DE1272861B - Process for preventing the formation of turbidity in beverages - Google Patents

Description

Process for preventing the formation of cloudiness in beverages The present invention relates to a method of prevention or aggravation the formation of turbidity in fermented or unfermented, from grain, fruits, other beverages made or parts thereof, especially in malt beverages, z. B. Beer, and fruit juices or wines.

Such drinks tend to be even if they are immediately after bottling in bottles are clear, leading to the formation of cloudiness during storage especially the appearance and taste of the drink are deteriorated. A similar one Cloudiness can arise when cooling down. The composition of the resulting turbidity or the precipitate formed is variable and not entirely known; one takes however, suggest that it is often caused by high molecular weight proteins that are either fail as such or those with naturally existing or as a special addition added tannin (tannic acid) form complexes that are soluble at room temperature and which fail during storage or cooling. In the production of beer the same is often treated with proteolytic enzymes or with tannin in order to High molecular weight proteins that are not desired in the largest possible way before filling Reduce or eliminate scope. However, it is not possible through this To completely prevent the development of cloudiness during storage or cooling of the beer, because the tannin after the removal of the tannin-protein complex obtained by adding tannin itself can also form opacities, which is possibly due to the fact that during polymerization or oxidation reactions take place during storage.

U.S. Patent 2,688,550 describes a method of prevention the formation of cloudiness of the type mentioned due to the addition of a precipitant, namely polyvinylpyrrolidone, hereinafter referred to as PVP for short, which causes the precipitation of tannin and possibly remaining tannin-protein complexes in the solution causes. According to this patent, it should be important that neither one to large nor too small an amount of polyvinylpyrrolidone is added, as this leads to a supposed to lead to worsened precipitation. However, it has been shown that an in Precipitation carried out in this way, the formation of opacities in the following Can't completely prevent storage and cooling; this is probably due to that the precipitation is incomplete and that new insoluble complexes during the Storage can be formed.

To achieve an optimal or maximum precipitation of the haze-forming Ingredients in beer beverages The required amount of PVP is different for each type of beer and varies depending on the average molecular weight of the PVP used up to about 8 g / hl (cf. the above-mentioned patent, according to which the additional amount PVP can vary between 2 and 8 g per 1001). From the USA patent specification goes clearly shows that the PVP preparation used has an average molecular weight must have of over 15,000, since tests have shown that PVP with a lower average Molecular weight does not prevent the precipitation of the haze-forming constituents of the beer can cause.

Based on this prior art to prevent formation of cloudiness in beverages, e.g. B. malt beverages, fruit juices and wines, whereby by adding polyvinylpyrrolidone or one of its homologues tannin or tannin-protein complexes are precipitated, the inventive method is characterized in that the polyvinylpyrrolidone or one of its homologues in excess in an amount which exceeds the amount required for maximum precipitation by at least 50%, but at least 1 g per 100 liters added.

Thanks to this way of working, it is surprisingly possible that the otherwise when storing beverages, e.g. B. malt beverages, fruit juices and wines, light to prevent occurring cloudiness. The upper limit for the amount of the PVP addition is not critical, but is mainly due to the cost of the PVP preparation determined. Apart from the cost, however, beer shouldn't be considered add more than 500 g per 1001, otherwise the desired properties of the beer, z. B. its taste, its foaming power, etc., can be deteriorated. It It has been found that no particular advantages are obtained when one altogether more added than 100 g PVP per 1001, regardless of whether it is high or low molecular weight PVP acts.

The total amount of PVP added can be between 1 and 500 g per 1001 vary. However, it is generally most convenient to have between 5 and to add 50 g of PVP per 1001, in any case at least 50 o / a over that The amount to be added is sufficient for the maximum precipitation of the haze-forming Components is required. It is preferable to use a PVP with a medium Molecular weight below about 15,000 as the required amount then. a bit lower than when using higher average molecular weight PVP.

As mentioned above, the average molecular weight of the PVP can be both below as well as above 15,000. In principle it is possible according to the invention on the one hand a PVP with an average molecular weight of only about 550, d. H. approximately corresponding to the pentamer of vinylpyrrolidone, or on the other hand To use PVP with such a high average molecular weight of about 2,500,000. Good results are achieved with a PVP whose average molecular weight is at least is around 2000, and the best results are usually obtained with PVP, its average molecular weight is about 7,500 to 40,000, preferably 7,500 to 15,000.

The method according to the invention can be implemented in four alternative embodiments be performed. According to the first alternative, a PVP that contains tannin is first used or tannin-protein complexes can form a precipitate, d. H. that a mean one Molecular weight above about 15,000 has been added in such an amount that the maximum amount of rainfall is obtained. The amount required is easy to determine by means of a preliminary test which can be carried out in the manner described below. Thereafter, the resulting precipitate is z. B. deposited by filtration. Then PVP is added in excess over the amount added first, with the excess is at least 50%. However, the total amount should be at least 1 g and preferably between 5 and 50 g per 1001.

Even after the second alternative, a will result in the formation of a precipitate suitable PVP added, directly in a total amount of at least 1 g and preferably 5 to 50 g per 1001, but at least 50% over the through a simple preliminary test determined the amount that leads to the maximum precipitation of the haze-forming constituents is required. The possibly educated Precipitate dissolves again and is converted into a soluble PVP complex or in a soluble compound that remains stable for a very long time.

The third alternative is to use PVP with a medium molecular weight below about 15,000, with no precipitate being formed, and continues overall at least 1 g per 100 l and preferably between 5 and 50 g per 100 l. The PVP forms directly soluble complexes or soluble compounds, and the existing one Excess is sufficient to prevent cloudiness from occurring later during to prevent clouding-forming compounds in the drink resulting from storage.

According to the fourth alternative, PVP is used in a total amount of at least 1 g, preferably between 5 and 50 g, added to drinks in which haze-forming Compounds that can form a precipitate with PVP do not occur, whereby other haze-forming compounds that are present from the start and those with PVP cannot form a precipitate, or haze-forming compounds that later are formed by the existing excess of PVP in the form of stable soluble Complex or soluble compounds are kept in solution.

Due to the excess of PVP that is present, the formation of Precipitates from insoluble, high molecular weight, tannin-containing or tannin-like substances prevented. It has also been shown that the addition of an excess of PVP according to the invention reduces the taste and smell of the beverage and, in the case of beer, also improve the foaming power and foam resistance can. The improvement in foaming ability and foam strength appears thereby causes the precipitation of certain high molecular weight proteins, their presence seems to be necessary for foam formation and foam strength, is prevented.

To determine the amount of PVP with which maximum precipitation is achieved and which usually varies between about 2 and 8 g per 1001 is measured a certain volume of the finished drink or drink being prepared and adds varying amounts of PVP to it. After a few days you can, for. B. visually or by centrifugation, easily determine the amount of PVP, which is the maximum Caused precipitation. Then proceed according to one of the alternatives mentioned above, d. That is, PVP is added to the drink so that there is a maximum amount of precipitation is formed, whereupon this precipitate is filtered off and also at least 50% of the amount added first, preferably between 5 and 50 g PVP per 1001 (alternative I) is added, or PVP is added directly in the same excess amount (alternatives II; HI or IV). It should be noted, however, that the added in each individual case Total PVP amount must be at least 1 g per 1001.

PVP, which is also a well-known blood plasma substitute, can be used without Disadvantage can be consumed per os and can therefore be added to drinks without danger will. PVP quickly dissolves in water to form a completely clear solution, which remains stable during cooking.

PVP can either be in the form of a powder or in the form of a solution in water or in the drink in question. The addition can be in take place at each stage of manufacture of the beverage, but is preferably done only after the removal of any solid precipitation Blows. The application of the invention is particularly advantageous in the production of malt beverages, z. B. of beer, thin beer and porter. Here, the addition of PVP can be in any Production stage related to the preparation of the mash and the bottling take place with the clarification treatment, e.g. B. with filtration or centrifugation, Pasteurization, treatment with ascorbic acid, proteolytic enzymes, bentonite, Diatomaceous earth, etc. In the case of the beverage being treated with tannin to precipitate For high molecular weight proteins, of course, the addition of PVP must be added after filtering off of the tannin protein precipitate. However, the addition is preferred either immediately before, during or after the separation or filtration takes place, which is carried out after storage but before bottling. Particularly good results is obtained when the additive is added after the final filtration according to any of the above Alternatives II, III or IV takes place. When using alternative I finds the first addition of PVP, preferably at the end of storage, but before the final filtration instead, the required excess of PVP being added after the final filtration will. If necessary, stir gently during the addition. The addition can, if one can improve the foaming power and at the same time wants to bring about the foam firmness of a beer, for example before or take place during mashing and during storage, with precipitation the so-called cold haze is wholly or partially prevented.

The addition takes place preferably at -5 to -I-25 ° C, but can even under heating, e.g. B. to a temperature between room temperature and 100 ° C, take place, for example in connection with pasteurization, or at even higher temperature, e.g. B. in connection with any sterilization carried out. If it is added immediately before the beverage is filtered and bottled, it is over For economic reasons, it is usually not favorable to carry out a special heating. When practicing the present method, it is expedient to first use a Solution of PVP in water or in the drink to which the solution is to be added, prepares. This solution can be of any concentration and is preferred 10 to 50 per cent.

The invention can provide the same advantage in the manufacture of all Drinks are used that are known to be in storage or when cooling down due to the presence of tannin or tannin-protein complexes cloudiness form, e.g. B. besides malt beverages also fruit juices and wines. By the invention The main addition is the storage stability, but also the smell and taste improved.

The invention is illustrated in more detail by the following examples.

Example 1 The treatment with PVP is carried out on the one hand in accordance with US Pat. No. 2688550 and on the other hand in accordance with the above-described alternatives I, II and III of the present invention with a number of equally large amounts of beer originating from the same brew. In the treatment according to the USA patent, the PVP was partly (A) added when the beer was transferred from the fermentation cellar to the storage cellar, and partly (B) after a pre-filtration 20 days before the final filtration. A part of the beer treated according to the later method (B) was also treated after the final filtration with PVP according to alternative I of the present invention. Additions to the filtered beer according to alternatives 1I and III were made the day before bottling. In all cases the beer was pasteurized. The cloudiness caused by oxidation and cold was observed; the observation results are shown in Table 1 below. Oxidation haze is the haze that occurs when beer is stored at 25 ° C, and cold haze is the haze that appears at 0 ° C and occurs when the beer alternates between 6 days at 25 ° C and 1 day at 0 ° C. The table shows that the resistance of the beer to cloudiness is improved to a high degree by the process according to the invention and that a particularly pronounced improvement is achieved by alternative III, ie when using PVP with an average molecular weight below about 15,000.

Example 2 A number of equally large amounts of beer from the same brew were treated with PVP with different average molecular weights. The whole amount of PVP was added to the filtered beer the day before bottling and all bottles were pasteurized. The amounts added and the results obtained are shown in Table 2. From Table 2 it can be seen that the best results are obtained with PVP with an average molecular weight between about 4200 and 38,000, but that PVP with a higher average molecular weight also gives a substantial improvement.

Example 3 Unpasteurized beer, obtained from different breweries and with different tendencies towards cloudiness, was admixed with an amount of PVP with an average molecular weight of 11,300 corresponding to 15 g per 100 liters . The bottle was first cooled to 0 ° C., whereupon 1 ml of a PVP solution was carefully added and the bottle was closed again. In a control sample, 1 ml of water was added instead of 1 ml of PVP solution. All bottles were pasteurized after the addition of PVP. Table 3 Number of weeks before occurrence Designation of the oxidation cloudiness the brewery with pyp Control sample 1 treated sample A 8 39 B 16 51 C 13 50 D 34 70 E 40 70 F 21 62 The results given show that the addition of PVP according to the invention results in a substantial improvement in all cases.

Example 4 Unpasteurized beer obtained from various breweries with a tendency towards very rapid cloud formation was treated with PVP as in Example 3. The bottles have not been pasteurized. Table 4 Number of weeks before occurrence Designation of the oxidation cloudiness *) the brewery with PVP Control sample [treated sample G 1 6 H 2 6 I 2 6 K 0.5 6 *) The observations were discontinued after 6 weeks broken as the beer wasn't pasteurized.

Claims (1)

Claim: Process for preventing the formation of opacities in beverages, e.g. B. malt beverages, fruit juices and wines, with the addition of Polyvinylpyrrolidone or one of its homologues tannin or tannin-protein complexes be precipitated, characterized in that one or the polyvinylpyrrolidone one of its homologues in excess in an amount which leads to the maximum precipitation exceeds the required amount by at least 50%, but at least 1 g per 1001, clogs. References considered: British Patent No. 736,565; U.S. Patent No. 2,688,550.