NZ782575A

NZ782575A - Method for preparing an extract containing gallic acid, aqueous concentrate containing gallic acid, and foodstuff and food supplement containing the aqueous concentrate

Info

Publication number: NZ782575A
Application number: NZ782575A
Authority: NZ
Inventors: Marcel Jenny; Josef Nachbagauer; Christian Rinderer; Isabella Winter
Original assignee: Red Bull Gmbh
Priority date: 2020-11-20
Filing date: 2021-11-22

Abstract

The present invention relates to a method for preparing an extract containing gallic acid, comprising performing an extraction treatment on plants or plant constituents containing tannins by means of water or an aqueous system in the presence of the enzyme tannase to obtain a product mixture containing gallic acid, and to a method for preparing an extract containing gallic acid, comprising performing an extraction treatment on plants or plant constituents containing tannins by means of a mixture containing a polar organic solvent and water to obtain a product mixture containing polyphenols, separating the plants or plant constituents from the product mixture to obtain a liquid extract, removing the polar organic solvent from the liquid extract, and treating the aqueous extract with the enzyme tannase to obtain an aqueous system containing gallic acid. In addition, the invention relates to an aqueous concentrate containing gallic acid, characterized by a dry weight in the range of 5 to 80% by weight, based on the total weight of the aqueous concentrate. Finally, the invention relates to a foodstuff or food supplement comprising the aqueous concentrate. ing gallic acid, and to a method for preparing an extract containing gallic acid, comprising performing an extraction treatment on plants or plant constituents containing tannins by means of a mixture containing a polar organic solvent and water to obtain a product mixture containing polyphenols, separating the plants or plant constituents from the product mixture to obtain a liquid extract, removing the polar organic solvent from the liquid extract, and treating the aqueous extract with the enzyme tannase to obtain an aqueous system containing gallic acid. In addition, the invention relates to an aqueous concentrate containing gallic acid, characterized by a dry weight in the range of 5 to 80% by weight, based on the total weight of the aqueous concentrate. Finally, the invention relates to a foodstuff or food supplement comprising the aqueous concentrate.

Description

Method for preparing an extract containing gallic acid, aqueous concentrate containing gallic acid, and foodstuff and food ment containing the aqueous concentrate Description This application claims priority from European patent application No. 40.3, filed 20 er 2021, and the entire contents of that application are orated herein by nce.

The present invention relates to a method for preparing an extract containing gallic acid, in particular in high concentrations. Moreover, the invention relates to an aqueous concentrate containing gallic acid. Furthermore, the invention relates to a foodstuff and food supplement containing the aqueous concentrate according to the ion.

Gallic acid (3,4,5-trihydroxy benzoic acid) is the acid component of gallotannins, which are hydrolyzable tannins. They are found, for e, in oak bark and in oak apples. Gallic acid is used to produce antioxidants, sunscreens and dyes. Furthermore, it has been postulated that gallic acid, due to its hypoglycemic ties, helps prevent adverse health effects in obese people that consume foods rich in gallic acid. The consumption of gallic acid is said to be associated with demonstrable DNA protection or reduced oxidation of DNA bases as well as reduced inflammation parameters (see also T. Setayesh et al. “Gallic acid, a common dietary phenolic protects against high fat diet induced DNA damage” in European Journal of ion, vol. 58, pages 2315 to 26, 2019).

According to EP 1 942 919 B1, a composition containing a polyphenol extract from grapes, which may comprise 400 to 1,500 ppm of gallic acid, is said to be suitable for treating metabolic syndrome or prehypertension.

According to EP 2 095 718 B1, a tea beverage based on a tea extract, in which the weight ratio of gallic acid to non-polymeric catechins must not exceed 0.3, is characterized by reduced ness and a reduced sour taste.

EP 2 143 344 B1 describes a beverage ition containing 0.5 to 25.0% by weight of non-polymeric catechins, a carbohydrate and a hydroxycarboxylic acid. In these compositions , the gallic acid content has to be less than 0.6% by weight.

Previously, gallic acid has often been obtained by means of aqueous extraction methods.

However, these s frequently produce only low yields of gallic acid and are intensive in terms of materials, equipment and costs.

The object of the present invention was therefore to provide a method for obtaining gallic acid that does not have the drawbacks of the prior art and, in particular, reliably and efficiently produces good yields of gallic acid. An alternative or additional object of the present invention was to at least e the public with a useful choice.

Thus, a method for preparing an extract ning gallic acid was found (also called first embodiment of the method according to the invention), comprising the steps of a) ing, in particular comminuted and/or, in particular and, dried, plants or plant constituents containing tannins, in particular tannic acid, b) providing the enzyme tannase (IUB 3.1.1.20), c) providing at least one polar organic solvent, d) optionally comminuting or further comminuting, respectively, the plants or plant constituents according to step a), and e) performing an extraction treatment on the plants or plant constituents ed, in particular comminuted, according to step a) and/or, in particular or, d), by means of water or an aqueous system in the presence of the enzyme tannase (IUB 3.1.1.20) to obtain a product mixture containing gallic acid.

For the, in particular comminuted and/or dried, plants or plant constituents, the following may be used: leaves, wood, bark, fruits, seeds and/or roots, pr eferably the fruits, of legumes , e.g. beans and peas; nuts, e.g. walnuts ns regia); grains; trees, e.g. oak (Quercus), preferably the cupules and/or fruits (Valonea), particularly preferably from varieties of oak growing in Asia Minor and/or in the southern s, and/or oak galls (Galla), in particular fromQuercus infectoria, Quercus petraea or Quercus robur, spruces (Picea), the carob tree (also ed to as St John’s bread) onia siliqua ), the Divi-Divi-tree (Caesalpinia coriaria), the kaki tree yros kaki), the sorb tree (Sorbus domestica), acacia (Acacieae), e.g. cutchtree (also referred to as catechu) (Senegalia catechu), willow (Salix), lan tree, mangrove tree (Rhizophora), mango tree fera indica), in particular bark, fruit pulp and/or kernel of the mango tree, hemlock ), the urunday tree (Astronium balansae), birch (Betula), Elaeocarpus, in particular the outer bark thereof, tree of heaven (Ailanthus ima), chestnut (Castanea), in particular the fruits and leaves from chestnut, the betel nut palm (Areca catechu), the cashew tree(Anacardium occi- dentale) and/or cho ( Aspidosperma quebracho-blanco); mimosa (Mimosa ); sumac plants (Rhus), ally Sicilian sumac (Rhus coriaria), in particular the fruits; hops lus); fruit, e.g. apples (Malus), pears (Pryus), strawberries (Fragaria), raspberries (Rubus idaeus), blackberries (Rubus sect. Rubus), rries nium vitis-idaea), s (Musa), grapes (Vitis vinifera), peaches (Prunus persica), quinces (Cydonia ob- longa) and/or plums s domestica); coffee beans (e.g. e.g. Coffea arabica or Coffea canephor); tea plants (Camellia sinensis) such as green tea (e.g. Japanese, Chinese and/or Indian teas), in particular the leaves of sencha green tea, black tea, in particular the leaves of Darjeeling, white tea, in ular the leaves of China Oolong white tea, and/or rooibos (Aspalathus linearis); cloves (Syzygium aromaticum), preferably the buds and/or leaves thereof, yarrow (Achillea millefolium); black cohosh (Actaea racemosa); bearberry (Arctostaphylos uva-ursi); tarragon isia dracunculus), tormentil (Potentilla erecta); and/or peat. Furthermore, for the, in particular comminuted and/or dried, plants or plant constituents, the following may be used: chebulic myrobalan, mango tree (Mangifera indi- ca), in particular the bark, fruit pulp and kernel, Elaeocarpus (Elaecoarpus ganitrus), in par- ticular the outer bark, jute mallow (Corchorus olitorius), red amaranth (Amaranthus cru- entus), cowpea (Vigna unguiculata), chard (Beta vulgaris var. cicla. ), Greek mountain tea itis raseri), American witch-hazel (Hamamelis virginiana), in particular the bark, Aleppo oak, dyer's oak (Quercus infectoria), currants (Vitis vinifera a), chicory coffee (Cichorium intybus), carob powder (Ceratonia siliqua), green oat (Avena sativa L. ), elm bark (Ulmus), chokeberry pomace a melanocarpa), linden bark (Tilia), elder bark (Sambucus nigra), lapacho bark (Tabebuia impetiginosa), chicory (Cichorium intybus), amla (Phyllanthus emblica), Chinese blackberry (Rubus suavissimus), pomegranate a granatum L. ), sage (Salvia), oregano (Origanum vulgare), cloudberry (Rubus chamaemorus ) and date palms (Phoenix).From the yarrow (Achillea millefolium), black cohosh (Actaea racemosa), bearberry (Arctostaphylos uva-ursi), tarragon (Artemisia culus) and tormentil (Potentilla erecta), preferably the whole plant is used for extraction. In the case of betel nut palm (Areca catechu) and the cashew tree (Anacardium occidentale), the seeds are preferably used for extraction.

In a preferred ment, the method according to the invention according to the first embodiment further comprises (step f)) separating the, in particular comminuted, plants or plant constituents from the product mixture obtained according to step e), in particular following step e), ably by means of a sieve.

Additionally or alternatively, the method according to the invention according to the first embodiment may further comprise (step g)) concentrating, in particular by evaporation, the product mixture containing gallic acid obtained according to step e) or f), in particular following step e) or f) and/or before step h).

Moreover, the method according to the invention according to the first embodiment may further additionally or alternatively comprise (step h)) treating the product mixture according to step e) or f) with the at least one polar organic solvent, in particular ethanol and/or methanol , and/or heat-treating the product mixture according to step e) or step f) or g). The treatment with the polar organic solvent, in particular ethanol, or, in particular and, the additional heat treatment consistently allow(s) the enzyme e to be deactivated. In ular , this is also achieved by ng the t mixture with the at least one polar organic t, in particular ethanol, in step h) at temperatures in the range of 40 to 80°C or above 45 to 80°C, preferably 40 to 75°C or 48 to 75°C and particularly preferably 50 to 70°C. For r optimization of method step h), in this step, additionally or alternatively, in particular additionally, the at least one polar organic solvent, in particular ethanol, may be added in an amount in the range of 15 to 70% by weight, preferably in the range of 20 to 65% by weight, particularly preferably in the range of 25 to 60 and in particular in the range of 40 to 60% by weight, in each case based on the total weight of the polar organic t and the water or the aqueous system. Step h), in particular the treatment with a polar t , in particular ethanol, consistently allows both the enzyme to be deactivated and phytoproteins and/or polysaccharides to be red and precipitated.

In an expedient embodiment, steps f) and g) occur in sequence. Moreover, steps f) and h) may be ed while omitting step g), or steps g) and h) may be combined while omitting step f). In a particularly preferred embodiment, method step e) is followed by method steps f), g) and h), the sequence f)/g)/h) being preferred.

In a preferred embodiment of the method according to the invention ing to the first embodiment, the d product mixture according to step h) is filtered, for example using a filter having a mesh size in the range of 0.10 to 1.0 µm, preferably in the range of 0.25 to 1.0 µm. In this way, a clear extract is generally obtained.

In many cases, it has also proved expedient to subsequently remove the polar organic solvent added in step h) from the d product mixture according to step h) or from the filtered product mixture according to step i) (step j).

The extraction ent according to step e) is preferably performed at temperatures in the range of 20 to 45°C or 30 to 43°C, with temperatures in the range of 35 to 40°C, in particular in the range of 36 to 38°C, being particularly preferred.

The object of the invention is further solved by a method for ing an extract containing gallic acid (also referred to as the second ment of the method according to the invention ), comprising the steps of 1) providing, in particular comminuted and/or, in particular and, dried, plants or plant constituents, containing s, in particular tannic acid, 2) providing the enzyme tannase (IUB 3.1.1.20), 3) providing at least one polar organic solvent, in particular ethanol, 4) optionally comminuting or further comminuting the plants or plant constituents according to step 1), ) performing an extraction treatment on the, in particular dried and/or comminuted, plants or plant constituents according to step 1) and/or, in particular or, 4) by means of a mixture containing the polar organic solvent, in particular l, and water to obtain a product mixture containing polyphenols, 6) separating the, in particular comminuted, plants or plant constituents from the product e according to step 5) to obtain a liquid extract containing the polyphenols, in particular by means of a sieve, 7) removing the polar organic solvent, in particular ethanol, from the liquid extract according to step 6) to obtain an aqueous extract containing the polyphenols, 8) treating the s extract ing to step 7) with the enzyme tannase (IUB 3.1.1.20) to obtain an s system containing gallic acid.

The object of the invention is also achieved ularly well by the method according to the second embodiment by performing the extraction treatment according to step 5) at temperatures in the range of 50 to 70°C, in particular in the range of 55 to 65°C.

In a preferred embodiment, the second embodiment t of the method according to the invention is also characterized in that in step 5), ethanol is added in an amount in the range of 60 to 90% by weight, preferably in the range of 70 to 85% by weight, in each case based on the total weight of ethanol and the water.

In the second embodiment of the method according to the invention, the treatment of the s extract according to step 8) with the enzyme tannase is preferably carried out at temperatures in the range of 20 to 45°C, preferably 30 to 43°C, particularly preferably 35 to 40°C, in particular in the range of 36 to 38°C.

Surprisingly, it has been shown that a particularly ent method is also achieved by the, in ular ground, preferably comminuted, plants or plant constituents being immobilized in step e) according to the first embodiment or step 5), respectively, according to the second embodiment, in particular immobilized in a sieve support.

The extraction treatment according to step e) in the first embodiment or step 5) in the second embodiment ably comprises or is a percolation process.

Particularly high yields or concentrations of gallic acid can also be achieved with the methods according to the invention by adjusting the amount of tannase in step e) according to the first embodiment or step 5) ing to the second embodiment in the range of 0.1 U/g to 100.0 U/g, preferably in the range of 0.2 U/g to 50.0 U/g, based on the amount of plants or plant constituents.

It has also proved to be particularly cal to concentrate the aqueous extract containing gallic acid obtained according to step i) or j) according to the first embodiment or the aqueous system containing gallic acid according to step 8) according to the second ment , in particular by evaporation, to obtain an aqueous concentrate. This aqueous trate is preferably a so-called spissum extract. Said aqueous trate or said spissum extract has in particular a Brix value in the range of 1° to 100° Brix, preferably in the range of 10° to 70° Brix and particularly preferably in the range of 20° to 50° Brix. Very particularly preferably, concentrates having Brix values in the range of 20° to 40° Brix, in particular in the range of 25° to 35° Brix, are aimed for or obtained in the concentrating step.

The ination of degrees Brix is familiar to a person skilled in the art. A liquid has a Brix value of 1° when the liquid has the same density as a solution of 1 g of saccharose in 100 g of saccharose/water solution, and a Brix value of 10° when the density of the liquid is that of a solution of 10 g of saccharose in 100 g of saccharose/water solution. Thus, a figure indicated in degrees Brix means that the density of the measured liquid corresponds to the density of a solution of saccharose in water that contains as many grams of saccharose per 100 g of on as the figure in s.

The object of the invention is further solved by an s concentrate containing gallic acid, in ular obtained according to the first embodiment, the dry-weight amount used for said aqueous concentrate being in the range of 5 to 80% by weight, preferably in the range of 10 to 50% by weight and particularly preferably in the range of 15 to 40% by weight, in each case based on the total weight of the aqueous concentrate. Said aqueous trates are particularly suitable for producing foodstuffs and food supplements, in particular those in the form of beverages.

Dry weight within the meaning of the invention is understood to be the dry weight obtained by removing all aqueous and non-aqueous solvents from the extracts that can be obtained according to the methods according to the invention.

In ular, those aqueous concentrates are preferred which are obtained either according to the method according to the invention according to the first embodiment or according to the method according to the invention according to the second embodiment, those aqueous concentrates being particularly preferred which can be obtained according to the method according to the invention according to the first embodiment.

In particular, the aqueous concentrates according to the invention, in particular obtained according to the first embodiment, have a pH in the range of 1.5 to 5.5, preferably in the range of 1.75 to 4.5 and particularly ably in the range of 2.0 to 4.0, or are adjusted to a pH in the range of 1.5 to 5.5, preferably in the range of 1.75 to 4.5 and particularly preferably in the range of 2.0 to 4.0.

In preferred aqueous trates according to the invention, in particular ed according to the first embodiment, the amount of gallic acid is at least 10 g/kg dry weight, preferably at least 50 g/kg dry weight and particularly preferably at least 75 g/kg dry weight. Those aqueous trates are particularly expedient in which gallic acid is present in an amount in the range of 10 to 250 g/kg dry weight, preferably in the range of 50 to 200 g/kg dry weight and particularly preferably in the range of 75 to 175 g/kg dry weight, in each case based on the total weight of the aqueous concentrate.

Suitable aqueous concentrates according to the invention, in particular obtained according to the first embodiment, preferably have a ve density [20/20] in the range of 1.001 to 1.4000, preferably in the range of 1.010 to 1.2500. The relative density [20/20] is the quotient of the density of the tested sample (measured at 20°C) and the density of water at °C. The measurement is taken in particular by means of a flexural oscillator according to § 35 LMBG 36.0 3a n Foodstuffs and Commodities Act in the version applicable on the date of application) (determination of the relative density d 20/20 of wort and beer (flexural oscillator method). Particularly suitable aqueous concentrates are characterized by a total phenol content in the range of 5 to 350 g GAE/kg, preferably in the range of 50 to 300 g GAE/kg and particularly preferably in the range of 75 to 250 g GAE/kg and in particular in the range of 125 to 200 g GAE/kg, in each case based on the dry weight of the extract.

The total phenol t can be determined ing to the method according to DIN ISO 14502-1:2007-11 mination of substances characteristic of green and black tea - Part 1: t of total polyphenols in tea - Colorimetric method using Folin-Ciocalteu t).

Furthermore, the object of the invention is solved by a foodstuff, for e a beverage, and by a food supplement, containing or formed from the aqueous concentrate according to the ion.

The t invention is accompanied by the surprising finding that, when the extraction methods according to the invention are used according to the first embodiment and according to the second embodiment variant, but in particular according to the first embodiment, high yields of gallic acid can be ed efficiently and inexpensively from a wide variety of plant materials or components thereof, meaning that aqueous concentrates having a very high gallic acid concentration can be ed. It was surprisingly found that the aqueous concentrates according to the invention in particular have a Trolox-equivalent antioxidant capacity in the range of 500 to 6,000 µmol/g, preferably in the range of 1,000 to 5,000 µmol/g and particularly preferably 2,000 to 4,000 µmol/g, in each case based on the dry weight of the extract. The Trolox-equivalent antioxidant capacity can be expediently determined by the DPPH (2,2-diphenylpicrylhydrazyl) assay. This determination method is familiar to a person skilled in the art and is described, for example, by O. Sharma and T. N.

Bhat in “DPPH antioxidant assay revisited”, Food Chemistry 113(4):1202-1205, April 2009, and by A. Karioti et al. in “Composition and idant ty of the essential oils of Xylo- pia aethiopica (Dun) A. Rich. (Annonaceae) leaves, stem bark, root bark, and fresh and dried fruits, growing in Ghana”, J. Agric. Food Chem. 29;52(26):8094-8, December 2004.

For example, in this method, 10 mg of the stable radical DPPH can be dissolved in 100 ml methanol, mixed with the particular sample extract or the standard (Trolox), and then incubated for 30 min at room temperature, and the absorbance is subsequently determined photometrically at 517 nm. The antioxidant ial of the samples can then be determined from a linear relationship between absorbance and the standard concentrations. The results can be calculated as Trolox equivalents or as micromoles of Trolox/g of the sample and in relation to the dry weight. With the described method, an absorbance difference is determined, from which the antioxidant capacity of the tested substance can be determined by comparison with the reduction in absorbance caused by Trolox at different concentrations.

The aqueous concentrates according to the invention can be directly used for producing foodstuffs, in particular beverages, and food supplements.

The es of the invention disclosed in the above description and in the claims may be ial either individually or in any desired ation for carrying out the various embodiments of the invention.

The term “comprising” as used in this specification and claims means “consisting at least in part of”. When interpreting statements in this specification and claims which include the term ising”, other features besides the features prefaced by this term in each statement can also be present. Related terms such as “comprise” and “comprises” are to be interpreted in a similar .

In this ication where reference has been made to patent specifications, other external nts, or other sources of information, this is generally for the purpose of providing a context for discussing the es of the invention. Unless specifically stated otherwise, reference to such external documents, or such sources of ation, is not to be construed as an admission that such documents, or such sources of information, in any iction , are prior art, or form part of the common general knowledge in the art.

Claims

1. A method for preparing an extract containing gallic acid, comprising the steps of a) providing, in particular dried , in ular and, comminuted, plants or plant constituents, containing tannins, in particular tannic acid, b providing the enzyme tannase, c) providing at least one polar organic solvent, d) optionally comminuting or further comminuting, respectively, the plants or plant constituents according to step a), e) ming an extraction treatment on the plants or plant constituents obtained , in particular comminuted, according to step a) and/or d) by means of water or an aqueous system in the presence of the enzyme tannase to obtain a product mixture containing gallic acid.

2. The method according to Claim 1, further comprising f) separating the, in particular comminuted, plants or plant constituents from the product mixture obtained ing to step e), in particular following step e), and/or, in particular and, g) concentrating, in particular by evaporation, the product mixture obtained according to step e) or f), containing gallic acid, in particular ing step e) or f) and/or before step h), , in particular and, h) treating the product mixture according to step e) or f) with the at least one polar organic solvent, in particular ethanol and/or ol, and/or, in particular and, heat-treating the product mixture according to step e) or f) or g), and i) optionally filtering the treated product e according to step h) and/or, in particular and, j) optionally removing the polar organic solvent added in step h) from the treated product mixture according to step h) or the filtered t mixture ing to step i).

3. The method according to Claim 1 or 2, wherein the extraction treatment according to step e) is carried out at temperatures in the range of 20 to 45°C.

4. The method ing to any one of the preceding claims, wherein the treatment of the product mixture with the at least one polar organic solvent, in particular ethanol, according to step h) is carried out at temperatures in the range of 40 to 75°C.

5. The method according to any one of the preceding claims, wherein in step h), the at least one polar organic solvent, in particular ethanol, is added in an amount in the range of 15 to 70% by weight, preferably in the range of 20 to 65% by weight and particularly ably in the range of 40 to 60% by weight, in each case based on the total weight of the polar organic solvent and the water or the aqueous system.

6. A method for preparing an extract containing gallic acid, comprising the steps of 1) providing, in particular, comminuted and/or, in particular and, dried plants or plant constituents containing tannins, in particular tannic acid, 2) providing the enzyme tannase, 3) providing at least one polar organic solvent, in particular ethanol, 4) ally uting or further comminuting the plants or plant constituents according to step 1), 5) ming an extraction treatment on the, in particular comminuted, plants or plant constituents according to step 1) and/or 4) with a e containing the polar or- ganic solvent, in particular ethanol, and water to obtain a product mixture, containing polyphenols 6) separating the, in particular comminuted, plants or plant constituents from the product mixture according to step 5) to obtain a liquid extract containing the polyphenols 7) removing the polar organic solvent, in particular ethanol, from the liquid extract according to step 6) to obtain an s extract containing the polyphenols, 8) treating the aqueous extract according to step 7) with the enzyme tannase to obtain an aqueous system, ning gallic acid.

7. The method according to any one of the preceding claims, wherein the plants or plant constituents, in particular ground, preferably uted, are immobilized in step e) or step 5), respectively, in particular immobilized in a sieve support.

8. The method according to any one of the preceding claims, wherein the extraction treatment according to step e) or step 5), respectively, comprises a percolation process.

9. The method according to any one of the preceding claims, n the amount of tannase in step e) or step 5), tively, is in the range of 0.1 U/g to 100.0 U/g, preferably in the range of 0.2 U/g to 50.0 U/g, based on the amount of plants or plant constituents.

10. The method according to any one of the preceding claims, further comprising concentrating , in particular by evaporation, the aqueous extract containing gallic acid obtained according to step i) or j), in particular according to step j), or the aqueous system containing gallic acid according to step 8), tively, to obtain an s trate, in particular a spissum extract.

11. The method according to Claim 10, wherein the s concentrate has a Brix value in the range of 1° to 100° Brix, ably in the range of 10° to 70° Brix and particularly preferably in the range of 20° to 50° Brix.

12. The method according to any one of Claims 6 to 11, wherein the extraction treatment according to step 5) is carried out at temperatures in the range of 50 to 70°C, in particular in the range of 55 to 65°C.

13. The method according to any one of the preceding claims, wherein the tion treatment according to step e) or the treatment of the aqueous extract according to step 8) with the enzyme e is d out at temperatures in the range of 35 to 40°C.

14 The method according to any one of Claims 6 to 13, wherein in step 5), ethanol is added in an amount in the range of 60 to 90% by weight, preferably in the range of 70 to 85% by weight, in each case based on the total weight of ethanol and the water.

15. An aqueous concentrate, containing gallic acid, in particular obtained or obtainable according to a method according to any one of the preceding claims, characterized by a dry weight in the range of 5 to 80% by weight, preferably in the range of 10 to 50% by weight and particularly preferably in the range of 15 to 40% by weight, in each case based on the total weight of the aqueous concentrate.

16. The aqueous concentrate according to Claim 15, characterized by a pH in the range of 1.5 to 5.5, preferably in the range of 1.75 to 4.5 and particularly preferably in the range of 2.0 to 4.0.

17. The aqueous concentrate according to Claim 15 or 16, characterized by an amount of gallic acid of at least 10 g/kg dry weight, preferably at least 50 g/kg dry weight and par- ticularly preferably at least 75 g/kg dry weight, and/or an amount of gallic acid in the range of 10 to 250 g/kg dry weight, preferably in the range of 50 to 200 g/kg dry weight and particularly preferably in the range of 75 to 175 g/kg dry weight, in each case based on the total weight of the aqueous concentrate.

18. An aqueous concentrate according to any one of Claims 15 to 17, characterized by a ve density [