may be batch processes prior to filling and enclosing a beverage 22 within an aluminum-bearing container, in-line, or within the aluminum container 10.

[0035] One method of the invention includes decreasing SO.sub.2 concentration prior to packaging through an oxygen addition. This may include micro-oxygenation and/or addition of hydrogen peroxide as an in-line or batch process.

[0036] One method of the present invention may include decreasing SO.sub.2 concentration during/in packaging through an oxygen addition. This includes micro-oxygenation and/or addition of hydrogen peroxide either in-line to packaging or as a batch process just prior to packaging.

[0037] One method of the present invention includes decreasing SO.sub.2 concentration during/in packaging through an oxygen addition during and through a process of filling the packaging by encouraging exposure of a fermented beverage to oxygen. Dissolved oxygen (DO) concentration in still wine generally increases by about 0.5 mg/L during bottling under ideal, industry best practice conditions (1.0-1.5 mg/L under less ideal conditions). Although packaging carbonated wines/spritzers etc., it is possible to decrease/maintain DO concentration below 0.1 mg/L. Theoretically, 1.0 mg/L of oxygen can react with 4 mg/L of SO.sub.2 to produce acetaldehyde. Thus, the process of bottling or canning a fermented beverage can also decrease concentration of SO.sub.2.

[0038] One method includes the step of decreasing SO.sub.2 concentration through an addition of a quantity of phenolics (e.g. resveratrol) or aldehydes (e.g. acetaldehyde) chemical agents or via a packaging containing materials such as aldehyde containing epoxies, e.g. formaldehyde or acetaldehyde. The phenolics may include nonflavonoids, such as hydroxycinnamates, benzoic acids, hydrolysable tannins, stilbenes (resveratrol), and/or flavonoids, such as anthocyanins, proanthocyanidins and condensed tannins, among others, and/or aldehydes. Antioxidants do not directly react with and decrease SO.sub.2 concentration, but their use is believed to permit the winemaker to decrease his/her addition of SO.sub.2 for the same or similar effect.

[0039] One method includes decreasing SO.sub.2 concentration by increasing pH. In one illustrative example, pH is increased to greater than 3.5. Increasing pH, decreases molecular SO.sub.2 concentration relative to other SO.sub.2 forms. Increasing pH also improves the corrosion resistance of aluminum.

[0040] One method includes the step of adding an antioxidant, for example resveratrol, to decrease the need for SO.sub.2, thus allowing the beverage producer/handler to decrease a concentration of SO.sub.2 added to a beverage.

ILLUSTRATIVE EXAMPLES

[0041] The present invention describes methods for controlling the production of H.sub.2S in beverages that are filled in aluminum containing packages. It describes beverage product and process modifications before, during or just after filling to reduce or prevent H.sub.2S formation. The following examples support a chemical reaction mechanism. Also, modification of the chemistry as outlined can protect the product.

[0042] This development applies to SO.sub.2 and acid containing beverages common in products like fermented beverages such as wines and ciders and is aimed at defining ways that such beverage products can be modified just before, during or just after filling into an aluminum container to reduce the propensity for H.sub.2S formulation.

[0043] Experiments were conducted to test efficacy of the principles of the invention. In these tests, 6 mm sized aluminum disks were subjected to various wine environments. The data presented below show average H.sub.2S concentrations in various wines (a model wine, red wine, and white wine) at various pH and SO.sub.2 concentrations after 14 days at 50° C. SO.sub.2 concentrations above a few ppm yielded H.sub.2S at concentrations greater than a sensory threshold, regardless whether SO.sub.2 was added or was decreased in the sample by volatilizing the SO.sub.2 through aeration or sparging the wine with a fluid, namely air or nitrogen gas, or through addition of hydrogen peroxide. Red wines offer additional protection due to SO.sub.2 complexing tanning and color molecules.

TABLE-US-00001 TABLE 1 Average H.sub.2S concentrations in a model white wine (10% ethanol, 5 g/L potassium bitartrate) at pH 3.00 with a 6 mm Al disk after 14 days at 50° C. Free SO2 (mg/L) pH H2S (μg/L) 0 3.0 0.0 3 3.0 0.0 10 3.0 0.0 17 3.0 11.7 25 3.0 24.6 29 3.0 27.5

TABLE-US-00002 TABLE 2 Red wine at constant 0.8 molecular SO.sub.2 with 6 mm Al disk, yields decreasing H.sub.2S with increasing pH Free SO2 (mg/L) pH H2S (μg/L) 8 2.8 10.3 13 3.0 6.1 40 3.5 0.6

TABLE-US-00003 TABLE 3 In white wines with 6 mm Al disk, adjusting pH and or SO.sub.2 can have a significant impact, above pH 3.5 and molecular SO.sub.2 less than 0.1 reduce H.sub.2S to below threshold levels. Free SO2 (mg/L) pH H2S (μg/L) 0 3.6 0.0 3 3.5 0.5 10 3.2 21.2 15 3.4 16.1 19 3.3 30.0

[0044] While the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying Claims.