Overview (1, 3)Edit
Kombucha is a fermented tea beverage that serves as a functional food by being rich in a plethora of vitamins and minerals. The slimy culture, known as a SCOBY (Symbiotic colony of baceria and yeast) is a living slab of Gluconacetobacter xylinus and one or more of the following yeasts; Saccharomyces cerevisiae, Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe, Torulaspora delbrueckii, and Zygosaccharomyces bailii.
The yeast is responsible for metabolizing the sugar into alcohol and the G.xylinus is a bacteria that ferments alcohols produced by yeast into acetic acid. This bacteria is also responsible for the cellulose structure of the SCOBY.G.xylinus is an aerobic bacteria that produces high amounts of extra cellular cellulose which is thought to provide the bacteria a means for floatation inorder to have access to the air, ie. an abundant source of oxygen. There are two enzymes present in wild-type G.xylinus that are major contributers to the production of crystalline-ribbon like microfibrils of cellulose; phosphoglucomutase & UDP-glucose. Mutant, non-cellulose producing, strains of this bacteria lack these two enzymes.
Biological Effects of Kombucha (2)Edit
There are not many studies being conducted on the risks and benefits of kombucha consumption. In several very rare cases kombucha comsumption has resulted in adverse reactions. However, the publications available on the fermented tea are almost all in agreement that consumption kombucha has beneficial effects.In one study conducted on induced-diabetic rats showed that kombucha acts as a better inhibitor of alpha-amylase and lipase activities in the pancreas comparesd with rats who consumed only black tea. Not only was kombucha a better inhibitor on alpha-amylase and lipase activities, but it also was a better suppressor of increased blood glucose levels, induced delay in LDL-cholesterol & triglyceride absorbtion and significantly increased levels of HDL-cholesterol.
Examination of histology samples from rats that consumed kombucha showed increased pancreas function, protection of liver and kidney function and decreased levels of creatine and urea contents.
There are many generic health claims suggesting kombucha is a 'wonder tonic'. However, more reseach much be done to determine other effects on the body, especially on humans. From the research that has been done, results lean toward the positive health benefics of kombucha more than the negative effects.
If you would like to grow your own, its easy! Just ask Rachael for a new SCOBY.
Directions for making the tea:
- Boil 4 c water with 1 c sugar until sugar is dissolved.
- Pour sugar water into gallon size glass bowl or jar.
- Add 6 black or green tea bags and let steep for 7 min.
- Remove tea bags, add 10c water.
- Place SCOBY on top of water so it floats.
- Cover with a towel or other breathable material and let sit for 7 days.
Its essential to use clean equiptment and to try to reduce contamination. Thankfully kombucha has anti-microbial properties that help to reduce a contaminated tea.
The SCOBYs grow fast and you will probably have a whole new one after 7 days. You can give to a friend, increase your own kombucha production or use it for many other things from a face mask to just eating it. Remeber to do some good research before attempting to use the SCOBY for anything but kombucha.
- Wikipedia. Kombucha. Last updated 24 Nov 2012.
- Aloulou, A, et al. Hypoglycemic and antilipidemic properties of kombucha tea in alloxan-induced diabetic rats. BMC Complement Altern Med. 2012, Vol 12, p63. PMCID: PMC3403982
- Nguyen, Vu Tuan, et al. Spntaneous mutation result in lower cellulose production by a Gluconacetobacter xylinus strain from kombucha. Carbohydrate Polymers. 2012, Vol 80 p337-343.
- Personal experience.