Kombucha

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Ripe kombucha approach. The Kombucha culture is clearly visible on the surface.
Kombucha culture, colored pink by fruit tea

Kombucha (pronounced kɔmˈbut͡ʃa for Japanese etymology or kɔmˈbuːxa , pronounced komb u cha, for Russian etymology ) is a fermented drink made from teas sweetened by fermentation , e.g. B. Green teas , with a Kombucha culture (so-called Kombucha mushroom or tea mushroom ) is produced. By alcoholic fermentation of Kombucha mushroom builds the sugar to carbon dioxide and ethanol from. The alcohol content varies between 0.5 and 2%. The Kombucha fungus is not an independent fungus , but a symbiosis of different yeasts (unicellular fungi), more precisely Ascomycota ( Saccharomyces cerevisiae , Saccharomyces ludwigii , Schizosaccharomyces pombe , Pichia fermentans etc.) and acetic acid bacteria ( Acetobacter a. Oxydanset .) , Acetobacter a. The yeasts reproduce in kombucha exclusively vegetatively by budding or splitting. They form a whitish, gelatinous layer on the tea surface, with new layers replicating again and again. The color can vary from light gray to pink to dark brown, depending on the type of tea used.

Tea fermented with kombucha is delicately sparkling and tastes a little sweet and sour and fermented. The drink is drunk cold.

Surname

One possible source of the name is a non-fermented Algenteegetränk from kelp, a brown seaweed , which Japanese.昆布kombu is called. This drink has been called Kombucha ( cha = 茶, tea) in Japan for centuries and is an algae tea.

Ingredients and effects

During fermentation, the yeasts break down the sugar into carbon dioxide and ethanol (approx. 0.5–2%) and partly form glucuronic acid and gluconic acid . Fermentation produces various metabolic products that are said to have a positive effect on wellbeing, including acetic acid , lactic acid , other organic acids and various enzymes that the organisms release into the nutrient solution. Kombucha contains u. a. various trace elements such as zinc and manganese . Among the proven ingredients include Vitamin B1 , B6 , B12 and C . The nitrogen required for the synthesis of proteins is obtained from the air by the bacterium Acetobacter nitrogenifigens through nitrogen fixation . The tea used in its production only contributes micronutrients . The resulting acids lower the pH of the drink. Up to the eighth day after the start of the culture, Kombucha is a fermented drink with a slightly sweet taste (depending on the room temperature), after about 20 to 30 days it is vinegar . In the case of industrially produced kombucha, fermentation is interrupted after a few days, syrup is added and the drink is pasteurized. All remaining yeast cells are killed in the process. Industrially produced kombucha often has little in common with the original kombucha. However, more and more manufacturers advertise that their drinks contain living organisms. The key difference here is whether pasteurization takes place in the manufacturing process or not. The heating during pasteurization kills the yeast cells and bacteria. If this is not done, the shelf life is shortened, but the living organisms are still contained.

The beneficial effects on human health attributed to the drink have allegedly been used for centuries. There have been sources of public awareness in Europe since the early 20th century.

The Kombucha drink is said to have a number of effects, most of which have not yet been scientifically proven. So it should, according to alternative medical practitioners in particular through the glucuronic acid in the purification help the body and the immune system strengthened.

Manufacturing

Freshly made kombucha. At the beginning of the fermentation process, the kombucha culture is at the bottom of the vessel.

The Kombucha drink is traditionally made from strong, sugared black or green tea.

As with all targeted fermentations, strict hygiene is also required in the production of kombucha. Otherwise undesirable, harmful microorganisms can multiply and produce a harmful end product. In the event of an unusual change in color and smell or noticeable mold formation , the entire culture must be discarded in order to rule out health risks.

The Kombucha culture can lift itself out of the liquid through gas formation. To avoid mold growth, the fungus must always be in contact with the liquid. In contrast to the production of vinegar, where the mother of vinegar is regularly mixed in, the Kombucha mushroom is pressed lightly “under water”.

The bacterium Gluconobacter oxydans , which occurs in the Kombucha culture , is used in a process to ferment maltose into gluconic acid in order to produce the drink Bionade .

rating

  • Kombucha drinks contain more or less sugar, depending on how they are made. Therefore, attention should be paid to the sugar content when consuming. Legally, they are not allowed to be referred to as "soft drinks". "Because of its high content of easily absorbable sugar, Kombucha is a very unfavorable drink, especially for people with diabetes, and therefore not recommended as a regular thirst-quencher."
  • According to the legal regulations for non-alcoholic beverages, the alcohol content of Kombucha drinks may not exceed two grams of alcohol per liter. The Bavarian State Ministry for the Environment, Health and Consumer Protection found higher values ​​in investigations of kombucha drinks, so that the drinks should no longer have been designated as alcohol-free. The alcohol content is stated by the manufacturers as 0.5 percent, which corresponds to the value of alcohol-free beer. Homemade kombucha can contain up to three percent alcohol. For dry alcoholics, like any other fermented drink, kombucha is unsuitable because of the risk of relapse.
  • There are no clinical studies on the potential therapeutic effects of Kombucha. Only laboratory tests provide evidence of a slight antibiotic effect.
  • The Bavarian State Ministry for Consumer Protection explains: “According to advertising statements from manufacturers, Kombucha drinks etc. a. 'Influence human well-being positively', 'support the body's own defenses' or 'strengthen the immune system'. However, such an effect cannot be derived from the method of manufacture and composition alone. "
  • The consumer center of Lower Saxony explains in a statement: “Kombucha is a harmless soft drink when properly manufactured (...). At best, its health effects are comparable to those of other fermented foods such as sour milk products, whose microorganisms can have a positive effect on the intestinal flora . (...) Scientifically proven are only slightly laxative and weak antibacterial effects, which can be attributed to the content of acetic and lactic acid. Industrially produced kombucha is pasteurized for shelf life reasons . This kills the microorganisms in the fermented drink - they become ineffective. "
  • “Kombucha is a tea-based drink similar to must. The advertising claims about therapeutic or health-preventive effects have not been scientifically proven ”, judges the German Nutrition Society . There are also no studies on possible probiotic properties of the cultures.

See also

Individual evidence

  1. ↑ Duden: Kombucha
  2. ↑ M. Remke: Kombucha is said to suddenly contain too much alcohol. on: welt.de , November 13, 2015.
  3. ↑ Kombucha. on: verbrauchzentrale.de , January 19, 2016.
  4. ↑ Richard Hosking: A Dictionary of Japanese Food - 日本 料理 用語 辞典 (英文): Ingredients & Culture. Tuttle Publishing, 1996, ISBN 0-8048-2042-2 , p. 208.
  5. ↑ J. Reiss: The tea mushroom and its metabolic products. In: Deutsche Lebensmittelrundschau. 83, 1987, 286n290.
  6. ↑ L. Komsta, M. Waksmundzka-Hajnos, J. Sherma: Thin Layer Chromatography in Drug Analysis. (= Chromatographic Science Series. 106). CRC Press, 2013, ISBN 978-1-4665-0715-9 .
  7. ^ B. Bauer-Petrovska, L. Petrushevska-Tozi: Mineral and water soluble vitamin content in the Kombucha drink. In: International Journal of Food Science & Technology. 35 (2), 2001, pp. 201-205.
  8. ↑ D. Dutta, R. Gachhui: Novel nitrogen-fixing Acetobacter nitrogenifigens sp. nov., isolated from Kombucha tea. In: Int J Syst Evol Microbiol. 56 (Pt 8), Aug 2006, pp. 1899-1903.
  9. ↑ Buy Kombucha | What brands are there? | Pay attention to In: Kombucha. Retrieved January 9, 2020 (German).
  10. ↑ The core of the bubble. In: Der Tagesspiegel . July 3, 2006, accessed September 12, 2012 .
  11. ↑ nutriinfo.de: Kombucha - what is it? ( Memento from March 21, 2005 in the Internet Archive )
  12. ↑ a b Bavarian State Ministry for the Environment, Health and Consumer Protection: Fermented drinks , March 11, 2008.
  13. ↑ On the risk of relapse in alcoholics
  14. ↑ Consumer advice center for Kombucha ( Memento from July 23, 2015 in the Internet Archive ), November 14, 2014
  15. ↑ DGE: Is Kombucha a Health Elixir? (2000)

literature

  • Günther W. Frank: Kombucha - the tea mushroom drink. Practical instructions for preparation and use. Ennsthaler, 2002, ISBN 3-85068-304-4 .
  • Günther W. Frank: Kombucha - Myth, Truth, Fascination. The biologically active natural drink. What it can do for you personally. Ennsthaler, 1999, ISBN 3-85068-555-1 .

Web links

Commons : Kombucha  - collection of images, videos and audio files
Wiktionary: Kombucha  - explanations of meanings, word origins, synonyms, translations