Vitamins and minerals

Vitamins

In the process of Kombucha fermentation, vitamins like B, C, and E are produced due to the activities of acetic acid bacteria and yeast. These vitamins can either capture free radicals or work together with antioxidants like citric acid (Antolak et al., 2021, Martínez Leal et al., 2018). Vitamin C, which some acetic acid bacteria species can produce, is crucial for supporting the immune system in the final drink. It acts as an antioxidant, repairing cells and tissues damaged by free radicals. Ascorbic acid also enhances the body’s ability to absorb iron and helps prevent tooth decay (Malbaša et al., 2011, Nurikasari et al., 2017). Vitamin E plays a role in preventing or delaying conditions like coronary heart disease and cataracts. B vitamins in Kombucha can combat fatigue, enhance concentration, and support memory. The fermentation of tea significantly increases the activity of these vitamins, thanks to the metabolic activity of acetic acid bacteria and yeast (Antolak et al., 2021, Ivanišová at al., 2020).

Tea infusions contain primarily low levels of B group vitamins, vitamins E, K, and A, with vitamin C uniquely present in green tea (Dufresne et al., 2000). During the fermentation of tea, the metabolic activity of acetic acid bacteria, lactic acid bacteria (if present), and yeasts significantly increases the vitamin content. In Kombucha, vitamin C is recognized as the primary vitamin, deriving from glucose metabolism, particularly by strains of the genus Gluconobacter. The synthesis of vitamin C from D-glucose involves six chemical steps and one fermentation process (D-sorbitol oxidation) (Sievers at al., 2020).

In the fermentation of Kombucha, selected strains of lactic acid bacteria and yeasts can synthesize B-complex vitamins. Riboflavin (vitamin B2) serves as a precursor to flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), acting as hydrogen carriers in biological redox reactions. Thiamine (vitamin B1) plays a crucial role in energy production and has a beneficial effect on the nervous system. Folate (vitamin B9) is involved in cell metabolism. Lactic acid bacteria, including selected strains of Lactococcus lactis, Lactiplantibacillus plantarum, and Limosilactobacillus reuteri fermentum (formerly Lactobacillus reuteri), can produce various forms of folates. Yeasts are sources of B-complex vitamins such as B1, B2, B5, B6, B7, B9, B12, as well as ergosterol, which can be converted to vitamin D2. Specific yeast strains belonging to Z. bailii, S. cerevisiae, can produce these bioactive compounds.

Studies have reported concentrations of vitamins in Kombucha, including 0.74 mg/mL of vitamin B1, 0.08 mg/mL of vitamin B2, 0.52 mg/mL of vitamin B6, 0.84 mg/mL of vitamin B12 (Bauer-Petrovska at al., 2000). Another study noted a continuous increase in vitamin C concentration, up to 28.98 mg/L on the 13th day of fermentation. The study also observed more efficient synthesis of B2 vitamin during fermentation of black and green teas by “native SCOBY” compared to projected consortia of AAB + Saccharomyces sp. and AAB and Zygosaccharomyces sp. Furthermore, the synthesis of vitamin C was more pronounced during green tea fermentation, indicating that Kombucha based on green tea possesses stronger antioxidant activity than green tea infusion alone (Malbaša et al., 2011).

Section references

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8532973/

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H. Antolak, D. Piechota, A. Kucharska. Kombucha Tea—A Double Power of Bioactive Compounds from Tea and Symbiotic Culture of Bacteria and Yeasts (SCOBY). Antioxidants, 10(10), Article 10 (2021), 10.3390/antiox10101541

J. Martínez Leal, L. Valenzuela Suárez, R. Jayabalan, J. Huerta Oros, A. Escalante-Aburto. A review on health benefits of kombucha nutritional compounds and metabolites. CyTA - Journal of Food, 16 (1) (2018), pp. 390-399, 10.1080/19476337.2017.1410499

R.V. Malbaša, E.S. Lončar, J.S. Vitas, J.M. Čanadanović-Brunet. Influence of starter cultures on the antioxidant activity of kombucha beverage. Food Chemistry, 127 (4) (2011), p. Article 4, 10.1016/j.foodchem.2011.02.048

M. Nurikasari, Y. Puspitasari, R.P.Y. Siwi. Characterization and Analysis Kombucha Tea Antioxidant Activity Based On Long Fermentation as a Beverage Functional. Journal of Global Research in Public Health, 2 (2) (2017), pp. 90-96 https://doi.org/10.30994

Ivanišová E., Meňhartová K., Terentjeva M., Harangozo Ľ., Kántor A., Kačániová M. The evaluation of chemical, antioxidant, antimicrobial and sensory properties of kombucha tea beverage. J. Food Sci. Technol. 2020;57:1840–1846. doi: 10.1007/s13197-019-04217-3.

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Villarreal-Soto S.A., Beaufort S., Bouajila J., Souchard J.-P., Taillandier P. Understanding kombucha tea fermentation: A review. J. Food Sci. 2018;83:580–588. doi: 10.1111/1750-3841.14068.

Bauer-Petrovska B., Petrushevska-Tozi L. Mineral and water soluble vitamin content in the Kombucha drink. Int. J. Food Sci. 2000;35:201–205. doi: 10.1046/j.1365-2621.2000.00342.x.

Malbaša R.V., Lončar E.S., Vitas J.S., Čanadanović-Brunet J.M. Influence of starter cultures on the antioxidant activity of kombucha beverage. Food Chem. 2011;127:1727–1731. doi: 10.1016/j.foodchem.2011.02.048.