Kombucha, a fermented tea prepared with a symbiotic culture of bacteria and yeast (SCOBY), offers a unique and unpredictable home-brewed fermentation process. Therefore, the need for a controlled kombucha fermentation process has become evident, which requiring a thorough understanding of the microbial composition and its relationship with the metabolites produced. In this study, we investigated the dynamics of microbial communities and metabolites over a 12-day fermentation period of a conventional kombucha-making process. Our findings revealed similarities between the microbial communities in the early (0-2 days) and late (10-12 days) fermentation periods, supporting the principle of back-slopping fermentation. Untargeted metabolite analysis unveiled the presence of harmful biogenic amines in the produced kombucha, with concentrations increasing progressively throughout fermentation, albeit showing relatively lower abundance on days 8 and 12. Additionally, a contrasting trend between ethanol and caffeine content was observed. Canonical correspondence analysis highlighted strong positive correlations between specific bacterial/yeast strains and identified metabolites. In conclusion, our study sheds light on the microbial and metabolite dynamics of kombucha fermentation, emphasizing the importance of microbial control and quality assurance measures in the production process.

Kombucha is a well-known fermented beverage traditionally made from black tea infusion. Recent studies have focused on finding alternative materials to create novel kombucha beverages with various health benefits. In this study, we prepared and evaluated two novel kombucha beverages using Rhodiola rosea and Salvia miltiorrhiza as materials. The effects of fermentation with the residue of these plants on the kombucha were also investigated. The antioxidant activities, total phenolic contents, and concentrations of the bioactive compounds of the kombucha beverages were determined by the Trolox equivalent antioxidant capacity test, ferric-reducing antioxidant power test, Folin-Ciocalteu method, and high-performance liquid chromatography, respectively. The results revealed that the kombucha beverages made with Rhodiola rosea and Salvia miltiorrhiza had strong antioxidant capacities and abundant phenolic contents. Additionally, the kombucha fermented with Rhodiola rosea residue had higher FRAP, TEAC and TPC values than that fermented without residue. On the other hand, the Salvia miltiorrhiza kombucha fermented with residue had similar FRAP and TEAC values but lower TPC values compared to that fermented without residue. The correlation analysis showed that gallic acid, salidroside, and tyrosol were responsible for the antioxidant abilities and total phenolic contents of the Rhodiola rosea kombucha, and salvianolic acid A and salvianolic acid B contributed to the antioxidant abilities of the Salvia miltiorrhiza kombucha. Furthermore, the kombucha fermented with Rhodiola rosea residue had the highest sensory scores among the kombucha beverages studied. These findings suggest that Rhodiola rosea and Salvia miltiorrhiza are suitable for making novel kombucha beverages with strong antioxidant abilities and abundant phenolic contents, which can be used in preventing and managing oxidative stress-related diseases.

Consumer demand for functional foods has increased, helping to popularize and increase the consumption of Kombucha. Other substrates have been used together with tea to improve the functional and sensory properties of the beverage. Thus, this study evaluated the comprehensive biochemical, microbiological, and sensory characteristics of kombuchas fermented with green tea (Camellia sinensis) and different concentrations of yam (0, 10, and 20 % w/v). Based on pre-tests to detect the best concentration of yam in the beverage (10, 20, 30, and 40 %) and fermentation time (5, 7, and 14 days),the concentrations of 10 and 20 % of yam and five days of fermentation were selected through pH, °Brix, and sensory analysis. During the kombucha fermentation, there was a decrease in °Brix and pH. Sucrose, glucose, fructose, citric, and succinic acids were related to the beginning of fermentation, and lactic and acetic acids were more related to the end of fermentation in the treatment containing 20 % yam. The fermentation time did not change the color of the kombucha. Fatty acids, phenols, terpenoids, and alcohols were the volatile groups with the most compounds identified. Only two yeast genera were identified (Brettanomyces bruxellensis and Pichia membranifaciens), and bacteria of the genera Acetobacter, Lactobacillus, Pantoea, Pseudomonas, Azospirillum, and Enterobacter. The beverage control showed less turbidity and more clear. The fruity descriptor was more perceived in treatments with yam. However, the perception of the apple descriptor decreases as the yam concentration increases. The yam\'s concentration alters the kombucha\'s microbiota and sensory characteristics, mainly appearance and acidity. Kombucha fermentation using yam extract is viable, and the product is sensorially accepted. However, technological improvements, such as yam flour, could be made mainly for appearance and taste attributes.

This research examined acetic acid bacteria (AAB) isolated from Kombucha beverages produced with Anatolian hawthorn (Crataegus orientalis) as next-generation probiotics. Eighty-six AAB were isolated from the samples and investigated in terms of biosafety, viability in vitro gastrointestinal conditions, technological and bioactive properties, and also in vitro adhesion abilities. Seventy-six isolates demonstrating γ-hemolysis exhibited resistance to erythromycin and ampicillin. Besides, these isolates survived at low pH and in the presence of bile salts. However, the majority of AAB isolates showed tolerance to phenol, pepsin, and pancreatin. Also, twenty-one isolates showed protease enzyme activity, while eight isolates had amylase enzyme activity. Despite most of the isolates showed viability at 1.5% salt, only 19 isolates survived at 10% salt. Most AAB isolates exhibited inhibition zones ranging from 8 to 26 mm against test bacteria, their antioxidant activities were above 80%. Additionally, some isolates exhibited auto-aggregation ability ranging from 0.66 to 23.62% and co-aggregation ability ranging from 1.18 to 71.32%, while hydrophobicity ranged from 1.32 to 69.87% toward xylene. Finally, the indigenous 76 AAB isolates that had remarkable probiotic properties were characterized based on 16S rRNA gene sequencing, and the isolates belonged to Komagateibacter sp. (64.47%), Komagateibacter saccharivorans (15.79%), K. rhaeticus (11.84%), and Gluconobacter sp. (7.90%). As a result, the isolates identified as Gluconobacter sp. A21, Komagataeibacter sp. A139, Gluconobacter sp. A141, and Komagataeibacter sp. A146, which showed high viability under gastrointestinal conditions, safe and acceptable in terms of technological, bioactive, and adhesion properties and could be evaluated as next-generation probiotics.

Kombucha is a potential probiotic tea-based drink with increasing worldwide consumption. Studies on this probiotic beverage are growing rapidly, especially about micronutrients and microbial population. As such, the present study performed the molecular identification of the microorganism and evaluated 5-methyltetrahydrofolate content by HPLC-DAD, phenolic compounds, flavonoids, carotenoids, antioxidant activity by spectrophotometric methods, and physicochemical composition of green tea kombucha on fermentation days 1, 3, 7, 14, and 21. DNA sequencing identified the Microbacterium genus as predominant. However, was unable to safely determine the species level because of the rRNA 16S gene sequence similarity between four species M. ureisolvens, M. yannicii, M. chocolatum e M. atlanticum. The concentration of 5-methyltetrahydrofolate found on the third day was 39.12 ± 1.32 μg/mL (liquid) and 45.78 ± 8.42 μg/mL (polymeric biofilm); On the twenty-first day it was 50.87 ± 3.56 μg/mL (liquid) and 54.88 ± 3.89 μg/mL (polymeric biofilm). Total phenolic compounds increased with fermentation; however, flavonoids and carotenoids were degraded by the process. The information on 5-methyltetrahydrofolate is unprecedented and highly relevant for food guidelines, since related deficiencies can lead to fetal malformation in the first three months of pregnancy. Lastly, the best fermentation time to obtain 5-methyltetrahydrofolate and others bioactive compounds is between days 7-14. Further analyses are also encouraged to understand the bioavailability of the vitamin.

This study aims to optimize the culture condition of semi-liquid sourdough using Kombucha as a starter culture and to evaluate the physicochemical properties, microbial viability and recovering ability of sourdough powder when packaged in different types of packaging for 120 days. Optimal maturation time (103.47 h) and maximum leavening rate (1.27 mL/h) of sourdough were achieved at an incubation temperature of 34 °C and interval refreshment time at 7 h. The optimized culture was spray-dried using 3% Arabic gum (w/v) as a carrier agent yielding 35.86% powder with acceptable viability of 8.71 log CFU/g lactic acid bacteria and 9.03 CFU/g yeast. The sourdough powder was packed in four packaging (LDPE, vacuumed LDPE, aluminum foil laminated pouch and vacuumed aluminum foil laminated pouch) and exhibited comparable physicochemical properties during 120 days of storage. The viability of both lactic acid bacteria and yeast count in sourdough powder when packed in vacuumed aluminum foil laminated pouch showed higher stability for 90 days (6.18 log CFU/g and 6.82 log CFU/g) but reduced to below detection limit after 120 days (5.54 and 5.94 log CFU/g). This suggested that Kombucha sourdough powder packed in vacuumed aluminum laminated pouch could be stored for up to 90 days.

UNASSIGNED: Kombucha is a fermented beverage with several health benefits; however, to improve its antioxidant activity, new raw materials such as hop, madimak and hawthorn were included in the present study.
UNASSIGNED: The somatic mutation and recombination test (SMART) was performed on the fruit fly (Drosophila melanogaster) to evaluate the antigenotoxic potential of black tea-flavoured kombucha and three other flavours of kombuchas (hop, madimak and hawthorn) against H2O2- and K2Cr2O7-induced genotoxicity. Furthermore, a lifespan assay was performed to assess the effects of kombuchas on the longevity of the fruit fly.
UNASSIGNED: According to the results obtained from the SMART assay, hop-flavoured kombucha attenuated genotoxicity induced by H2O2, and madimak-flavoured kombucha reduced genotoxicity induced by H2O2 and K2Cr2O7. Black tea- and hop-flavoured kombucha prolonged the lifespan of the fruit fly (Drosophila melanogaster) after the treatment with H2O2 and K2Cr2O7.
UNASSIGNED: Hop-flavoured kombucha is a promising antioxidant that protects the genome and extends the lifespan of the fruit fly. This study sheds light on novel beverages that can combat ageing and protect against genotoxicity.

The organoleptic and bioactive properties of truffles place these fungi as interesting materials for use in the of design functional foods based on fruiting bodies outside commercial standards. Moreover, kombucha beverages have become more popular in the Western world, leading to novel drinks using alternative substrates instead of tea leaves. In this work, two truffle species (Tuber melanosporum, TMEL; Tuber aestivum, TAES) and three different symbiotic consortia of bacteria and yeasts (SCOBYs: SC1, SC2, and SC3) were tested. Fermentation (21 days) was monitored in terms of physicochemical (pH, viscosity), biochemical (total carbohydrates, alcohol, soluble proteins, phenolic compounds), and sensory attributes (volatile organic compounds, VOCs). The obtained pH ranges were adequate, alcohol levels were undetectable or very low, and sugar content was lower than in traditional kombuchas or other beverages. In most cases, the usual bottling time could be applied (7-10 days), although longer fermentations are recommended (14 days) to reach higher protein and phenolic compounds contents. Truffle kombuchas produced up to 51 volatile organic compounds (alcohols, acids, esters, ketones, and aldehydes, among others), with TMEL showing a more complex profile than TAES. During the first week, acidic compound production was observed, especially acetic acid. Similar behavior in the VOC profile was reported with different SCOBYs.

Kombucha was fermented by the pure cultured tea fungus, and the changes of functional compounds and their transformation were explored. After fermentation, the contents of total polyphenols, total flavonoids, quercetin, kaempferol and catechins respectively enhanced by 77.14%, 69.23%, 89.11%, 70.32% and 45.77% compared with the control, while flavonol glycosides reduced by 38.98%. The bioavailability of polyphenols and flavonoids respectively increased by 29.52% and 740.6%, and DPPH and ABTS respectively increased by 43.81% and 35.08% compared with the control. Correlation analysis showed that microorganisms and the antioxidant activity were highly positive correlation with total polyphenols, total flavonoids, EGC, EC, EGCG, ECG, quercetin and kaempferol, and negative correlation with kaempferol-3-glucoside. The constructed models confirmed that organic acids were more likely to damage the structure of tea leaves, and enzymes (polygalacturonidase and tannase) and solvents (acids, alcohols and esters) had a synergistic effect on the biotransformation of functional compounds.

(1) Background: The human microbiota is essential for maintaining a healthy body. The gut microbiota plays a protective role against pathogenic bacteria. Probiotics are live microorganisms capable of preventing and controlling gastrointestinal and balancing the immune system. They also aid in better nutrients and vitamins absorption. Examples of natural probiotic cultures are kefir and kombucha. (2) Methods: Therefore, the aim of this review was to address the beneficial properties of probiotic kefir and kombucha using a Boxplot analysis to search for scientific data in the online literature up to January 2024: (Latin American and Caribbean Health Sciences (LILACS), PubMed, Medical Literature Analysis (MED-LINE), Science Direct, Google Scholar/Google Academic, Bioline Inter-national and Springer Link). Boxplots showed the summary of a set of data \"Index Terms-Keywords\" on kefir and kombucha in three languages (English, Portuguese and Spanish). (3) Results: Google Scholar was the database with the highest number of articles found, when the search for the keywords used in the study (containing ~4 × 106-~4 million articles available). This was Followed by the Science Direct database, containing ~3 × 106-~3 million articles available, and the BVS databases-Biblioteca Virtual de Saúde (Virtual Health Library) e Lilacs, both containing a value of ~2 × 106-~2 million articles available. The databases containing the smallest number of articles found were Nutrients and Medline, both containing a value of ≤0.1 × 106-≤100 thousand articles. (4) Conclusions: Scientific studies indicate that kefir and kombucha certainly contain various functional properties, such as antimicrobial, antitumor, anticarcinogenic and immunomodulatory activity, in addition to having a microbiological composition of probiotic bacteria and yeasts. Kefir and kombucha represent key opportunities in the food and clinic/medical fields.