Method for producing a carbonic acid-containing beverage

Abstract

The invention relates to a method for producing a carbonic acid-containing beverage, wherein an anion exchanger (AX) which is loaded with carbonate or hydrogen carbonate is mixed with an acid in an aqueous environment in order to produce an ion exchange reaction between the anion exchanger (AX) loaded with carbonate or hydrogen carbonate and the acid. The carbonate in the anion exchanger (AX) is replaced with the acid anion, whereby the carbonate or hydrogen carbonate is reacted with the hydronium ion of the acid, and carbonic acid is formed.

Description

[0001] Process for producing a carbonated beverage

[0002] Technical area

[0003] The invention relates to a process for producing a carbonated beverage.

[0004] State of the art

[0005] Carbon dioxide has long been used to produce carbonated beverages. Carbon dioxide is created through a chemical reaction between CO2 and water. Pressure is generally required for the CO2 gas and water particles to combine to form carbonic acid. There are many well-known processes for producing carbonated beverages using pressure, such as using pressure cartridges or pressure bottles. The disadvantage of pressure cartridges and bottles is that they are usually deposit bottles and must always be replaced. Furthermore, these pressure cartridges are made of metal and are heavy due to the high internal pressure. Another disadvantage of pressure cartridges is that additional accessories such as kitchen utensils are required, and handling the pressure cartridge is not without risk.

[0006] In another known process for producing carbonated beverages, the carbonic acid is generated chemically by mixing an alkali metal carbonate or alkali metal bicarbonate with an acid. For example, US Pat. No. 2,742,363 A describes a process in which an alkali metal bicarbonate and a sulfonic acid-type cation exchange resin are mixed in water, forming carbonic acid. A disadvantage of this process is that a salt is dissolved in the water, which increases conductivity and can impart an unpleasant taste to the water. The dissolved salt only comes into insufficient contact with the ion exchanger, so that the alkali metal ions are only partially exchanged for hydrogen by the ion exchanger.

[0007] EP3381298A1 also describes a process in which a mixture of a cation exchanger with a solid in the form of a carbonate and an initiator salt is used in water to form carbonic acid. The solid is dissolved by the cation exchanger. Alkali or alkaline earth metal salts are used as carbonate salts. These salts are sometimes only slightly soluble and are not completely decomposed during the reaction with the cation exchanger. This affects the taste of the water.

[0008] Object of the invention

[0009] The present invention is based on the object of providing a process by means of which a carbonated beverage can be produced in a simple manner, whereby the complex provision of print cartridges or other devices can be dispensed with, and by means of which a beverage with a pleasant taste can be produced without a salty aftertaste or impurities and free from harmful anions.

[0010] Description of the invention

[0011] This object is achieved by a process for producing a carbonated beverage, wherein a carbonate (CO3 2”) or hydrogen carbonate (HCO3-), also called bicarbonate, is mixed with an acid in an aqueous environment to cause an ion exchange reaction between the anion exchanger (AX) loaded with carbonate or hydrogen carbonate and the acid, whereby the carbonate in the anion exchanger (AX) is replaced by the acid anion, whereby the carbonate or hydrogen carbonate reacts with the hydronium ion of the acid, and carbonic acid (H2CO3) is formed. Anion exchangers (AX) are basic ion exchangers in which a cationic group (cation) is covalently bound to a solid, insoluble matrix, also called ion exchange resin, while the counter anion (neutral) is only ionically bound and is therefore exchangeable by other anions. The ion exchange resins have a selective affinity for anions and can bind and exchange them. In this case, the carbonate or hydrogen carbonate anion is exchanged by an acid anion.The anion exchanger (AX) can be a strong base anion exchanger (SAX) or a weak base anion exchanger (WAX).

[0012] Examples of a strongly basic anion exchanger (SAX) are anion exchangers (SAX) that contain a quaternary ammonium or phosphonium group as the active group. Strongly basic anion exchangers (SAX) use type I and type II anion exchangers. The distinction between types I and II relates to their thermal stability and exchange capacity properties. A type I anion exchanger is more thermally stable but has a lower exchange capacity than a type II exchanger. The exchange-active group of a type I exchanger is usually a trimethylammonium group.

[0013] Examples of weakly basic anion exchangers (WAX) are anion exchangers containing an amino group. In the process according to the invention for producing carbonated beverages, a strongly basic anion exchanger (SAX) with a quaternary ammonium or phosphonium group is preferably used, particularly preferably an anion exchanger (SAX) with a quaternary ammonium group. Examples of particularly suitable strongly basic anion exchangers (SAX) are polystyrene-divinylbenzene copolymers substituted with quaternary ammonium or phosphonium groups; polyacrylates, polymethacrylates, or polyacrylonitriles crosslinked with divinylbenzene; phenol-formaldehyde resins; or polyalkylamine resins.

[0014] The anion exchanger (AX) is preferably present in a filter bag, a pad, a cartridge, or a membrane and is surrounded by a filter that is permeable to water and gases, but impermeable to the anion exchanger (AX). Suitable filters include membranes, sieves, filters, films, or fabrics that have the required pore size to be permeable to water and gases, but impermeable to the anion exchanger (AX). The filters preferably have a thickness of 20-200 micrometers and a pore size of 5-500 micrometers. Anion exchange membranes, which are only permeable to negatively charged particles, i.e., anions, are particularly suitable. The anion exchanger (AX) is preferably introduced into the aqueous environment in a filter bag, a cartridge, or a membrane. The anion exchanger (AX) and the filter bag or membrane are preferably compostable, thus reducing the burden on the environment.An anion exchanger (AX) in a filter bag, pad, cartridge or membrane is preferred so that the anion exchanger (AX) remains in the filter bag, pad, cartridge or membrane during the reaction and does not enter the beverage, so that the beverage is free of anion exchanger (AX) for drinking.

[0015] Preferably, the filter bag, the pad, the cartridge or the membrane is designed in such a way or filled with such a quantity of anion exchanger (AX) that one liter of drinking water which is used as test water and which has a content of 20 - 50 mg / l of carbon dioxide is enriched by using the filter bag, the pad or the cartridge to a carbon dioxide content of more than 100 mg / l, particularly preferably more than 500 mg / l and most preferably more than 1000 mg / l.

[0016] Any acid permitted in foodstuffs can be used. Examples of such acids include citric acid, ascorbic acid, acetic acid, sodium hydrogen sulfate, lactic acid, malic acid, fumaric acid, tartaric acid, phosphoric acid, metatartaric acid, adipic acid, and succinic acid. Citric acid is particularly preferred because it is a safe, tablet-sized solid, whose flavor is acceptable in soft drinks, and because it is very soluble in water, which accelerates the formation of carbon dioxide. However, the other acids are also suitable, depending on the desired flavor.

[0017] In a preferred embodiment, the acid is introduced into the aqueous environment in tablet form. This is particularly preferred when the acid is to be introduced easily and in any desired amount. This allows the intensity of carbonation to be influenced. Thus, the consumer can determine the degree of carbonation, i.e., the intensity of carbonation, by using one, two, or more acid tablets.

[0018] The more acid added, the more carbonic acid is formed, until the capacity of the anion exchange resin (AX) is reached. Additionally, the acid concentration in the aqueous environment can be increased to neutralize any taste of the anion exchange resin (AX), particularly the amine taste. Even if the acid or acid tablet is not completely dissolved during the reaction, it does not negatively affect the taste of the beverage, as acids, especially citric acid, are often used in beverages to enhance their flavor. This is a major difference from conventional processes using a carbonate salt. If the carbonate salt is not completely reacted, it leaves a negative salty taste in the beverage.

[0019] In a further embodiment, the acid is introduced into the aqueous environment together with the anion exchanger (AX) in a filter bag, a cartridge or in a membrane, which significantly simplifies the handling of the process.

[0020] The anion exchange resin (AX) can be regenerated after one or more uses to regain full reactivity. Suitable regeneration chemicals are used for regeneration, preferably bicarbonate or carbonate solutions, especially sodium carbonate or sodium bicarbonate solutions.

[0021] During the process of producing a carbonated beverage, additional additives may be added to influence the taste or nature of the beverage. Examples of such additives include sweeteners, flavor enhancers, electrolytes for the production of electrolyte drinks, vitamins, caffeine, taurine, flavorings, or other psychoactive substances or dietary supplements.

[0022] The process is preferably carried out in a sealable container, preferably one in which pressure can be built up. The process is particularly preferably carried out in a pressurized bottle to retain the carbon dioxide in the water for as long as possible. When the pressurized bottle is opened, the excess carbon dioxide escapes through the bottle opening.

[0023] The method according to the invention is carried out, for example, as follows and comprises the following steps:

[0024] A) A sealable bottle, preferably a pressure bottle, or a sealable container is filled with water;

[0025] B) The anion exchanger (AX), preferably a strongly basic anion exchanger (SAX) with a quaternary ammonium or phosphonium group, is added to the water preferably in a filter bag, pad or cartridge;

[0026] C) One or more acid tablets are added;

[0027] D) The bottle or vessel is closed and the reaction takes place;

[0028] E) After the reaction, the beverage is consumed and the filter bag or pad containing the anion exchanger (AX) is disposed of or regenerated; the order of steps B) and C) can also be reversed.

[0029] The water to be carbonated is at room temperature or chilled to 4°C. The cooler the water, the higher the CO2 concentration in the water. At 8°C, for example, the CO2 concentration is 1000 mg / l, while at 50°C it is only 670 mg / l.

[0030] If the anion exchanger (AX) has a capacity many times greater than the amount of acid used, it can be used several times before being regenerated or disposed of.

[0031] The following reactions leading to the release of carbonic acid take place. Citric acid is chosen as the example acid, and the acid is represented as a monoprotic acid. The degree of deprotonation depends on the pH of the system. A strongly basic anion exchanger (SAX) is chosen as the anion exchanger (AX):

[0032] 1 . SAX + HCO3- + H + Citrate -> SAX + Citrate + H2CO3

[0033] 2. H2CO3 -> H2O + CO2

[0034] A particular advantage of the present process is that no metal salt, in particular no alkali or alkaline earth metal carbonate salt, is used in the production of the carbonated beverage. This distinguishes the inventive process from conventional processes, in which the carbonate is necessarily used as a salt, in particular as an alkali or alkaline earth metal carbonate salt. This offers the particular advantage that the carbonated beverage produced by the inventive process has no salty taste.

[0035] A further advantage of the present process is that it can be used to produce a healthy and high-quality carbonated beverage, since the anion exchanger (AX), in addition to reacting with the acid anion, removes certain undesirable anions or impurities from the water or beverage. By removing certain anions, such as CT, Br, BrOs', SÜ4 2 By removing nitric oxide (NO2) and especially NO3, unwanted taste changes or chemical reactions that could impair the quality of the carbonated beverage can be avoided. This improves the quality of the beverage.

[0036] The invention also relates to a filter bag, a pad, a cartridge or a membrane for use in the process according to the invention comprising at least one anion exchanger (AX) loaded with a carbonate or bicarbonate.

[0037] Furthermore, the invention relates to a carbonated beverage produced by a process according to the invention.

[0038] Combinations of two or more of the above-listed designs and variants are conceivable and claimed.

[0039] Further advantages of the invention will become apparent from the following description, in which the invention is explained in more detail using exemplary embodiments.

[0040] Embodiments of the invention

[0041] The present invention is described in more detail below by means of an embodiment which, however, does not limit the scope of protection of the method according to the invention.

[0042] 50 g of a type I strong base anion exchange resin (SAX), for example, Amberlite® IRA-402, a polystyrene-divinylbenzene copolymer with quaternary ammonium groups, with a particle diameter of 600-750 micrometers and an exchange capacity of 1.9 mmol OH- / g dry particles, was shaken for 2 hours in a solution of 25 g NaHCO3 in 500 ml water, then filtered and dried at 40°C in a convection oven for 16 h. The result was a dried product of a bicarbonate-loaded anion exchange resin (SAX) in the form of SAX. + HCO3'. 13.4 g of the dried product were placed in a filter bag in a solution of 2.88 g citric acid (H + Citrate _ ) in 1000 ml of tap water at room temperature (about 25°C), whereby the reaction took place in SAX +Citrate + H2CO3 and finally in water to form CO2. 158 ml of CO2 was generated (measured using an inverted graduated cylinder filled with water), which corresponds to approximately 300 mg / l CO2.

Claims

Patent claims 1. A process for producing a carbonated beverage, characterized in that an anion exchanger (AX) loaded with carbonate or bicarbonate is mixed with an acid in an aqueous environment to effect an ion exchange reaction between the anion exchanger (AX) loaded with carbonate or bicarbonate and the acid, wherein the carbonate in the anion exchanger (AX) is replaced by the acid anion, whereby the carbonate or bicarbonate reacts with the hydronium ion of the acid and carbonic acid is formed.

2. Process according to claim 1, characterized in that the anion exchanger (AX) is a strongly basic anion exchanger (SAX) and comprises a quaternary ammonium or phosphonium group.

3. The method according to claim 1 or 2, characterized in that the anion exchanger (AX) is introduced into the aqueous environment in a filter bag, a pad, a cartridge or in a membrane, wherein the filter bag, the cartridge or the membrane has a filter which is permeable to water and gas and which is impermeable to the anion exchanger (AX).

4. Process according to one of the preceding claims, characterized in that the acid is citric acid.

5. A process according to any one of the preceding claims, characterized in that the acid is introduced into the aqueous environment in tablet form.

6. Process according to one of claims 1 to 4, characterized in that the acid is introduced into the aqueous environment together with the anion exchanger (AX) in a filter bag or in a cartridge.

7. Process according to one of claims 1 to 5, characterized in that the anion exchanger (AX) is regenerated after one or more uses.

8. Process according to claim 7, characterized in that the anion exchanger (AX) is regenerated in a bicarbonate or carbonate solution.

9. Method according to one of the preceding claims, characterized in that the anion exchanger (AX) and the filter bag are compostable.

10. A process according to any one of the preceding claims, characterized in that no metal salt is used to produce the carbonated beverage. 11 . Method according to one of the preceding claims, characterized in that the method is carried out in a pressure bottle.

12. Filter bag or cartridge for use in a process according to any one of the preceding claims, comprising at least one anion exchanger (AX) loaded with a carbonate or bicarbonate.