SK10552000A3 - Method for producing alcohol-free and low alcohol beverages based on wort or malt wort, including alcohol-free and low alcohol beer - Google Patents

Abstract

A batch or continuous fermentation of a beerwort or wort is carried out by means of the mutant yeast with failure in synthesis of citric acid cycle enzymes. The yeast immobilized in calcium pectate are preferably used. The fermentation is carried out at a temperature of from 5 to 35 °C and at concentration of soluble oxygen up to 20 mg/l.

Description

Technical field

The invention relates to a process for producing non-alcoholic and low-alcoholic wort or wort-based beverages including low-alcoholic and non-alcoholic beer by fermentation, batch or continuous, in the presence of yeast mutants with impaired citrate cycle enzyme synthesis using free or immobilized cells.

BACKGROUND OF THE INVENTION

Non-alcoholic beer production has been a long-term problem in the brewing industry. The consumer's demands on sensory properties are the same as for classic beers, but alcohol content may be limited for various legislative or health reasons. The production of low-alcohol beer requires changes in technological processes. In practice, two methods of production are most applied, namely the fermentation limitation so that the alcohol concentration remains below the desired value in the product and the second option is the separation of alcohol from beer produced by conventional technology.

Systems for the production of low-alcohol and non-alcoholic beers using immobilized yeast have also been tested. In the plants, perforated tray fermenters are applied, where DEAE cellulose is used as the carrier. Such systems are used in the Netherlands and Denmark. A bioreactor with internal recycle of the substrate was also used to produce the non-alcoholic beer, wherein the yeasts were immobilized in a silicone carbide carrier [Van de Winkel, L., Van Beveren, P.C., Masschelein, C.A., Proc. EBC Congr. 1991, p. 574]. The beer produced in this way has an alcohol content in the range of 0.50.1% by volume, but with a slight yeasty flavor and a rich aroma. In addition to the two low-alcohol beer carriers, yeasts immobilized on a sintered glass surface having a particle diameter of 1-2 mm with a porosity of up to 55% of macroporous glass were used [Aivasidis, A., Wandrey, C., Eils, HG, Katzke, M. Proc. EBC Congr. 1991, p. 569]. The fermentation was carried out in a fluidized bed reactor and the residence time of the product was 16 hours. The beer thus obtained was evaluated by a tasting test and compared with

- 2 beers produced by classical "stop-fermentation". Four of the tasters preferred the reference beer and three clearly preferred the beer produced by the new technology. The advantages of this method of producing low-alcohol beer are mainly in the possibility of controlling fermentation parameters [Steven, A.H., Power, J., Ryder, D.S .: Brew. diges., 1, 1991., p.44], which also affects the sensory and analytical parameters of the finished product. By controlling the flow rate, fermentation temperature and the amount of biomass, the balance of individual parameters of the finished product can be controlled.

Since it is not possible to use the stabilizing effects of ethanol as in the case of conventional beers when storing non-alcoholic and low-alcoholic beverages, pH reduction is mainly used to protect against bacterial contamination. This is accomplished by the addition of lactic acid to the wort or wort, or is added to the medium by the added lactic acid strains [Pittner, H., Back, W .: Tech. Quart. -Master Brew. Assoc. Amer., 32, 1995, p. 163; Stevens, B., Brew. Dist. Internation. 24,1993, p. 76].

Polysaccharide carriers, such as alginate and calcium pectate, are used in the production of classical beers by discontinuous [Poledníková, M., Voborsky, J., Chládek, L., Šruma, T., Kvasný prumysl, 39, p. Šmogrovičová, D., Domains, Z., Gemeiner, P., Malovíková, A., Šturdík, E .: Biotech. Tech., 4, 1997, p.261]. Alginate and pectate beads were compared in continuous wort fermentation in a gas-lift reactor and packed column [Šmogrovičová, D., Domains, Z., Gemeiner, P., Malovíková A., Šturdík, E .: Biotech. Tech., 4, 1997, p.261]. Among these carriers, calcium pectate has been favored for higher mechanical stability [Gemeiner, P., Nahalka, J., Vikartovska, A., Nahalkova, J., Tomaska, M., Sturdik, E., Markovic, O., Malovikova, A., Zatkova, I., Ilavsky, M., Immobilized Cells: Basics and Applications, Elsevier Science BV, Amsterdam 1996, p.76]. However, calcium pectate as an immobilizing material in the production of low-alcohol beer has not yet been described in the literature. Its other properties and parameters are described in more detail in the patent collective patent [Šmogrovičová, D., Domains, Z., Šturdík, E., Gemeiner, P., Malovíková, A .: Patent SR, 1650-96].

It is an object of the present invention to allow the production of non-alcoholic and low-alcoholic beverages based on both wort and wort, including non-alcoholic and low-alcohol beer, without the need to inoculate them with a lactic acid strain to enhance stabilization.

3 Summary of the Invention

The object of the present invention is to provide a process for producing non-alcoholic and low-alcoholic worts based on wort or wort, including low-alcohol and non-alcoholic beer, by fermenting the wort or wort of the invention by continuous or batch fermentation at 0 to 35 ° C and pH from 1.5 to 7 SUMMARY OF THE INVENTION The fermentation is carried out in the presence of mutant strains of yeast Saccharomyces cerevisiae with impaired citrus cycle enzyme synthesis, wherein the yeast is in the free or immobilized state.

It has been found to be advantageous if the yeast is immobilized in a calcium pectate gel and a further increase in efficacy occurs when a continuous fermentation method is used, which is even more advantageous when using a perforated tray reactor.

Non-toxic carriers are used for immobilization, which ensure good transfer of nutrients to the cells and at the same time they are also resistant to physical influences in the fermentation medium. When using the immobilized system, it is possible to work above the critical dilution rate.

The advantage of the solution according to the invention lies in particular in that the production of organic acids by mutant strains of yeast eliminates the need for the addition of an acid or acid. inoculation with a lactic acid strain to enhance stabilization of wort or wort based soft and low alcohol beverages including low alcohol and non-alcoholic beer.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

Process for batch fermentation of free yeast wort w

A pure culture of yeast mutants was added to the batch reactor [Subík J .: Authorial Certificate No. 272963]. Fermentation at four different oxygen concentrations in the fermenter was carried out at fermentation of wort containing reducing saccharides in the range of 80 to 120 g / l, pH 5.6 and Saccharomyces cerevisiae cell concentration of 1.10 ⁷ cells / ml medium. Mutant yeast strains (especially Saccharomyces) were used

- 4 cerevisiae JS10-3C, 5. cerevisiae JS10-3CxJS 10-96, S. cerevisiae E2, S. cerevisiae EF2, and S. cerevisiae K303AKGD1 (other may also be used) with impaired fumarase enzyme synthesis, 2-oxo- glutarate dehydrogenase and other citrate cycle enzymes. The temperature range was from 5 to 35 ° C. The fermentation time was from 70 to 85 h, with the best beverage being obtained at 15 ° C. When the value of the actual extract had stabilized, the fermentation was terminated.

The beverage thus obtained had a low pH, substantially eliminating the acidification step of the non-alcoholic beer (prevention of contaminants). The fermentation time, the actual extract and the pH after fermentation for the most optimal strain (Saccharomyces cerevisiae JS10-3C) are shown in the following table.

Oxygen concentration 0 mg / l 2 mg / l 4 mg / l 6 mg / l Fermentation time 84 81 76 71 Actual extract (w / w) 4.21 4.13 4.12 4.11 Ethanol% (v / v) 0.39 0.34 0.28 0.21 PH 2.13 2.11 2.02 1.98

Example 2

Process for batch fermentation of wort with immobilized yeast

For immobilized yeast application, the procedure was analogous to Example 1 except that yeast as in Example 1 immobilized in calcium pectate was used for fermentation.

(a) Method for preparing a biocatalyst

Saccharomyces cerevisiae was cultured in flasks at 28 ° C. The culture was separated from the fermentation broth by centrifugation and the sediment was suspended in distilled water so that the yeast concentration in yeast milk was 10-fold higher than the concentration in the immobilisate. A suspension of 5% potassium pectate, 10% yeast milk and distilled water was prepared. A viscous composition was prepared from the above ingredients which dropped into 0.1 M CaCl ₂ solution to give beads with immobilized yeast.

b) Fermentation of wort

Various yeast strains (see Example 1) were used, mutant in the synthesis of citrate cycle enzymes, which were immobilized as described above. Worked in

- 5 temperature range from 5 to 35 ° C. The fermentation time was from 61 to 72 h. The highest quality beverage was obtained at 15 ° C. When the value of the actual extract had stabilized, the fermentation was terminated. The beverage thus prepared had a low pH, thereby eliminating the acidification step of the non-alcoholic beer (preventing contaminants). The fermentation time, the actual extract and the pH after fermentation with the most optimal strain (Saccharomyces cerevisiae JS10-3C) are summarized in the following table.

Oxygen concentration 0 mg / l 2 mg / l 4 mg / l 6 mg / l Fermentation time 72 71 65 61 Actual extract (w / w) 4.11 4.14 4.09 4.07 Ethanol% (v / v) 0.38 0.38 0.29 0.21 PH 2.15 2.05 2.01 1.89

Example 3

Production method by continuous fermentation of free yeast wort

Continuous fermentation using free yeast (see Example 1) was performed in a tubular fermenter as follows. The culture medium was fed to the tubular reactor from the bottom of the container and the product was fed to the top of the container.

Fermentation of wort containing reducing saccharides ranging from 80 to 120 g / L, pH 5.6 and Saccharomyces cerevisiae cell concentration of 1.10 cells / ml, fermentation was performed at four different concentrations of oxygen in a perforated tray fermenter. Various strains of yeast (see Example 1) mutant in the synthesis of citrate cycle enzymes were used. We worked in the temperature range from 5 to 35 ° C. The highest quality beverage was obtained at 15 ° C. The residence time in the fermenter was set so that the product at the exit of the fermenter was completely fermented. The conversion was fastest at the highest oxygen concentration. The achieved pH and the actual extract in the product for the most optimal strain (Saccharomyces cerevisiae JS10-3C) are shown in the following table.

Oxygen concentration 0 mg / l 2 mg / l 4 mg / l 6 mg / l Delay Time (h) 28 28 26 21 Actual extract (w / w) 4.13 4.11 3.97 3.86 Ethanol% (v / v) 0.34 0.31 0.28 0.23 eh 2.24 2.18 2.11 2.06

- 6 Example 4

Production method by continuous fermentation of wort with immobilized yeast

For immobilized yeast application (see Example 1), the procedure was analogous to Example 3 except that yeast immobilized in calcium pectate was used for fermentation.

The yeast was immobilized by the same procedure in the pectate gel as in Example 2. The differences were mainly in the retention time. Continuous fermentation with immobilized cells proceeded faster than in Example 3. The residence times, pH and actual extract values are shown in the following table.

Oxygen concentration 0 mg / l 2 mg / l 4 mg / l 6 mg / l Delay Time (h) 19 18 18 17 Actual extract (w / w) 4.12 4.09 4.01 3.01 Ethanol% (v / v) 0.37 0.34 0.28 0.19 PH 2.27 2.21 2.15 2.06

Example 5

Process for batch fermentation of free yeast wort

Example 5 was carried out similarly to Example 1, except that for the fermentation by free yeast, beer wort was used as the fermentation medium instead of wort. The difference between wort wort is that wort is hopped with natural hops in either dried or granulated form. It is also possible to use various hop preparations (extracts, including isoextract) in the preparation of wort. The results are shown in the following table.

Oxygen concentration 0 mg / l 2 mg / l 4 mg / l 6 mg / l Fermentation time 85 83 79 76 Actual extract (w / w) 4.44 4.28 4.21 4,21 Ethanol% (v / v) 0.31 0.28 0.21 0.17 pH 2.09 2.08 2.07 1.97

Example 6

Process for batch fermentation of wort with immobilized yeast

Example 6 was carried out similarly to Example 2 except that for the batch fermentation by free yeast, beer wort was used as a fermentation medium instead of wort. The difference between wort wort is that wort is hopped with natural hops in either dried or granulated form. It is also possible to use various hop preparations (extracts, including isoextract) in the preparation of wort. The results for the best optimal strain (Saccharomyces cerevisiae JS10-3C) are shown in the following table.

Oxygen concentration 0 mg / l 2 mg / l 4 mg / l 6 mg / l Fermentation time 77 75 69 67 Actual extract (w / w) 4.43 4.39 4,21 4.15 Ethanol% (v / v) 0.41 0.28 0.21 0.19 EH 2.24 2.17 2.11 1.97

Example 7

Production method by continuous fermentation of free yeast wort

Example 7 was carried out in a similar manner to Example 3 except that for the batch fermentation using free yeast, beer wort was used as the fermentation medium instead of wort. The results for the most optimal strain (Saccharomyces cerevisiae JS10-3C) are shown in the following table.

Oxygen concentration 0 mg / l 2 mg / l 4 mg / l 6 mg / l Delay Time (h) 31 30 29 27 Actual extract (w / w) 4.19 4.18 3.99 3.85 Ethanol% (v / v) 0.34 0.31 0.29 0.21 J * 2.19 2.11 2.04 2.01

Example 8

Production method by continuous fermentation of wort with immobilized yeast

Example 8 was carried out similarly to Example 4, except that for the batch fermentation by free yeast, beer wort was used as a fermentation medium instead of wort. The results for the most optimal strain (Saccharomyces cerevisiae JS10-3C) are shown in the following table.

Oxygen concentration 0 mg / l 2 mg / l 4 mg / l 6 mg / l Delay Time (h) 20 19 18 18 Actual extract (w / w) 4.24 4.16 4.09 3.98 Ethanol% (v / v) 0.39 0.36 0.28 0.21 pH 2.25 2.21 2.11 2.03

Industrial usability

The process according to the invention can be used in the production of low-alcohol and non-alcoholic wort and wort-based drinks, including low-alcohol and non-alcoholic beer, by fermentation using free and immobilized yeast in a batch and continuous manner.

WM55-0t)

Claims (4)

PATENT CLAIMS Process for the preparation of low-alcohol and non-alcoholic worts based on wort or wort, including low-alcohol and non-alcoholic beers, by fermentation of beer wort and / or wort, at a temperature of from 5 to 35 ° C and a pH of from 1.5 to 7.0, in that the fermentation is carried out in the presence of yeast mutants with impaired citrate cycle enzyme synthesis. The method of claim 1, wherein the mutant is a yeast mutant of Saccharomyces cerevisiae. A method according to claim 1 or 2, characterized in that the yeast is immobilized in a calcium pectate gel. A process according to claim 1, 2 or 3, by continuous fermentation, characterized in that the fermentation is carried out in a perforated tray reactor.