Tea, Kombucha, and health: a review

Alternative Substrates for the Development of Fermented Beverages Analogous to Kombucha: An Integrative Review

Kombucha is a fermented beverage that originated in China and is spread worldwide today. The infusion of Camellia sinensis leaves is mandatory as the substrate to produce kombucha but alternative plant infusions are expected to increase the opportunities to develop new fermented food products analogous to kombucha, with high technological potential and functional properties. This review gathers information regarding promising alternative substrates to produce kombucha-analogous beverages, focusing on plants available in the Amazonia biome. The data from the literature showed a wide range of alternative substrates in increasing expansion, with 37 new substrates being highlighted, of which ~29% are available in the Amazon region. Regarding the technological production of kombucha-analogous beverages, the following were the most frequent conditions: sucrose was the most used carbon/energy source; the infusions were mostly prepared at 90-100 °C, which allowed increased contents of phenolic compounds in the product; and 14 day-fermentation at 25-28 °C was typical. Furthermore, herbs with promising bioactive compound compositions and high antioxidant and antimicrobial properties are usually preferred. This review also brings up gaps in the literature, such as the lack of consistent information about chemical composition, sensory aspects, biological properties, and market strategies for fermented beverages analogous to kombucha produced with alternative substrates. Therefore, investigations aiming to overcome these gaps may stimulate the upscale of these beverages in reaching wide access to contribute to the modern consumers' quality of life.

Kombucha as a Health-Beneficial Drink for Human Health

Kombucha is a unique fermented beverage made from a symbiotic culture of yeast and bacteria. Kombucha is normally based on black tea added to water, then sugar is added as a substrate for fermentation in this beverage. This unique beverage is composed of amino acids, flavonoids, vitamins, and some active enzymes. Several beneficial health effects such as antioxidant, antimicrobial effects have been reported as a result of probiotics and prebiotics presence. These health effects of kombucha are attributed to its bioactive chemical and biological agents of probiotics bacteria e.g., Gluconobacter, Acetobacter and yeasts like Saccharomyces sps., along with glucuronic acid as the main sources of the health protection. This review focuses on the beneficial effects of Kombucha including antimicrobial, antioxidant, anti-cancer antidiabetic properties, as well as liver protection, treat of gastrointestinal problems, AIDS, gastric ulcers, obesity (and energy production), detoxification, and skin health.

Metagenomic, organoleptic profiling, and nutritional properties of fermented kombucha tea substituted with recycled substrates

Kombucha fermentation yields a diverse range of beneficial macro and micronutrients. In our study, we examined the metabolites, antioxidant activity, organoleptic characteristics, and nutritional attributes of traditionally prepared kombucha tea, using black tea and sugar (control) as substrates, and compared them with tea made from tea dust and blackstrap molasses (test). Kombucha tea crafted from functional raw materials exhibited enhanced sensory qualities and improved health-promoting properties. The levels of tannins, flavonoids, and phenols play a crucial role in determining the antioxidant activity of kombucha tea. Using the DPPH and FRAP methods, we investigated the antioxidant activity throughout the fermentation period, ranging from day 0 to day 12, under optimized conditions. The results consistently demonstrated an initial increase in antioxidant activity from day 0 to 6, followed by a decline from day 6 to 12. Notably, statistical analysis revealed that the antioxidant activity of the test sample was significantly better (p > 0.001) compared to the control sample. The nutritional content of the kombucha from day 6 of the test sample is higher than the control sample provided sugars (fructose 0.4 ± 0.1, glucose 0.7 ± 0.1, sucrose 1.4 ± 0.1) g/100 mL, minerals (calcium, 19.4 ± 0.15, iron 23.1 ± 0.25, and potassium 28.3 ± 0.25) mg/100 mL, vitamins (B1 0.58 ± 0.01, B2 0.30 ± 0.02, B3 0.33 ± 0.02, B6 0.75 ± 0.02, B9 0.19 ± 0.03, B12 0.9 ± 0.03, and C 1.38 ± 0.06) mg/100 mL, sodium 4.35 ± 0.25 mg/100 mL, calories 14.85 ± 0.25 mg/100 mL, carbohydrates 3.135 ± 0.12, and acids (acetic acid 4.20 ± 0.02, glucuronic acid 1.78 ± 0.02) mg/100 mL on day 12. The predominant microbial species identified in both control and test samples included Komagataeibacter rhaeticus, Gluconobacter oxydans, Brettanomyces bruxellensis, and Zygosaccharomyces bailli, each with varying dominance levels. These microorganisms play essential roles in metabolizing sugars, generating acids, and contributing to the distinctive flavor profile of kombucha. Sensory evaluations of the control and test samples were analyzed, and the overall preference was 88% for the test sample with tea dust and molasses. The sensory characteristics of the test sample included a fruity smell (41%), fizzy texture (66%), bright color (47%), and a fruity taste (67%), with overall acceptability (56%) rating it as excellent. Our research contributes to a deeper understanding of the interplay between raw materials, microbial composition, and the resulting composition of bioactive compounds.

Fermented foods and gastrointestinal health: underlying mechanisms

Although fermentation probably originally developed as a means of preserving food substrates, many fermented foods (FFs), and components therein, are thought to have a beneficial effect on various aspects of human health, and gastrointestinal health in particular. It is important that any such perceived benefits are underpinned by rigorous scientific research to understand the associated mechanisms of action. Here, we review in vitro, ex vivo and in vivo studies that have provided insights into the ways in which the specific food components, including FF microorganisms and a variety of bioactives, can contribute to health-promoting activities. More specifically, we draw on representative examples of FFs to discuss the mechanisms through which functional components are produced or enriched during fermentation (such as bioactive peptides and exopolysaccharides), potentially toxic or harmful compounds (such as phytic acid, mycotoxins and lactose) are removed from the food substrate, and how the introduction of fermentation-associated live or dead microorganisms, or components thereof, to the gut can convey health benefits. These studies, combined with a deeper understanding of the microbial composition of a wider variety of modern and traditional FFs, can facilitate the future optimization of FFs, and associated microorganisms, to retain and maximize beneficial effects in the gut.

Kombucha Fermentation of Olympus Mountain Tea (Sideritis scardica) Sweetened with Thyme Honey: Physicochemical Analysis and Evaluation of Functional Properties

This study implemented kombucha fermentation of Olympus Mountain tea (Sideritis scardica) sweetened with honey (OMTWH) in order to investigate the potential for producing a novel beverage with functional properties. The increase in the total count of bacteria and yeast suggests that the OMTWH acts as a viable substrate for supporting the proliferation of the microorganisms of the Kombucha symbiotic culture. The fermentation resulted in a reduction in pH and increased total titratable acidity. After fermentation, a statistically significant increase in the vitamins C, B1, B2, B6, B7, and B12 content was observed (p < 0.05). Total phenolics and antioxidant activity of the fermented beverage was significantly enhanced, as assessed by the method of Folin-Ciocalteu and ABTS assay, respectively. Results revealed that OMTWH had a potent inhibitory activity of α-amylase, α-glucosidase, acetylcholinesterase, and butyrylcholinesterase; OMTWH fermented with a kombucha consortium exhibited even higher inhibition. Hence, the process of kombucha fermentation can convert OMTWH into a novel beverage with enhanced functional properties.

Unveiling the Aromas and Sensory Evaluation of Hakko Sobacha: A New Functional Non-Dairy Probiotic Fermented Drink

At the dawn of a food transition encouraging the consumption of healthy and sustainable non-dairy probiotic products, the development of a fermented functional drink based on Sobacha is considered. Sobacha is an infusion of roasted buckwheat seeds widely consumed in Asian countries for its health benefits. As fermentation improves the nutritional and organoleptic status of grains, the mixed fermentation process involved in the development of kombucha beverages (fermented sweet tea) is conducted by inoculating a symbiotic culture of bacteria and yeasts into the transposable matrix (Sobacha instead of tea). Sobacha, a healthy pseudo-cereal matrix with promising aromas, could be fermented to potentially develop an innovative drink, named "Hakko Sobacha". This neologism would reveal the fermented character of the infusion, Hakko meaning fermented in Japanese. Considering the beverage characterization, the kinetics of the volatile organic compound syntheses were determined using stir-bar sorptive extraction followed by gas chromatography coupled to mass spectrometry analysis. Odor-active compounds were theoretically calculated to estimate the flavor composition. Finally, sensory analyses highlighted the appreciation and preferences of the consumer towards the beverages. The fermentative yield differences observed between the two buckwheat concentration modalities tested seemed to be correlated with the sugar and nutrient levels available from the starch (buckwheat) matrix. Having characterized Hakko Sobacha, this study proposed the possibility of developing new beverages by monitoring the fermentative process. This should enable improved control and enhancement of their sensorial properties, which could in turn lead to greater customer acceptability.

Kombucha tea as an anti-hyperglycemic agent in humans with diabetes - a randomized controlled pilot investigation

Introduction

Kombucha is a popular fermented tea that has attracted considerable attention due, in part, to its suggested health benefits. Previous results from animal models led us to hypothesize kombucha may reduce blood sugar levels in humans with diabetes. The objective of this pilot clinical study was to evaluate kombucha for its anti-hyperglycemic activities in adults with diabetes mellitus type II.

Methods

The study was organized as a prospective randomized double-blinded crossover study at a single-center urban hospital system. Participants (n = 12) were instructed to consume either a kombucha product or a placebo control (each 240 mL) for 4 weeks. After an 8-week washout period, participants consumed the alternate product. Fasting blood glucose levels were self-determined at baseline and at 1 and 4 weeks during each treatment period. Secondary health outcomes, including overall health, insulin requirement, gut health, skin health, mental health, and vulvovaginal health were measured by questionnaire at the same time points. The kombucha microbiota was assessed by selective culturing and 16S rRNA gene (bacteria) and ITS (fungi) sequencing. Fermentation end products were assessed by HPLC. Statistical significance of changes in fasting blood glucose was determined using paired, two-tailed student's t-tests.

Results

Kombucha lowered average fasting blood glucose levels at 4 weeks compared to baseline (164 vs. 116 mg/dL, p = 0.035), whereas the placebo did not (162 vs. 141 mg/dL, p = 0.078). The kombucha microbiota, as assessed by cultural enumeration, was mainly comprised of lactic acid bacteria, acetic acid bacteria, and yeast, with each group present at about 106 colony forming units (CFU)/mL. Likewise, 16S rRNA gene sequencing confirmed that lactic acid and acetic acid bacteria were the most abundant bacteria, and ITS sequencing showed Dekkera was the most abundant yeast. The primary fermentation end products were lactic and acetic acids, both less than 1%. Ethanol was present at 1.5%.

Discussion

Although this pilot study was limited by a small sample size, kombucha was associated with reduced blood glucose levels in humans with diabetes. Larger follow-up studies are warranted.

Clinical trial registration

ClinicalTrials.gov, identifier NCT04107207.

Microbiological and Physico-Chemical Characteristics of Black Tea Kombucha Fermented with a New Zealand Starter Culture

Kombucha is a popular sparkling sugared tea, fermented by a symbiotic culture of acetic acid bacteria (AAB) and yeast. The demand for kombucha continues to increase worldwide, mainly due to its perceived health benefits and appealing sensory properties. This study isolated and characterised the dominant AAB and yeast from a starter culture and kombucha broth after 0, 1, 3, 5, 7, 9, 11, and 14 days of fermentation at ambient temperature (22 °C). Yeast and AAB were isolated from the Kombucha samples using glucose yeast extract mannitol ethanol acetic acid (GYMEA) and yeast extract glucose chloramphenicol (YGC) media, respectively. The phenotypic and taxonomic identification of AAB and yeast were determined by morphological and biochemical characterisation, followed by a sequence analysis of the ribosomal RNA gene (16S rRNA for AAB and ITS for yeast). The changes in the microbial composition were associated with variations in the physico-chemical characteristics of kombucha tea, such as pH, titratable acidity, and total soluble solids (TSS). During fermentation, the acidity increased and the TSS decreased. The yield, moisture content, and water activity of the cellulosic pellicles which had developed at the end of fermentation were attributed to the presence of AAB. The dominant AAB species in the cellulosic pellicles and kombucha broth were identified as Komagataeibacter rhaeticus. The yeast isolates belonged to Debaryomyces prosopidis and Zygosaccharomyces lentus.

Fermented Beverage Benefits: A Comprehensive Review and Comparison of Kombucha and Kefir Microbiome

Beverage fermentation is an ancient ritual that has been practised for millennia. It was slowly disappearing from households and communities due to the advancement of manufacturing technology and the marketing of soft drinks until the recent revival of the beverage fermentation culture due to an increase in the demand for health drinks amid the COVID-19 pandemic. Kombucha and kefir are two well-known fermented beverages that are renowned for their myriad of health benefits. The starter materials for making these beverages contain micro-organisms that act like microscopic factories producing beneficial nutrients that have antimicrobial and anticancer effects. The materials modulate the gut microbiota and promote positive effects on the gastrointestinal tract. Due to wide variations in the substrates and types of micro-organisms involved in the production of both kombucha and kefir, this paper compiles a compendium of the micro-organisms present and highlights their nutritional roles.

Kombucha Beverages Produced from Fruits, Vegetables, and Plants: A Review on Their Pharmacological Activities and Health Benefits

Kombucha is a traditional health beverage produced by fermenting sweetened tea with a symbiotic culture of bacteria and yeasts. Consumption of kombucha beverages has been growing and there is kombucha commercially available worldwide as one of the most famous low-alcohol beverages. Kombucha beverages have been claimed to have beneficial effects on human health because they contain a variety of bioactive compounds that possess various functional properties. At present, several kinds of raw material (e.g., milk, fruit, vegetables, and herbs) have been fermented with kombucha consortium and consumed as kombucha beverages. Although several studies have been written regarding the biological activities of kombucha and raw materials, there is however little information available on the characterization of their components as well as the biological activities of fermented kombucha from many raw material mixtures. Several pharmacological activities were reviewed in the scientific literature, describing their potential implications for human health. In addition, the adverse effects and toxicity of kombucha consumption were also reviewed. In this study, we focused on the main and latest studies of the pharmacological effects of kombucha beverages produced from various kinds of raw materials, including antioxidant, anti-inflammatory, immunomodulatory, antimicrobial, anticancer, antidiabetic, antihypertensive, and antihyperlipidemic effects in in vitro and in vivo studies.

Characterization of Aroma Active Compound Production during Kombucha Fermentation: Towards the Control of Sensory Profiles

Since the sensorial profile is the cornerstone for the development of kombucha as a beverage with mass market appeal, advanced analytical tools are needed to gain a better understanding of the kinetics of aromatic compounds during the fermentation process to control the sensory profiles of the drink. The kinetics of volatile organic compounds (VOCs) was determined using stir bar sorptive extraction-gas chromatography-mass spectrometry, and odor-active compounds were considered to estimate consumer perception. A total of 87 VOCs were detected in kombucha during the fermentation stages. The synthesis of mainly phenethyl alcohol and isoamyl alcohol probably by Saccharomyces genus led to ester formation. Moreover, the terpene synthesis occurring at the beginning of fermentation (Δ-3-carene, α-phellandrene, γ-terpinene, m- and p-cymene) could be related to yeast activity as well. Principal component analysis identified classes that allowed the major variability explanation, which are carboxylic acids, alcohols, and terpenes. The aromatic analysis accounted for 17 aroma-active compounds. These changes in the evolution of VOCs led to flavor variations: from citrus-floral-sweet notes (geraniol and linalool domination), and fermentation brought intense citrus-herbal-lavender-bergamot notes (α-farnesene). Finally, sweet-floral-bready-honey notes dominated the kombucha flavor (2-phenylethanol). As this study allowed to estimate kombucha sensory profiles, an insight for the development of new drinks by controlling the fermentation process was suggested. Such a methodology should allow a better control and optimization of their sensory profile, which could in turn lead to greater consumer acceptance.

Quality Chemistry, Physiological Functions, and Health Benefits of Organic Acids from Tea (Camellia sinensis)

Organic acids account for around 3% of the dry matter in tea leaves, and their composition and contents vary in different types of tea. They participate in the metabolism of tea plants, regulate nutrient absorption and growth, and contribute to the aroma and taste quality of tea. Compared with other secondary metabolites in tea, the researches on organic acids are still limited. This article reviewed the research progresses of organic acids in tea, including analysis methods, the root secretion and physiological function, the composition of organic acids in tea leaves and related influencing factors, the contribution of organic acids to sensory quality, and the health benefits, such as antioxidation, promotion of digestion and absorption, acceleration of gastrointestinal transit, and regulation of intestinal flora. It is hoped to provide references for related research on organic acids from tea.

An overview of probiotic health booster-kombucha tea

Traditional herbal medicine (THM) is a significant division of traditional Chinese medicine (TCM) that plays an important role in maintaining health and disease prevention. WHO has consistently highlighted the significance of traditional, complementary, and alternative medicine in human healthcare. Most people in Eastern Asia will start their day with a cup of tea. The tea provides a nourishing effect, and it has become an inevitable part of life. There are several types of tea, like black tea, green tea, oolong tea, white tea, and herbal tea. Besides the refreshments, it is important to consume beverages that benefit health. One such alternative is a healthy probiotic drink called kombucha, a fermented tea. Kombucha tea is aerobically fermented by infusing sweetened tea with a cellulose mat/ pellicle called SCOBY (symbiotic culture of bacteria and yeast). Kombucha is a source of bioactive compounds that include organic acids and amino acids, vitamins, probiotics, sugars, polyphenols, and antioxidants. Currently, studies on kombucha tea and SCOBY are gaining attention for their remarkable properties and applications in the food and health industries. The review gives an overview of the production, fermentation, microbial diversity, and metabolic products of kombucha. The possible implications for human health are also discussed.

Fermented Black Tea and Its Relationship with Gut Microbiota and Obesity: A Mini Review

Fermentation is one of the world’s oldest techniques for food preservation, nutrient enhancement, and alcohol manufacturing. During fermentation, carbohydrates such as glucose and starch are converted into other molecules, such as alcohol and acid, anaerobically through enzymatic action while generating energy for the microorganism or cells involved. Black tea is among the most popular fermented beverages; it is made from the dried tea leaves of the evergreen shrub plant known as Camellia sinensis. The adequate consumption of black tea is beneficial to health as it contains high levels of flavanols, also known as catechins, which act as effective antioxidants and are responsible for protecting the body against the development of illnesses, such as inflammation, diabetes, hypertension, cancer, and obesity. The prevalence of obesity is a severe public health concern associated with the incidence of various serious diseases and is now increasing, including in Malaysia. Advances in ‘omic’ research have allowed researchers to identify the pivotal role of the gut microbiota in the development of obesity. This review explores fermented black tea and its correlation with the regulation of the gut microbiota and obesity.

Kombucha: Production and Microbiological Research

Kombucha is a sparkling sugared tea commonly prepared using a sugared tea infusion and fermented at ambient temperature for several days using a cellulose pellicle also called tea fungus that is comprised of acetic acid bacteria and yeast. Consumption of Kombucha has been reported as early as 220 B.C. with various reported potential health benefits and appealing sensory properties. During Kombucha fermentation, sucrose is hydrolysed by yeast cells into fructose and glucose, which are then metabolised to ethanol. The ethanol is then oxidised by acetic acid bacteria (AAB) to produce acetic acid which is responsible for the reduction of the pH and also contributes to the sour taste of Kombucha. Characterisation of the AAB and yeast in the Kombucha starter culture can provide a better understanding of the fermentation process. This knowledge can potentially aid in the production of higher quality products as these microorganisms affect the production of metabolites such as organic acids which are associated with potential health benefits, as well as sensory properties. This review presents recent advances in the isolation, enumeration, biochemical characteristics, conventional phenotypic identification system, and modern genetic identification techniques of AAB and yeast present in Kombucha to gain a better understanding of the microbial diversity of the beverage.

Tailoring the Optimized Fermentation Conditions of SCOBY-Based Membranes and Milk Kefir Grains to Promote Various Functional Properties

Kombucha culture (named SCOBY-Symbiotic Culture of Bacteria and Yeasts) and milk kefir grains represent multiple consortia of wild microorganisms that include lactic acid bacteria, acetic acid bacteria and yeasts with valuable functional properties. Their fermentative potential provides a wide range of derivate metabiotics (prebiotics, probiotics, postbiotics and paraprobiotics) with valuable in vitro and in vivo benefits. This study targeted the evaluation of the functionality of a co-culture of SCOBY-based membranes and milk kefir grains, used as freeze-dried starter cultures, for the fermentation of a newly formulated medium based on black tea infusion, supplemented with bovine colostrum and sugar, in order to produce bioactive compounds with functional properties. The design and optimization of the biotechnological process were achieved by using the Plackett–Burman experimental design (six factorial points, three center points) and the response surface methodology and central composite design (three factorial points, six axial points and two center points in axial) tools. The statistical analysis and the mathematical modelling of the responses such as the pH, titratable acidity, antioxidant activity and antimicrobial activity (against Bacillus subtilis, Escherichia coli, Staphylococcus aureus and Aspergillus niger) were investigated. Further, the composition of organic acids, polyphenols and flavonoids of the fermented product obtained under the optimized fermentation conditions was also analyzed. The fermentation of the medium containing 6.27% (w/v) bovine colostrum powder, 1.64% (w/v) black tea, 7.5% (w/w) sugar, pH 6.7, with an inoculum based of 0.36% (w/v) milk kefir grains powder and 0.5% (w/v) SCOBY-based membrane (both as freeze-dried culture), at 30 °C, for 5 days, in an aerobic stationary system, revealed an antifungal activity between 80 and 100% against Aspergillus niger, an antibacterial activity of 8–22 mm against Escherichia coli and Bacillus spp. And a titratable acidity of 445 °Th. The chemical composition of the obtained product had a positive impact on the functional properties of the fermented products in terms of the antimicrobial and antioxidant properties.

Simple Isolation of Cordycepin from Cordyceps militaris by Dual-Normal Phase Column Chromatography and Its Potential for Making Kombucha Functional Products

Cordycepin (3′-deoxyadenosine) is a potent bioactive metabolite of the medicinal fungus Cordyceps militaris, which has been increasingly exploited to treat various chronic diseases in humans. However, the current synthesis and purification procedures of cordycepin are principally laborious and complicated. This study provides a simple protocol approach to isolate and purify cordycepin from C. militaris by normal phase column chromatography at room temperature. Besides, this is the first to investigate the potential of cordycepin and cordycepin-included extracts from C. militaris for making Kombucha functional products. By a repeated column chromatography, an amount of 1.16 g of cordycepin is isolated from 2.8 kg of fruiting bodies of C. militaris, which obtained an efficiency of 83.26% compared to that estimated by high-performance liquid chromatography (HPLC). The purity of cordycepin is confirmed by thin-layer chromatography (TLC), HPLC, and proton nuclear magnetic resonance (1H NMR). In addition, kombucha-fermented extracts from cordycepin and cordycepin-included fractions show potential biological activities in terms of antioxidant, anti-diabetes via α-glucosidase inhibitory assay, and cytotoxicity via MTT assay on Meg-01 and HL-60 cell lines. Further studies on optimization of extraction protocol and verification of health benefits of kombucha products from cordycepin should be conducted prior to the official mass production.

Storage time and temperature affect microbial dynamics of yeasts and acetic acid bacteria in a kombucha beverage

Kombucha is a mildly sweet, slightly acidic fermented beverage, commercially available worldwide, that has attracted increasing consumers' interest due to its potential health benefits. Kombucha is commonly prepared using sugared black or green tea, but also other plant substrates are frequently utilised. Kombucha is obtained by fermentation using a symbiotic culture of bacteria and yeasts, whose composition varies depending on inoculum origin, plant substrates and environmental conditions. After fermentation, kombucha drinks are usually refrigerated at 4 °C, in order to maintain their biological and functional properties. There are no reports on the fate of microbial communities of kombucha in relation to long-term storage time and temperature. Here, for the first time, we monitored the diversity and dynamics of the microbial communities of a kombucha beverage fermented with different herbs during storage at 4 °C and at room temperature, for a period of 90 days, utilising culture-dependent and independent approaches. Moreover, cultivable yeasts and acetic acid bacteria (AAB) were isolated from the beverage, inoculated in pure culture, identified by molecular methods, and yeasts assessed for their functional properties. Total yeast counts were not affected by storage temperature and time, although their community composition changed, as Saccharomyces species significantly decreased after 45 days of storage at room temperature, completely disappearing after 90 days. On the other hand, Dekkera anomala (Brettanomyces anomalus), representing 52 % of the yeast isolates, remained viable up to 90 days at both storage temperatures, and was able to produce high levels of organic acids and exopolysaccharides. Data from DGGE (Denaturing Gradient Gel Electrophoresis) band sequencing confirmed that it was the dominant yeast species in all samples across storage. Other yeast isolates were represented by Saccharomyces and Zygosaccharomyces species. Among AAB, Gluconobacter oxydans, Novacetimonas hansenii and Komagataeibacter saccharivorans represented 46, 36 and 18 % of the isolates, whose occurrence remained unchanged across storage at 4 °C and did not vary up to 20 days of storage at room temperature. This work showed that the combination of culture-dependent and independent approaches is important for obtaining a complete picture of the distinctive core microbial community in kombucha beverages during storage, elucidating its diversity and composition, and preliminary characterizing yeast strains with putative functional activities.

Kombucha tea improves glucose tolerance and reduces hepatic steatosis in obese mice

Nonalcoholic fatty liver disease (NAFLD), often associated with obesity, is becoming one of the most common liver diseases worldwide. It is estimated to affect one billion individuals and may be present in approximately 25% of the population globally. NAFLD is viewed as a hepatic manifestation of metabolic syndrome, with humans and animal models presenting dyslipidemia, hypertension, and diabetes. The gut-liver axis has been considered the main pathogenesis branch for NAFLD development. Considering that foods or beverages could modulate the gastrointestinal tract, immune system, energy homeostasis regulation, and even the gut-liver axis, we conducted an exploratory study to analyze the effects of kombucha probiotic on hepatic steatosis, glucose tolerance, and hepatic enzymes involved in carbohydrate and fat metabolism using a pre-clinical model. The diet-induced obese mice presented glucose intolerance, hyperinsulinemia, hepatic steatosis, increased collagen fiber deposition in liver vascular spaces, and upregulated TNF-alpha and SREBP-1 gene expression. Mice receiving the kombucha supplement displayed improved glucose tolerance, reduced hyperinsulinemia, decreased citrate synthase and phosphofructokinase-1 enzyme activities, downregulated G-protein-coupled bile acid receptor, also known as TGR5, and farnesol X receptor gene expression, and attenuated steatosis and hepatic collagen fiber deposition. The improvement in glucose tolerance was accompanied by the recovery of acute insulin-induced liver AKT serine phosphorylation. Thus, it is possible to conclude that this probiotic drink has a beneficial effect in reducing the metabolic alterations associated with diet-induced obesity. This probiotic beverage deserves an extension of studies to confirm or refute its potentially beneficial effects.

Metagenome-Assembled Genomes of Komagataeibacter from Kombucha Exposed to Mars-Like Conditions Reveal the Secrets in Tolerating Extraterrestrial Stresses

Kombucha mutualistic community (KMC) is composed by acetic acid bacteria and yeasts, producing fermented tea with health benefits. As part of the BIOlogy and Mars EXperiment (BIOMEX) project, the effect of Mars-like conditions on the KMC was analyzed. Here, we analyzed metagenome-assembled genomes (MAGs) of the Komagataeibacter, which is a predominant genus in KMC, to understand their roles in the KMC after exposure to Mars-like conditions (outside the International Space Station) based on functional genetic elements. We constructed three MAGs: K. hansenii, K. rhaeticus, and K. oboediens. Our results showed that (i) K. oboediens MAG functionally more complex than K. hansenii, (ii) K. hansenii is a keystone in KMCs with specific functional features to tolerate extreme stress, and (iii) genes related to the PPDK, betaine biosynthesis, polyamines biosynthesis, sulfate-sulfur assimilation pathway as well as type II toxin-antitoxin (TA) system, quorum sensing (QS) system, and cellulose production could play important roles in the resilience of KMC after exposure to Mars-like stress. Our findings show the potential mechanisms through which Komagataeibacter tolerates the extraterrestrial stress and will help to understand minimal microbial composition of KMC for space travelers.

Chemical Composition of Kombucha

Kombucha is a fermented sweetened tea with a mixed fermenting culture of yeast and acetic acid bacteria. While the history of kombucha is not completely clear, it is now available around the world and has shown an increase in availability and demand in the United States market. The proponents of kombucha consumption tout the varied health benefits it can provide. The final kombucha flavor and composition is a function of both the initial tea used and the fermentation process. While the ascribed benefits are varied and numerous, the number of direct studies has been limited. This review focuses on the current state of understanding of the chemical composition and the potential health effects both positive and negative reported in the literature.

Date Fruits as Raw Material for Vinegar and Non-Alcoholic Fermented Beverages

Currently, foods and beverages with healthy and functional properties, especially those that claim to prevent chronic diseases, are receiving more and more interest. As a result, numerous foods and beverages have been launched onto the market. Among the products with enhanced properties, vinegar and fermented beverages have a high potential for growth. Date palm fruits are a versatile raw material rich in sugars, dietary fibers, minerals, vitamins, and phenolic compounds; thus, they are widely used for food production, including date juice, jelly, butter, and fermented beverages, such as wine and vinegar. Furthermore, their composition makes them suitable for the formulation of functional foods and beverages. Microbial transformations of date juice include alcoholic fermentation for producing wine as an end-product, or as a substrate for acetic fermentation. Lactic fermentation is also documented for transforming date juice and syrup. However, in terms of acetic acid bacteria, little evidence is available on the exploitation of date juice by acetic and gluconic fermentation for producing beverages. This review provides an overview of date fruit’s composition, the related health benefits for human health, vinegar and date-based fermented non-alcoholic beverages obtained by acetic acid bacteria fermentation.

Isolation and characterisation of dominant acetic acid bacteria and yeast isolated from Kombucha samples at point of sale in New Zealand

The demand for Kombucha, a sparkling sugared tea beverage fermented by a symbiotic culture of acetic acid bacteria (AAB) and yeast is increasing worldwide. Despite the popularity of the beverage which is mainly due to its perceived health benefits and appealing sensory properties, the microbial composition of the products at the time of consumption is unknown. Such information is important to both manufacturers and consumers. Therefore, this study characterised the dominant AAB and yeast present in six commercial Kombucha samples sold in New Zealand which comprised of three domestic and three imported samples. Acetic acid bacteria and yeast were isolated from the Kombucha samples using glucose yeast extract peptone mannitol (GYPM) and yeast extract glucose chloramphenicol (YGC) media, respectively. Phenotypic and taxonomic identification of AAB and yeast were achieved by morphological and biochemical characterisation, followed by sequence analysis of ribosomal RNA genes (16S rRNA for AAB and 26S rRNA for yeast). Viable AAB and yeast were only found in domestically produced Kombucha samples and not in the imported products. The dominant AAB species were identified as Acetobacter musti and Gluconobacter potus. The yeast isolates belonged to Dekkera bruxelensis, Schizosaccharomyces pombes, Hanseniaspora valbyensis, Brettanomyces anamalus, Pichia kudriavzevii, Starmerella vitis and Saccharomyces cerevisiae. The yeast communities were more complex and variable than the AAB communities in the analysed Kombucha samples.

Health-beneficial aroma and taste compounds in a newly developed kombucha using a Huanglongbing-tolerant mandarin hybrid

Huanglongbing (HLB) is a destructive citrus greening disease; no commercially applicable measures exist. 'LB8-9' Sugar Belle^® (SB), originally developed for the fresh market, is the most HLB-tolerant cultivar among commercially available varieties. Due to the limited capacity of the fresh fruit market, there is a need to increase the demand for SB juice. Kombucha is a fermented tea beverage with black tea and sugar, and is considered a healthy drink with an increasing market. Therefore, we aim to study the potential of using SB juice in kombucha production. Regular (black tea with no citrus juice added), Hamlin (black tea with Hamlin juice added), and SB kombucha (black tea with SB juice added) were prepared and analyzed to observe the composition of aroma and taste compounds in the kombuchas. Aroma and taste compounds in the kombuchas were analyzed using gas chromatography-mass spectrometry/olfactometry and liquid chromatography-triple quadrupole mass spectrometry, respectively. For aroma compounds, SB kombucha was characterized by high concentrations of terpenes and their derivatives, which have mandarin-like aroma characteristics and health benefits such as antidiabetic and antioxidant effects. For taste compounds, SB kombucha contained higher amount of fructose and organic acids, which have the potential to increase the intensity of sweetness and sourness, and flavonoids. This would support the potential benefits of using SB to make kombucha. This study provides valuable information about the aroma and taste compounds in SB kombucha and its potential health benefits, compared with regular and Hamlin kombucha. PRACTICAL APPLICATION: This experiment provided valuable information on the elevated aroma and taste compounds, their potential health benefits, and the changes of those compounds during kombucha fermentation in 'LB8-9' Sugar Belle^® kombucha, compared to regular and Hamlin kombucha. In the absence of an effective cure or therapy for HLB, this can be the first step for developing alternative citrus product to help the citrus industry mitigate the negative impacts from HLB.

Kombucha analogues around the world: A review

Kombucha is a traditional healthy beverage usually made by the fermentation of sweetened tea with a symbiotic culture of bacteria and yeast. The consumption of kombucha is associated with numerous health benefits and therefore the beverage has attracted the attention of consumers worldwide. Non-typical substrates (fruits, vegetables, plants, herbs, dairy, and by-products) are being inoculated with the kombucha consortium in an attempt to develop new products. This review paper reviews the fermentation parameters for different non-tea substrates used to make kombucha, in addition to the findings obtained in terms of physico-chemical analysis, biological activities and sensory evaluation.

The Healthy Eater’s Idea and Related Behavior of a Healthy Diet—A Case Study with Kombucha Drinkers

Consumers’ demand for ‘healthy’ food is growing at a fast pace. Beverages are one of the fastest-growing segments in the healthy food market. Kombucha is a product with a rapid market growth and is considered a ‘healthy beverage’. Kombucha drinkers (n = 296) in the contiguous United States (U.S.) were targeted to investigate differences in the various consumer segments regarding the healthy eater’s behavior, namely—(1) healthy diet stage-of-change attitudes, (2) healthy eating criteria, and (3) label information usage. An online survey questionnaire was used as a data collection tool. The data were analyzed via chi-square tests and multiple correspondence analysis (MCA). The majority of kombucha consumers were health-conscious and kombucha fitted into their view of a healthy diet. The female, older, western U.S. residents, and higher-educated consumers were more likely to take action and maintain a healthier diet. Healthy eaters’ idea of a healthy diet was very similar to that of the general population. Kombucha consumers focused mainly on sugar/calories and natural/organic ingredients. Additional investigations to expand the understanding of the healthy eater’s behavior with actual kombucha samples are needed in the future.

The Technological Perspectives of Kombucha and Its Implications for Production

Fermentation is one of the oldest biotechnological tools employed by mankind. Fermenting food gives them better sensory and nutritional qualities, the latter including vitamins, phenolic compounds, antioxidants, and antimicrobials. Kombucha is the result of the fermentation of a sweetened Camellia sinensis infusion by the action of a symbiotic community of yeasts and bacteria organized in a cellulosic biofilm called SCOBY and has gained great prominence among fermented foods and beverages, with a considerable increase in its popularity in the last decade, both among consumers and within the scientific community. This is explained by the particular functional and microbial characteristics of this beverage, such as its antioxidant and antimicrobial potential, long-term stable microbial communities, its suitability for fermentation under different conditions of time and temperature, and amenability to other carbon sources besides sucrose. Thus, this review aims to present and discuss the functional, microbial, and physicochemical aspects of kombucha fermentation, covering the many challenges that arise in its production, in domestic, commercial, and legislation contexts, and the next steps that need to be taken in order to understand this drink and its complex fermentation process.

Inoculation, Growth and Bactericidal Effects of Three Kombucha Cultures

Kombucha, a domesticated consortium of several microorganisms grown on sugared tea, has been valued as a nutritive health aid for over a millennium. In this study, three cultures of kombucha were obtained from diverse sources. Different inoculation methods were compared, and the wet and dry weights of the nascent pellicles were measured when cultured on several carbon sources. In addition, the anti-bacterial properties of the fermented kombucha teas were tested against Escherichia coli and Staphylococcus epidermis. Inoculation with macerated pellicles gave the fastest kombucha growth. The best carbon sources for growth of the nascent kombucha pellicles were sucrose, glucose, and fructose. On maltose, galactose, and lactose, not only did the kombucha pellicles grow poorly but 25% were also contaminated by common airborne molds. Good growth of the kombucha cultures was correlated with low pH of the fermented tea. Antibacterial effects of concentrated fermented teas and vinegar were similar to those of 1 mmol ampicillin against Escherichia coli or 0.01 mmol penicillin against Staphylococcus epidermis. When the pH of concentrated kombucha teas was neutralized, their bactericidal effects were no better than unfermented controls.

Microbial and Chemical Profiles of Commercial Kombucha Products

Kombucha is an increasingly popular functional beverage that has gained attention for its unique combination of phytochemicals, metabolites, and microbes. Previous chemical and microbial composition analyses of kombucha have mainly focused on understanding their changes during fermentation. Very limited information is available regarding nutrient profiles of final kombucha products in the market. In this study, we compared the major chemicals (tea polyphenols, caffeine), antioxidant properties, microbial and metabolomic profiles of nine commercial kombucha products using shotgun metagenomics, internal transcribed spacer sequencing, untargeted metabolomics, and targeted chemical assays. All of the nine kombucha products showed similar acidity but great differences in chemicals, metabolites, microbes, and antioxidant activities. Most kombucha products are dominated by the probiotic Bacillus coagulans or bacteria capable of fermentation including Lactobacillus nagelii, Gluconacetobacter, Gluconobacter, and Komagataeibacter species. We found that all nine kombuchas also contained varying levels of enteric bacteria including Bacteroides thetaiotamicron, Escherischia coli, Enterococcus faecalis, Bacteroides fragilis, Enterobacter cloacae complex, and Akkermansia muciniphila. The fungal composition of kombucha products was characterized by predominance of fermenting yeast including Brettanomyces species and Cyberlindnera jadinii. Kombucha varied widely in chemical content assessed by global untargeted metabolomics, with metabolomic variation being significantly associated with metagenomic profiles. Variation in tea bases, bacteria/yeast starter cultures, and duration of fermentation may all contribute to the observed large differences in the microbial and chemical profiles of final kombucha products.

Preventive and Therapeutic aspects of Fermented Foods

In recent times, the status of some fermented foods which are considered as functional foods that confer health benefits in certain disease conditions has grown rapidly. The health benefits of fermented foods are due to the presence of probiotic microbes and the bioactive compound formed during fermentation. Microbes involved and metabolites produced by them are highly species-specific and contribute to the authenticity of the fermented foods. Several studies pertaining to the effect of fermented foods on various disease conditions have been conducted in recent years using both animal models and clinical trials on humans. This review focuses on the impact of fermented foods on conditions like diabetes, cardiovascular disease (CVD), obesity, gastrointestinal disorder, cancer and neurodegenerative disorders.

Senescence-Mediated Redox Imbalance in Liver and Kidney: Antioxidant Rejuvenating Potential of Green Tea Extract

This study investigates the catechin composition and protective effect of green tea extract on senescence-mediated redox imbalance in the livers and kidneys of aged mice. The results showed that the seven catechins in the green tea extract analyzed in this study could be completely separated within 30 min and the main components of catechins in green tea extract were EGCG, EGC and ECG. In terms of the anti-senescence effects of green tea extract, green tea extract supplementation at doses of 125, 625 and 1250 mg/kg for 4 weeks significantly alleviated the senescence-mediated redox imbalance, as exhibited from significantly (p < 0.05) reduced thiobarbituric acid-reactive substances (TBARS) and protein carbonyls levels in the serum, and increased glutathione (GSH) and total thiols contents in the plasma. Additionally, hepatic and renal protein carbonyls levels were significantly diminished (p < 0.05) and the activities of superoxide dismutase (SOD), catalase, glucose-6-phosphate dehydrogenase (G6PD), glutathione peroxidase (GSH-Px) and glutathione reductase (GSH-Rd) in the liver and kidney were remarkably elevated (p < 0.05). Overall, these results clearly show that green tea extract exhibits extremely potent protective effects against senescence-mediated redox imbalance in the livers and kidneys of mice by inhibiting oxidative damage of lipids and proteins and increasing the activities of antioxidant enzymes in organs.

Kombucha ameliorates experimental autoimmune encephalomyelitis through activation of Treg and Th2 cells

Multiple sclerosis (MS) is the most common inflammatory disorder of the central nervous system (CNS). Kombucha is produced by the fermentation of sugared tea with a symbiotic culture of bacteria and yeasts. This research was designed to reveal the therapeutic impact and the molecular and cellular processes determining the effect of kombucha on MS alleviation in an experimental autoimmune encephalomyelitis (EAE). The EAE was induced using myelin oligodendrocyte glycoprotein (MOG35-55) peptide emulsified in CFA and injected subcutaneously over two flank areas in C57BL/6 mice. In addition, pertussis toxin was injected intraperitoneally and repeated 48 h later. Treatment groups were received three different doses of kombucha (K1: low dose, K2: medium dose and K3: high dose) to obtain a maximum protection. Clinical scores and other criteria were followed daily for the 25 days. At the end of the course, T-helper-related cytokines (IFN-γ, IL-17, IL-4, and TGF-β) were measured through ELISA. Moreover, nitric oxide (NO) concentration in spinal cord tissue was detected. The severity of disease on the peak of disease in K1, K2, and K3 groups were 3.4 ± 0.18 and 2.6 ± 0.18 and 2 ± 0.14 respectively, compared to the CTRL group with 4.5 ± 0.19 (p < 0.001). Kombucha increased production of interleukin IL-4 (K1 = 95 ± 5, K2 = 110 ± 10, K3 = 115 ± 5 and CTRL = 65 ± 5; p < 0.05) and TGF-β (K1 = 1750 ± 80, K2 = 2050 ± 65, K3 = 2200 ± 75 and CTRL = 850 ± 85; p < 0.001) but concurrently resulted in a remarkable reduction in the production of IFN-γ (K1 = 950 ± 70, K2 = 890 ± 65, K3 = 850 ± 85 and CTRL = 3850 ± 115; p < 0.001) and IL-17 (K1 = 1250 ± 75, K2 = 1050 ± 90, K3 = 970 ± 80 and CTRL = 6450 ± 125; p < 0.001). Moreover, NO concentration in spinal cord tissue in the treatment groups was significantly less than the control group (K1: 35.42 ± 2.1, K2 = 31.21 ± 2.2, K3 = 28.24 ± 2.6 and CTRL = 45.25 ± 2.7; p < 0.05). These results supported that kombucha could reduce the severity of disease in an EAE model through motivating polarization of CD4+ T cells by induction of IL-4 and TGF-β as well as inhibition of IFN-γ and IL-17.

Evolution of Food Fermentation Processes and the Use of Multi-Omics in Deciphering the Roles of the Microbiota

Food fermentation has been practised since ancient times to improve sensory properties and food preservation. This review discusses the process of fermentation, which has undergone remarkable improvement over the years, from relying on natural microbes and spontaneous fermentation to back-slopping and the use of starter cultures. Modern biotechnological approaches, including genome editing using CRISPR/Cas9, have been investigated and hold promise for improving the fermentation process. The invention of next-generation sequencing techniques and the rise of meta-omics tools have advanced our knowledge on the characterisation of microbiomes involved in food fermentation and their functional roles. The contribution and potential advantages of meta-omics technologies in understanding the process of fermentation and examples of recent studies utilising multi-omics approaches for studying food-fermentation microbiomes are reviewed. Recent technological advances in studying food fermentation have provided insights into the ancient wisdom in the practice of food fermentation, such as the choice of substrates and fermentation conditions leading to desirable properties. This review aims to stimulate research on the process of fermentation and the associated microbiomes to produce fermented food efficiently and sustainably. Prospects and the usefulness of recent advances in molecular tools and integrated multi-omics approaches are highlighted.

Efficacy of the Kombucha Beverage Derived from Green, Black, and Pu’er Teas on Chemical Profile and Antioxidant Activity

Kombucha is a symbiotic culture of bacteria and yeast which produces a high-end fruity fitness beverage by fermentation of normal tea for approximately two weeks. In addition to the advantage of being a low-sugar probiotic-rich drink, kombucha also offers the benefits of the tea used for its preparation, especially its high antioxidant content. In this research, kombucha tea was prepared by using three different tea types: green, black, and pu’er tea, and the chemical profiles and antioxidant activity were analyzed during the fermentation process (up to 20 days). The results showed that the tea type has an obvious influence on the factors associated with the antioxidant potential. The fermentation process caused a marked increase in polyphenol content and antioxidant activity initially, but this slowed progressively over time. In contrast, the fermentation of black tea contributed to the degradation of flavonoids but showed no significant effect on the other tea types. Therefore, we conclude that the tea type selected to make kombucha affects the end product as well as the fermentation time.

Ethanol Concentration of Kombucha Teas in British Columbia, Canada

ABSTRACT

Kombucha is a sweetened tea beverage fermented by bacterial and yeast cultures. Sweeteners, such as glucose, sucrose, fructose, and others are converted by yeasts into ethanol and then by Acetobacter and other bacterial species into a weak acetic acid solution that is diluted, flavored, and packaged into glass or aluminum cans for consumer consumption. Naturally, fermented kombucha contains 0 to 3% alcohol by volume (ABV). However, kombucha containing ethanol is concerning for pregnant women and young children for whom low levels of ethanol consumption (<3% ABV) create adverse medical outcomes. In the province of British Columbia (BC), Canadian beverages containing >1% ABV are regulated as liquor. This study assessed ethanol concentrations in kombucha collected from processors and purchased at retail venues in BC. Ethanol values were compared with the place of manufacture (country or province) and place of purchase (grocery stores, restaurants, farmers' markets, recreational centers, and processors). Ethanol (n = 684) levels were measured by using a headspace gas chromatography-mass spectrometry method with a detection limit of 0.0002% ABV for ethanol. Overall, teas contained mean and median ethanol of 0.77 and 0.62% ABV, respectively, ranging from nondetectable up to 3.62% ABV. Four kombucha teas (0.6%) made by BC processors tested over 3% ABV, and 31.5% of samples contained ethanol that exceeded the BC regulatory limits for nonalcoholic beverages of 1% ABV. Kombucha manufactured in BC had significantly higher mean ethanol values (1.16% ABV) in comparison to all other places of manufacture. Similarly, mean ethanol tea values obtained from BC processors (1.2% ABV) and restaurants (1.01% ABV) were significantly higher than those obtained at other retail venues. This study demonstrates the potential for alcohol harm to at-risk populations consuming kombucha teas sold in BC.

HIGHLIGHTS

Novel use of Kombucha consortium to reduce Escherichia coli in dairy shed effluent

BACKGROUND

Faecal contamination from dairy farm effluent is a major risk to water quality in New Zealand. In this experiment we have tested the efficacy of Kombucha SCOBY (symbiotic culture of bacteria and yeast), to reduce the concentration of Escherichia coli in dairy shed effluent (DSE).

RESULTS

Kombucha SCOBY was highly effective in lowering the number of E. coli colony forming units (CFUs) to levels that were undetectable. The decrease in CFUs occurred rapidly within 48 h of Kombucha SCOBY being inoculated to the effluent matrix and was accompanied by a corresponding decline in pH.

CONCLUSION

We conclude that Kombucha SCOBY was effective in reducing the abundance of E. coli in DSE due to its effect on solution pH. Further work is required to assess the practicality of treating DSE with Kombucha SCOBY within a farm environment where effluent management and climatic complexities are important. © 2021 Society of Chemical Industry.

Kombucha Tea-A Double Power of Bioactive Compounds from Tea and Symbiotic Culture of Bacteria and Yeasts (SCOBY)

Kombucha is a low alcoholic beverage with high content of bioactive compounds derived from plant material (tea, juices, herb extracts) and metabolic activity of microorganisms (acetic acid bacteria, lactic acid bacteria and yeasts). Currently, it attracts an increasing number of consumers due to its health-promoting properties. This review focuses on aspects significantly affecting the bioactive compound content and biological activities of Kombucha tea. The literature review shows that the drink is characterized by a high content of bioactive compounds, strong antioxidant, and antimicrobial properties. Factors that substantially affect these activities are the tea type and its brewing parameters, the composition of the SCOBY, as well as the fermentation parameters. On the other hand, Kombucha fermentation is characterized by many unknowns, which result, inter alia, from different methods of tea extraction, diverse, often undefined compositions of microorganisms used in the fermentation, as well as the lack of clearly defined effects of microorganisms on bioactive compounds contained in tea, and therefore the health-promoting properties of the final product. The article indicates the shortcomings in the current research in the field of Kombucha, as well as future perspectives on improving the health-promoting activities of this fermented drink.

Effect of fermentation time on the content of bioactive compounds with cosmetic and dermatological properties in Kombucha Yerba Mate extracts

Kombucha is a beverage made by fermenting sugared tea using a symbiotic culture of bacteria belonging to the genus Acetobacter, Gluconobacter, and the yeasts of the genus Saccharomyces along with glucuronic acid, which has health-promoting properties. The paper presents the evaluation of ferments as a potential cosmetic raw material obtained from Yerba Mate after different fermentation times with the addition of Kombucha. Fermented and unfermented extracts were compared in terms of chemical composition and biological activity. The antioxidant potential of obtained ferments was analyzed by evaluating the scavenging of external and intracellular free radicals. Cytotoxicity was determined on keratinocyte and fibroblast cell lines, resulting in significant increase in cell viability for the ferments. The ferments, especially after 14 and 21 days of fermentation showed strong ability to inhibit (about 40% for F21) the activity of lipoxygenase, collagenase and elastase enzymes and long-lasting hydration after their application on the skin. Moreover, active chemical compounds, including phenolic acids, xanthines and flavonoids were identified by HPLC/ESI-MS. The results showed that both the analyzed Yerba Mate extract and the ferments obtained with Kombucha may be valuable ingredients in cosmetic products.