Use of a yeast protein extract to stabilise beer haze

Abstract

The present invention relates to the use of a yeast protein extract to stabilise the haze or cloudiness of a drink, particularly beer and preferably white beer.

Claims

1. A method comprising introducing into a beer a yeast protein extract, wherein said beer comprises suspended particles, wherein the yeast protein extract is prepared by plasmolysis of an intact yeast, separation by centrifugation and recovery of a soluble fraction comprising the yeast protein extract, and wherein said introducing results in preventing the precipitation of said suspended particles, thus stabilize haze or turbidity of said beer.

2. A method as claimed in claim 1, wherein the yeast protein extract comprises from 30 to 40% by weight of proteins having a molecular weight of greater than 15 kDa.

3. A method as claimed in claim 1, wherein the yeast protein extract comprises from 10 to 14% by weight of ribonucleotides having a mean number of bases of 280.

4. A method as claimed in claim 1, wherein the yeast protein extract is in the form of a powder or liquid.

5. A method as claimed in claim 1, wherein the yeast is selected from the group consisting of Saccharomyces, Kluyveromyces, Torula and Candida.

6. A method as claimed in claim 1, wherein the yeast protein extract is in the form of powder and is introduced into the beer in a content ranging from 5 g (grams) to 80 g per hectoliter (hl) of beer.

7. A method as claimed in claim 1, wherein the yeast protein extract stabilizes the haze of the beer, at a turbidity ranging from 40 to 120 EBC, for up to 80 days, the turbidity values being measured using a 90/25 nephelometer at a temperature of 4° C. and for a 90° angle (Analytica EBC — method 9.30).

8. A method as claimed in claim 1, wherein the yeast protein extract comprises from 30 to 40% by weight of proteins having a molecular weight of greater than 30 kDa.

9. A method as claimed in claim 1, wherein the yeast is Saccharomyces cerevisiae.

10. A method as claimed in claim 1, wherein the yeast protein extract is in the form of powder and is introduced into the beer in a content ranging from 30 g (grams) to 50 g per hectoliter (hl) of beer.

11. A method as claimed in claim 7, wherein the yeast protein extract stabilizes the haze of the beer at a turbidity ranging from 60 to 100 EBC up to 80 days.

Description

EXAMPLES

Example 1

Comparison of the YPE of the Invention with a Clouding Agent of the Prior Art, “Biocloud®”

(1) This example studies the influence of the concentration of the clouding agent (YPE or Biocloud) on the turbidity of stabilized beer of “pils” type.

(2) The YPE clouding agent (Spring'Finer) according to the invention is compared to the Biocloud® clouding agent of the prior art.

(3) The beer used is of “pils” type. It is also referred to as pilsener, pilsen or pilsner. It is a clear, blonde beer of low fermentation, similar to a lager type. It has a content of approximately 5 degrees alcohol and has a medium bitterness, depending on the type of hops used.

(4) Before addition thereof into bottles, each clouding agent (YPE or Biocloud) is dissolved in a volume of pils beer equivalent to one bottle. The mass of clouding agent used is such that the latter is concentrated 100 times. It is then necessary to add the clouding agent in solution to the bottles at an amount of 1/100 of the volume thereof.

(5) The final concentrations tested range from 0 to 50 grams (g) of clouding agent per hectoliter (hl) of pils beer.

(6) In order to illustrate the foregoing, a numbered example for the final concentration of 50 g/hl of clouding agent is now presented. 12.5 g of clouding agent are dissolved in 250 ml of pils beer, giving a concentration of 5000 g/hl. Next, 2.5 ml of this solution are added to 250 ml bottles of pils beer. Since the dilution factor is 100 (250/2.5), the final concentration is indeed 50 g/hl of clouding agent per 250 ml bottle of pils beer.

(7) The samples are homogenized (agitated) before measurement. The measurements of turbidity at a 90° angle and at a 25° angle of the samples of beer are carried out at 4° C. with the Haffmans VOS ROTA 90/25 nephelometer. The turbidity values are expressed in EBC.

(8) Results

(9) The results are illustrated in FIG. 1 (FIG. 1a and FIG. 1b).

(10) The turbidity values increase linearly with the concentration of the clouding agent.

(11) The YPE causes finer haze in the beer than Biocloud. Indeed, it is noted that the turbidity for the YPE is higher at 90° than at 25°, while the opposite is observed for Biocloud.

(12) Conclusion

(13) It appears that the YPE gives finer haze than Biocloud, affording it the advantage of being more homogeneous and therefore more attractive for the consumer. Moreover, it has less tendency to sediment in the bottom of the bottle, thus providing a positive influence on the stability of the haze over time.

Example 2

Influence of the Type of Beer and the Temperature on the Turbidity Values Obtained with the YPE

(14) Products tested:

(15) Clouding agent of the invention YPE (Spring'Finer)

(16) Beer A: filtered, stabilized (all the “protein-polyphenol” complexes responsible for haze have been removed) and pasteurized beer.

(17) Beer B: centrifuged and pasteurized beer (non-stabilized).

(18) Beer C: centrifuged beer (non-pasteurized and non-stabilized).

(19) Before addition to the bottles, the clouding agent YPE is dissolved in a volume of beer A, B or C equivalent to one bottle, and is pasteurized for 20 minutes at a temperature of 70° C. The mass of clouding agent used is such that the latter is concentrated 100 times. It is then necessary to add the clouding agent in solution to the bottles at an amount of 1/100 of the volume thereof.

(20) The final concentration in each bottle is 30 grams (g) of YPE dissolved beforehand per hectoliter (hl) of beer.

(21) The samples are homogenized (agitated) before measurement.

(22) The measurements of turbidity of the beer samples are carried out at an angle of 90°, at a temperature of 20° C. and 4° C. with the Haffmans VOS ROTA 90/25 nephelometer. The turbidity values are expressed in EBC.

(23) Results

(24) The results are illustrated in table 1 below.

(25) TABLE-US-00001 TABLE 1 Turbidity values (EBC) at 90° angle for samples of beers (A, B, C) comprising 30 g/hl of YPE (pasteurized beforehand in solution) and for two commercial Belgian white beers (white 1, white 2), at 20° C. and 4° C. Turbidity at 90° Turbidity at 90° (EBC) (EBC) Beer 20° C. 4° C. A (test 1) 13 30 A (test 2) 26 51 B 20 96 C 28 100 White 1 23 100 White 2 35 100

(26) The turbidity values are higher for a temperature of 4° C. than for a temperature of 20° C.: the YPE is involved in the formation of chill haze due to the association of polypeptides and polyphenols.

(27) As expected, the formation of chill haze in the presence of the YPE is improved in the non-stabilized beers (B and C). This is because, in the stabilized beer (A), all the “protein-polyphenol” complexes responsible for the haze were removed.

(28) Conclusion

(29) The YPE added to the non-stabilized beers (B and C) makes it possible to achieve a chill haze similar to that of commercial Belgian white beers (white 1 and white 2).

Example 3

Stability of the Haze Associated with the Use of the YPE in Non-Stabilized Beers

(30) Products tested:

(31) Clouding agent YPE (Spring'Finer) of the invention

(32) Beer C: centrifuged beer (non-pasteurized and non-stabilized).

(33) Before addition to bottles, the clouding agent YPE is dissolved in a volume of beer C equivalent to one bottle. The mass of clouding agent used is such that the latter is concentrated 100 times. It is then necessary to add the clouding agent in solution to the bottles at an amount of 1/100 of the volume thereof.

(34) Treatments:

(35) No pasteurization: Native YPE

(36) Solution of YPE concentrated 100 times (obtained by dissolving beforehand in beer C), pasteurized for 20 minutes at 70° C. before addition to bottles.

(37) The concentrations finally tested in the bottles are 0, 20, 30 and 50 g of YPE dissolved beforehand/hl of beer.

(38) The measurements of turbidity of the beer samples are carried out at 90°, at a temperature of 20° C. and 4° C. with the Haffmans VOS ROTA 90/25 nephelometer. The turbidity values are expressed in EBC.

(39) The turbidities of the beers containing the YPE are measured over a period of time of 75 days. The beers are stored at 20° C. and 4° C. and the turbidity thereof is measured before homogenization (agitation) and after homogenization of the samples (in order to reproduce the conditions of serving the beer: “first pour half a glass and gently swirl the bottle before filling the glass”).

(40) Results

(41) The results are illustrated in FIGS. 2 to 6.

(42) 1) Native YPE in Solution (no Pasteurization of the Clouding Agent YPE)

(43) The turbidity values obtained as a function of time for the beer C to which the native YPE was added at different concentrations are illustrated:

(44) FIG. 2a (no agitation before measurement) and FIG. 2b (agitation before measurement), for a temperature of 20° C.,

(45) FIG. 3a (no agitation before measurement) and FIG. 3b (agitation before measurement), for a temperature of 4° C.

(46) 2) YPE in Solution, Pasteurized for 20 Minutes at a Temperature of 70° C. before Addition to Bottles

(47) The turbidity values obtained as a function of time for the beer C to which the pasteurized YPE in solution was added at different concentrations are illustrated:

(48) FIG. 4a (no agitation before measurement) and FIG. 4b (agitation before measurement), for a temperature of 20° C.,

(49) FIG. 5a (no agitation before measurement) and FIG. 5b (agitation before measurement), for a temperature of 4° C.

(50) 3) Summary of Points 1 and 2 for the Concentration of 30 g/hl

(51) The turbidity values for the beer C, to which native YPE and pasteurized YPE in solution had been added at an amount of 30 g/hl, measured at 20 and 4° C., with or without agitation, are illustrated in FIG. 6.

(52) Observations and Conclusion from FIGS. 2 to 6

(53) The main aim of the use of a clouding agent is that the haze remains stable over time and therefore does not sediment at the bottom of the bottles.

(54) Although the haze of the beers due to the use of the (native or pasteurized) YPE decreases slightly at first, it eventually stabilizes.

(55) Again, the turbidity values are higher for a temperature of 4° C. than for a temperature of 20° C.: the YPE is involved in the formation of chill haze due to the association of polypeptides and polyphenols.

(56) The use of the native YPE is therefore a good choice, since on the one hand it is simple to use and on the other hand it enables good stability of the haze of the beer over time.

Example 4

Stability of the Haze Associated with the use of the YPE in a Pils Beer

(57) Products tested:

(58) Clouding agent of the invention YPE (Spring'Finer)

(59) Beer A: filtered, stabilized (all the “protein-polyphenol” complexes responsible for haze have been removed) and pasteurized beer.

(60) Before addition to bottles, the clouding agent YPE is dissolved in a volume of beer A equivalent to one bottle. The mass of clouding agent used is such that the latter is concentrated 100 times. It is then necessary to add the clouding agent in solution to the bottles at an amount of 1/100 of the volume thereof.

(61) Treatments:

(62) No pasteurization: Native YPE

(63) Solution of YPE concentrated 100 times (obtained by dissolving beforehand in beer A), pasteurized for 20 minutes at 70° C. before addition to bottles.

(64) Pasteurization of the bottles for 20 minutes at 70° C. after addition of the 100 times concentrated, non-pasteurized YPE solution.

(65) The concentrations finally tested in the bottles are 0, 20, 30 and 50 g of YPE dissolved beforehand/hl of beer.

(66) The measurements of turbidity of the beer samples are carried out at 90°, at a temperature of 20° C. and 4° C. with the Haffmans VOS ROTA 90/25 nephelometer. The turbidity values are expressed in EBC.

(67) The turbidities of the beers containing the YPE are measured over a period of time of 75 days. The beers are stored at 20° C. and 4° C. and the turbidity thereof is measured before homogenization (agitation) and after homogenization of the samples.

(68) Results

(69) The turbidity values measured at an angle of 90° for the beer A, to which native YPE (30 g/hl), dissolved YPE pasteurized beforehand (30 g/hl), and YPE dissolved and pasteurized in the bottles with the beer (30 g/hl) was added, at 20 and 4° C., with or without agitation, are illustrated in FIG. 7.

(70) Observations and Conclusions

(71) It can be seen from FIG. 7 that the haze in the beer comprising the native YPE or the pasteurized YPE decreases significantly during the storage of the beer.

(72) The stability of the haze over time in the presence of the YPE (native or pasteurized) at 4° C. is negatively impacted in stabilized beers, whereas this is not the case for non-stabilized beers (see FIG. 6).

(73) This is because, in stabilized beers of pils type (beer

(74) A), all the “protein-polyphenol” complexes responsible for the haze have been removed.

(75) Moreover, the pasteurization of the beer comprising the YPE dissolved beforehand appears to have an impact on the clouding agent in terms of its structure and therefore affects the stability of the haze. This is because, when the sample is not homogenized before measurement, a significant decrease in the haze is observed; however, said haze is completely resuspended when the bottle is agitated, which suggests that the YPE has been degraded.

Bibliography

(76) 1. Steiner E., Becker T. and Gastl M., Turbidity and Haze Formation in Beer—Insights and Overview, 2012, J. Inst. Brew., 116, 360-368. 2. Delvaux, F., Delvaux, F. R., Delcour, Characterisation of the colloidal haze in commercial and pilot scale Belgian white beers, 2000, J. Inst. Brew., 106, 221-227. 3. Bamforth, C. W., Beer haze. 1999, J. Am. Soc. Brew. Chem., 57(3), 81-90. 4. Loisa, M., Nummi, M. and Daussant, J., Quantitative determination of some beer protein components by an immunological method, 1971, Brauwissenschaft, 24(10), 366-368. 5. Asano, K., Shinagawa, K. and Hashimoto, N., Characterization of haze-forming proteins of beer and their roles in chill haze formation, 1982, J. Am. Soc. Brew. Chem., 40(4), 147-154. 6. Limure, T., Nankaku, N. Watanabe-Sugimoto, M., Hirota, N., T. Z., Kihara, M., Hayashi, K., Ito, K. and Sato, K., Identification of novel haze-active beer proteins by proteome analysis, 2009, J. Cereal Sci., 49(1), 141-147. 7. Leiper, K. A., Stewart, G. G. and McKeown, I. P., Beer polypeptides and silica gel. Part I. Polypeptides involved in haze formation, 2003, J. Inst. Brew., 109(1), 57-72. 8. Nadzeyka, A., Altenhofen, U. and Zahn, H., The significance of beer proteins in relationship to cold break and age-related haze Formation, 1979, Brauwissenschaft, 32(6), 167-172. 9. Siebert, K. J., Carrasco, A. and Lynn, P. Y., Formation of protein-polyphenol haze in beverages, 1996, J. Agr. Food Chem., 44(8), 1997-2005. 10. Revue des cenologues, N° 120; pages 47-50, 2006.