CA2184084A1 - Alcohol-free refreshing drink - Google Patents

Abstract

To obtain an alcohol-free refreshing drink: a) an aqueous solution containing a source of nitrogen for nourishing microorganisms is prepared and, if this solution does not contain glucose or any other such sugar or does not contain a sufficient quantity thereof, it is mixed with glucose and/or a sugar from which glucose can be released; b) the solution obtained in a) is mixed with a microorganism capable of converting glucose to gluconic acid, and the glucose is at least partially fermented; c) when fermentation is complete, at least 15 mmol/1 of the gluconic acid is converted to the corresponding gluconate by addition of an alkalizing mineral salt.

Description

- 21 840~4 ALCOHOL-FREE nt~lttSHlNG DRINK

The invention relates to sn alcohol-free refreshing drink and to a process for its production.
There is already known a ~reat number of alcohol-free ~non-alcoholic) rer,eshingdrinks or soft drinks. These are rnainly fruit juices, fruit nectars, rnodified fruit juices, soda pops and lemonades. For preparing these refreshing drinks, water is normally admixed with fruit juices or fruit extracts or its substitute, as well as with sugar or sweetening sgents snd with scids, preservatives, coloring agents snd flavoring agents. In addition, such drinks csn be more or less sl-on,JIy carbonated.
The consumers are becomin~ more and more criticsl of "a,lirici~lly produced"
foodstuffs including drinks. There exists therefore a need for an alcohol-free (non-aicoholic~ rer,eshing drink which is obtained using pure natural products via a biological rouee.
An slcohol-free refreshing drink fulfillin~ these requirements is slready described in German patent application P 40 12 000.7.
It is the object of the present invention to provide sn improved slcohol-free refreshin~ drink of the above mentioned kind which has been produced by using pure nstursl products as well ss vis a biolo~ical route which does not contain "artificial ins~, edienls. n This object is obtained by an slcohol-free refreshing drink according to the teachin~
of clsim 1. The drink disclosed does not conlain slcohol.
For producing the alcohol-free refreshing drink of the invention, one can start from an aqueous extract of toxicologicslly and chemi~,e"y u-)ob~eclionable plant psrts of one - 21 ~4~4 plant or of several plants. The plant parts can originate from tea and herbs. It is for instance possible to use parts of a tea plant, in particular, tea leaves; parts of the maté
tree, ;n particular, parts of the maté leaves; and all herbs which are generally recognized as safe with respect to the alimentary physiology and which are generally recognized as safe, for instance, peppermint, mallow, rose-hip, chamomile and so on. It is possible to use fermented (black) tea as well as unfermented (green~ tea as tea.
It is, however, a prerequisite for producing the refreshing drink of the invention that the solution to be fermented (as explained further below) contains a nitro~en source for the nourishment of microor~anisms. Therefore, at least one of the plants or plant parts, respectively, has to release or deliver, respectively, when beiny extracted with water a nitrogen source to the aqueous extract since the nitrogen source is needed for the nourishment of the microorganisms or bacteria, respectively, which are explained in detail further below and which are used for the fermentation. Tea is, for instance, such a plant or plant part, respectively, donsting or releasing such a nitrogen source. It is known to the artisan which plants or plant parts release such a nitrogen source to the extract or the aqueous solution obtained thereby during the extraction.
For producing the ref,eshing drink of the invention, one can also start out fromcommon fruit juices including date juice, etc. In case such juices do not contain a r,iL-oge source, the latter has to be added, of course.
However, a common wort produceable in a brewery is preferably used as a solutioncontainin~ a nitro~en source for producing the refreshing drink of the invention. As a wort, any common wort can be used which can serve for producing beer. As malt for the production of the wort, pure barley malt, and any other possible malt can be used, such as Pilsen malt, dark malt, caramel malt and so on. A part of said malt can also be wheat meal or raw fruits such as rice, corn, rye and son one.
It is possible to use a normal Pilsen-first wort having an ori~inal or base wortcontent of about t 4%. The first malt is considered that part of the malt which flows after the mashing frorn the defector to the brewing pan. Said first malt is preferably diluted to about 1 h . Such a dilution is, however, not absolutely necessary. The greater the original or base wort content is the "stronger" is the finally obtained rerresh;ng drink.In case the aqueous solution containing a nitrogen source used does not contain glucose or does not contain any sugar from which glucose can be liberated, or in case this solution does not contain glucose or a sugar in a sufficient amount, ~lucose as such or a sugar from which ~lucose can be liberated, is added. The expression "sugar from which 21 ~40~4 glucose can be libefaled" denotes all those sugars which are capable of releasing or liberatin~ ~lucose in an a~ueous solution, for instance by acidifyin~ or vi~ enzymatic cleava~e and so on. Such su~ars are invert sugar, honey and so on. The sugar must therefore provide ~lucose so that the glucose can be processed or digested, respectively, 5 by the microorganism or microor~anism system, to be described. If necessary, the ~lucose is liberated from the sugar before the fermentation described below in a suitable manner, in particular by acidifying or by enzymatic treatment.
If, for instance, the above described malt is used as an aqueous solution, then it is possible to cleave the rnaltose already contained in the malt enzymatically to Qlucose. In 10 this case, it is therefore not at all necessary to add glucose or sugar.
I~owever, pure glucose is preferably used.
The microorganism used converts the glucose which has been added or which has been provided within the system, to gluconic acid. To accomplish this, all microorganism or rnicroorganism systems which are capable of doing so can be employed. The following 15 are exsmples: Gluconobacter oxydans, Gluconobacter suboxydans, Aspergillus niger, several Acetobacter, for instance Acetobacter suboxydans. Furthermore, it is possible to produce the gluconic acid from the ~lucose enzymatically by using ~lucose oxydase and catalase. The expression "microorganism" denotes therefore all bacteria or other"systemsR which are capable of produciny gluconic acids by fermentation from glucose.
20 Said microor~anism can be used as such or as pure culture, and also in admixture. By the way, the gluconic acid need not be the only product which is obtained by the fermentation. It is possible to use microorganisms which can produce other acids besides ~luconic acid, for instance ~lucoronic acid. Of course, no microorganism should be employed which ferments one of the substances contained in the aqueous solution to 25 alcohol. Preferably, Gluconobacter oxydans is used.
The aqueous solution to be fermented is preferably admixed with 5~ of a charge partially fermented or of a solution already completely fermented.
The fermentation of the added çllucose (the process of the invention in the following described by using pure glucose which is representative of all sugars releasing ~lucose) is 30 preferably perrG..ned up to a pH value smaller than-2.8 and in particular to a pH value of 2.3. tJe~dl~ss to say, a sufficient amount of glucose has to be presenl for the rer.,.enl~lion so that the desired pH value can be obtained.
The pH value obtained does not depend only on the amount of glucose, but also onhow completely the fermentation is performed. It is possible to perform the fermentation 21 840~4 completely and therefore to a point where the glucose is consumed. It is also possible to ferment in such 8 manner thst a residual amount of glucose remains in the aqueous solution and is therefore not fermented.
For performin~ the fermentation, it is necesssry that oxygen is supplied to the microor~anisn,. This can be done by any means or ways. It is advisable to aerate the aqueous solution to be fermented. Advisably, it is aerated stron~ly, in particular with about 0.51 air/l/min. during a period of 48 to 96 hours; in particular durin~ a period of about 72 hours. In addition, it is preferably agitated.
A further important feature of the present invention is the following. It has to be taken care that at least 15 mmolll salts of the gluconic acid (i.e. gluconates) have to be present in the refreshing drink of the invention. Said salts are mineral salts and in particular, those from alkali metals and alkaline earth metals. Said gluconates can be produced in the solution as such by converting a part of the ~luconic acid obtained by the fermentation to the corresponding gluconate. For doing this, at least one alkalizin~ mineral salt is added to the fermented solution. For instance, carbonates, hydro~en carbonates and/or hydroxides and also oxides of alkali metals and alkaline earth metals can be used.
~eferably at least two of the above mentioned alkaline metals and alkaline earth metals are used. In particular, saits of sodium, potassium, magnesium or calcium or any possible mixture of at least two of said salts are preferred.
It is for instance, possible to produce 1~ mmol/l potassium gluconate ;n the solution by adding 15 mmol/l potassium hydroxide to the fermented solution. In case an alkaline earth hydroxide is added, it has to be talcen into account that the alkaline earth metals are bivalent. Therefore, at least 7.5 mmolll calcium hydroxide ~Ca~0~)2~ has to be added. In addition, it is possible to convert the gluconic acid by using hydrogen carbonates and carbonates into the corresponding gluconate. Then, the corresponding equivalent amount has to be employed.
The mineral salts mentioned here are predominantly the alkaline salts and alkaline earth salts which are generally accepted as safe and which are valuable with respect to the alimentary physiology. Nevertheless, it is also possible to use a small amount of alkalizin~ salts of trace elements and other metals if said metal ions are allowed to be presenl in a foodstuff such as a drink.
The question of how ~reat the amount of gluconate shall be in the rer,eshin~ drink and how ~reat therefore the smount of the mineral salt to be added depends on the purpose for which the refreshing drink of the invention shall be used. In case it is desired 21 840~4 to produce a drinlc for an athlete with a high mineral content then said amoùnt should be chosen accordingly high. The refreshing dr;nk of the invention therefore contains preferably 20 to 80 mmol/l gluconate. The unit of quantity mmot relates thereby to the anion of the gluconic acid. The valence of the cation is not taken into account. Therefore, 5 at least 15 rrlmol/l alkali gluconate has to be present which corresponds to 7.5 mmol/l alkaline earth gluconate.
When the present specification and claims refer to the end of the fermentation or a completed fermentation, this does not mean that the glucose has been cornpletely converted to give gluconic acid. It is to be underslood that this means that thelO fermentation process has come to an end or has been completed by filtering off the microor~anism or by stopping the fermentation process by any other known technique.
Consequently, the embodiment accordlng to which the complete glucose is convertsd to give ~luconic acid as well as the embodiment according to which only a part has been converted and glucose is still present are included according to the teaching of the present 1 5 invention.
When referring in the specification and claims to a mineral salt, then the term "salt"
is not to be interpreted in a restricted manner. The mineral salts co"~ris~ rather all mineral compounds which are capable of converting gluconic acid into the corresponding salt and therefo~e in the gluconate. The kind of anion of the mineral salt is not critical.
20 Needless to say, a mineral salt is used which is generally accepted as safe with respect to the alimentary chemistry and which is suitable for the drink industry. The salt need not be added in solid form but can of course also be added in the form of an squeous solution.
It has surprisingly been found that, due to the presence of gluconates, in particular of calcium, sodium, potassiurn, magnesium gluconate, it is not necessA~-/ to employ a 25 bacteriostatic agent or a preservative. It has in particular been surprisingly found that the gluconates and in particular the mentioned alkaline gluconates and alkaline earth gluconates inhibit yeast fermentation. This holds true in particular when at least 15 mmol/l gluconate are present. In particular, the potassium gluconate is active. The bacteriostatic and preserving action is in particular then very stron~ when at least two metal cations are 30 present.
By adding the mineral salt, a part of the gluconic acid obtained fermentatively is converted into the corresponding gluconates. The refreshing drink of the invention thereby does not only contain the pleasant tastin~ ~luconic acid, which imparts a ref.eshing acidic taste to the drink, but also minerals so that the alcohol-free refreshin~ drink of the - 21 840~34 invention is a nutritional mineral drink having valuable properties with respect to the alimentary physiology. In addition, no preserving agent is necessary.
The glucose is preferably fermented to a pH value of smaller than about 2.8 snd in particular to a pH value of about 2.3. Needless to say, a sufficient amount of ~lucose has 5 to be added or to be liberated in the solution to be fermented so thst it is possible to perform the fermentation to such a pH value or to such a content of gluconic acid. Even if it is preferably fermented to the above given values, there does not exist any limitation of the refreshing aspect of the invention with respect to the content of ~luconic acid. The question of how much free gluconic acid shall be present in the finished refreshing drink ~0 depends primarily upon the taste one wants to obtain. A drink having a high content of Qluconic acid tastes of course more acidic than a drink containing only a small arnount of free gluconic acid or of no free gluconic acid at all. The finished or final alcohol-free .~f-asl1ing drink contains preferably however at least 5 g/l, in particular 10 to 40 9/l, of gluconic acid.
For the sake of completeness, it is mentioned that the microorganism used for producing the refreshing drink of the invention can be filtered off according to any known method, for ins~ance after having performed step b) or after haviny performed step c~.
Steps b~ and c) are preferably performed at about room temperature.
The drink of the invention has, by the way, a light yellow color after the fermentation and after the addition of the mineral salt.
It has in addition been surprisingly found that the color and/or the taste of the refreshing drink of the invention can be changed. For doin~ this, the complete amount of glucose prese"l is fermented so that no oxygen consumption by microorganisms can take place. In addition, it is necessary to obtain a pH value of smaller than 2.8 and in particular of about 2.-~. Furthermore, the mineral salt is added in such an amount that the pH value obtained thereafter is ~reater than about 2.8.
After the addition of the mineral salt, it is aerated in step d) once more; and preferably it is agitated. By doing this, the carbonic acid eventually present is expelled.
In addition, an oxygen uptake takes place. Preferably, it is aerated in said step d) for a period of 12 to 60 hours, in particular for 24 to 48 hours. Thereafter, the original color of the liquid has changed only slightly.
After the end of the aeration, the liquid or the drink is allowed to stand (stored) for preferably 6 to 10 days, in particular for about 8 days. The storage temperature is preferably 3t) to 35C. During said storage, no new oxy~en or only a small amount of 21 ~40~4 new oxyg~n should be fed imo the liquid. It is therefore posgible to work under the exclusion of air or ~o leave the liquid standing open whereby, however, a new active aeration should be a~oided.
During the storage a chan3e takes place which is referred to in the present 5 s~ec;rication as "maturing." The stored liquid chan~es not only ir color but also its taste.
The de~ree of the chan~e of ~he taste and the color depends, arnong other factors, on the stora~e time. The liquid havin~ a li~ht yellow color in the beginning turns first light red and then finslly dark red like burgundy. Tlle taste which is, in the beginning, an acidic tagte with a lemon flavor becomes fruity and resem~les tl~at one of the black cutren~. The 10 ;,llensit~ of the tas~e and of the color depends of course also from the concel,lration of the malt used in the be~inning.
By varyin~ the abo~e mentioned paramr~ters it is therefore possible to obtain a differently colored and a differently taetin~ refreshing drink completely free of alcohol.
It i5 advieable TO expel the oxysen aT the end of the storage from the drink, for 15 instance by injecting C2- The drink thus obta;ned after step c) or e) can then be adrnixed accord;n~ to need vvith a sweetenin~ a~ent, for instance, saccharose. In addition, it is advisable to filtrate. Fur~herrnore it can be diluted wi~h wa~er. In addition it is preferably ca,~or,alt:d. Then the drink is bottled.
By the expresgion "thereby obtainable" in the claims it shall be made clear that the 20 claimed re~,e:.h;ng drink can be obt~ined in the manner described in the clairns. The process features serve the purpose of characterizing the product (refreshin~ drink) as such.
1~ is not excluded that the sarne rerreal"ny drink can be produced via another route. It would be conceivable to add the allcaline ~luconates and the alkaline earth gluconates as such. In addilion, ~he amoun~s mentioned in ~he clairns refer ~o the fini_hed or final 25 refr~shing drink. 1~ is of course possible to work also with lower and alqo with higher concentrations and then to wiLbdra\rl water or to diluts with v~/at~r, The w~ter can be v~i~l,dra~n by using reverse osmosis so thal a concentrate is produced.
The final and therefore consumable refreshing drink contains preferably at least 3g/1 in particulat 10 to 20 gA, ~luconic acid and in addition at least 15 rnmoltl, in partiçular 20 30 to 80 rnrnol/l, gluconate.
~ ccordin~ to the presen~ invention it is therefore pos_ible to ~brew ' an alcohol-free refreshing drink ~la~ from rnalr, sugar and wa~er in a manner like a beer. Thereby obtainin~ a nlutritional minersl drink ha~rin~ valuable prope"ies with respect to ~he 21 840~4 .

alinlentary physiology, Said drink can be produced wi~h a relatively low need f~r capital inves~ment in any brewery.
The invention is also directed to a process for producing an alcohol-free refreshing drink according tO the teachin~ of claim 11.
The production of the refreshins~ drink of Ihe invenlion is described in ~reater details in the followin~ examples.

Example 1 A norrnal Pilsen-first malt with an original or base wort content of about 1 4g~ is diluted with watet to an ori~inal base wort content of 15. Then 3~ glucos~ll are added;
the pH-value is about 5.6. Said ~alt-~ co~e-rnixtur~ is admixed with 5% bacteriacontaining fermented rnalt from an earlier charge. The bacteria are Gluco,~obacter oxydans.
The rnixture obtained is then stirred with a ma~netie stirrer at 920 rlmin at room temperaturc for about 72 hours and aerated. Tllis happens in a fermenter. After about 72 hours (according to temperatur~ and oxygen injection) the conlent of the ~luconic acid is about 35 g/l. The fermentation is finished; no more ~I~JOOS~ is pr~sent. The pH-value is abou~ 2.3. Then it is filtered.
Thereafter 1 g CaC0~ K;~C0l and 2.5 9 MgCOJI are added ~o the filtrated solu~ion. By the addition of sa;d ~,Londles a part of the gluconic acid is converted into the corresponding ~luconate. The p~l-value is thereby raised ~o abo~ t 3.3 to 3.5. In addition C2 i5 liberated. Thc 31uconic acid content drops to about 13 9/l.
Thereafter il is further aerated and stirred ~t roo n temperature. After 24 to 48 hours the liquid has chan~ed its original color only slightly. The ae~ation and ~he stirrin~
are stopped.
Tl.ereafler the liquid is stored under the exclusion of air at about 35C. A*er a sto~age of 8 days the liquid has adapted a dark red color and a fruity taste.
The liquid is then admixed with 100 ~ saccharose, filtrated, m;xed with water ina ra~io 1:1, carbc~nized and bot~led.

A drink having the followin~ composition is obtained;

pH-valLle 3.2 to 3.4 su~ar ~onle.~ 50 9/l ~isotonic) .

cu~ nl of calories about 200 kcal./l ~luconic acid abou~ 6 g/l alcohol non detectable potassium about 250 mg/l calciurn about 200 my/l ma~nesium about 350 mgll color light red.

Exarnple 2 A malt i5 diluted with water tO 0.7% and adrnixed ~vith 20 ~ dextro~e per li~re.Then after the addition of Gluconobacter oxydans it is fermented as described in exafnple 1 to an acid value of 20 g/l gluconic acid ~p~l = 2.50~.
Thereafter 2 9/l calcium carbor,dle snd 1 ~/1 magnesium c~rl,onale are added whereby the acid cont~nl is reduced to about 10 ~11 gluconic acid; the pH value rises ~hereby to about 3.40. The mineral con~ent is then about 800 myl calciurn and 300 rn~A
1 5 ma3nesium.
The drink thus obtained is then accordin~ to need filtrated, diluted with water,ca~boni2ed, etc. Th0n it is bottled.
For producin~ the malt a pure barley malt can be used as malt (for instance Pilsen-~alt, dark rnalt, caramel Inalt). A par~ of the rnalt can be replaced by wheat flour or raw fruils, for instance rice, corn, ray and so on.
The cultivation of Gluconobacter oxydans is, by the way, known to the expert andalso described in the German parent spplication P 40 17 000.7. The disclosure of said patent application is hereby inco,pGraled in the present documents.

Example 3 The malt of the exarnple 2 is replaced by black tea (prepared by extraction of 2 ~
tea leaves per litte watel; the tea leaves are filtered off). Then on~ proceeds as described in example 2.

Claims (11)

Claims

1. An alcohol-free refreshing drink wherein a) an aqueous solution containing a source of nitrogen for nourishing microorganisms is prepared and that glucose and/or a sugar from which glucose can be released is added to said solution if said solution does not contain glucose or any such sugar or does not contain a sufficient quantity thereof, b) the solution obtained in a) is admixed with a microorganism capable of converting glucose to gluconic acid and that the glucose is at least partially fermented and c) when fermentation is complete, at least 15 mmol/l of the gluconic acid is converted to the corresponding gluconate by addition of an alkalizing mineral salt to obtain said drink.

2. Alcohol-free refreshing drink according to claim 1 wherein an alkali carbonate, alkali hydrogen carbonate, alkali hydroxide, alkaline earth carbonate, alkaline earth hydrogen carbonate or alkaline earth hydroxide or a mixture thereof on the basis of in particular at least two metal cations is added as mineral salt in step c).

3. Alcohol-free refreshing drink according to claim 2 wherein a mineral salt of Na, K, Ca and/or Mg is added in step c.

4. Alcohol-free refreshing drink according to one of the preceding claims wherein an undiluted or diluted beer wort or an extract of toxicologically and food chemically safe parts of one or several plants is used as an aqueous solution.

5. Alcohol-free refreshing drink according to claim 4, wherein a work with an original gravity of about 1% is used which is mixed with a 5% fermented wort containing microorganisms from an earlier charge or batch, respectively.

6. Alcohol-free refreshing drink according to any one of the preceding claims wherein Gluconobacter oxydans is used as microorganism in step b).

7. Alcohol-free refreshing drink according to one of the preceding claims wherein it is fermented in step b) up to a pH-value of at least c about 2.8 and in particular of about 2.3 and that the mineral salt is added in such an amount that the pH-valueafter the addition is greater than about 2.8.

8. Alcohol-free refreshing drink according to claim 7 wherein the glucose present is completely fermented in step b) and that after the addition of the mineral salt d) it is aerated again 12 to 60 hours, in particular 24 to 48 hours and e) the solution is allowed to stand thereafter 6 to 10 days, in particular about 8 days, and that eventually CO2 is injected for removing oxygen.

9. Alcohol-free refreshing drink according to one of the preceding claims wherein either afrer step c) or after step e) a sweetening agent is added and it is filtered, diluted with water, carbonized and/or bottled.

10. Alcohol-free refreshing drink according to one of the preceding claims, characterized by at least 5 g/l, in particular 10 to 20 g/l, gluconic acid and at least 15 mmol/l, in particular 20 to 80 mmol/l, gluconate in particular in the form of Na-, K-, Mg- and/or Ca-gluconate.

11. Process for preparing an alcohol-free refreshing drink characterized in that the process steps described in one of claims 1 to 9 are performed.