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Here is the magic of fermented drink that is fizzy, a flavorful drink that’s both tasty and rumored to be good for you, made from tea, sugar and living SCOBY. It is called 'Kombucha' it is a delicious probiotic-rich drink.
I adopted Kombucha as a fermented food because I am tea connoisseur. I needed a clarity on how the ingredients work together to create probiotics, beneficial bacteria that promote a healthy gut, which is important for your overall health, especially your immune system.
Kombucha is a fermented, lightly effervescent, sweetened black tea drink . It is a source of bioactive compounds that include organic acids and amino acids, vitamins, probiotics, sugars, polyphenols, and antioxidants. Kombucha has been around for nearly 2,000 years. It was first brewed in China and then spread to Japan and Russia. It became popular in Europe in the early 20th century. Sales in the United States are on the rise because of its reputation as a health and energy drink.
AAB are Gram-negative, aerobic rods, which can be single, in pairs, or clusters. Cell sizes range from 0.4-1.0 μm in width and 0.8-4.5 μm in length. These bacteria are mostly catalase-positive and oxidase negative. The optimum growth temperature varies from 25 °C-30 °C, some thermotolerant strains can grow at up to 42 °C and some AAB can grow under acidic conditions. AAB can oxidise sugar alcohols such as glycerol and convert them to DHA.
To make kombucha, sugar and a microbial community are added to the tea, . This community is usually a giant slimy blob that goes by many names: mother, SCOBY (for symbiotic community of bacteria and yeast), and pellicle. This microbial community is a perfect example of a microbial biofilm, a dense microbial mat fused together by substances that the microbes secrete. In this case, it’s cellulose that is produced by the bacteria that is primarily responsible for the glued together community.
Kombucha is fermented from sweetened tea using a symbiotic culture of bacteria and yeast which is abbreviated to SCOBY. The SCOBY is also known as tea fungus, or consortium. The microbial community in Kombucha is diverse and varies between fermentations, but it is composed of AAB and yeast , although, the presence of small amounts of LAB in Kombucha has also been reported . These microorganisms have been suggested to be potential probiotics.
LAB are gram-positive, anerobic, non-sporulating microorganisms that have been isolated from several different environments.LAB belonging to the Firmicutes phylum and is characterized based upon their metabolic, physiological, and certain morphological characteristics. Optimum growth for these microorganisms is between 25–40°C and a pH of 4–6. Several LAB, have also been categorized as probiotics due to their health promoting benefits.
Making kombucha involves letting bacteria grow in a liquid you’re going to drink. Many of the bacteria are considered probiotics, but if it’s not prepared properly, it can grow harmful bacteria or mold.
LAB produce amino-acid decarboxylase enzymes which convert amino acids to biogenic amines. The presence of biogenic amines in foods can cause intoxication symptoms such as heart palpitations, redness, headaches, vertigo, and altered blood pressure and can be fatal at high concentrations.
in this symbiotic relationship, the yeast community hydrolyses the sucrose present in the medium to glucose and fructose, and produces ethanol from glucose. AAB use glucose, fructose and ethanol to produce gluconic acid, glucuronic acid, acetic acid, d-saccharic acid-1,4-lactone and bacterial cellulose . The produced acetic acid further stimulates the production of ethanol by the yeasts, and this ethanol is then converted to acetic acid by AAB.
https://doi.org/10.1016/j.ijgfs.2020.100272
