Probiotic and antioxidant kombucha drink

Abstract

The kombucha drink (50) comprises a fermented liquid obtained by using sweet tea (30) and natural red berry juice (26) as a fermentation substrate, the natural red berry juice (26) not being pasteurised or dehydrated.

Description

[0001] PROBIOTIC AND ANTIOXIDANT KOMBUCHA DRINK DESCRIPTION TECHNICAL SECTOR OF THE INVENTION

[0002] The present invention belongs to the field of food biotechnology, with a specific focus on fermented and probiotic beverages.

[0003] OBJECT OF THE INVENTION

[0004] The present invention relates to a food product, specifically a probiotic and antioxidant kombucha beverage, obtained by a fermentation process.

[0005] BACKGROUND OF THE INVENTION AND TECHNICAL PROBLEM TO BE SOLVED

[0006] Kombucha is a fermented beverage, traditionally made from tea, using a kombucha SCOBY as a starter culture. The term "SCOBY" comes from the acronym for "Symbiotic Culture of Bacteria and Yeast." In other words, a SCOBY refers to a symbiotic colony of microorganisms, in this case, bacteria and yeast, which is usually disc-shaped.

[0007] Kombucha is known for its many beneficial properties, primarily derived from the fermentation process. It provides antioxidants such as polyphenols and flavonoids, which help combat oxidative stress and protect cells from damage. It also contains organic acids like acetic and gluconic acid, which improve digestion and act as natural antimicrobials. The probiotics present, such as Lactobacillus and Saccharomyces, support gut health by promoting a healthy balance of the gut microbiota.

[0008] Document US2023193175A1 describes how fermented kombucha beverages have a low, acidic pH, resulting in a sour taste. It also states that many kombucha producers add natural fruits and / or synthetic flavors to mask the sourness, and that many of these natural fruits and synthetic flavors are metabolized by live microorganisms and degraded, resulting in unpleasant tastes and aromas. Furthermore, any added flavor is lost or diminished during the fermentation process and / or while the kombucha is stored for future consumption. Additionally, document US2023193175A1 describes how natural fruits contain microorganisms that interfere with the fermentation process.Therefore, US2023193175A1 indicates a need for flavored kombucha beverages that appeal to consumers so they can benefit from the numerous health benefits provided by kombucha. To this end, US2023193175A1 discloses a method for providing flavors compatible with kombucha microorganisms for the production of high-alcohol fermented tea beverages, and mentions the use of a mixture of fruits and vegetables, including red fruit juices at 0.5% by volume (Fig. 4).

[0009] The technical problem to be solved is obtaining a kombucha beverage rich in probiotics and antioxidants that also allows for low production costs.

[0010] EXPLANATION OF THE INVENTION

[0011] The present invention relates to a probiotic and antioxidant kombucha beverage, i.e., a food product.

[0012] In a manner unknown in the state of the art, the kombucha beverage of the present invention presents the differentiating characteristics described below.

[0013] Kombucha drink is made by adding red fruit juice, using sweetened tea and natural red fruit juice as a fermentation substrate.

[0014] That is, the kombucha beverage comprises a fermented product obtained by using sweetened tea and natural red fruit juice as fermentation substrates. The natural red fruit juice used as fermentation substrates is neither pasteurized, nor dehydrated, nor freeze-dried. In this invention, a "freeze-dried" element is understood to be a subclass of "dehydrated."

[0015] That is, the kombucha beverage of the present invention is a fermented beverage (fermented) that is obtained by a fermentation process in which natural red fruit juice and sweetened tea act as fermentation substrates.

[0016] Kombucha beverage is obtained by a process in which a sweetened tea is prepared by adding at least 50 grams of sugar and at least 10 grams of tea per liter of water, optionally distilled.

[0017] The term “sugar” or “sweetened” used throughout this description should be understood in a broad and non-restrictive sense, and includes sugar, sugar substitutes, sweeteners, or a combination thereof. Examples of sweeteners include sucralose, stevia, honey, etc. Similarly, kombucha is obtained through a process in which a kombucha SCOBY and natural red fruit juice are added to previously prepared sweetened tea, in the following proportions per liter: between 50 and 800 milliliters of the natural red fruit juice, topped up to one liter with the prepared sweetened tea.Thus, for example, some options, by way of illustration but not limitation, of the proportions per liter described above are: at least 50 milliliters of said natural red fruit juice and complete the rest of the liter with said sweetened tea, at least 100 milliliters of said natural red fruit juice and complete the rest of the liter with said sweetened tea, at least 600 milliliters of said natural red fruit juice and a maximum of 400 milliliters of the previously prepared sweetened tea, 800 milliliters of said natural red fruit juice and a maximum of 200 milliliters of said sweetened tea.

[0018] Throughout this document, the term “scoby” used as a starter culture for the fermentation of kombucha beverage is widely used in the technical field, and comes from the English acronym for “Symbiotic Culture of Bacteria and Yeast” which translates to “symbiotic colony of bacteria and yeasts”, that is, a symbiotic colony of microorganisms.

[0019] Kombucha scobys can have a variety of shapes, although they are usually disc-shaped.

[0020] Likewise, the kombucha beverage is obtained by a process in which the kombucha scoby, natural red fruit juice, and sweetened tea are fermented for 5 to 7 days at a temperature between 18 and 28 °C, obtaining a fermented product.

[0021] Throughout this document, each indicated temperature includes deviations of ± 1 °C, and these deviations are therefore within the scope of the present invention.

[0022] Also, the kombucha beverage is obtained by a process in which the kombucha scoby has been removed from the fermented product.

[0023] Similarly, kombucha beverage is obtained through a process in which the fermented material obtained with the removed kombucha scoby has been filtered, packaged, carbonated, and refrigerated to stop fermentation and for preservation.

[0024] Optionally, in the kombucha beverage, the fermented material obtained with the kombucha scoby removed has been subsequently filtered and then packaged.

[0025] Preferably, in kombucha, the fermented and packaged beverage has been carbonated. Optionally, in kombucha, the carbonated fermented beverage has been subsequently refrigerated to stop the fermentation and for preservation.

[0026] The advantages of the kombucha beverage of the present invention are described below in relation to its differentiating characteristics.

[0027] The kombucha beverage of the present invention is obtained through a process that uses unpasteurized natural red fruit juice, comprising between 5% and 80% of the recipe's volume, as a fermentation substrate, along with sweetened tea. This ensures optimal preservation of nutrients, vitamins, and bioactive compounds in the kombucha beverage. While the fermentation process used to obtain the kombucha beverage is relevant, the primary focus of the present invention is on the substrates used in the kombucha beverage, specifically the natural red fruit juice, obtained from red fruits, optionally by pressing.

[0028] Unlike other kombucha beverages that use concentrated musts or heat-treated juices at the start of fermentation, the present invention is based on the use of natural red fruit juice, i.e., fresh juice, as a fermentation substrate, which favors a richer interaction between the microbiota of the natural red fruit juice and the microorganisms of the kombucha scoby, resulting in a more complete nutritional profile.

[0029] Therefore, the present invention provides a technological solution where the kombucha beverage comprises a fermented product obtained by using a higher quantity of natural, unpasteurized juice from red fruits, between 5% and 80% by volume of the recipe, to enrich the kombucha beverage with probiotics and antioxidants. Being a natural juice, derived from fresh fruit, neither dehydrated nor freeze-dried, it presents a microbiological load that interacts with the lactic acid bacteria and yeasts characteristic of kombucha.

[0030] By incorporating fruits, especially those rich in bioactive compounds such as berries (strawberries, blackberries, blueberries, raspberries, etc.), kombucha is enriched with vitamins C and B, minerals, and additional antioxidants. Natural berry juice provides polyphenols, known for their anti-inflammatory properties and protective effects against chronic diseases such as cancer and cardiovascular disease. The vitamin C present in these fruits strengthens the immune system and contributes to cell regeneration.

[0031] In addition to its antioxidant properties, natural red berry juice also provides flavonoids, specifically anthocyanins, which are the most prominent pigments responsible for vibrant colors (red, purple, blue) and act as protectors against damage caused by free radicals. This combination of antioxidants, provided to the fermented kombucha by the SCOBY and the natural red berry juice, maximizes the kombucha beverage's ability to reduce inflammation, improve metabolic and cardiovascular health, and protect the body against premature aging.

[0032] The present invention relates to a kombucha beverage obtained through a process for producing kombucha from natural red fruit juice and tea, expanding the range of probiotic products available on the market. This beverage is not only an alternative to traditional tea-based kombucha, but also harnesses the beneficial properties of red fruits, such as vitamins, minerals, and bioactive compounds, which are known for their antioxidant properties and ability to strengthen the immune system.

[0033] This kombucha beverage contributes to dietary diversification, providing a natural source of beneficial bacteria for gut health. Furthermore, the use of natural red fruit juice, including strawberries, raspberries, blueberries, and blackberries, individually or in combination, not only adds nutritional value but also offers an appealing fruity flavor that enhances the consumer experience.

[0034] The invention presents a kombucha beverage obtained by fermenting tea and a high percentage of natural red fruit juice: strawberries, cherries, blueberries, raspberries, blackberries, currants, among others, either as an individual product or a mixture of the aforementioned fruits, using kombucha scoby as a fermentation agent.

[0035] Unlike kombucha made with tea as the fermentation substrate in the state of the art, the red fruit and tea kombucha beverage of the present invention offers a probiotic fermented beverage with a superior nutritional profile. This is due to the presence of vitamins, minerals, and bioactive compounds inherent to red fruits, incorporated into the natural juice of the kombucha beverage. Specifically, red fruits are known for their high content of anthocyanins, a type of flavonoid. These anthocyanins include subclasses such as cyanidins, pelargonidins, peonidins, and delphinidins, which differ in their chemical structure and the types of color they produce (red, blue, and purple). These substances possess antioxidant and anti-inflammatory properties and have been shown to help reduce the risk of cardiovascular disease and certain types of cancer. Furthermore, they may improve cognitive function and visual health.

[0036] In the case of red fruits, such as strawberries, cherries, blueberries, raspberries, blackberries and currants, they stand out for their high content of vitamin C, polyphenols and antioxidants, reaching very high volumes in the waste.

[0037] The present invention covers both the case of using as a fermentation substrate natural juice, either made from red fruits that meet supermarket standards, or made from red fruits that do not meet these standards and are classified as rejects, or a combination of these.

[0038] As an optional advantage, we can utilize red fruits that do not meet the aesthetic standards required by supermarkets, due to insufficient size, shape, or color, and which are otherwise discarded. In this way, we revalue a byproduct that would initially be thrown away, resulting in savings in emissions, water, and land use. One advantage of this invention is its focus on sustainability. The present invention enables the use of fruits that would be discarded for aesthetic reasons, such as size or non-commercial appearance, contributing to the reduction of food waste. This feature not only reduces production costs but also aligns the kombucha beverage product with global sustainability and responsible consumption goals, offering an accessible option for environmentally conscious consumers.

[0039] Advantageously, this invention allows the use of red fruits discarded for aesthetic reasons, which result in very high volumes of waste. It promotes more sustainable production, reduces food waste, and utilizes ingredients that still retain their nutritional value. This practice not only contributes to a circular economy but also offers a fermented beverage with an improved nutritional profile and a smaller environmental footprint.

[0040] Other optional features, along with the advantages of each, are described below.

[0041] Ideally, kombucha is made by adding a kombucha SCOBY and natural red fruit juice to prepared sweetened tea, in the following proportions per liter: at least 600 milliliters of the natural red fruit juice, and topping it up to one liter with the prepared sweetened tea. Preferably, the kombucha SCOBY used for fermentation is either fresh or dehydrated.

[0042] In one option, in the kombucha beverage, the fermented product obtained, filtered and packaged has been subjected to natural carbonation for 12 to 48 hours at a temperature between 18 and 28 °C.

[0043] As an alternative to natural gasification, the filtered and packaged fermented product has been subjected to exogenous gasification by the addition of pressurized carbon dioxide.

[0044] Preferably, in kombucha beverage, the fermented product obtained has, on a logarithmic scale, more than 7 CFU / mL of lactic acid bacteria to guarantee its probiotic potential.

[0045] Throughout this document, the term “ufe” or “CFU” should be understood as “colony forming unit” which is an indicator of the amount of live microorganisms in a liquid, in this case said liquid corresponds to the fermented product obtained from the kombucha scoby, sweetened tea, and unpasteurized natural red fruit juice.

[0046] Throughout this document, the term “L” should be understood as “liter” and the term “mL” should be understood as “milliliter” or thousandth of a liter.

[0047] Preferably, where the fermented product obtained has a concentration of phenolic compounds greater than or equal to 50 mg of gallic acid equivalent / 100 mL, and has an antioxidant activity greater than or equal to 0.2 mmol Fe 2+ / 100 mL, to validate its functional and antioxidant potential.

[0048] Throughout this document, the term “g” should be understood as “gram” and “mg” should be understood as “milligram”.

[0049] Throughout this document, the expression “mg of gallic acid equivalent” also refers to the expression “mg GAE”.

[0050] Throughout this document, the term “mmol” refers to one-thousandth of a mole. Optionally, in kombucha, the fermented product has been pasteurized or subjected to high hydrostatic pressure to extend its shelf life by storing it at room temperature. Additionally, in kombucha, the natural red fruit juice used as a fermentation substrate is obtained from red fruits discarded for aesthetic reasons.

[0051] Optionally, in kombucha, the natural red fruit juice used as a fermentation substrate comprises strawberry, cherry, blueberry, raspberry, blackberry, and / or currant juice, or a combination of these juices. Advantageously, the juice of these red fruits can be easily extracted from them, as they do not contain rinds or peels covering the edible portions.

[0052] Optionally, in kombucha beverage, the fermentation substrate lacks milk, lactose or dairy products, making kombucha beverage suitable for consumers with lactose intolerance and / or vegans.

[0053] Alternatively, milk, lactose, or dairy products may be added to the kombucha beverage during the production process, depending on the target market.

[0054] Additionally, in the kombucha beverage, the natural red fruit juice used as a fermentation substrate has been previously extracted from red fruits by pressing.

[0055] Optionally, in the kombucha beverage, the fermentation substrate comprises exclusively said natural red fruit juice and said sweetened tea.

[0056] BRIEF DESCRIPTION OF THE DRAWINGS

[0057] To complement the description of the object of the invention and to aid in a better understanding of its distinguishing characteristics, this descriptive document includes, as an integral part thereof, a set of figures which, for illustrative and non-limiting purposes, depict the following:

[0058] Figure 1 represents each of the stages of the method by which the kombucha beverage (food product) that is the subject of the present invention is obtained; and

[0059] Figure 2 represents, on the vertical axis, the concentration in phenolic compounds, that is, the total content of phenolic compounds (in milligrams of gallic acid equivalent, mg GAE) per 100 milliliters, of different kombucha drinks represented from left to right on the horizontal axis: strawberry, blueberry and blackberry; where the values ​​shown have been determined at two times: the white columns represent after fermentation at 22 °C for 5 days, and the black columns represent after seven days of refrigeration at 5 ± 1 °C, and where for each column of the figure three samples (n = 3) have been taken and the average value is shown;

[0060] Figure 3 represents, on the vertical axis, the equivalent ferric antioxidant potential, in millimoles of Fe 2+per 100 milliliters, of different kombucha beverages represented from left to right on the horizontal axis: strawberry, blueberry and blackberry, where the values ​​shown have been determined at two times: the white columns represent after fermentation at 22 °C for 5 days, and the black columns represent after seven days of refrigeration at 5 ± 1 °C, and where for each column in the figure three samples have been taken (n = 3) and the mean value is shown; and

[0061] Figure 4 represents, on the vertical axis, the lactic acid bacteria (probiotics) present, in colony-forming units (CFU) per milliliter on a logarithmic scale (“log CFU / ml”), of different kombucha drinks represented from left to right on the horizontal axis: strawberry, blueberry and blackberry, where the values ​​shown have been determined at two times: the white columns represent after fermentation at 22 °C for 5 days, and the black columns represent after seven days of refrigeration at 5 ± 1 °C, and where for each column in the figure three samples (n = 3) have been taken and the average value is shown.

[0062] DETAILED EXPLANATION OF MODES OF REALIZATION / EXAMPLES

[0063] Reference 50 in Fig. 1 refers to the fermented kombucha beverage (50) of the present invention obtained by the process shown in Fig. 1 itself, which shows the key process steps, listed as 30, 31, 32, 33, 35, 36 and 37.

[0064] The probiotic and antioxidant kombucha beverage (50) of Fig. 1 comprises a fermented product obtained by using as a fermentation substrate sweetened tea (30) and natural red fruit juice (26), the natural red fruit juice (26) not being pasteurized, dehydrated, or freeze-dried.

[0065] To obtain the kombucha beverage (50), which is a fermented beverage, the process in Fig. 1 comprises the step of preparing sweetened tea (30) by adding at least 50 grams of sugar (27) and at least 10 grams of tea (28) per liter of water (29), preferably distilled (decalcified).

[0066] Any type of tea can be used (28): green, red, black, or a combination of these, among others.

[0067] Preferably, black tea (28) is used.

[0068] Preferably, the prepared sweetened tea (30) is allowed to cool to room temperature. After the step of preparing the sweetened tea (30), the process comprises the step of adding (31) to the prepared sweetened tea (30) in a container the following: kombucha scoby (16), for example a scoby disc, and said natural red fruit juice (26), in the following proportions per liter: one kombucha scoby disc (16) previously cultivated in a step that will be described later, between 50 and 800 milliliters of said natural red fruit juice (26), and making up to one liter with the prepared sweetened tea (30), to activate the fermentation process.

[0069] Preferably, the add step (31) includes the step of covering the container with a gauze that allows oxygen to pass through.

[0070] After the adding stage (31), the process comprises the fermentation stage (32) of the kombucha scoby (16), the natural red fruit juice (26), and the sweetened tea (30) for 5 to 7 days at a temperature between 18 and 28 °C, obtaining a fermented product.

[0071] In Fig. 1, after the adding stage (31), the process comprises a fermentation stage (32), which is a primary fermentation carried out over a period of 5 to 7 days between 18 and 28 °C.

[0072] During primary fermentation, acetic bacteria, lactic acid bacteria and yeasts ferment the sugars in natural red fruit juice (26) and sweetened tea (30), generating compounds such as lactic acid, acetic acid, small amounts of alcohol and carbon dioxide, which gives the kombucha drink (50) a slight natural carbonation.

[0073] In other words, during fermentation stage (32), the sugars (fructose and glucose) from the unpasteurized natural red fruit juice (26) and the sweetened tea (30) (sucrose) are metabolized by the bacteria and yeasts in the kombucha scoby (16). The natural red fruit juice (26), along with the sweetened tea (30), enriched with the kombucha scoby (16), are transformed into a primary fermented product obtained in fermentation stage (32). Following Fig. 1, after fermentation stage (32), the process includes a step of removing (33) or separating the kombucha scoby (16) from the fermented product obtained in fermentation stage (32). The kombucha scoby (16) is removed by filtration, for example, using a strainer or mesh, among other options.

[0074] Optionally, after the removal step (33), the kombucha scoby (16) may be reused for future batches of kombucha drinks (50), or the kombucha scoby (16) may be discarded.

[0075] Optionally, after the removal step (33), the process includes a sweetening step (34). The sweetening step (34) is optional and will depend on the market. Sugar or sweeteners such as sucralose, stevia, honey, etc., can be used.

[0076] Following the removal step (33), the process comprises the filtering and packaging step (35) of the resulting fermented product. The filtering and packaging step (35) includes the filtering step and the packaging step into a container; for example, the filtering and packaging step (35) includes a bottling step after the fermented product has been filtered through a mesh filter.

[0077] After the filtering and packaging stage (35), the process includes the stage of gasifying (36) naturally or exogenously, so that the fermented product obtained, filtered and packaged, carbonates, since the microorganisms are present in the fermented product, and it continues to ferment.

[0078] Optionally, the carbonation stage (36) includes naturally carbonating the fermented product for 24 to 48 hours between 18 and 28 °C to carbonate it.

[0079] As an alternative to natural gasification, the gasification stage (36) includes exogenously gasifying (carbonating) the fermented product by injecting pressurized carbon dioxide (CO2), ensuring more precise control of the gasification level and avoiding spillage of the fermented product that may occur when doing natural gasification.

[0080] Following the carbonation step (36), the resulting fermented product is cooled in a refrigeration step (37) of the process to halt fermentation and preserve the organoleptic, probiotic, and functional properties of the kombucha beverage (50). For example, the fermented product obtained after the carbonation step (36) is stored under refrigeration at 5 °C for 24 to 48 hours, although other combinations of temperature and refrigeration time are acceptable. This ensures the stability of the kombucha beverage (50).

[0081] In Fig. 1, after the cooling stage (37), the kombucha beverage (50) is obtained, which is a fermented beverage by the process described above.

[0082] Optionally, the kombucha beverage (50) is obtained by a process that includes the pasteurization stage or application of high hydrostatic pressures (38).

[0083] In any case, this pasteurization stage or application of high hydrostatic pressures (38) is after the gasification stage (36), always using the kombucha drink (50) as a fermentation substrate in the previous fermentation stage (32) unpasteurized natural red fruit juice (26).

[0084] Preferably, this pasteurization stage or application of high hydrostatic pressures (38) is after the refrigeration stage (37).

[0085] If a longer shelf life and room temperature are desired, the red fruit kombucha beverage (50) can be pasteurized at this stage of pasteurization or application of high hydrostatic pressures (38), for example, at 70 to 85 °C for 10 to 20 seconds, with the consequent reduction in probiotic properties, vitamins and bioactive compounds and antioxidant capacity.

[0086] High hydrostatic pressure (HHP) is a non-thermal treatment used as an alternative to traditional pasteurization to preserve bioactives and probiotics without significantly affecting flavor, texture, and nutritional content. In the case of kombucha (50), HHP offers an effective way to control pathogenic microorganisms and extend shelf life while maintaining the probiotic benefits and sensory properties of the product. For example, an appropriate dose of such high hydrostatic pressure would be 200 MPa for 5 to 10 minutes.

[0087] The kombucha beverage (50) of the present invention is obtained by the process described above, which uses natural red fruit juice (26) from strawberries, blueberries, blackberries, currants, etc., due to its high anthocyanin content and antioxidant activity. Advantageously, this mixture of sweetened tea (30) and unpasteurized natural red fruit juice (26), used as a fermentation substrate in the fermentation stage (32), provides an optimal balance of acidity and natural sugars (fructose and glucose), which facilitates fermentation and gives the kombucha beverage (50) an attractive organoleptic profile, rich in vitamins, minerals, and anthocyanins such as cyanidins, pelargonidins, peonidins, and delphinidins. These compounds possess antioxidant and anti-inflammatory properties and have been shown to help reduce the risk of cardiovascular disease and certain types of cancer.In addition, they can improve cognitive function and visual health.

[0088] The kombucha scoby (16), rich in lactic acid bacteria, acetic bacteria and yeasts, ferments the natural red fruit juice (26) in the fermentation stage (32), with some microbiological competition occurring since the natural red fruit juice (26) also has microorganisms that can alter the fermentation in the fermentation stage (32).

[0089] However, as shown in Fig. 4, the red fruit kombucha beverage (50) obtained using the process described above, after 7 days of refrigeration, has a concentration of lactic acid bacteria (probiotics) greater than 7 log CFU / mL, even exceeding 7.5 CFU / mL and approaching 8 log CFU / mL. This guarantees the probiotic effects of the kombucha beverage (50), as well as a high richness in bioactive compounds, since the bioactive compounds provided by the prepared sweetened tea (30) are combined with those provided by the natural red fruit juice (26). These values ​​are obtained both when using strawberry, blueberry, and blackberry individually as fermentation substrates, and when using the prepared sweetened tea.

[0090] As discussed above, any combination of red fruits in the natural red fruit juice (26), acting as a substrate in the fermentation stage (32) is within the scope of the present invention, and the proportions of strawberry, blueberry, blackberry, and / or other red fruit juice can be selected to achieve a concentration of lactic acid bacteria (probiotic) greater than 7 log CFU / mL.

[0091] In Fig. 2, the total polyphenol (phenolic compound) content of the kombucha beverage (50) after 7 days of refrigeration is greater than or equal to 50 mg GAE / 100 mL using strawberry, blueberry or blackberry individually, and is greater than 80 mg GAE / 100 mL using strawberry and / or blackberry juice in the process, supporting a kombucha beverage (50) with a high richness in bioactive compounds.

[0092] Any combination of red fruits in the natural red fruit juice (26), acting as a substrate in the fermentation stage (32), is within the scope of the present invention, and the proportions of strawberry, blueberry, blackberry, and / or other red fruit juice may be selected to achieve a desired total polyphenol content of the kombucha beverage (50) within the range of 50 or more mg GAE / 100 mL. Throughout this specification, “mg GAE” refers to milligrams of gallic acid equivalent.

[0093] In Fig. 3, the antioxidant activity of the kombucha beverage (50) after 7 days of refrigeration is greater than or equal to 0.2 mmol Fe 2+ / 100 mL, for example, for cranberry and blackberry juice, and greater than 0.4 mmol Fe 2+ / 100 mL for blackberry juice, guaranteeing a kombucha beverage (50) with a high richness in bioactive compounds.

[0094] Any combination of red fruits in the natural red fruit juice (26), acting as a substrate in the fermentation stage (32), falls within the scope of the present invention, and the proportions of strawberry, blueberry, and blackberry juice and / or other red fruit can be selected to achieve a desired antioxidant activity value within said range of values ​​greater than or equal to 0.2 mmol Fe 2 7100 mL. The values ​​shown in Figs. 2 to 4, for the kombucha beverage (50) obtained by the process of Fig. 1, are used in the following proportions in the fermentation stage (32): at least 600 milliliters of unpasteurized natural red fruit juice (26), and the remainder to complete the liter is said prepared sweetened tea (30).

[0095] In the kombucha beverage (50) obtained in Fig. 1, the fermentation substrate lacks milk, lactose or dairy products, making the kombucha beverage (50) suitable for consumers with lactose intolerance and / or vegans.

[0096] In the kombucha beverage (50) obtained in Fig. 1, the fermentation substrate comprises exclusively said natural red fruit juice (26) and said sweetened tea (30).

[0097] The kombucha beverage (50) obtained with the process of Fig. 1, described above, guarantees a final food product with a high content of vitamins, antioxidants and bioactive compounds present in the fruits, making it a healthier and more functional kombucha beverage (50), compared to traditional kombucha beverages.

[0098] According to this invention, the red fruit kombucha beverage (50) obtained from natural red fruit juice (26) and tea as fermentation substrates in the fermentation stage (32), has the characteristics described above.

[0099] The results in Figs. 2 to 4 demonstrate that, unlike the traditional state-of-the-art kombucha tea beverage, the kombucha beverage (50) of the present invention offers a probiotic fermented beverage with a superior nutritional profile, due to the presence of bioactive compounds with high antioxidant potential.

[0100] The kombucha beverage (50), obtained by the process described above, may have other optional steps, such as a preparation step (10) to obtain kombucha scoby (16) and a step to obtain (20) natural red fruit juice (26), also shown in Fig. 1 and described below.

[0101] Optionally, before the addition step (31) the process includes the preparation step (10) to obtain kombucha scoby (16).

[0102] This stage of preparing (10) the kombucha scoby (16) includes the stage of obtaining (11) a scoby, preferably fresh. SCOBY discs or scoby can be obtained from various sources, but are commonly cultivated from other existing SCOBY mother cultures. This fresh scoby is obtained from individuals who already have it in cultivation, from specialized suppliers, or from microbiology laboratories. It is preferable to opt for specialized suppliers.

[0103] Thus, the preparation step (10) comprises the cultivation step (12) of the scoby or scoby discs, either after the obtaining step (11) as shown in Fig. 1 or during the obtaining step (11), being partially cultivated both before and after the obtaining step (11), as described above.

[0104] In the cultivation stage (12), the SCOBY is initially placed in a liquid culture medium. This liquid medium may consist of 250 mL of softened culture water, 50 g of culture sugar, and 10 g of culture tea. The liquid medium provides nutrients to the bacteria and yeast present in the SCOBY, thus initiating the cultivation stage (12). This liquid medium is maintained for seven days at a temperature between 18 and 24 °C, resulting in cultured kombucha SCOBYs (16), which may be used in the addition stage (31) described above, as shown in Fig. 1.

[0105] Optionally, after the cultivation stage (12), the process includes the maintenance stage (13) of the scoby. In this maintenance stage (13), the kombucha scoby (16) is kept healthy between cultivation stages, i.e., between one cultivation stage (12) and a subsequent cultivation stage (12). Once the kombucha scoby (16) removed in the removal stage (33) has been recovered, it is kept in water that is changed weekly. Optionally, the scoby that participated in the cultivation stage (12) can be carefully filtered and reused in a new batch of liquid medium.

[0106] Additionally, after the cultivation stage (12) and / or the maintenance stage (13), the process comprises the stage of storing (14) the kombucha scoby (16), which includes the stage of immersing and the stage of freezing or drying the kombucha scoby (16).

[0107] The immersion stage involves immersing the kombucha scoby (16) in maintenance sugar water with maintenance tea, allowing it to be kept for several months at a temperature between 5 and 8 °C, these temperatures slowing down microbial activity, prolonging the time between fermentations.

[0108] In this freezing stage, the kombucha scoby (16) is carefully washed, lightly dried, and then frozen in a freezer, for example, at temperatures of -18°C to -20°C, inside an airtight freezing container. This freezing stage allows the kombucha scoby (16) to be preserved for several months.

[0109] In this drying stage, the kombucha scoby (16), for example, in the form of vapor discs, is dried in a dehydrator at a low temperature or freeze-dried. After drying, the kombucha scoby (16) is kept in an airtight container, allowing it to be rehydrated later to reactivate the culture.

[0110] Optionally, the process includes, after the storage stage (14), the stage of reactivating (15) the kombucha scoby (16).

[0111] In the event that the kombucha scoby (16) is frozen in the storage stage (14), the reactivation stage (15) comprises the stage of slowly defrosting the kombucha scoby (16) in the freezer, and then the stage of immersing the kombucha scoby (16) in the liquid medium described above.

[0112] In the case where the kombucha scoby (16) is dried (dehydrated) in the storage step (14), the reactivation step (15) comprises placing the kombucha scoby (16) in water and rehydrating it until it regains its fermentation capacity, ready for use in the fermentation step (31). Thus, as shown in Fig. 1, the cultivated kombucha scoby (16) may be used in the fermentation step (31) either directly after the cultivation step (12), or after the cultivation (12), maintenance (13), storage (14), and reactivation (15) steps, or a combination thereof. Optionally, before the addition step (31), the process includes the step of obtaining (20) natural red fruit juice (26).

[0113] This stage of obtaining (20) natural red fruit juice (26) optionally includes the stage of disinfecting (21) some equipment and materials to be used, using 15% peracetic acid, leaving it to act for 5 minutes before using them, and without rinsing the equipment and materials with water afterwards.

[0114] This stage of obtaining (20) natural red fruit juice (26) also includes the stage of selecting (22) a raw material, that is, one or more types of red fruits, including strawberries, cherries, blueberries, raspberries, blackberries, currants, etc. These red fruits must be healthy and show no signs of rot. However, fruits that cannot be marketed fresh, either due to their small size or the presence of deformities, may be used, thus promoting the revaluation of by-products.

[0115] This step of obtaining (20) natural red fruit juice (26) additionally includes the step of washing and rinsing the raw material (23). The raw material is disinfected with water and food-grade bleach at a concentration of 2 mL of sodium hypochlorite / L of water for 5 to 10 minutes. Other disinfectants such as peracetic acid, chlorine dioxide, or acetic acid may be used. After washing, the raw material is rinsed thoroughly with water to remove any remaining disinfectant.

[0116] This stage of obtaining (20) natural red fruit juice (26) comprises the extraction stage (24) of the natural red fruit juice (26) from the red fruits, where the juice is extracted from the red fruits using either a hydraulic or pneumatic press, a centrifugal or screw extractor, a blender, a crusher, or other equipment. Red fruits such as strawberries, blueberries, blackberries, currants, etc., are used to take advantage of their high anthocyanin content and, therefore, their high antioxidant capacity.

[0117] In one option, the natural unpasteurized red fruit juice (26) including its pulp (25a) may be directly added at the addition step (31).

[0118] Alternatively, after the extraction step of the natural red fruit juice (26), the obtaining step (20) preferably comprises the filtration step (25) of the natural red fruit juice (26), obtaining, on the one hand, the filtered natural red fruit juice (26) to be added in the adding step (31), and, on the other hand, the pulp (25a), as shown in Fig. 1. Advantageously, in this preferred embodiment, the filtration step (25) facilitates the stability of the kombucha beverage product (50) by removing suspended solids, pulp, skin and seed particles, or any other unwanted residue. Mesh filters, plates, or membranes may be used, in addition to centrifugation. Preferably, a fine mesh filter with a diameter of 0.5 to 2 millimeters is used. The scope of the present invention is defined by the following claims.

Claims

CLAIMS 1.- Probiotic and antioxidant kombucha beverage (50) characterized in that it comprises a fermented product obtained by using as a fermentation substrate sweetened tea (30) and natural red fruit juice (26), the natural red fruit juice (26) not being pasteurized or dehydrated.

2. Kombucha beverage (50) according to claim 1, obtained by: Prepare sweetened tea (30) by adding at least 50 grams of sugar (27) and at least 10 grams of tea (28) per liter of water (29), preferably distilled; add to the prepared sweetened tea (30) kombucha scoby (16) and said natural red fruit juice (26), in the following proportions per liter: between 50 and 800 milliliters of said natural red fruit juice (26), and top up to 1 liter with the prepared sweetened tea (30); and Ferment the kombucha scoby (16), the natural red fruit juice (26), and the sweetened tea (30) for 5 to 7 days at a temperature between 18 and 28 °C, obtaining a fermented product; and where the kombucha scoby (16) has been removed from the fermented product obtained.

3. Kombucha beverage (50) according to claim 2, wherein the fermented beverage obtained with the removed kombucha scoby (16) has been filtered, packaged, carbonated, and refrigerated to stop fermentation and for preservation. 4.- Kombucha beverage (50) according to claim 1, 2 or 3, obtained by adding to the prepared sweetened tea (30) kombucha scoby (16) and said natural red fruit juice (26), with the following proportions per liter: at least 600 milliliters of said natural red fruit juice (26), and making up to 1 liter with the prepared sweetened tea (30).

5. Kombucha beverage (50) according to claim 2 or 3, wherein the kombucha scoby (16) added to obtain the fermented beverage is in fresh or dehydrated form.

6. Kombucha beverage (50) according to claim 1, 2, 3, 4 or 5, wherein the fermented beverage obtained, filtered and packaged has been subjected to natural carbonation for 12 to 48 hours at a temperature between 18 and 28 °C. 7.- Kombucha beverage (50) according to claim 1, 2, 3, 4 or 5, wherein the filtered and packaged fermented product has been subjected to exogenous gasification by the addition of pressurized carbon dioxide.

8. Kombucha beverage (50) according to any one of the preceding claims, wherein the fermented product obtained has, on a logarithmic scale, more than 7 cfu / mL of lactic acid bacteria.

9. Kombucha beverage (50) according to any one of the preceding claims, wherein the fermented product obtained has a concentration of phenolic compounds greater than or equal to 50 mg of gallic acid equivalent / 100 mL, and has an antioxidant activity greater than or equal to 0.2 mmol Fe 2+ / 100 mL.

10. Kombucha beverage (50) according to any one of claims 1 to 6, wherein the fermented product obtained has been subjected to pasteurization treatments or application of high hydrostatic pressures to extend its shelf life by keeping it at room temperature.

11. Kombucha beverage (50) according to any one of the preceding claims, wherein the natural red fruit juice (26) used as a fermentation substrate comprises strawberry, cherry, blueberry, raspberry, blackberry, and / or currant juice, or a combination of these juices. 12.- Kombucha beverage (50) according to any one of the preceding claims, wherein the fermentation substrate is free of milk, lactose or dairy products.

13. Kombucha beverage (50) according to any one of the preceding claims, wherein the natural red fruit juice (26) used as a fermentation substrate has been previously extracted from red fruits by pressing. 14.- Kombucha beverage (50) according to any one of the preceding claims, wherein the fermentation substrate comprises exclusively said natural red fruit juice (26) and said sweetened tea (30).

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