ITMI20120915A1 - PROCEDURE FOR TREATING BEVERAGES OF VEGETABLE ORIGIN - Google Patents

Description

PROCESS OF TREATMENT OF BEVERAGES OF VEGETABLE ORIGIN

DESCRIPTION

The present invention relates to a process for treating beverages of vegetable origin, including, in particular, wine and vinegar.

As is known, alcoholic beverages are generally produced through a broadly defined phase of fermentation of a fruit juice. For example, wine is produced from grape juice that is fermented in the presence (natural or by addition) of yeasts, such as Saccharomyces Cerevisiae. In some cases, the fermented product is then subjected to a distillation phase, eliminating the heads and tails from the final product, so as to avoid the presence of toxic methanol. In this way grappa and other liqueurs are produced.

Fruit juices, in addition to water, sugars, esters and vitamins, generally beneficial for health and with a mostly pleasant taste, may also contain substances that are harmful to human health or that can compromise the organoleptic properties, as much as the juice starting point how much of the fermented drink that is obtained.

If, for example, grapes have been attacked by pathogens, the wine obtained from them may contain ochratoxin A (from Aspergillum and Penicillum bacteria), 1-obtain-3-ol, 1-obtain-3-one, 2- methylisoborneol, furfural, benzaldehyde, phenylacetaldehyde (from Botyric cinerea), geosmin (from penicillum expansum). Even at very low concentrations (ng / l) these substances can give the wine anomalous odors of mold, earth or fungus, thus compromising its quality. Moreover, ochratoxin A is considered carcinogenic and, therefore, its elimination would be desirable.

Another category of substances derived from grapes and which give unpleasant odors to wine is represented by metoxypyrazines and aldehydes, responsible for the negative vegetable and herbaceous note in wine. These substances are mostly present in wines derived from grapes that are not completely ripe and / or that have undergone excessive mechanical stress during the preparation of the must.

During fermentation, other substances with negative olfactory characteristics can then be produced, such as volatile ethyl- and vinyl-phenols, which give an animal odor and a â € œchemicalâ € odor and which are produced by contaminated yeasts of the genus Brettanomyces; sulfur compounds, such as sulphides, thiols and mercaptans, which give unpleasant odors, such as burnt gum, cauliflower, onion, garlic and which derive from yeast metabolism during fermentation; the metabolites of some lactic bacteria, such as pyrrolidines and pyridines, which give the smell of mouse and cellar; oxidation products, such as acetaldehyde, sotolone and acetaminophenone, which give smells of honey, wet rag, rotting apple.

As we have seen above, most of the negative effects, at least at the olfactory and taste level, already take place at very low concentrations of contaminants, of the order of the nanogram or microgram per liter.

In the prior art, measures are known to try to avoid the formation of such substances, but they do not always have the desired effect and the formation of those substances can take place in any case and it may even be impossible to prevent it, even only partially.

There are also some curative treatments, but they are very limited in number and reduce their action to a few cases and often prove to be excessively drastic, leading to the simultaneous elimination of positive substances, as occurs by practicing an absorption with activated carbon, practically completely non-specific.

In beverages derived from vegetable matrix, the problem of protein instability in the bottle is frequent, due to some protein fractions that remain in solution during the entire production process, but which tend to aggregate in case of heating during transport and distribution of the finished product, causing the appearance of precipitates in the bottle. In some beverages, the presence of these deposits, although of natural origin, is rejected by the consumer and therefore leads to a significant depreciation of the product. In wine, the main unstable protein fractions have been identified in chitinase and proteins similar to thaumatin, or TLP, produced by the vine, especially in response to fungal attacks, as well as in lysozyme, used to inhibit the development of lactic bacteria.

To avoid the appearance of protein precipitates in the bottle, the wine is normally treated with bentonite, a montmorillonite clay which is kept in suspension in the wine for a certain period of time, during which it absorbs the unstable proteins that are dragged to the bottom of the container when the bentonite settles and, therefore, are eliminated with the subsequent decanting or filtration. However, this process is not selective and, when high doses of bentonite are required to reach protein stability (even over 300g / hl), the treated wine is impoverished in aroma, taste and color. Furthermore, bentonite, swelling, retains not negligible quantities of wine and its use involves substantial product losses (up to 10%).

Another category of unwanted proteins in wine are the oxidase enzymes, produced by grapes (tyrosinase), which can cause oxidation phenomena in the must and wine that damage the quality of the wine.

WO03 / 085 002 describes the synthesis of cyclodextrin polymers, but does not describe any application thereof for the purification of beverages.

The problem underlying the invention is to eliminate as much as possible the harmful and unpleasant substances from beverages of vegetable origin, including musts, wines, vinegars and distilled spirits, so as to overcome the previously mentioned drawbacks and allow instead, not to eliminate from these drinks the substances in any way positive and beneficial. This purpose is achieved through a process of treatment of juices and beverages of vegetable origin for the selective removal of unwanted molecules contained in them, characterized by what involves the contact between the beverage and a synthetic polymer, obtained by polymerization of selected monomers. in the group consisting of Î ± -, β-, γ-cyclodextrins, methacrylic acid, vinylpyridine, tetraethylorthosilicate, 3-aminopropyltrimethoxysilane and their derivatives and mixtures.

As it has been seen, the present invention refers to a process for the treatment of beverages of vegetable origin, comprising the contact between the beverage and a polymer, in order to have the harmful substances absorbed on the polymer, so as to effectively remove them from the juice or derivative.

The procedure can be applied to fruit juices as they are, such as orange, lemon, grapefruit, pineapple, apple, pear, apricot, peach, tomato, grape, blueberry, raspberry, cherry, black cherry, cedar and others. It can be applied to vegetable oils, such as olive oil, soybean oil, sunflower oil, corn oil and others. It can be applied to musts. It can be applied to fermented beverages, such as wine, cider, beer and their respective vinegars. It can be applied to distilled spirits, such as grappa, whiskey, vodka, rum, cognac, tea infusions, drinks based on plant extracts and others.

Polymers synthesized by polymerization, for example radicalic or via sol-gel, of Î ± -, β-, γ-cyclodextrins, methacrylic acid, vinylpyridine, tetraethylorthosilicate, 3-aminopropyltrimethoxysilane and their derivatives and mixtures can be used. The aforesaid polymers can also be co-polymerized with inorganic substances, such as bentonite and silica gel. As derivatives it is possible to use those obtained using active carbonyl compounds, organic anhydrides, diisocyanates, ethylene glycol dimethacrylate, polyamidoamine, 2,2-bis (acrylamido) acetic acid, 2-methylpiperazine as crosslinkers. Among the active carbonyl compounds, carbonyl-diimidazole and triphosgene are preferred. Among the organic anhydrides, pyromellitic anhydride is preferred.

The polymers, synthesized, as we have seen, according to the common methods of organic chemistry, are put into contact with the beverage to be treated. The contact can take place in different ways, for example by immersion and suspension of the polymer in the beverage, possibly under stirring and subsequent decanting or filtration after sufficient time has passed to allow sufficient absorption of the harmful substances by the polymers. A possible variant to this embodiment is to mix the polymer with filter aids, such as diatomaceous earth and cellulose, so that the absorption phenomenon occurs during the passage of the beverage through the filtration panel. Another possibility is to fill a column, for example a chromatographic column, with polymer, for example in granules, in powder or in spheres and to pass the beverage to be treated with a calculated flow rate in order to allow the beverage itself a residence time in the column sufficient to allow the above absorption. In this case, it is advisable to equip the column with a filtration system at its end, so as to prevent the polymer from escaping during the treatment. In any case, the insolubility in water of the polymers used in the treatment according to the present invention means that they do not mix with juices and / or derivatives (perhaps altering their flavor), which is particularly important in the case of wines and beverages. more valuable. If the polymer is put in suspension, once the time necessary for absorption has passed, the polymer is left to decant and is then removed by decantation, centrifugation and / or filtration. If operating in a column, the polymer can be subjected to regeneration cycles, for example by treating it with organic solvents, such as ethanol, or with aqueous solutions, having suitable pH and ionic strength. The column process has the advantage that the loss of drink due to the treatment is in effect negligible.

The effect of the treatment according to the present invention can in some cases be improved by using the so-called molecular mold technique for the synthesis of polymers. In this case, the polymer is synthesized in the presence of a substance (called templating molecule) equal to or similar to the one to be absorbed; at the end of the synthesis, the template is removed by washing. The use of polymers synthesized according to the molecular mold technique is useful in case you want to eliminate molecules, such as, in particular, methoxypyrazines, aldehydes, geosmin, 1-obtain-3-ol, 1-obtain-3-one, 2 -methylisoborneol, furfural, benzaldehyde, phenylacetaldehyde, sulphides, thiols, mercaptans, pyridines, pyrrolines, sotolone, acetoaminophenone, singly or in combination with each other. The treatment with molecularly molded polymers can take place by simultaneously treating the drink with different molecularly molded polymers or with template polymers so as to be able to absorb various unwanted substances at the same time. Alternatively, it may be advantageous to perform multiple treatment stages, each with a different molecularly molded polymer, thus removing unwanted substances, one per treatment stage.

A further embodiment of the present invention provides for using the polymers mentioned above, immobilizing on them enzymes and / or proteins that can be advantageously used in the beverage industry. For example, without wishing to limit ourselves to it, in the wine industry pectinase and glucanase are used, for the reduction of viscosity and for the improvement of the extraction of juice from grapes, glycosidases for the enhancement of the aromatic profile, lysozyme to reduce the bacterial load and urease to eliminate the precursors of potentially toxic substances. Preferably, the immobilized proteins are selected from pectinase, protease, glucanase, glycosidase, lysozyme and urease. By immobilizing the enzymes on the polymers used in the practice of the present invention, it is possible to subject the drinks to the treatment with the desired enzymes, without them remaining in excess in the drink, so as to avoid problems of subsequent elimination and / or recovery.

The process according to the present invention can be used for the protein stabilization of beverages, in particular wines. The process according to the present invention is also useful when it is not able to completely eliminate all unwanted substances from a drink; in this case, it may still be necessary to treat the drink with a non-specific absorbent, such as bentonite or activated carbon, but the amount of substance used in this case will be significantly less, so that the removal of substances beneficial for the drink, with obvious advantages in terms of quality and costs.

Preferably, the polymer is added to the beverage in an amount ranging from 0.1 mg to 200g per hectolitre of beverage.

The polymers to be used in the process according to the present invention can be synthesized in various ways. Some summary examples are reported below. The function of such examples is purely illustrative and it is understood that such examples do not absolutely limit the present invention. It should also be borne in mind that these examples are extremely general and must be adapted each time to the particular type of polymer chosen.

EXAMPLE OF SUMMARY 1

Carbonylimidazole is added to a mixture of dimethylformamide and cyclodextrin. If you want to proceed according to the molecular mold technique, you also add an appropriate dose of template molecule. It is subjected to sonication at room temperature, then causing crosslinking at 75 ° C in an oil bath, stirring for 1 hour, then at room temperature for 24 hours. The polymer is then crushed, washed with water, filtered, dried and, if necessary, ground up to obtain a powder. It is washed with ethanol (as it is or in aqueous solution) to eliminate the residues of the reagents.

EXAMPLE OF SUMMARY 2

Methacrylic acid is reacted in solution with ethylene glycol dimethacrylate and azoisobutyronitrile, subjecting the mixture to sonication at room temperature. If one wishes to proceed according to the molecular mold technique, a suitable dose of template molecule is also added. The polymerization reaction takes place at 60 ° C in an oil bath, with nitrogen flow and under continuous stirring for 6 hours, then it is allowed to proceed up to 24 hours at room temperature. The polymer obtained is crushed, washed with water, filtered, dried and, if necessary, ground to obtain a powder. Washing is carried out with ethanol or with an aqueous solution of ethanol to remove possible reagent residues.

EXAMPLE OF SUMMARY 3

Aminopropyltrimethoxysilane and tetraethylorthosilicate are reacted in water, adding micro particles of silica. If mixed silica-cyclodextrin polymers are to be obtained, cyclodextrins must be added to this reaction mixture. Ammonium hydroxide is added. It is kept under stirring at 40 ° C, until complete salification. The residual water is eliminated, drying the product. The solid is crushed to the desired size and the residues are washed with ethanol or with an aqueous solution of ethanol.

EXAMPLES

In the following, the effects of the present invention will be illustrated in more detail, using some application examples, intended to illustrate, but not to limit, the invention.

EXAMPLE 1

A synthetic wine contains high quantities of hexanal, a substance that derives from the oxidation of lipids in grapes and which gives the wine an unpleasant herbaceous smell. It is subjected to a treatment with three different polymers, according to the present invention. In test A, the βCD-CDI polymer in powder form is added to the wine, based on βcyclodextrins cross-linked with carbonyldimidazole; in test B AM-VP-EGDMA is used, based on methacrylic acid and vinylpyridine and ethylene glycol dimethacrylate as crosslinker; in test C a polymer of AM-EGDMA is used, based on methacrylic acid and ethylene glycol dimethacrylate. 3.7 g of polymer are used per hectolitre of wine, corresponding to 3.7 mg of polymer per mg of hexanal, since the concentration of hexanal in wine is 10 mg / l. The polymer is kept in suspension for 24 hours. The results are in Table 1.

Table 1

Test Polymer Reduction% after 24 hours of treatment

<A> Î'-CD-CDI <30.00%>

B AM-VP-EGDMA 30.00%

C AM-EGDMA 39.00%

As can be seen from the previous table, after only 24 hours a significant reduction in the concentration of hexanal is obtained, which may be sufficient to bring the latter out of the warning limit.

EXAMPLE 2

A synthetic wine containing 2-methoxypyrazine was subjected to the following treatments. Test A, polymer Î ± CD-CDI in powder form, based on Î ± -cyclodextrins cross-linked with carbonyldiimidazole, in a dose of 0.5 mg of polymer per hectolitre of wine containing metoxypyrazine; test B, βCD-CDI polymer, based on β-cyclodextrins cross-linked with carbonyldiimidazole, under the same conditions as test A; test C, AM-EGDMA polymer, based on methacrylic acid and ethylene glycol dimethacrylate, under the same conditions as tests A and B; test D, polymer AM-EGDMA, in a dose of 20 mg of polymer per hectolitre of wine containing methoxypyrazine; test E, VP-EGDMA polymer, based on vinylpyridine and ethylene glycol dimethacrylate, at the same doses as test D. The polymer is kept in suspension for 24 hours for tests A-C and 120 hours for tests D and E; the polymers were subjected to a molecular mold, synthesizing them in the presence of 2% and 10% of 2-methoxypyrazine, as well as synthesized without template. The results are reported in Table 2.

Table 2

Tests Polymer Dose of Reduction Time Treatment Reduction Treatment reduction% with% with po-% with po- (mg poly- (hours) polymer limer non-mere limer / µg 2- template template template

MP) 2% 10%

AÎ ± CD-CDI 0.25 24 16% 30% 5%

BβCD-CDI 0.25 24 26% 26% 14%

C AM-EGDMA 0.25 24 36% 18% 7%

D AM-EGDMA 10 120 65% - 3%

E VP-EGDMA 10 120 58% - 8%

As can easily be seen from Table 2, the molecular mold technique allows to significantly increase the affinity and specificity of the polymer for a specific compound and demonstrates that, by using the right combination of template and monomer in the synthesis process (in the for example, a concentration of 2% is better than that of 10%) It is possible to reduce to a large extent the content of a substance in the wine, in order to bring its concentration below the threshold of sensory perception.

EXAMPLE 3

To aqueous solutions of lysozyme at a concentration of 120 mg / l some polymers were added for a variable time, namely: EB 12 and EB5, nanosponges derived from β-cyclodextrin, AM-EGDMA based on methacrylic acid and ethylene glycol dimethacrylate and βCD -HMDI 1: 2, another polymer based on β-cyclodextrins and hexamethylene diisocyanate. The results are reported in Table 3.

Table 3

<Polymer test> Polymer dose (mg Treatment time% polymer reduction / mg li- (hours) sozyme content) lysozyme A EB12 100 1 38.00%

B EB12 200 1 74.00%

C EB12 1.7 2 58.00%

D EB12 3 2 99.00%

E EB12 16.7 2 97.00%

F EB12 33.3 2 98.00%

G EB12 83.3 2 95.00%

H EB5 1.7 2 90.00%

I EB5 3 2 95.00%

L EB5 16.7 2 95.00%

M EB5 33.3 2 98.00%

N EB5 83.3 2 100.00%

O AM- 83.3 1 12.00% EGDMA

AM- 166.7 24 32.00%

EGDMA <P> Î'CD- 166.7 24 20.00% HDMI 1: 2

<Q> Î'CD- 166.7 24 16.00% HDMI 1: 4

<R> Î'CD- 166.7 24 18.00% HDMI 1: 8

Table 3 shows that some polymers are able to eliminate all (or substantially all) of the proteins present from the system, even very quickly and at doses of 10-20 g / hl. Furthermore, the results reveal significant differences between the various polymers.

EXAMPLE 4

The results of example 2 were confirmed, using a synthetic wine, containing 120 mg / l of lysozyme. The polymers were left in suspension in the wine for a time of 12 or 24 hours and then they were eliminated by centrifugation, then determining the quantity of residual lysozyme in the synthetic wine. The polymers used were EB12 and a pyromellitic nanosponge based on β-cyclodextrins, defined NS-p18. Blank tests were also carried out, without adding any polymer. The results are reported in Table 4.

Table 4

Polymer test Polymer dose - Treatment time% reduction of mere g / hl tament (hours) lysozyme content

A - 0 12 1.00%

- 0 24 2.00%

B EB12 10 12 90.00%

EB12 10 24 92.00%

C NS-p18 10 12 79.00%

NS-p18 10 24 79.00%

The results of Table 4 show the absorption potential of the two polymers used, in particular of EB12.

EXAMPLE 5

Three different types of white wine and two different types of red wine were treated with NS-p18. 50 g / hl of polymer were added to the wines and left to settle at the bottom of the vessel. Then centrifugation was carried out and the protein instability of the wines was evaluated, before and after the treatment; this evaluation took place through a hot test, commonly used in cellars, by heating the wine to 80 ° C for 30 minutes and measuring turbidity in ∠† NTU. The results are summarized in Table 5.

Table 5

Wine Instability wine tal Instability wine treated - Variation ∠† NTU which (∠† NTU) tato with 50 g / hl of

NS.p18 (∠† NTU)

White 1 16.5 3.3 -80.00%

White 2 7.66 0.1 -99.00%

White 3 6.5 2.9 -56.00%

Red 1 87.6 0.1 -99.00%

Red 2 4.43 0.11 -98.00%

The results show the reduction of the protein instability indices in the treated wines, always higher than 50% and on some wines even practically total. In three out of five cases the wine has become completely stable and in the other two it has brought the instability index below the values that recommend treatment with bentonite.

EXAMPLE 6

A white wine from Sauvignon blanc grapes was treated with increasing doses of EB12 and NS-p18, according to the same methods described in the previous Examples. The concentration of the protein fractions was precisely determined by electrophoresis. The treatment was also performed in the presence of an excellent quality bentonite, commonly used for these purifications. The results are reported in Table 6.

Table 6

Adjuvant Adjuvant doses (g / hl)

0 25 100 1000 Concentration in unstable proteins (mg / l)

Bentonite E 490 371 96

EB12 490 389 330 205

NS-p18 490 414 37 20

The different efficacy of possible adjuvants can be seen from the results shown in Table 6; particularly good results are obtained using NSp18, while EB12 proved to be the least effective.

It is understood that the invention must not be considered limited to the particular examples illustrated above, which are only exemplary embodiments of it, but that various variants are possible, all within the reach of a person skilled in the art, without thereby departing from the scope of protection of the invention itself, as defined by the following claims.

Claims (18)

CLAIMS 1) Process of treating beverages of vegetable origin to selectively eliminate unwanted molecules contained in them, characterized by what involves the contact between the beverage and a synthetic polymer, obtained by polymerization of monomers selected from the group consisting of Î ± -, β -, γ-cyclodextrins, methacrylic acid, vinylpyridine, tetraethylorthosilicate, 3-aminopropyltrimethoxysilane and their derivatives and mixtures. 2) Procedure as in 1), characterized by what is applied to drinks chosen from the group consisting of orange juice, lemon juice, grapefruit juice, pineapple juice, apple juice, pear juice, d 'juice apricot, peach juice, tomato juice, grape juice, cranberry juice, raspberry juice, cherry juice, sour cherry juice, lime juice, olive oil, soybean oil, sunflower oil, sunflower oil corn, must, wine, cider, beer, wine vinegar, apple vinegar, beer vinegar, grappa, whiskey, vodka, rum, cognac, tea infusions and beverages based on plant extracts. 3) Process as in any one of claims 1) and 2), characterized in that said polymers are synthesized by radical polymerization or via sol-gel and optionally co-polymerized with bentonite and / or silica gel. 4) Process as in claim 3), characterized in that said polymers are obtained using as crosslinkers active carbonyl compounds, organic anhydrides, diisocyanates, ethylene glycol dimethacrylate, polyamidoamine, 2,2-bis (acrylamido) acetic acid, 2-methylpiperazine. 5) Process as in claim 4), characterized in that said active carbonyl compounds are selected from carbonyl-diimidazole and triphosgene. 6) Process as in 4), characterized by what is called the organic anhydride pyromellitic anhydride. 7) Process as in any one of the preceding claims, characterized in that said polymers are synthesized according to the molecular mold technique, in the presence of one or more molecules, equal or similar to those to be eliminated from the beverage. 8) Process as in 7), characterized by what are removed from the drinks methoxypyrazines, aldehydes, geosmin, 1-obtain-3-ol, 1-obtain-3-one, 2-methylisoborneol, furfural, benzaldehyde, phenylacetaldehyde, sulphides, thiols, mercaptans, pyridines, pyrrolines, sotolone, acetoaminophenone, singly or in combination with each other. 9) Procedure as in 8), characterized by what metoxypyrazine and / or hexanal are removed from the drink. 10) Process as in any one of the preceding claims, characterized in that the unstable protein fractions of the drink and any unwanted enzymes present in the drink are removed from the drink. 11) Process as in any one of claims 7) to 10), characterized in that the beverage is treated simultaneously with different molecularly molded polymers or with polymers designed in such a way as to be able to simultaneously absorb various unwanted molecules. 12) Process as in any one of claims 7) to 10), characterized in that one operates in several treatment stages, each with a different molecularly molded polymer, removing the unwanted substances, one per treatment stage. 13) Process as in any one of the preceding claims, characterized in that enzymes and / or proteins are immobilized on the polymers. 14) Process as in claim 13), characterized in that the substances immobilized on said polymers are selected from pectinase, protease, glucanase, glycosidase, lysozyme and urease. 15) Process according to any one of the preceding claims, characterized in that the polymers are put into contact with the beverage to be treated by immersion and suspension of the polymer in the beverage, possibly under stirring and subsequent filtration after sufficient time has passed to allow absorption of harmful substances by polymers. 16) Process as in claim 15), characterized in that the polymer is mixed with filter aids, such as diatomaceous earth or cellulose. 17) Process according to any one of claims 1) to 14), characterized in that a column of polymer is filled, for example in granules, powder or spheres, and the juice or derivative to be treated is passed through with a calculated flow rate so as to allow the beverage itself a sufficient residence time in the column to allow the aforementioned absorption. 18) Process as in any one of the preceding claims, characterized in that the polymer is added in an amount ranging from 0.1 mg to 200 g per hectolitre of beverage.