Method for preparing a fermented beverage and fermented beverage produced by said method

Abstract

The present invention relates to a method for preparing a fermented beverage from tea or rooibos together with a carbon source. Said method comprises the sequential addition of a lactic bacterium and a yeast, so that two independent fermentations occur with a simplified microbial consortium, while the duration of the claimed method is less than 7 days. Advantageously, the method of the invention allows manufacturing times to be reduced, and the features of the resulting beverage to be optimally customised. The present invention also relates to the fermented beverage produced.

Description

[0001] PROCEDURE FOR PREPARING A FERMENTED BEVERAGE AND FERMENTED BEVERAGE OBTAINED BY SAID PROCEDURE

[0002] OBJECT OF THE INVENTION

[0003] The present invention relates to a method for preparing a fermented beverage, as well as to the fermented beverage obtained by said method.

[0004] Specifically, the process of the invention is based on a controlled and sequential fermentation from tea or rooibos using a simplified microbial consortium, based on at least one bacterium and one yeast, which advantageously allows manufacturing times to be reduced to less than 7 days, as well as guaranteeing a fully reproducible quality and characteristics of the fermented beverage obtained.

[0005] BACKGROUND OF THE INVENTION

[0006] Beverages obtained from an infusion or plant extract in which fermentation takes place are known in the state of the art and are especially advantageous from a nutritional and organoleptic point of view.

[0007] Specifically, fermented beverages from the kombucha family are known, which are usually produced by fermenting black tea sweetened with sugar (or sweetened with honey or another type of sugar solution) with a complex microbial consortium of bacteria and yeast that form a thick, gelatinous layer known as SCOBY (an acronym for the expression Symbiotic Consortium of Bacteria and Yeast).

[0008] As mentioned, this consortium is a complex combination of bacterial species (mainly acetic, but also lactic) and yeasts. Although kombucha's organoleptic properties can vary greatly depending on the fermentation time, it generally has a vinegary flavor due to the production of acetic acid.

[0009] Another example of this type of well-known beverage is the drink called jun, which is made from green tea instead of black tea and honey instead of sugar, resulting in a more bubbly and less acidic drink than kombucha. In the case of jun, fermentation is also carried out by a complex SCOBY in which acetic fermentation predominates.

[0010] The complexity of the microbial community of the SCOBY used to obtain the known fermented beverages results in the difficulty of standardizing these beverages, and, therefore, of producing them on an industrial scale, since the fermentation times are long (2-4 weeks), and the fermentation is not very reproducible, with large variations in the duration, acidity, sugar content, alcohol or flavor of the final product.

[0011] Additionally, known fermented beverages have a high acidity, so for them to be accepted by certain consumers, it is necessary to incorporate a high content of sugar, sweetener, or similar, which reduces the quality of the resulting beverage.

[0012] Thus, the applicant of the present invention detects the need to develop a simplified procedure in terms of the consortium of microorganisms used and the production time, which allows for the precise and reproducible selection of the characteristics of the fermented beverage obtained for its production on an industrial scale.

[0013] DESCRIPTION OF THE INVENTION

[0014] The procedure recommended below solves the problem described above, making it possible to obtain a fermented beverage with the desired parameters in a minimum amount of time and with reproducible characteristics, which facilitates its production at an industrial level.

[0015] To this end, the process developed in the present invention is based on a controlled and sequential fermentation of a tea, a rooibos or similar, using for this purpose a simplified microbial consortium composed of at least one bacterium and at least one yeast, based on the steps described below:

[0016] - Preparation of a tea infusion blend, preferably green tea (although any other type of tea could be used), or rooibos, and a carbon source, such as sugar or honey, to obtain a must. It should be noted that the carbon source is a compound containing carbohydrates, such as refined sugar, cane sugar, or honey.

[0017] - Addition or inoculation of at least one food-grade lactic acid bacteria (GRAS / QPS) and fermentation for at least one day, for the partial consumption of carbon by the lactic acid bacteria and the production of organic molecules, providing aromas, flavors, lactic acidity, etc. In the context of the present invention, GRAS / QPS refers to microbial safety standards, where GRAS is the acronym for the English expression 'Generally Recognized As Safe' used by the FDA (Food and Drug Administration) of the United States to classify microorganisms considered safe from a food point of view, while QPS is the acronym for the English expression 'Qualified Presumption of Safety' used by the EFSA (European Food Safety Authority).

[0018] - Addition or inoculation of a food-grade yeast (GRAS / QPS) and fermentation for at least one day, for partial carbon consumption by the yeast, generating a quantity of CO2 and alcohol and providing aromas, flavors and acidity.

[0019] In this regard, the detailed steps take place in a bioreactor or thermoregulator with a free outlet for fermentation gas, so that both fermentation steps described above are carried out in an open environment. Preferably, the bioreactor is equipped with aeration means to maintain the culture under optimal conditions for fermentation.

[0020] Additionally, it should be noted that, unlike the known processes for obtaining fermented beverages, the fermentation caused by lactic bacteria and the fermentation caused by yeast take place sequentially and are independent stages, such that, advantageously, the procedure lasts less than 7 days, preferably between 2 and 7 days, which represents a drastic reduction in the time to obtain the beverage compared to known processes, in which fermentation takes place between 2 and 4 weeks as a minimum.

[0021] Adjusting the amount of carbon source added and the fermentation time with each of the microorganisms allows for precise control of the acidity and organoleptic characteristics of the final product, as well as the amount of carbon or residual sugar and alcohol in the fermented beverage obtained. This standardization and controllability of the product is a significant advantage over known fermented beverage production procedures.

[0022] Thus, the process of the invention produces a fermented beverage with a pH between 2.5 and 4.5, in a time that may vary depending on the content of alcohol, sugar, gas or other compounds that are desired in the final product, but always within a maximum of one week.

[0023] As detailed above, the addition of the lactic acid bacteria and the addition of the yeast occur sequentially, and therefore, the two fermentations are sequential and independent processes. The incorporation of a lactic acid bacteria and a yeast, the minimum amount required to achieve an organoleptically optimal product, allows the process and its results to be reproduced, in contrast to known kombuchas where the microbial consortium contains multiple bacteria and / or yeasts that are added all at once in bulk, which hinders scalability and product reproducibility. Thus, the process of the invention preferably uses a minimum of two microorganisms and a maximum of 10.

[0024] The bacteria used are preferably chosen from Lactiplantibacillus plantarum, Lactiplantibacillus paraplantarum, Levilactobacillus brevis, Lacticaseibacillus paracasei, Lacticaseibacillus casei, Pediococcus pentosaceus and / or Pediococcus acidilactici, while the yeast is also preferably chosen from Saccharomyces spp, Bretanomyces, Zygosaccharomyces, Torulaspora, Lachancea, and / or Kluyveromyces. In relation to the order in which these microorganisms are sequentially inoculated, in a preferred embodiment of the invention the addition of the lactic acid bacteria takes place before the addition of the yeast, such that the fermentation with the lactic acid bacteria takes place before the fermentation with the yeast.

[0025] However, it is possible to reverse the order of the aforementioned steps, so that according to another embodiment of the invention the addition of the yeast takes place before the addition of the lactic acid bacteria, so that the fermentation with the yeast takes place before the fermentation with the lactic acid bacteria.

[0026] On the other hand, using lactic acid bacteria instead of acetic acid fermentation bacteria, as in popular kombuchas, improves the acidity profile and, in general, the organoleptic qualities of the beverage. Furthermore, lactic acid bacteria may have probiotic properties and improve overall health.

[0027] If a more acetic profile is desired for the fermented beverage obtained by the present invention, the claimed process contemplates the optional addition of vinegar, long-fermented kombucha, and / or acetic acid. This addition can be made at either the beginning or the end of the process, or even at both times. If the addition is made at the end of the process, after the two sequential fermentations, it has the advantage of stopping the fermentation process, acting as a preservative and stabilizing the product.

[0028] Also optionally, in order to adapt the fermented beverage obtained to the preferences of each consumer, after the two sequential open fermentations, the addition of:

[0029] - a sweetener to modify the residual sugar content to the consumer's taste, preferably xylitol, aspartame, erythritol, or steviol,

[0030] - flavorings, preferably: aromas, plant extracts and / or spices, or

[0031] - probiotic microorganisms, preferably those of the Bacillus genus. - carbon dioxide, to adjust the amount of carbonation in the beverage to each consumer's preferences.

[0032] Finally, it should be noted that the process of the invention includes a final stage in which the fermented beverage obtained is transferred to a closed container where a third fermentation takes place. This third closed fermentation occurs residually based on the sugar content from the carbon source remaining after the two open fermentations with the lactic acid bacteria and yeast, generating most of the gas that the final product will contain. The final amount of gas in the fermented beverage to be consumed will be determined by the remaining fermentable sugar (from the initial carbon source or from sweeteners added later) and the storage time of the beverage in the closed container, as well as by the amount of carbon dioxide added artificially.

[0033] For all the above reasons, the main advantages and novel aspects of the present invention can be summarized as follows:

[0034] - Organoleptic properties of the fermented beverage. The production of lactic acid instead of acetic acid as the end product of the fermentation process allows for a beverage with much more pleasant organoleptic characteristics, while maintaining the acidity characteristic of this type of beverage.

[0035] - Possibility of adding probiotic strains. As detailed above, during the process of the invention, the added lactic acid bacteria strain(s) allow for varying the desired functional characteristics of the beverage, for example, regulating intestinal transit, providing antioxidant activity, having effects on the immune system, having the ability to synthesize vitamins, etc.

[0036] - Reproducibility. As described above, producing kombucha or jun using traditional methods requires the use of a SCOBY to carry out the fermentation process. Because it involves a complex microbial community, the resulting product is not always reproducible due to unexpected and virtually impossible-to-control changes in the bacteria and yeast that comprise this community. In contrast, the present development uses a simplified microbial consortium composed primarily of bacteria and yeast, applied sequentially, allowing for much finer microbiological control of the fermentation process.

[0037] - Drastic reduction in fermentation time. Kombucha or jun production typically requires between 7 and 30 days to complete the fermentation process. In the case of this development, this time is reduced to a maximum of 7 days, thanks to the sequential addition of selected strains.

[0038] - No SCOBY is produced. The absence of acetic acid bacteria prevents the formation of a SCOBY, which is often expensive to manage and difficult to standardize.

[0039] PREFERRED EMBODIMENT OF THE INVENTION

[0040] An example of an embodiment of the method claimed in the present invention is detailed below.

[0041] Thus, according to this example, first, an infusion is prepared with 10 grams per liter of green tea and 80 grams of honey per liter of water, stirring the infusion periodically so that the water impregnates all the tea, to obtain a must.

[0042] Next, the bacterial or yeast inocula are prepared, depending on which inoculation is to be added first. The inoculation can be fresh (from a liquid or plate culture) or lyophilized. For fresh inoculation, a solution in 0.9% saline solution is prepared by measuring the optical density at 600 nm and adjusting it to the desired concentration. For lyophilized inoculation, the desired amount is weighed.

[0043] When the must reaches a temperature between 30 e C-37 e C is followed by the addition of the first food-grade microorganism, i.e., the bacteria or yeast are inoculated, depending on the order selected. Optionally, if you wish to adjust the initial pH of the wort, vinegar, long-fermented kombucha, or acetic acid can be added before this first addition.

[0044] Once the bacteria or yeast has been added, the first fermentation begins, which lasts a minimum of one day, at an approximate temperature of 30 e C. After the first fermentation time has elapsed, the inoculum is prepared and the second microorganism is added (bacteria or yeast, depending on which was the first microorganism added). The second fermentation takes place for a minimum of one day, at a temperature of 30 e C. Once fermentation is complete after the second addition, a fermented beverage with a pH between 2.5 and 4.5 is obtained. The acidity can then be adjusted by adding vinegar or long-fermented kombucha, as well as the sweetness by adding an artificial sweetener (xylitol, erythritol, steviol, etc.). Finally, the beverage is transferred to an airtight container and a third fermentation takes place.

Claims

1. Procedure for preparing a fermented beverage comprising the steps of: - preparation of a mixture of tea or rooibos infusion and a carbon source to obtain a must, - addition of at least one food-grade lactic acid bacterium (GRAS / QPS) and fermentation for at least one day, for partial consumption of the carbon source and production of organic molecules by the lactic acid bacterium, - addition of a food-grade yeast (GRAS / QPS) and fermentation for at least one day, for the partial consumption of carbon by the yeast, generating CO2 and alcohol. characterized in that the detailed steps take place in a bioreactor with free exit of fermentation gas, such that the fermentation caused by the lactic acid bacteria and the fermentation caused by the yeast are carried out in the open and take place sequentially, being independent steps, while the steps of the fermentation process occur in less than 7 days, allowing to obtain a fermented beverage with a pH between 2.5 and 4.

5.

2. Method for preparing a fermented beverage, according to claim 1 a , characterized in that the addition of the lactic bacteria takes place before the addition of the yeast so that the fermentation with the lactic bacteria takes place before the fermentation with the yeast.

3. Method for preparing a fermented beverage, according to claim 1 a , characterized in that the addition of yeast takes place before the addition of lactic acid bacteria so that fermentation with yeast takes place before fermentation with lactic acid bacteria.

4. Method for preparing a fermented beverage, according to any of the preceding claims, characterized in that the bioreactor is provided with aeration means.

5. Method for preparing a fermented beverage, according to any of the preceding claims, characterized in that the fermented beverage is taken to a closed container where a third fermentation takes place.

6. Method for preparing a fermented beverage, according to claim 1 a , characterized by the fact that the carbon source is honey or sugar.

7. Method for preparing a fermented beverage, according to claim 1 a , characterized by the fact that the tea is green tea.

8. Method for preparing a fermented beverage, according to claim 1 a , characterized in that after open fermentations, a sweetener is added, preferably xylitol, aspartame, eth-tol or steviol.

9. Method for preparing a fermented beverage, according to claim 1 a , characterized by the fact that after open fermentations, carbon dioxide is added.

10. Method for preparing a fermented beverage, according to claim 1 a , characterized by the addition of vinegar, long-fermented kombucha and / or acetic acid.

11. Method for preparing a fermented beverage, according to claim 1 a, characterized in that the bacteria used is preferably chosen from Lactiplantibacillus plantarum, Lactiplantibacillus paraplantarum, Levilactobacillus brevis, Lacticaseibacillus paracasei, Lacticaseibacillus case i, Pediococcus pentosaceus and / or Pediococcus acidilactici.

12. Method for preparing a fermented beverage, according to claim 1 a , characterized in that the added yeast is preferably chosen from Saccharomyces spp, Bretanomyces, Zygosaccharomyces, Torulaspora, Lachancea, and / or Kluyveromyces.

13. Method for preparing a fermented beverage, according to claim 1 a , characterized by the addition of flavorings, preferably: aromas, plant extracts and / or spices.

14. Method for preparing a fermented beverage, according to claim 1 a, characterized in that, after open fermentations, probiotic microorganisms are added, preferably microorganisms of the Bacillus genus.

15. Fermented beverage obtained according to the method set forth in any of the preceding claims, characterized in that it has a pH between 2.5 and 4.5.

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