PRODUCTION OF ALCOHOL-FREE FERMENTED VEGETABLE JUICE WITH PICHIA KLUYVERI YEAST

Abstract

The invention relates to methods for preparing vegetable juice comprising the fermentation of a plant substrate with Pichia kluyveri. The fermented vegetable juice obtained according to the method has improved flavor profiles, particularly reduced earthy flavors. The invention also provides strains of Pichia kluyveri suitable for the fermentation of plant substrates, which can be further processed to obtain beverages or other consumer products.

Description

PRODUCTION OF ALCOHOL-FREE FERMENTED VEGETABLE TUGO WITH PICHIA KLUYVERI YEAST FIELD OF INVENTION The present invention relates to the preparation of low- or no-alcohol beverages of plant origin, and more particularly to preparations of plant juices. The present invention also relates to the use of microorganisms in preparing such beverages. BACKGROUND OF THE INVENTION Vegetables are a valuable dietary source of important nutrients required by the human body. Diets based on vegetable juices have become increasingly popular. Vegetable juice is considered a healthy alternative to fruit juice because it contains less sugar. The problem with vegetable juice, however, is that the flavor profile is not always appealing. The taste of fresh vegetable juices can be earthy (as in beet, carrot, and cabbage juice) or sulfurous (as in leek and onion juice), which is the main reason why vegetable juices are not as palatable as fruit juices. The ongoing challenge of producing a vegetable juice acceptable to a wide range of consumers involves balancing flavor, aroma, appearance, and a satisfying mouthfeel. Ref. 314977 Furthermore, when vegetable juices are heat-treated for long-term storage through pasteurization, unpleasant flavors are often produced or intensified during the process. Some of these off-flavors are described as "cooked vegetables," which are unappealing to consumers. To address this issue, the juice industry frequently blends vegetable juice with fruit juice. Fermentation processes have been used to improve the flavor of beverages. Corona et al. (Corona, Onofrio, et al. Characterization of kefir-like beverages produced from vegetable juices. LWT-Food Science and Technology 66 (2016): 572-581) describe the fermentation of fruit and vegetable juices with a kefir culture containing both lactic acid bacteria and Saccharomyces cerevisiae. The lactic acid bacteria consist of Leuconostoc mesenteroides, Lactococcus lactis, Lactobacillus kefir, and Lactobacillus fermentum. The fermented vegetable and fruit juices were analyzed by a sensory panel of 15 untrained panelists. The only juice with a desirable flavor profile was the kefir-like carrot beverage. However, the kefir-like carrot beverage has an alcohol content of over 3%, which is undesirable for a health beverage. CN108244425 describes a functional beverage prepared by fermenting beetroot (Beta vulgaris) juice with lactic acid bacteria and mixing it with tomato juice. Lactobacillus plantari, Lactobacillus rhamnosus, and Lactobacillus fermentum are used to ferment the beetroot juice. Other ingredients such as lemon extract, mint extract, fennel extract, honey, and isomaltooligosaccharides are added to provide aroma and a refreshing taste. WO2012066176 describes the production of alcoholic fermented orange juice using the strain Píchia kluyverí, registered as CECT 13055. This strain is capable of fermenting the reducing sugars present in orange juice, resulting in a final product containing non-reducing sugars, such as sucrose, and thus providing a pleasant-tasting product. Furthermore, the final product typically has an alcohol content of around 2.5%. WO2011134952 describes the inoculation of Píchia kluyverí into grape juices. The yeast, which is added in frozen form, is thawed in liquid form before being added to the medium. It has been found that frozen yeast can be used for direct inoculation without a significant loss in cell count and consequent activity. The reference does not describe any improvement in the flavors of the beverages. US20170258113 describes a method for preparing fermented red berry juice using Píchia kluyverí XT110. As described, Píchia kluyverí XT110 is capable of fermenting at a pH between 2.5 and 3.0, which is important for maintaining stable anthocyanin levels and therefore does not lead to significant color loss in the final product. The prepared fermented red berry juice has a bright color, a high anthocyanin content, a rich, balanced fruity flavor, and a low alcohol content (<0.5%). WO2015117978 describes the use of two strains of Pichia kluyveri, PK-KR1 and PK-KR2, for preparing cider from apple and / or pear juice. The resulting product was found to contain higher amounts of hexyl acetate and other desirable flavor compounds, particularly hexyl acetate and isobutyl acetate. The two strains of Pichia kluyveri, PKKR1 and PK-KR2, were originally described in WO2009110807, which stated that they could be used to increase thiol (3MH and 3MHA) levels in the wine fermentation process. 3MH and 3MHA have distinctive aromas and flavors, such as grapefruit and passionflower. PK-KR1 and PK-KR2 were also used with different hop varieties to brew beer (WO2013030398), as well as low-alcohol or non-alcoholic beer (WO2014135673). However, there is no single solution for improving the flavor of vegetable juices. New methods are needed to prepare vegetable juices with desirable flavor profiles, such as reducing unwanted flavors. BRIEF DESCRIPTION OF THE INVENTION The present invention provides a novel method for preparing vegetable juices with enhanced flavors. It has been found that Pichia kluyveri can be advantageously used to ferment vegetable juice to obtain a product with an improved flavor profile and, therefore, greater palatability. As mentioned previously, in contrast to fruit juice, the flavor profile of vegetable juice is not always appealing. Therefore, the present invention provides a different approach to improving its flavor without resorting to mechanical techniques or blending fruit juices. In more detail, it has been discovered that Pichia kluyveri can be used to produce higher levels of flavor compounds, such as isoamyl acetate, isobutyl acetate, β-phenylethanol, α-terpineol, c-whisky lactone, and vanillin. According to a sensory evaluation, it is clear that earthy flavors are perceived much less in vegetable juices fermented with Pichia kluyveri. The fermented juices also have a fruitier and spicier flavor and are generally preferred compared to unfermented juices. The present invention provides, in a first aspect, the use of Pichia kluyveri for preparing beverages comprising root plant material. It has been found that Pichia kluyveri can be advantageously used to treat vegetable juice, especially vegetable juice with an undesirable earthy flavor. An earthy flavor is common in vegetable juice prepared from plant material grown in or in contact with soil. Therefore, it is desirable to improve the flavor of vegetable juice by reducing the earthy taste. The present invention thus provides an alternative strategy for improving the flavor profile, different from current methods used in the industry, which involve the use of mechanical techniques or the blending of fruit juices. The preferred Pichia kluyveri include strain 1, strain 2, and strain 3 of Pichia kluyveri, as well as their mutants. In another aspect, the invention provides for the use of Pichia kluyveri to reduce the earthy taste of plant material. This use involves the fermentation of the plant material, especially the roots. In one further aspect, the present invention provides methods for treating vegetable juice to reduce its earthy flavor and the resulting vegetable juice. In one embodiment, the method comprises the steps of (a) providing a substrate comprising root vegetable material, (b) adding at least one strain of Pichia kluyveri to the substrate, (c) fermenting the substrate, and (d) obtaining the fermented vegetable juice. It is understood that the substrate may comprise more than one type of root vegetable. In other respects, the present invention also provides the plant juice obtained by the methods described in the application, as well as the plant juice comprising one or more Pichia kluyveri, such as the strains of Pichia kluyveri described herein. The present invention further provides a new strain of Pichia kluyveri, deposited on 2014-03-05 in the German Collection of Microorganisms and Cell Cultures (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH; DSMZ), Inhoffenstr. 7B, D-38124 Braunschweig and given the membership number: DSM 28484. DEFINITIONS As used in this document, the term vegetable refers to an edible portion of a plant consumed by humans. The edible portion of a plant may be a root, such as turnip, beet, carrot, and sweet potato; a tuber or storage stem, such as potato and taro; a stem, as in asparagus and swede; a sprout, such as Brussels sprouts; a bulb, such as onion and garlic; a petiole or leaf stalk, such as celery and rhubarb; a leaf, such as cabbage, lettuce, parsley, and spinach; or an immature flower, such as cauliflower, broccoli, and artichoke. As used in this document, the term root vegetable is the edible portion of a plant that is in contact with the soil. Root vegetables are generally storage organs, enlarged to store energy in the form of carbohydrates. It should be noted that the term root vegetable, as used herein, is not limited to the botanically defined root, but also includes both true roots (such as taproots and tuberous roots) and stems (such as bulbs, rootlets, rhizomes, and tubers). In general, an off-flavor refers to the presence of unpleasant tastes and / or odors in food. Earthy is a flavor that resembles soil. Since this flavor is undesirable in food products, it is also referred to as earthy flavors in this document. The smell of earth has been largely attributed to the presence of geosmin (Gerber, NN, and HA Lechevalier. Geosmin, an earthy-smelling substance isolated from actinomycetes. Applied Microbiology 13.6 (1965): 935-938). Geosmin has been characterized in the soil (Buttery, Ron G., and John A. Garibaldi. Geosmin and methylisoborneol in garden soil. Journal of agricultural and food chemistry 24.6 (1976): 1246-1247) and has been shown to be responsible for the earthy odor of root vegetables such as beets (Aeree, TE, et al. Geosmin, the earthy component of table beet odor. Journal of Agricultural and Food Chemistry 24.2 (1976): 430-431). However, geosmin is difficult to measure due to the specific equipment required. Nevertheless, the earthy taste caused by geosmin can be reliably assessed using sensory analyses known in the art. Therefore, reducing the earthy taste, as used herein, refers to a decrease in the magnitude of the perceived earthy taste. This can be achieved by comparing the earthy taste before and after treatment with Píchia kluyverí. This can be assessed using sensory evaluation methods known in the art, such as those described in Meilgaard et al. (Meilgaard, Monten C., B. Thomas Carr, and Gail Vanee Civille. Sensory evaluation techniques. CRC Press, 1999) or as described in this application. Earthy flavor can be measured with sensory analysis as described in the example. The term substrate refers to a material that is fermentable by Píchia kluyverí. The term alcohol-free here refers to an alcohol content of less than 0.5% v / v. The term "improving the flavor of a product" means enhancing the flavor profile of a product to make it more palatable. This can be determined, for example, through a sensory evaluation conducted by an expert in the field. The term fermentation generally refers to any activity or process involving the enzymatic breakdown (digestion) of organic materials by microorganisms. The term fermentation encompasses both anaerobic and aerobic processes, as well as processes involving a combination or succession of one or more anaerobic and / or aerobic stages. The term "mutant" shall be understood as a strain derived from a strain of the invention by, for example, genetic engineering, radiation, and / or chemical treatment. Preferably, the mutant shall be a functionally equivalent mutant, for example, a mutant having substantially equal or improved properties to the parent strain. In the present context, a mutant of the invention with equal or improved properties with respect to the reduction of earthy flavors is preferred. Such a mutant is a part of the present invention. A mutant may be a strain obtained by subjecting a strain of the invention to any conventionally used mutagenization treatment, including treatment with a chemical mutant such as ethanol methanol sulfonate (EMS) or N-methylN'-nitro-N-nitroguanidine (NTG), ultraviolet light, or a spontaneously occurring mutant.A mutant may have undergone several mutagenization treatments (a single treatment being understood as a mutagenization step followed by a selection step), but currently, it is preferred that no more than 1000, 100, 20, 10, or 5 treatments be performed. In a currently preferred mutant, less than 5%, 1%, or even less than 0.1% of the nucleotides in the bacterial genome have been modified (e.g., by substitution, insertion, deletion, or a combination thereof) compared to the parent strain. BRIEF DESCRIPTION OF THE FIGURES Figure 1 shows the sensory analysis of beetroot juice prepared by fermentation with strain 1 of Pichía kluyverí and strain 2 of Pichía kluyverí. DETAILED DESCRIPTION OF THE INVENTION The present invention falls within the technical field of non-alcoholic beverages. It should be understood that such beverages have an ethanol concentration of less than 0.5% (v / v). Driven by health-conscious consumers seeking to limit their alcohol intake, the low- and no-alcohol sector is growing rapidly. Vegetable juice, in particular, is becoming increasingly popular among health-conscious consumers. However, the flavor profile of vegetable juice is not always appealing. Therefore, there is a constant need to provide products with improved flavor profiles for the market. In a first aspect, the present invention provides a method for obtaining fermented vegetable juice, which consists of adding at least one strain of Pichia kluyveri to a substrate comprising root vegetables and fermenting the substrate to obtain fermented vegetable juice. The present invention is based on the finding that Pichia kluyveri has advantageous properties useful in the treatment of vegetable juices, especially in reducing earthy flavors and enhancing fruity and floral flavors. In a preferred embodiment, the method comprises: a) provide a substrate comprising plant roots, b) add at least one strain of Pichia kluyveri to the substrate, and c) ferment the substrate comprising the Pichia kluyveri strain. In another preferred embodiment, the method comprises: a) provide a substrate comprising plant roots, b) adjust the pH of the substrate, c) add at least one strain of Pichia kluyveri to the substrate, and d) ferment the substrate comprising the Pichia kluyveri strain. In a second aspect, the present invention also provides fermented vegetable juice obtained by the methods described herein. Fermented vegetable juice does not contain alcohol. For example, the alcohol content (v / v) of fermented vegetable juice is less than 0.5%, such as less than 0.4%, less than 0.3%, less than 0.2%, less than 0.1%, less than 0.09%, or less than 0.08%. Pichia kluyveri is considered particularly useful for treating all vegetables with an earthy flavor. This especially includes root vegetables. The earthy flavor, a characteristic of many vegetable juices, is caused by the aromatic compound geosmin. Geosmin (trans-1,10-dimethyl-trans-9-decalol) is a compound with an earthy, musty, beetroot, even turnip-like flavor and has an extremely low sensory threshold of up to 10 ppm. It is a metabolite of several actinomycetes and fungi. It has been found to be responsible for earthy contamination in various foods, including fish and wine. Some bacteria, such as Bacillus subtilis and Pseudomonas, have been reported to biodegrade geosmin. However, fermentation with Pichia kluyveri has never been reported to reduce the perception of geosmin's unpleasant flavor. To prepare a vegetable juice according to the present invention, a substrate comprising root vegetables is provided. The root system can be derived from one or more types of plants. For example, the substrate may be composed of material from a specific root vegetable or from different types of root vegetables. Furthermore, the substrate may also contain other plant material. For example, the substrate may comprise a mixture of root vegetable types and fruits. In another configuration, the substrate consists primarily of root vegetables. The substrate according to the present invention comprises root vegetables. For example, root vegetables are any of the known species of root vegetables. Suitable root vegetables include, but are not limited to, true roots, for example, tuberous roots and taproots, and non-roots, for example, tubers, rhizomes, bulbs, and corms. A true tuber may be a primary root and / or a tuberous root. Among the examples of fingerling roots are, inter alia, the arracachia [Arracada xanthorrhiza) , the bush carrot (Abelmoschus moschatus), the beet and mangelwurzel {Beta vulgaris) , the colinabo and turnip {Brassica spp.), the black cumin {Bunium persicum), burdock {Arctium), carrot {Daucus carota subsp. sativas), celery {Apium graveoiens rapaceum), daikon {Raphanus sativus var. longipínnatus), dandelion (Taraxacum spp.), maca (Lepidíum meyeníí) , yam daisy (Microseris scapigera), jicama and ahipa (Pachyrhizus spp.), chirivia (Pastinaca sativa), parsley root (Petroselinum spp.), radish (Raphanus sativus), salsify black (Hispanic Scorzonera), skirret (Sium sisarum), salsify (Tragopogon spp.) and wild duck (Vigna lanceolata). Examples of tuberous roots include, among others, the yellow lily yam (Amorphophallus galbra), the piñón or earth nut (Conopodium majus), the nagaimo, the Chinese yam, the Korean yam (Dioscorea opposita), the native ginger (Hornstedtia scottiana), the sweet potato (Ipomoea batatas), the desert yam (Ipomoea costata), the cassava or yucca or manioc (Manihot escalenta), the mauka or chago (Mirabilis extensa), the breadroot, the tipino or prairie turnip (Psoralea escalenta), and the yacon (Smallanthus sonchifolias). An example of a root vegetable that comprises a root-like stem is the Florida arrowroot (pumila). A non-root vegetable comprises a tuber, a rhizome, a bulb, and / or a corm. Examples of corms include, among others, konjac (Amorphophallus konjac), taro (Colocasia escalenta), Chinese water chestnut (Eleocharis dulcis), ensebe (Ensote spp.), water lily (Nelumbo nucifera), arrowhead or wapatoo (Sagittaria spp.), and taro or malanga (Xanthosoma spp.). Examples of rhizomes include, among others, turmeric (Curcuma longa), ginseng (Panax ginseng), rengarenga and vanilla lily (Arthropodiam spp.), canna (Canna spp.), ti (Cordyline fraticosa), arrowroot (Maranta arundinacea), lotus root (Nelumbo nucifera), cattail or cattail (fypha spp.), ginger, galangal (officinale). Among the examples of tubers figure, among others, the pork potato or peanut (Apios americana), the chufa or chufa (Cyperus esculentus); the yam, ube (Dioscorea spp.), the Jerusalem artichoke or sunchoke (Helianthus tuberosas), the daylily (Hemerocallis spp.), ground pea (Lathyrus tuberosas), New Zealand yam and goose (Oxalis tuberosa), kembili, dazo (Plectranthus edulis and P. esculentus), potatoes (Solanum tuberosum), Chinese artichoke or crosne (Stachys affinis), mashua or anu (Tropaeolum tuberosum), and ulluco (Ullacas tuberosas). Examples of bulbs include, but are not limited to, garlic, onions, shallots, leeks, etc. (Alliam spp.), curd (Camassia qamsh), bush onion (Cyperas balbosas), katakuri (Erythronium spp.), fennel (Foenicalum valgare) and lilies (Lilium spp.) . Root vegetables can vary in their nutritional content, for example, their carbohydrate composition. Tubers, for instance, may contain more starch than a true root vegetable, which may contain more simple sugars. Both true and non-root vegetables are sources of other vitamins, minerals, and nutrients, such as fiber, potassium, vitamin A, calcium, vitamin B6, vitamin C, biotin, vitamin B1, vitamin B2, vitamin B3, iron, copper, and magnesium. The appropriate tuber used to prepare vegetable juice can be a monocot, a dicot, or a combination of both. Examples of monocots include yams, such as white yam, yellow yam, Kokoro, Japanese mountain yam, purple yam, jicama, taro, or combinations thereof. Examples of a dicotyledon include a sweet potato, a Batas, Brazilian sweet potatoes, Dingess sweet potatoes, Japanese purple sweet potatoes, Okinawa sweet potatoes, Mokuau sweet potatoes, Covington sweet potatoes, Beauregard sweet potatoes. The substrate described here may comprise, for example, one or more types of root vegetables. For instance, the substrate may include carrots and beets. In some cases, the substrate comprises 2, 3, 4, 5, 6, 7, 8, 9, 10, or more different types of root vegetables. Among the preferred examples of root vegetables are, among others, carrot, beetroot, parsnip, swede, turmeric, ginger, potato, sweet potato, turnip, swede, cassava, swede, onion, garlic, celery root, horseradish, daikon, jicama, radish, Jerusalem artichoke, and yam. The substrate preparation process can be described as follows: washing the vegetables, optionally grinding them to obtain the pulp, and extracting (preferably by pressing) the juice from the vegetables without the pulp. Depending on the type of vegetable, it can be pasteurized or sterilized if desired. Additional ingredients may also be included in the substrate. In one method, the vegetable juice can be acidified. This can be done, for example, by adding an acidifying agent such as citric acid, lactic acid, lemon juice, or similar. Alternatively, this could also be done through fermentation with lactic acid bacteria. Acidification can be used to stabilize the juice in order to reduce pathogen growth in the final product. Thus, in another embodiment, the present invention provides a method comprising: a) provide a substrate comprising plant roots, b) adjust the pH of the substrate, c) add at least one strain of Pichia kluyveri to the substrate, and d) ferment the substrate comprising the Pichia kluyveri strain. Preferably, the pH is adjusted between 2.5 and 6.5, such as between 2.5 and 6 or between 3 and 5.5. Pichia kluyveri is capable of fermenting juice at these pH ranges. The substrate pH can be adjusted according to the product desired by consumers. The method according to the present invention comprises the step of adding Pichia kluyveri to the substrate. This may include the addition of one or more strains of Pichia kluyveri, such as 1, 2, 3, 4, 5, or more strains of Pichia kluyveri. As used herein, a strain of Pichia kluyveri means a genetic variant of Pichia kluyveri, which can be readily determined by a person skilled in the art based on its genetic makeup. Pichia kluyveri is added to the substrate in a sufficient quantity to initiate and maintain fermentation. The expert will be able to easily determine the appropriate inoculation concentrations of Pichia kluyveri based on the description and examples. In preferred forms, Pichia kluyveri is inoculated at a concentration of at least 1x104 CFU / ml, as at least 5x104 CFU / ml, as at least 1x105 CFU / ml, as at least 5x105 CFU / ml, as at least 1x106 CFU / ml, as at least 5x106 CFU / ml. In some forms, a mixture of more than one strain can be used, such as 2, 3, 4, 5 or more strains of Pichia kluyveri. In addition, the added Pichia kluyveri may be in frozen, liquid, or dry form, including, for example, freeze-dried form and spray-dried / fluidized bed form, or frozen or freeze-dried concentrates. The method according to the present invention comprises the step of fermenting the substrate comprising the added Pichia kluyveri. The fermentation of the substrate is preferably carried out by controlled fermentation in sterile environments. During the fermentation process, an expert in the field may choose to exercise other options known to him, such as the addition of pectinase during milling / pressing, pH adjustment, the addition of sulfur dioxide as an antimicrobial agent, clarification and filtration, to obtain the desired final product. Preferably, the fermentation of the substrate with Pichia kluyverí is carried out for at least 12 hours, for example, for 18 hours, for example, for 24 hours, for example, for 36 hours, for example, for 48 hours. It is preferable that the fermentation not exceed 48 hours, because the alcohol content can rise to an undesirable level for the final product. An expert in the field can easily select the appropriate fermentation time based on the desired properties of the product. In some varieties, fermentation does not exceed 36 hours. In others, fermentation takes place between 12 and 48 hours. Ideally, the fermentation conditions using Pichia kluyveri are semi-anaerobic. Fermentation can begin aerobically and proceed anaerobically after all the oxygen has been consumed. In some embodiments of the present invention, Pichia kluyveri is added to the substrate as a starter culture. The term starter culture refers to a composition comprising live microorganisms capable of initiating or effecting the fermentation of organic material, optionally after having been cultivated in a separate starter medium to obtain a high-density culture. Accordingly, in one embodiment, a starter culture of the invention may be a high-density culture obtained by propagating a starter culture in a suitable medium. An initial culture according to the present invention may also contain, in addition to microorganisms, buffering agents and nutrients or preservatives that stimulate growth or other carriers. In a preferred embodiment, the first starter culture contains at least 102 colony-forming units (CFU) / g of Pichia kluyveri, at least 103 CFU / g, at least 104CFU / g, at least 105CFU / g, at least 106CFU / g, at least 107CFU / g, at least 108CFU / g, at least 109CFU / g, at least 1010CFU / g, at least 1011CFU / g, at least 1012CFU / g, at least 1013CFU / g. Fermentation can be carried out at a temperature between 4 and 35°C. In the preferred methods, fermentation is carried out at a temperature between 18 and 22°C, such as between 19-21°C, or 20°C. Fermentation can be terminated by any suitable method known to the art, including cooling, preferably to below 4°C, and / or pasteurization. The fermented plant juice is then obtained. Preferably, the fermentation liquid is separated from the solids using any suitable method known to the art, for example, by filtration or centrifugation. Depending on the product, additional components may also be included in the fermented juice, such as thickeners, sugar, sweetener, dietary fiber, syrup, buffers, pH adjusting agents, salt, essential minerals, pectin, proteins, flavorings, colorings, vitamins, preservatives, antioxidants, etc. It is also anticipated that the fermented liquid can be further processed, for example, by concentration, dilution, or mixing with other products. The fermented juice is preferably bottled and optionally pasteurized. In other cases, the fermented juice is not pasteurized. Acetate esters are important flavor compounds in beverages. For example, the best-known acetate esters are isoamyl acetate and ethyl acetate. Ethyl acetate is a fruity-smelling liquid with a brandy note and is a common ester in fruits. Researchers have discovered that the level of ethyl acetate in vegetable juice containing Pichia kluyveri increases after fermentation. In some forms, the ethyl acetate level is at least 10 ppm, such as at least 12 ppm, at least 13 ppm, at least 14 ppm, at least 15 ppm, at least 16 ppm, at least 17 ppm, at least 18 ppm, at least 19 ppm, at least 20 ppm, at least 21 ppm, at least 22 ppm, at least 23 ppm, at least 24 ppm, at least 25 ppm, at least 26 ppm, at least 27 ppm, at least 28 ppm, at least 29 ppm, or at least 30 ppm. Isoamyl acetate, also known as isopenyl acetate, is an organic compound that is the ester formed by isoamyl alcohol and acetic acid. Isoamyl acetate occurs naturally in banana plants. It has a strong odor that is often described as smelling like banana or pear. However, in large quantities, it produces a distinct acetone odor that can be perceived as unpleasant. The inventors have discovered that the level of isoamyl acetate in vegetable juice with Píchia kluyverí iviA / a / ¿u¿ i / uu ioo / increases after fermentation. In some preferred embodiments, the isoamyl acetate in the fermented vegetable juice prepared according to the present invention is at least 2 ppm, such as at least 2.1 ppm, at least 2.2 ppm, at least 2.3 ppm, at least 2.4 ppm, at least 2.5 ppm, at least 2.6 ppm, at least 2.7 ppm, at least 2.8 ppm, at least 2.9 ppm, at least 3.0 ppm, at least 3.1 ppm, at least 3.2 ppm, at least 3.3 ppm, at least 3.4 ppm, at least 3.5 ppm, at least 3.6 ppm, at least 3.7 ppm, at least 3.8 ppm, at least 3.9 ppm, or at least 4.0 ppm. The ratio of the weight of isoamyl acetate to that of ethyl acetate is a good indicator of fruiting. Like ethanol, ethyl acetate is the ester of ethanol and acetic acid, and it acts as a solvent. It contributes to the release of the flavor of isoamyl acetate. The inventors have discovered that this weight ratio in the juice of vegetables fermented with Pichia kluyveri increases after fermentation. Among some preferred embodiments, the weight ratio of isoamyl acetate to ethyl acetate of the fermented juice prepared according to the present invention is at least 0.1, such as at least 0.11, at least 0.12, at least 0.13, at least 0.14, at least 0.15, at least 0.16, at least 0.17, at least 0.18, at least 0.19, or at least 0.2. Preferably, the weight ratio of isoamyl acetate to ethyl acetate in the fermented juice is at least 0.2, such as at least 0.21, at least 0.22, at least 0.23, at least 0.24, at least 0.25, at least 0.26, at least 0.27, at least 0.28, at least 0.29, or at least 0.30. The inventors have discovered that the weight ratio of isoamyl acetate to ethanol in vegetable juice fermented with Pichia kluyveri increases after fermentation. Specifically, the weight ratio of isoamyl acetate to ethanol in the fermented juice prepared according to the present invention is at least 0.0002, as well as at least 0.0003, at least 0.0004, at least 0.0005, at least 0.0006, at least 0.0007, at least 0.0008, at least 0.0009, at least 0.001, at least 0.0011, at least 0.0012, or higher. Vegetable juice fermented with Pichia kluyveri has been found to contain more flavor compounds, including β-phenylethanol and α-terpineol. β-Phenyleneethanol has a rose-like flavor and works synergistically with other flavor compounds such as esters to enhance the overall fruity impression. The inventors have found that the β-phenylethanol content of vegetable juice fermented with Pichia kluyveri increases after fermentation. In some preferred embodiments, the β-phenylethanol content in the fermented vegetable juice is at least 0.2 ppm, at least 0.3 ppm, at least 0.4 ppm, at least 0.5 ppm, at least 0.6 ppm, and at least 0.7 ppm. α-Terpineol has a pleasant, lilac-like odor. It is a terpene alcohol found in natural oils such as pine oil. It is also one of the most commercially important monoterpene alcohols for the flavor industry. The inventors have found that α-terpineol in plant juice fermented with Pichia kluyveri increases after fermentation. In some preferred embodiments, the α-terpineol in the fermented plant juice is at least 5 ppb, at least 10 ppb, at least 20 ppb, at least 30 ppb, at least 40 ppb, at least 50 ppb, at least 60 ppb, or at least 70 ppb. c-Whisky lactone (cis-whisky lactone), also known as (3S,4S)-3-methyl-4-octanolide, is an important component in the aroma of whisky and other spirits aged in oak barrels. It is sometimes added to liquor as a flavoring agent. The inventors have discovered that c-whisky lactone in plant juice fermented with Pichia kluyveri increases after fermentation. In some preferred forms, the c-whisky lactone in the fermented vegetable juice is at least 1 ppb, as at least 2 ppb, as at least 3 ppb, as at least 4 ppb, as at least 5 ppb, as at least 6 ppb, as at least 7 ppb. Vanillin, a phenolic aldehyde, is the main flavor and aroma compound in vanilla. With its sweet, creamy vanilla scent, vanilla is more often used than natural vanilla extract as a flavoring agent in foods, beverages, and pharmaceuticals. The inventors have discovered that the vanillin content in plant juice fermented with Pichia kluyveri increases after fermentation. In some preferred embodiments, the vanillin content in the fermented plant juice is at least 2 ppb, at least 3 ppb, at least 4 ppb, at least 5 ppb, at least 6 ppb, and at least 7 ppb. In a broader sense, the present invention provides fermented vegetable juice with improved flavor profiles. A vegetable juice prepared according to the present invention comprises root vegetables and Pichia kluyveri, which may be, for example, Pichia kluyveri strain 1, Pichia kluyveri strain 2, Pichia kluyveri strain 3, mutants thereof, or any combination thereof. Pichia kluyveri strain 1 was deposited on March 5, 2014 in the German Collection of Microorganisms and Cell Cultures (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH; DSMZ), Inhoffenstr. 7B, D-38124 Braunschweig and given the membership number: DSM 28484. Pichia kluyveri strain 2 was deposited on August 24, 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia), by the University of Auckland, College of Biological Sciences, Auckland 1142 (New Zealand), with membership number V06 / 022711. Pichia kluyverí strain 3 was deposited on August 24, 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia), by the University of Auckland, College of Biological Sciences, Auckland 1142 (New Zealand), with membership number V06 / 022712. In a broader sense, the present invention provides for the use of Pichia kluyveri for fermenting root vegetables. In some cases, Pichia kluyveri strain 1, Pichia kluyveri strain 2, Pichia kluyveri strain 3, mutants, or any combination thereof are used to ferment root vegetables to obtain vegetable juice as described herein. The inventors have demonstrated that strains of Pichia kluyveri have a significant effect on the flavor profile of the final fermented juice product. Remarkably, substantial increases were found in all desirable flavor compounds, such as asters and terpenes. As the examples show, the flavor analysis closely matches the sensory evaluation. The sensory evaluation demonstrated that vegetable juices fermented with Pichia kluyveri have significantly less earthiness and more fruity and spicy aroma compared to a non-fermented control. The present invention further provides a product that is Pichia kluyveri strain 1 in frozen, freeze-dried, or liquid form, including, for example, freeze-dried form and spray-dried / fluidized bed form, or frozen or freeze-dried concentrates. The preparation of the different forms is known in the art and is described, for example, in document WO2011 / 134952 (Chr. Hansen A / S). Pichia kluyveri can be cultivated in a heater and concentrated. Cryoprotectants can also be added to maintain the viability of the yeast at low temperatures. The product can be added directly to the substrate comprising the root vegetable. Furthermore, the present invention provides a composition for preparing fermented beverages, comprising strain 1 of Pichia kluyveri. ITEMS The following elements are preferred embodiments of the present invention: 1. A method for reducing the earthy taste of vegetable juice, comprising the steps of a) provide a substrate comprising plant roots, b) add at least one strain of Pichia kluyveri to the substrate, c) ferment the substrate comprising the strain Pichia kluyveri for less than 48 hours, d) obtain fermented vegetable juice. 2. The method in point 1, in which the root vegetable is selected from the group consisting of carrot, beetroot, parsnip, swede, turmeric, ginger, potato, sweet potato, turnip, swede, cassava, swede, onion, garlic, celery root, horseradish, daikon, jicama, radish, Jerusalem artichoke, and yam. 3. The method of any of the above points, in which Pichia kluyveri is selected from the group formed by a) Pichia kluyveri was deposited on March 5, 2014 in the German Collection of Microorganisms and Cell Cultures (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH; DSMZ), Inhoffenstr. 7B, D-38124 Braunschweig and given the membership number: DSM 28484, b) Pichia kluyveri deposited on 24 August 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia) , by the University of Auckland, Faculty of Biological Sciences, Auckland 1142 (New Zealand), with registration number V06 / 022711, c) Pichia kluyveri deposited on 24 August 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia), by the University of Auckland, Faculty of Biological Sciences, Auckland 1142 (New Zealand), with registration number V06 / 022712, and d) changers of a), b) oc). 4. The method of any of the preceding elements, wherein the weight ratio of isoamyl acetate to ethyl acetate is at least 0.1, preferably at least 0.2, 5. The method of any of the above points, wherein step b) further comprises the addition of a strain of lactic acid bacteria to the substrate. 6. The method of any of the above points, wherein the fermentation in step c) is carried out at a temperature between 4 and 35°C, more preferably between 18 and 22°C. 7. The method of any of the above points, wherein β-phenylethanol in the fermented vegetable juice is at least 0.4 ppm. 8. The method of any of the above points, wherein α-terpineol in the fermented plant juice is at least 50 ppb. 9. The method of any of the above points, wherein the c-whisky lactone in the fermented vegetable juice is at least 4 ppb. 10. The method of any of the above points, wherein the vanillin in the fermented vegetable juice is at least 4 ppb. 11. Fermented vegetable juice obtained by the methods according to any of the above points. 12. Fermented vegetable juice comprising root vegetables and Pichía kluyverí. 13. The fermented vegetable juice according to point 12, where Pichía kluyverí is selected from the group consisting of: a) Píchía kluyverí was deposited on March 5, 2014 in the German Collection of Microorganisms and Cell Cultures (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH; DSMZ), Inhoffenstr. 7B, D-38124 Braunschweig and given the membership number: DSM 28484, b) Píchía kluyverí deposited on 24 August 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia) , by the University of Auckland, Faculty of Biological Sciences, Auckland 1142 (New Zealand), with registration number V06 / 022711, c) Píchía kluyverí deposited on 24 August 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia) , by the University of Auckland, Faculty of Biological Sciences, Auckland 1142 (New Zealand), with registration number V06 / 022712, and d) mutants of a), b) oo) . 14. Fermented vegetable juice according to any of points 12-13, wherein the weight ratio of isoamyl acetate to ethyl acetate is at least 0.1, preferably in and / or where the weight ratio of isoamyl acetate to ethanol is at least 0.0002, preferably at least 0.0008. 15. Fermented vegetable juice according to any of Points 12-14, where β-phenylethanol in fermented vegetable juice is at least 0.4 ppm. 16. Fermented vegetable juice according to any of points 12-15, where α-terpineol in fermented vegetable juice is at least 50 ppb. 17. Fermented vegetable juice according to any of points 12-16, wherein the c-whisky lactone in the fermented vegetable juice is at least 4 ppb. 18. Fermented vegetable juice according to any of points 12-17, wherein the vanillin c in the fermented vegetable juice is at least 4 ppb. 19. Use of Pichía kluyverí to ferment root vegetables. 20. The use of article 19, in which the root vegetable is selected from the group consisting of carrot, beetroot, parsnip, swede, turmeric, ginger, potato, sweet potato, turnip, swede, cassava, swede, onion, garlic, celery root, horseradish, daikon, jicama, radish, Jerusalem artichoke and yam. 21. The use of article 19 or 20, in which Píchia kluyverí is selected from the group formed by: a) Píchia kluyverí was deposited on March 5, 2014 in the German Collection of Microorganisms and Cell Cultures (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH; DSMZ), Inhoffenstr. 7B, D-38124 Braunschweig and given the membership number: DSM 28484, b) Píchia kluyverí deposited on 24 August 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia) , by the University of Auckland, Faculty of Biological Sciences, Auckland 1142 (New Zealand), with registration number V06 / 022711, c) Píchia kluyverí deposited on 24 August 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia), by the University of Auckland, Faculty of Biological Sciences, Auckland 1142 (New Zealand), with registration number V06 / 022712, and d) mutants of a), b) oc). 22. Píchia kluyverí as deposited on March 5, 2014 in the German Collection of Microorganisms and Cell Cultures (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH; DSMZ), Inhoffenstr. 7B, D-38124 Braunschweig and given the membership number: DSM 28484 and its mutants. 23. A fermentation composition comprising the Pichía kluyveri of Article 22. 24. The composition according to point 23, where the composition is in frozen, freeze-dried or liquid form. The use of the terms "a" and "one," "an," and "the," and other similar referents in the context of the description of the invention (especially in the context of the following claims) should be construed as encompassing both the singular and the plural, unless otherwise indicated herein or clearly contradicted by the context. The terms "comprising," "having," "including," and "containing" should be construed as open terms (i.e., meaning "includes, but is not limited to"), unless otherwise indicated. The recitation of ranges of values ​​herein is intended simply as a shorthand method for referring individually to each separate value within the range, unless otherwise indicated herein, and each separate value is incorporated into the description as if recited individually herein. All methods described herein may be performed in any suitable order, unless otherwise stated herein or clearly contradicted by the context. The use of any and all examples, or exemplary language (e.g., such as) provided herein is intended merely to further illuminate the invention and does not limit its scope, unless otherwise claimed. Nothing in the description should be construed as indicating that any unclaimed element is essential to the practice of the invention. DEPOSIT AND EXPERT SOLUTION The applicant requests that a sample of the deposited microorganisms indicated below may only be made available to an expert, until the date on which the patent is granted. Strain 1 of Pichia kluyveri was deposited in the DSMZ (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Inhoffenstrasse 7B, D-38124 Braunschweig) on ​​5 March 2014 by Chr. Hansen A / S, Denmark, and received membership number DSM 28484. The deposit was made under the conditions of the Budapest Treaty on the International Recognition of the Deposit of Microorganisms for the Purposes of Patent Procedure. Pichia kluyveri strain 2 (PK-KR1) and Pichia kluyveri strain 3 (PK-KR2) were deposited on 24 August 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia), by the Faculty of Biological Sciences of the University of Auckland, Auckland 1142 (New Zealand), and received membership numbers V06 / 022711 and V06 / 022712, respectively, as described in document WO 2009 / 110807. EXAMPLES EXAMPLE 1 Carrot juice with a pH of 4.5 was provided as the plant substrate. It was prepared by diluting the carrot juice concentrate. Fermentations were carried out on a laboratory scale (200 ml). Carrot juice was inoculated with two different Pichia kluyveri strains, namely strain 1 (DSM 28484) and strain 2 (deposited with the National Institute of Measurement under registration number V06 / 022711) at 10⁵ CFU / ml. The fermentations were placed in an incubator at 20°C for 24 hours. Samples were then taken. Ethanol analysis Ethanol was measured using the Boehringer Mannheim Ethanol Enzymatic Bioanalysis Kit. Ethanol concentrations of the fermentation products after 24 h of fermentation with Pichia kluyveri strain 1 and strain 2 are shown in Table 1. iviA / a / ¿u¿ i / uu ioo / Table 1: Ethanol concentration before and after fermentation Samples % EtOH (v / v) EtOH (ppm) Unfermented 0.12 946.8 Fermented with Pichia kluyverí strain 1 0.34 2682.6 Fermented with Pichia kluyverí strain 2 0.30 2367 As shown, the ethanol concentrations in the final fermented carrot product were below 0.05% (v / v). Flavor analysis The flavor analysis of all fermentation products was carried out at the Flavor Analysis and Enology Laboratory in Zaragoza, Spain. Table 2-6 shows the concentrations of the different flavor compounds in the samples. Table 2: Ethyl acetate concentrations before and after fermentation Samples Ethyl acetate (ppm) Unfermented 0.00 Fermented with strain 1 Pichia kluyverí 10.30 Fermented with strain 2 of Pichia kluyverí 25.06 Table 3: Acetate ester concentrations (isoamyl acetate and isobutyl acetate) before and after fermentation Samples Isoamyl acetate (ppm) Isobutyl acetate (ppm) Unfermented 0.12 0.01 Fermented with Pichia kluyveri strain 1 2.27 0.07 Fermented with Pichia kluyveri strain 2 2.56 0.18 Table 4: Isoamyl acetate / ethyl acetate ratio before and after fermentation Samples Ratio between isoamyl acetate (ppm) and ethyl acetate (ppm) Unfermented 0.00 Fermented with Pichia kluyveri strain 1 0.22 Fermented with Pichia kluyveri strain 2 0.10 Table 5: Isoamyl acetate / ethanol ratio before and after fermentation Samples Ratio between isoamyl acetate (ppm) and ethanol (ppm) Unfermented 0.00013 Fermented with Pichia kluyveri strain 1 0.00085 Fermented with Pichia kluyveri strain 2 0.00108 Table 6: β-phenylethanol concentrations before and after fermentation Samples β-phenylethanol (ppm) Unfermented 0.10 Fermented with Pichia kluyveri strain 1 0.86 Fermented with Pichia kluyveri strain 2 0.44 Table 7: α-terpineol concentrations before and after fermentation a-terpineol samples (ppb) Unfermented 2.67 Kluyveri fermented with Pichía strain 1 55.77 Kluyveri fermented with Pichía strain 2 51.52 Table 8: Concentrations of aromatic compounds (cwhiskylactone and vanillin) before and after fermentation Samples c-whiskylactone (ppb) Vanillin (ppb) Unfermented 0.00 1.24 Fermented with Pichia kluyveri strain 1 5.44 4.31 Fermented with Pichia kluyveri strain 2 4.91 4.17 Tables 2-4 clearly show that fermenting carrot juice with Pichia kluyveri improves the ester profile in the final fermented product. After only 24 hours of fermentation, the concentrations of ethyl acetate, isoamyl acetate, and isobutyl acetate increased at least twofold in the fermented carrot juices. Pichia kluyveri was shown to increase the ratio of isoamyl acetate (ppm) to ethyl acetate. Strain 1 of Pichia kluyveri produced less ethyl acetate than strain 2 of Pichia kluyveri, but similar amounts of isoamyl acetate. Consequently, the isoamyl acetate / ethyl acetate ratio is higher in strain 1 of Pichia kluyveri. Furthermore, Pichia kluyveri was shown to increase the isoamyl acetate (ppm) to ethanol (ppm) ratio. Strain 1 of Pichia kluyveri showed a lower isoamyl acetate (ppm) to ethanol (ppm) ratio compared to strain 2 of Pichia kluyveri, but similar amounts of isoamyl acetate. Tables 6-7 show the concentrations of two flavor compounds, β-phenylethanol and α-terpineol, respectively. Both compounds increased significantly in the fermented product and contributed to its floral and spicy notes. Strain 1 of Pichía kluyverí produces more β-phenylethanol and α-terpineol than strain 2. In addition to esters, alcohols, and terpenes, the inventors also discovered some lactones and even increased the vanillin content, imparting a sweeter flavor to the fermented product. The concentrations of c-whiskylactone and vanillin are shown in Table 8. EXAMPLE 2 Fresh, unacidified beet juice was provided as the plant substrate. It was prepared by pressing the beet. Fermentations were carried out on a laboratory scale (400 ml). The beet juice was inoculated with the same strains of Pichia kluyveri, strain 1 and strain 2, as described in Example 1. The fermentations were placed in an incubator at 20°C for 24 hours. Samples were then taken. Sensory analysis A sensory evaluation was carried out using the descriptive analysis technique according to Lawless et al (Lawless, H. T., and H. Heymann. Sensory Evaluation of Food: Practices and Principles. Food Science Texts Series. Chapman and Hall. New York (2010)) to evaluate how Píchía kluyverí contributes to the flavor profile. After fermentation, four apparent attributes of the fermented beet juices were determined. These attributes were: earthy, generally fruity, spicy, and sweet. Nine panelists were selected and a training session was conducted focusing on these attributes. During the training, the panelists were taught to recognize the aroma and flavor associated with each attribute. This was done by smelling raw beets for the earthy attribute, pepper for the spicy attribute, tropical fruit juice for the fruity attribute, and carrot juice for the sweet attribute. Following the training session, the panelists were invited to a tasting session of the fermented juices. The different juices, along with the unfermented beetroot juice, were assigned three random numbers and served to each judge. The juice was served at approximately 10°C in wine glasses. The panelists rated the four flavors (aroma and taste combined) of the juices using a 145 mm scale (0 representing not present, 145 representing highly present), as well as their subjective overall taste / acceptance of the juice. Figure 1 shows the results of the sensory evaluation. The figure shows how the different juices were evaluated on a scale of 0-145 for five different attributes: earthy, overall fruity, spicy, sweet, and overall similarity. Figure 1 shows that all juices fermented by Pichía kluyverí were rated as significantly less earthy compared to unfermented beet juice (beet control in Figure 1). Furthermore, the sweetness level of the fermented juices was very similar to that of the unfermented beet control. Additionally, they were perceived as fruitier and spicier compared to the control. Fermented beet juice from Pichia kluyveri is generally preferred over unfermented beet juice because it reduces the earthy flavor and enhances the fruity taste. Pichia kluyveri strain 1 was generally preferred over Pichia kluyveri strain 2, although the earthy flavor was perceived as slightly higher in beet juice fermented with Pichia kluyveri strain 1 compared to strain 2. The greatest flavor differences were found for esters and α-terpineol. A closer look at acetate ester concentrations reveals that the isoamyl acetate / ethyl acetate ratio, a good measure of fruitiness, is increased in both strains of Pichia kluyveri. This aligns well with the sensory evaluation, which showed that fermentation of the vegetable juice resulted in higher scores for fruitiness and spiciness, and significantly lower scores for earthy flavors, compared to unfermented beet juice. It is hereby stated that, as of this date, the best method known to the applicant for putting the aforementioned invention into practice is the one that is clear from the present description of the invention.

Claims

CLAIMS Having described the invention as above, the following claims are claimed as property:

1. A method for reducing the earthy taste of vegetable juice, characterized in that it comprises the steps of a) providing a substrate comprising vegetable roots, b) adding at least one strain of Pichia kluyveri to the substrate, c) fermenting the substrate comprising the Pichia kluyveri strain, d) obtaining fermented vegetable juice.

2. The method according to claim 1, characterized in that the root vegetable is selected from the group consisting of carrot, beetroot, parsnip, swede, turmeric, ginger, potato, sweet potato, turnip, swede, cassava, swede, onion, garlic, celery root, horseradish, daikon, jicama, radish, Jerusalem artichoke and yam.

3. The method according to any of the preceding claims, characterized in that Pichia kluyveri is selected from the group consisting of a) Pichia kluyveri deposited on 2014-03-05 in the German Collection of Microorganisms and Cell Cultures (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH; DSMZ), Inhoffenstr.7B, D-38124 Braunschweig and given the membership number: DSM 28484, b) Pichia kluyveri deposited on 24 August 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia), by the University of Auckland, Faculty of Biological Sciences, Auckland 1142 (New Zealand), with registration number V06 / 022711, c) Pichia kluyveri deposited on 24 August 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia), by the University of Auckland, Faculty of Biological Sciences, Auckland 1142 (New Zealand), with registration number V06 / 022712, and d) mutants of a), b) c).

4. The method according to any of the preceding claims, characterized in that the weight ratio of isoamyl acetate to ethyl acetate is at least 0.1, preferably at least 0.2, and / or wherein the weight ratio of isoamyl acetate to ethanol is at least 0.0002, preferably at least 0.0008.

5. The method in accordance with any of the preceding claims, characterized in that step b) further comprises the addition of a strain of lactic acid bacteria to the substrate.

6. The method in accordance with any one of the preceding claims, characterized in that the fermentation in step c) is carried out at a temperature between 4 and 35°C, more preferably between 18 and 22°C.

7. The method in accordance with any of the preceding claims, characterized in that the βphenylethanol in the fermented vegetable juice is at least 0.4 ppm.

8. The method in accordance with any of the preceding claims, characterized in that the aterpineol in the fermented vegetable juice is at least 50 ppb.

9. The method of any of the preceding claims, characterized in that the c-whisky lactone or vanillin in the fermented vegetable juice is at least 4 ppb.

10. Fermented vegetable juice obtained by methods in accordance with any of the preceding claims, characterized in that the juice comprises Pichia kluyveri.

11. Fermented vegetable juice characterized in that it comprises root vegetables and Pichia kluyveri.

12. The fermented vegetable juice according to claim 11, characterized in that Pichia kluyveri is selected from the group consisting of: iviA / a / ¿u¿ i / uu ioo / a) Pichia kluyveri deposited on 2014-03-05 in the German Collection of Microorganisms and Cell Cultures (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH; DSMZ), Inhoffenstr.7B, D-38124 Braunschweig and given the membership number: DSM 28484, b) Pichia kluyveri deposited on 24 August 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia), by the University of Auckland, Faculty of Biological Sciences, Auckland 1142 (New Zealand), with registration number V06 / 022711, c) Pichia kluyveri deposited on 24 August 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia), by the University of Auckland, Faculty of Biological Sciences, Auckland 1142 (New Zealand), with registration number V06 / 022712, and d) mutants of a), b) c).

13. Use of Pichia kluyveri to ferment root vegetables.

14. The use in accordance with claim 13, wherein Pichia kluyveri is selected from the group consisting of: a) Pichia kluyveri deposited on 2014-03-05 in the German Collection of Microorganisms and Cell Cultures (Deutsche Sammlung ven Mikroorganismen und Zellkulturen GmbH; DSMZ), Inhoffenstr. 7B, D-38124 Braunschweig and given the membership number: DSM 28484, b) Pichia kluyveri deposited on 24 August 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia) , by the University of Auckland, Faculty of Biological Sciences, Auckland 1142 (New Zealand), with registration number V06 / 022711, c) Pichia kluyveri deposited on 24 August 2006 at the National Institute of Measurement, 541-65 Clarke Street, South Melbourne, Victoria 3205 (Australia), by the University of Auckland, Faculty of Biological Sciences, Auckland 1142 (New Zealand), with registration number V06 / 022712, and d) mutants of a), b) c).

15. Pichía kluyveri, characterized by being deposited on March 5, 2014 in the German Collection of Microorganisms and Cell Cultures (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH; DSMZ), Inhoffenstr. 7B, D-38124 Braunschweig and given the accession number: DSM 28484 and its mutants.