Search Results (42)

Oxidative stress and inflammation are critical factors in hypertension and type 2 diabetes mellitus (T2DM). Kombucha, a fermented tea beverage, is enriched with bioactive compounds during fermentation. This study evaluated the antihypertensive, antihyperglycemic, antioxidant, and anti-inflammatory activities of kombucha made from mulberry leaf green tea (MLGT) and black tea (MLBT) during in vitro digestion. The bioaccessibility of 1-deoxynojirimycin (DNJ), γ-aminobutyric acid (GABA), phenolics, and flavonoids was assessed through simulated oral, gastric, and intestinal phases. MLGT kombucha exhibited higher initial antioxidant activity, while MLBT showed greater compound stability and ACE inhibitory activity during digestion. Notably, α-glucosidase inhibition declined significantly in the intestinal phase, in parallel with reduced DNJ and flavonoid content. Strong correlations were observed between specific phenolic acids and bioactivity profiles, highlighting ρ-coumaric and sinapic acids in ACE inhibition and DNJ in antiglycemic activity. These findings demonstrate the functional potential of mulberry leaf kombucha as a beverage to support metabolic health, pending confirmation through in vivo studies. Full article

Kombucha, traditionally fermented from black or green tea, is well known for its potential health benefits. However, its high caffeine content may limit consumption for certain individuals. Therefore, this study aimed to develop a low-caffeine kombucha using lotus root tea as an alternative to black or green tea. Lotus root was roasted and brewed to prepare the tea base, to which sugar and a SCOBY were added for primary fermentation. Subsequently, Lactobacillus plantarum (1.0 × 10⁹ and 3.0 × 10⁹ CFU/mL) was inoculated to carry out secondary fermentation. The kombucha samples were assessed for their organic acid composition, antioxidant activity, antimicrobial effects, β-glucuronidase inhibition, and protective effects against Salmonella infection in a Caenorhabditis elegans model. The caffeine concentration of lotus root tea kombucha was significantly lower than that of conventional kombucha. L. plantarum fermentation increased the lactic acid concentration and enhanced antimicrobial activity, particularly against Escherichia coli OP50 and Salmonella typhimurium. Additionally, β-glucuronidase inhibition significantly improved, suggesting potential gut health benefits. In C. elegans, kombucha consumption improved survival rates following Salmonella infection, indicating a protective effect. This study demonstrates that fermentation using Lactobacillus plantarum can enhance the bioactivity of lotus root kombucha, highlighting its potential as a low-caffeine functional beverage. Full article

Plastic pollution and environmental degradation necessitate the development of natural, biodegradable food preservation materials. This study examined chitosan-based film-forming solutions using kombucha derived from black tea, lemon balm, and chamomile as natural solvents rich in bioactive compounds. Lemon balm kombucha solutions were used to create chitosan films and coat red peppers. The study assessed the mechanical properties of the films and the effects of chitosan coating on peppers, including texture, ascorbic acid content, sensory attributes, and antioxidant activity. Microbiological tests showed that a chitosan–lemon balm kombucha solution acted against Escherichia coli, Pseudomonas aeruginosa and Salmonella enterica. Lemon balm kombucha had high total phenolic (381.67 µg GAeq/mL) and flavonoid (21.05 µg Qeq/mL) contents. The chitosan film exhibited a tensile strength of 11.08 MPa and an elongation at break of 53.45%. The water vapor transmission rate of the obtained chitosan film was 131.84 g/m²·24 h. Coated peppers showed a 32% increase in skin strength and retained 11% more ascorbic acid after 15 days. Sensory evaluation revealed no significant differences from controls. These results highlight lemon balm kombucha as a promising natural solvent for chitosan coatings, which have the potential to extend red pepper shelf life and to support food preservation. Full article

Teas derived from Camellia sinensis are traditionally used in kombucha fermentation, a process in which bacteria and yeasts play key roles. This study aimed to evaluate the effects of green, black, and white teas, as well as their combinations, on the physicochemical properties, antioxidant capacity, and total phenolic compound content of kombucha. In addition, the production of kombucha flavored with fruits. Statistical analysis of simplex centroid mixture design indicated that green tea promoted a positive increase in total phenolic content and antioxidant activities against ABTS and DPPH free radicals, being observed at 5868.46 µmol/mL, 705.40 µmol/mL, and 380.77 mg GAE/100 mL in the kombucha prepared using this tea individually. Then, six kombucha beverages were prepared from green tea, flavored with grape, caja, cashew apple, genipap, passion fruit, and tamarind. The phenolic profile analysis revealed the presence of twenty-six compounds, including twenty-five phenolics and one caffeine derivative. Among the beverages, tamarind-flavored kombucha stood out, exhibiting the highest total flavonoid content (156.77 mg EQ/g), which highlights the positive influence of tamarind on the bioactive properties of kombucha beverages. These results provide valuable insights to optimize kombucha production and explore the potential beneficial effects of flavored non-alcoholic beverages. Full article

Background/Objectives: Plant-derived compounds are increasingly valued in drug discovery for their therapeutic potential. This study aims to examine the antimicrobial, antioxidant, and anticancer properties of kombucha beverages fermented with Gardenia jasminoides (GJ) and various types of Camellia sinensis teas: matcha green tea (MGT), organic green tea (OGT), and decaffeinated green tea (DGT). Methods: Two experimental designs were employed: (1) using black tea as a base substrate, infusing the four teas post-fermentation over 0–14 days, and (2) directly fermenting tea–herb combinations over 0–21 days. Antioxidant activity was assessed via the DPPH assay. Microbial dynamics were analyzed through total mesophilic bacteria and Lactobacillus counts. Antimicrobial potential was evaluated against E. coli, S. aureus, and S. enteritidis over 24 h. Cytotoxicity assays were conducted on Caco-2 and U251 cell lines to assess anticancer effects, with pH-adjusted controls used to differentiate bioactivity from acidity. Results: In the first experiment, GJ kombucha displayed the highest antioxidant potential (IC50: 14.04 µg/mL), followed by MGT (IC₅₀: 32.85 µg/mL) and OGT (IC₅₀: 98.21 µg/mL). In the second setup, unfermented GJ kombucha initially showed high antioxidant activity (IC₅₀: 12.94 µg/mL), improving during fermentation to reach an IC₅₀ of 18.26 µg/mL by day 21. Microbial analysis indicated moderate increases in total mesophilic bacteria and Lactobacillus in GJ kombucha after 14 days, while MGT, OGT, and DGT exhibited higher increments. GJ kombucha consistently demonstrated the highest antimicrobial activity against E. coli, S. aureus, and S. enteritidis, with significant inhibitory effects observed by 24 h. Cytotoxicity assays showed that GJ kombucha reduced Caco-2 cell viability to 20% at 800 µg/mL after 14 days, while U251 cells maintained 50% viability at the same concentration. Conclusions: This study highlights the antimicrobial, antioxidant, and anticancer potential of GJ kombucha, with fermentation enhancing bioactive metabolite production. Optimizing fermentation conditions, identifying specific bioactive compounds, expanding cytotoxicity testing, and exploring broader therapeutic applications of kombucha could maximize its health benefits and establish it as a natural antimicrobial and anticancer agent. Full article

The relationship between Kombucha fermentation process parameters and microbial composition was investigated. Green tea Kombucha fermented slower, producing a higher sugar/acid ratio, residual sucrose, and sweeter taste compared to black tea Kombucha. No known probiotic bacteria were identified in Kombucha since Zygosaccharomyces, Brettanomyces, Komagataeibacter, and Gluconacetobacter were the dominant genera observed based on 16s rRNA sequencing analysis. Green tea epigallocatechin and epigallocatechin gallate inhibited bacterial growth in black tea Kombucha broth in a concentration-dependent manner. Green tea Kombucha produced from a 10-day inoculum had a higher sugar/acid ratio, residual sucrose, acetic acid, gluconic acid, and a pleasant flavor compared to a 15-day inoculum. In blended green and black tea Kombucha, a solid bacterial pellicle 9-day inoculum increased the amounts of glucose, fructose, acetic acid, gluconic acid, and ethanol, yet there was a lower sugar/acid ratio and residual sucrose, but no change in the catechin profile, compared to a completely liquid inoculum. Increasing the surface area/volume ratio to 0.16 during Kombucha production increased levels of glucose, fructose, and gluconic acid, while acetic acid and ethanol levels remained the same by favoring aerobic vs. anaerobic fermentation. These Kombucha fermentation process parameter results will help producers devise strategies for better quality control. Full article

Kombucha, a functional beverage rich in glucuronic acid, is fermented in the presence of acetic acid bacteria and yeast as the primary microorganisms. Glucuronic acid is recognized for its various physiological benefits, such as detoxification, antioxidation, and anti-inflammation. To optimize the glucuronic acid content in kombucha, various strain combinations by selecting fermented sources were accomplished. According to the experimental results, kombucha produced through co-fermentation with Pichia anomala and Komagataeibacter hansenii, with glucose-added black tea as the carbon source, exhibited the highest glucuronic acid production. A response surface methodology found that under optimized conditions of a 12.27% (w/v) carbon source concentration, a 10.07% (w/v) substrate concentration, and a 28.4 °C temperature, the highest glucuronic acid production reached 80.16 g/L, which represented a 2.39-fold increase compared to the original kombucha. Furthermore, the total polyphenol content increased by 3.87-fold, while DPPH and ABTS free radical–scavenging capacities increased by 1.86- and 2.22-fold, respectively. To sum up, these observations reveal the potential for commercial production of glucuronic acid–enriched kombucha and contribute to the development of functional food products related to kombucha in the future. Full article

Traditionally, kombucha is produced by the fermentation of black or green tea infusions with the use of SCOBY (Symbiotic Culture of Bacteria and Yeasts). However, SCOBY exhibits the ability to ferment other substrates as well, which can be used to create novel products with new sensory and health-promoting properties. This paper investigates the antioxidant activity, chemical composition, and sensory properties of mint, nettle, and blackcurrant leaf-based kombucha analogs. It has been demonstrated that the fermentation process with SCOBY significantly influenced (p ≤ 0.05) sugar, organic acids, and mineral contents, with the increase in iron, magnesium, and calcium amounts in all tested herbal kombucha. The study shows that the type of herb infusion has a significant influence on the parameters associated with antioxidant potential. The fermentation with SCOBY resulted in an increase in antioxidant activity as measured by the superoxide anion radical (O₂^•−) inhibition of all three tested herbal infusions, with the greatest changes observed in nettle kombucha. Herbal kombucha was characterized by significantly increased total phenolic content as determined by Folin’s reagent and a changed phenolic compound profile by LC-MS/MS (liquid chromatography with tandem mass spectrometry) in comparison to nonfermented infusions. Very high sensory scores were achieved for fermented mint and blackcurrant-based kombucha. Full article

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. Full article

Background: Kombucha, a fermented tea, has been suggested as an adjuvant in the treatment of obesity. Although animal and in vitro studies indicate its promising benefits, exploring kombucha’s impact on human health is necessary. Methods: This quasi-experimental pre–post-intervention assessed the effect of black tea kombucha consumption on cardiometabolic parameters for 8 weeks, considering the quality of the diet of individuals with and without obesity. Diet quality was assessed through the Dietary Inflammatory Index^® and Dietary Total Antioxidant Capacity. Paired t-test/Wilcoxon was applied to compare differences between pre- and post-intervention (α = 0.05). Results: After the intervention, individuals with obesity showed a decrease in insulin, HOMA-IR, and GGT; those without obesity showed an increase in total cholesterol and alkaline phosphatase, but this was only observed in those with a worsened diet quality. Conclusion: kombucha intake demonstrated positive impacts on the metabolic health of individuals with obesity beyond the importance of combining it with healthy eating patterns. Full article

In this study, the influence of different tea extract substrates on the biological activities of kombucha beverages was investigated. The variations in bioactive compounds such as polyphenols and flavonoids and their potential health-promoting properties represented by antioxidant activity were analyzed. Our findings shed light on the diverse effects of tea substrates on the production of bioactive compounds and their subsequent impact on the biological activities of kombucha, providing valuable insights for optimizing kombucha production and its potential health benefits. The new tea substrate for kombucha, called horchata, an Ecuadorian tea, shows a similar trend but with a low content of phenolics (4.511 ± 0.111 mg gallic acid equivalent (GAE)/g dry weight (DW)) and flavonoids (1.902 ± 0.0455 mg quercetin equivalent (QE)/g DW), and antioxidant activity (DPPH—33.569 ± 1.377 µmol TROLOX/g DW, ABTS—20.898 ± 2.709 µmol TROLOX/g DW, FRAP—34.456 ± 2.0618 Fe²⁺ mM/100 g DW compared to black and green tea as substrates for kombucha. Through HPLC-DAD, several polyphenols were registered, and homovanillic acid showed the highest concentration (74.45 mg/100 g). Horchata kombucha scored the highest in sweetness and smell, reflecting its popularity among the tasters, making it a valuable candidate as a kombucha substrate. Full article

Kombucha is a traditional, fermented beverage made with an essential biomaterial known as SCOBY (symbiotic culture of bacteria and yeast). Three different tea types, namely black, green, and oolong, were compared in kombucha fermentation in terms of pH dynamics, the formation of SCOBY biomass, and the production of acetic acid. The rational, exponential, and polynomial models described pH dynamics with good fit, R² > 0.98. The formation of SCOBY biomass and the production of acetic acid were modelled using sigmoidal functions, with three-parameter logistic and Gompertz models and four-parameter Boltzmann and Richards models. The F-test indicated that the three-parameter models were statistically adequate; thus, the Gompertz model was modified to present the biological meaning of the parameters. The SCOBY biomass formation rates ranged from 7.323 to 9.980 g/L-day, and the acetic acid production rates ranged from 0.047 to 0.049% acid (wt/vol)/day, with the highest values from the non-conventional substrate, oolong tea. The correlations between pH and SCOBY biomass or acetic acid using polynomial models enable the prediction of product formation in kombucha processing. Full article

Kombucha is a traditional beverage obtained by the microbial fermentation of tea using a symbiotic culture of bacteria and yeasts. In addition to several documented functional properties, such as anti-inflammatory activity and antioxidant activity, kombucha is often credited with high levels of vitamins, including riboflavin. To our knowledge, the vitamin B2 content in traditionally prepared kombucha has been determined in only two studies, in which the concentration measured by the HPLC technique ranged from 2.2 × 10⁻⁷ to 2.1 × 10⁻⁴ mol dm⁻³. These unexplained differences of three orders of magnitude in the vitamin B2 content prompted us to determine its concentration during the cultivation of kombucha under very similar conditions by spectrofluorimetry. The B2 concentrations during the 10-day fermentation of black tea ranged from 7.6 × 10⁻⁸ to 3.3 × 10⁻⁷ mol dm⁻³. Full article

(1) Objectives: Traditional kombucha (K) is a fermented beverage obtained from black or green tea infusion. Besides traditional substrates, the possibility of using alternative ingredients resulted in changes in metabolic profile and biological activity. The aim of this work was to study an alternative kombucha (KJ) prepared by the addition of jujube powder to black tea. (2) Materials and Methods: Changes in pH, protein, sugars, phenolic (TPC), flavonoid (TFC), and vitamin C and B12 content were evaluated at different time points over a period of 45 days. The identification of polyphenols by HPLC DAD and the antioxidant capacity by DPPH, ABTS, and FRAP tests of all samples was also carried out. (3) Results: The results showed higher protein, total phenolic content, and antioxidant capacity in KJ samples than in K ones. Vitamin C content increased during fermentation and reached its maximum concentration on day 45 (7.1 ± 0.3 mg/100 mL) for KJ. Caffeine in the supplemented samples was the main biocompound among those identified. Vitamin B12 formed on day 4 in K and after 24 h in KJ samples, remaining constant at the initial value of 2.30 ± 0.01 mg/100 mL up to day 45. (4) Conclusions: The results highlight that the fortification of kombucha with jujubes improved its biological activity and the content of bioactive compounds. Full article

This study aimed to investigate the influence of galvanized steel coupons on black tea kombucha fermentation. As a secondary objective, the corrosion activity of the fermented medium at different stages of fermentation was investigated. The results revealed significant interactions among microorganisms, the metal, and the fermented medium. On one hand, mass loss measurement, scanning electron microscopy (SEM) analysis, and released zinc and iron ion analysis showed the deterioration of galvanized steel coupons. On the other hand, HPLC-RI analysis showed that the presence of steel coupons improved the kinetics of fermentation. The chemical composition and bioactivity of kombucha were also influenced by the presence of galvanized steel. The results showed the detection of eleven phenolic compounds by HPLC-DAD, including trihydroxyethylrutin, methyl 3,5-dihydroxybenzoate, and ethyl 4-hydroxy-3-cinamate, which were found only in kombucha in the presence of galvanized steel (K+GS). In addition, a total of 53 volatile compounds were detected by GC-MS before and after derivatization, including eleven constituents identified for the first time in K+GS. Concerning antioxidant activity, a higher percentage of inhibition against the DPPH radical was attributed to the ethyl acetate extract found in K+GS (IC₅₀ = 8.6 µg/mL), which could suggest the formation of inhibitors. However, according to the electrochemical findings, the corrosion current density increased threefold during the fermentation process compared to acidified black tea, indicating that corrosion activity was promoted in the kombucha medium and suggesting several competing phenomena between corrosion and inhibition. Full article