DE1160812B - Process to increase the protein stability of beer - Google Patents

Description

Method for increasing the protein stability of beer The invention relates to a method for increasing the protein stability of beer.

Because of the purity law applicable in Germany, here in general to improve the protein stability of beer bentonite (aluminum silicate of the type des montmorillonite). For this purpose, the bentonite is in the to be stabilized Beer introduced, resulting in a very fine suspension with strong swelling. This suspension cannot be filtered or is extremely difficult to filter. the For this reason, the bentonite is removed from the beer by sedimentation achieved. To do this, the beer mixed with bentonite must go through its own process, which consists in the fact that the already matured beer is an additional Storage of 5 to 12 days is subjected, during which then the bentonite largely settles as sediment. The supernatant clear beer is filtered and bottled. The bentonite sludge with the beer it contains usually has to be discarded because the beer cannot be recovered from it by simple means. The resulting beer loss depends on the amount of bentonite and can up to 611 / o and above.

The bentonite turns the beer into high-molecular-weight proteins distant, but not very selective. The bentonite not only binds that specifically Protein responsible for the formation of cloudiness. Rather, he removes it from the beer also contains other protein substances, their presence in the beer for reasons of foam content and the full-bodiedness is also desirable. So it happens that beers that Treated with higher amounts of bentonite due to special stability requirements must be (100 g / hl and more) in their foam content and also in taste may show significant changes to their disadvantage.

The treatment of beer with freshly precipitated silicic acid hydra-t or Silica hydrate dried while maintaining the hydrate character to increase the Protein stability is also already known. The ones used in this procedure However, silica gels proved to be protein-stabilizing compared to amberite Effect as inferior. Also the complexity of the procedure and the lack of it Purity taking into account the purity law led to the process was practically not applied. Experiments by the inventors with the known ones Silica gels prepared according to regulations led to unsatisfactory results. It is known that the adsorptive properties of pebbles depend on their physical and the fine chemical structure. This fine structure depends on the manufacturing method of silica gels and can vary within extremely wide limits. So vary naturally also the adsorptive properties, so that by no means every popular one Silica gel is suitable for protein adsorption from beer or as opposed to bentonite Brings advantages.

In the systematic study of silica gels more diverse Production method has shown that for the adsorption of haze-forming Protein substances from beer only come into question for very specific products. It deals These are so-called wide-pored silica gels of a very specific nature. Porous silica gels were actually made according to the aforementioned known method already used to increase the protein stability of beer, but not the wide-pored silica gels known for other purposes with a bulk density of highest 0.5 kg / 1, with a surface area of 200 to 400 m2 / g, with a pore volume of more than 0.6 ml / g and a pore diameter of more than 60 Å, which furthermore finely ground, largely dehydrated and therefore storable products (Xerogede) which do not change their volume when they absorb water, i.e. do not swell Water release does not shrink and in which the absorption and release of capillary water reversible.

It has been shown that with very careful washing it is more like this Wait-pore silica succeeds in keeping its share of water-soluble substances up to below 1%, so that from the point of view of the Reinheltsgebot there is no Concerns about the use of such silica gels to stabilize protein Beer. Careful washing of the world-pored silica gels is therefore a necessary prerequisite for carrying out the invention.

The production of such globally pored silica gel is known. World-pore products can be obtained in the familiar way via the manufacture of Silicic acid jellies come from alkali silicate and acids. You can also use Silica precipitates go out, the z. B. in the precipitation of silica with Mineral acids occur if certain conditions are observed or if the silica is precipitated from alkali metal silicate with carbonic acid. Furthermore you can also convert crystallized sodium metal silicate with << 0% sulfuric acid or digest other silicates with acids. But there are still many more other ways are known (see Gmelins Handbuch der Inorganic Chemistry, Vol. 1513, Verlag Chemie, 1959).

Such global pore silica gels are useful for protein stabilization beer has considerable advantages compared to the well-known bentonites. You own a particularly good and selective adsorption effect compared to the high molecular weight Protein substances in beer, but there is also the advantage that the Silica gel at any time by filtration, if necessary under that known per se Shared use of a filter aid, e.g. B. diatomaceous earth or cellulose, again the beers can be removed. The adsorption effect of a globally porous silica gel is so good that z. B. when using 100 o, / hl already a few minutes exposure time sufficient to cause extensive adsorption of the protein substances that cause turbidity to get. Naturally, the effect increases with a longer exposure time a little more. But even then, there is nothing that makes filterability difficult Swelling of the silica gel, so that even if there is a very long exposure time a silica gel sediment should have formed, this silica gel sediment without beer losses can be filtered off completely.

A very significant improvement in the adsorption effect or the The protein stability is increased if the silica gel according to the invention is used Texture - regardless of how it was made - after its world-pore Structure is fixed, subjected to an additional acid treatment known per se will. In principle, any strong acid is suitable for acid aftertreatment, but hydrochloric acid or nitric acid should be given preference because their last traces after washing, evaporate during the final drying of the silica gel. The effect the acidity increases with increasing concentration. The acid treatment can be carried out both in the cold and in the warm. It is with consideration on the legal provisions (beer tax and food law) in Germany it is important that the end products are so far free of excess acid, that they have a ptt value of 5 to in 5o / o suspension in distilled water 7 have.

The advantage of the acid treatment is that in addition to the known better washout effect with respect to water-soluble substances a considerable improvement the adsorptive properties, especially in terms of selectivity will. The adsorption effect is also improved in quantitative terms, however this increase does not fall so. very important as the improvement of the selectivity. The world-pore character thus apparently mainly determines the amount of per weight unit Silica gel made from nitrogen bound by beer. The acid aftertreatment, on the other hand, has the effect of that the adsorbent is made particularly selective in its action, so that it specifically binds the proteins that are responsible for the protein cloudiness are and others. leaves desired proteins in the beer.

Comparative tests with the world-pore proposed according to the invention Silica gels and with the known methods for increasing the amount already mentioned above the protein stability of beer already used, while maintaining the hydratractor dried, granular silicic acid hydrates gave clear results. The cold haze after the same storage times of the beer was after in Kosumbier Treatment after the procedure over four times as severe as after equivalent treatment with the same amount of the globally porous silica gel. Compared to a post-treated with acid Beer mixed with world-pore silica gel showed that treated according to the old method same beer almost six times the cold cloudiness.

The following Examples 1 to 3 provide more detailed information about these experiments: Example 1 12.5 "ounce consumer beer was filled into 1-1 beer bottles and cooled to 0" C. in ice water. Graduated amounts of various silica gels described below were added to this beer. The samples were shaken vigorously and then remain in ice water for about 4 hours to allow the silica gel to sediment. Thereafter, all samples were filtered in the same way at a room temperature of 2. C through folded filters into other sample bottles with a capacity of 0.35 l. This sample bottle. which all had the same empty space in the bottle neck of 10 ml, were then first placed at 40 ° C. for 4 days and then placed in melting ice for 24 hours. After 6 hours and after 24 hours, the increase in the relative turbidity was measured, which is to be regarded as a measure of the stabilizing effect that has occurred. In addition, the ammonium sulfate precipitation limit was determined in the samples, which is also a measure of the stability of a beer. The results of this experiment are compiled in Table 1 below. Table 1 Ammonia cold haze Sulfate; after precipitation t; Hours'_'- 1 hour limit ice is ice Untreated equal beer ...... 0.90 350 560 Silica gel B j 0.25 gil ......... 0.97 I 190 320 0.59111 .......... I 1.08 i 120 240 1.0 gfl .......... l., 34 90 170 Silica gel ST 0.25 g, 11 ......... 1.15 95 230 0, _5 g1 .......... 1.35 70 160 1.0 g.'1 .......... , 1, 7 @j 65 130 Table 1 (continued) Ammonia cold haze Sulfate after precipitation 6 hours 124 hours limit ice 1 ice Pattern 1 1.0 g / 1 .......... 0.95 230 370 2.0 gll .......... 1.07 200 310 Pattern 2 1.0 g / 1 .......... 0.96 230 380 2.0 g / 1 .......... 0.98 200 310 Pattern 3 1.0 g / 1 .......... 0.95 370 480 2.0 g 11 .......... 1.00 180 360 The following different types of silica gels were used: silica gel B Wide-pore silica gel (commercial product) with the following properties: inner surface (m2 / g). . 300 to 350 pore volume (cm3 / g) .... 0.75 to 0.80 Average pore diameter (A) ....... 80 to 90 Bulk weight (kg / 1) ...... 0.38 up to 0.42 silica gel ST.

Wide-pored silica gel (commercial product) with the aforementioned properties aftertreated with acid.

Sample 1 Made from water glass 40 B6 diluted 1: 1 with water by adding concentrated hydrochloric acid diluted 1: 1 with water (in a ratio of Table 2 First cold test Second cold test Ammonium sulfate turbidity after turbidity after maturity limit 6 hours 24 hours 6 hours I 24 hours Ice ice ice ice cream Untreated reference beer 0.95 400 960 960 1950 Silica gel ST 0.25 g / 1 ................. 1.14 100 230 420 950 0.5 g / 1 .................. 1.29 60 140 280 840 1.0 g / 1 .................. 1.45 40 60 150 350 Pattern 2 1.0 gll .................. 1.05 160 290 740 1100 2.0 g ( 1 .................. 1.14 90 210 440! 950 Pattern 3 1.0 gll .................. 1.05 200 350 950 1800 2.0 g / 1 .................. 1.12 140 190 800 1000 Pattern 5 1.0 g / 1 .................. 0.96 200 1 300 900 `@ 1700 2.0 g / 1 .................. 1.02 150 250 850 1100 Pattern 6 1.0 g / 1 .................. 1.08 240 420 900 1800 2.0 g / 1 .................. 1.12 200 290. 600 1000 2.8 parts of dilute waterglass solution to 1 part of dilute acid) silica gel obtained and precipitated with 25% ammonia solution, granulated and dried at 100 ° C with the following properties: Inner surface (m2 / g) ......... 136 , 3 pore volume (cms / g) ............ 0.605 mean pore diameter (A) ... 177.6 Bulk weight (kg / l) .............. 0.222 Sample 2 From water glass diluted 1: 1 with water by adding it to 3N hydrochloric acid cooled in ice water (in the ratio 4.5 parts of dilute waterglass solution to 1 part of acid) is obtained and granulated and dried in a stream of warm air, precipitated by adding 25% ammonia solution. Sample 3 As in sample 2, but with 1.5N hydrochloric acid (in a ratio of 2.25 parts of dilute water glass solution to 1 part of acid), silica gel precipitated and dried with ammonia, as in sample 2, with the following properties: Inner surface (m2 / g) .......... 125.7 pore volume (cm3 / g) ............ 0.76 mean pore diameter (A) .... 239.8 bulk weight (kg / 1) .............. 0.452 Example 2 The procedure described in Example 1 was followed, but a different beer was used. In the example of Example 1, the cold stability test was carried out after the samples had been stored at 40 ° C. for 5 days. In addition, after this cold test, the samples were again kept at 40 ° C. for 4 days and then checked again for cold haze. The results can be found in Table 2 below. The following different types of silica gel were used: ST silica gel As indicated in Example 1. Pattern 2 As indicated in example 1. Pattern 2 As indicated in example 1. Pattern 3 As indicated in example 1. Sample 5 One from sample 1 after suspending in distilled water (40 g of silica gel in 11), shaking for 1 hour, suction. Another 1 hour shaking in distilled water, suction, repeated shaking in distilled water and drying of the product then sucked off for 4 hours at 150 ° C obtained silica gel. Table 3 First cold test Second cold test Ammonium sulfate turbidity after turbidity after maturity limit 6 hours 24 hours% @ hours 2-1 hours Ice ice cream j ice cream ice cream f Untreated comparison beer 0.90 160 300 85t) 1700 Silica gel ST ' 0.25 gl ................. 1.23 50 / -5 ' 9 ( ) i> 50 0.5g / 1 .................. 1.41 40 50 2 <, i) 550 1.0 ga .................. 1.67 35 40 11) (2.0 Pattern 2 1.0g / 1 ......... ......... 1.09 45 1.30 500 900 2.0 g .................. 1_, 23 30 60 400 750 Pattern 3 1.0 g. " 1 .................. 1.09 45 125 65t) 950 2.0 gll .................. 1.26 40 70 3190 500 Pattern 5 1.0 g / 1 .................. 1.05 80 160 9 ',) 0 1,100 2.0 g / 1 .................. 1.15 40 110 500 900 Pattern 6 1.0 g, `1 .................. 1.03 40 170 750 900 2.0g11 ........... . ...... l., 23 30 100 -150 850 Example 4 Use of a wide-pored and acid-treated silica gel according to the invention, which after its preparation and careful washing in 5% aqueous suspension has a p11 value of 8.0, is treated with 5N nitric acid for 1 hour Held at 100 ° C. The acid is then washed out and the preparation is dried at 200 ° C. for 6 hours. From this preparation treated with acid and also from the starting material, 0.5 g and 1.0 g are placed in 500 ml of carbonated beer and shaken for 1/10 of an hour. It is then filtered and the total nitrogen in the filtrate is determined. Its reduction provides information about the adsorption effect in quantitative terms. In addition, the ammonium sulfate precipitation limit is determined in the filtrate. This test provides information about changes in colloidal stability. The higher the value sample 6 one from sample 1 by stirring with nitric acid (40 g silica gel, 400 ml distilled water and 100 ml concentrated nitric acid), leaving to stand overnight, then boiling for one hour, adding the batch to 51 distilled water, decanting after 3 hours Silica gel obtained, suction, washing and drying for 1 hour at 150 ° C.

Example 3 This example was carried out with a third, also 12.5% consumer beer. The procedure was as described in the previous examples, but the filtered samples were initially kept at 60 ° C. for 4 days before the cold stability was tested. After this test, the samples came to 40 ° C for another 5 days, in order to be examined a second time for cold stability. The results can be found in Table 3 below.

The types of silica used correspond to those used in Example 2. is, the more stable the beer and the more selective the silica gel was. Analysis results Ammonium Total N sulfate precipitation border 1. Untreated beer 68.6 mg-100 ml 0.9 2. Untreated Silica gel 0.5 g / 500 ml ...... 65.2 mg / 100 ml 1.24 1.0 g / 500 ml ....... 63.7 mg @ 100 ml 1.47 3. Acid treated Silica gel 0.5 g / 500 ml ...... 64.9 mgi 100 ml 2.40 1.0 g / 500 ml ....... 63.2 mgi l00 ml 2.90 Example 5 Implementation of wide pore acid treated silica gel according to the invention compared to bentonite.

a) Beer is made with 150 g / hl bentonite (on the filing date under the trademark "Deglutan" available from Protex). It remains for sedimentation of the bentonite stand at 0 ° C for 7 days. Then the protruding, largely clarified Beer filtered and bottled.

b) The same beer is used with 150 g / hl of a world-pore according to the invention, treated with acid treated silica gel and after an exposure time of 5 minutes filtered off and bottled.

c) The beer used under a) and b) is filtered and bottled without treatment. Results of the analyzes a) b) c) Total N. (mg / 100 ml) .... 60.6 66.6 71.0 Ammonium sulfate settlement limit ... 1.3 2.4 0.9 Foam value ...... 119 127 128 Cold cloudiness ...... 0 0 450 Turbidity after Forced test on Protein stability. . 350 410> 2000 This example shows that beers a) and b) have approximately the same protein stability. When the beer was treated with globular silica gel, the total N was only reduced by 4.4 mg / 100 ml, while 10.4 mg N was bound by the bentonite. Among the nitrogen substances bound by bentonite there are therefore very many substances that are not at all important for protein stability. As a result of this less selective action of the bentonite, foam-promoting substances have apparently also been bound, which is expressed in the considerable drop in the foam number.

Claims (2)

Claims: 1. Method for increasing the protein stability of Beer using global pore silica gel as an adsorbent, d a d u r c h g e - indicates that the beer is treated with a finely ground silica gel, that has a surface area of 200 to 400 m2 / g, a pore volume of more than 0.6 ml / g and has a pore diameter greater than 60 Å. 2. The method according to claim 1, characterized in that the silica gel is a known acid aftertreatment : is subjected and the usual subsequent washing with water carried out so far is that the dry product in 5o / o suspension in distilled water a shows pH from 0.5 to 7.0. Publications considered: German Patent Specifications No. 710 785, 758 041; Gmelin's "Handbook of Inorganic Chemistry", 1959, 13d. 1513, P. 473.