First, do a good job of disinfection. The most important thing is disinfection. The container for cultivating black tea fungus must be disinfected. Methods 1, boiling water 10 min; Method two. Disinfect with disinfectant. (If other bacteria are found on the surface during culture, you can spray alcohol on the surface twice a day. )

Second, the selection of strains. It is necessary to choose excellent strains from Russia, which are of good quality and easy to survive. Choose those with thick strains, large membrane area, strong bacteria and not easy to be changed by enzymes (there is no white hair on them).

Large strain is strong, fast preparation and high quality. Make more bacterial liquid at a time. Many excellent qualities of black tea fungus can be maintained by traditional methods and high permeability tank culture.

Small strains can only be used to make small cups for 10 day at a time (only half of them are left except evaporation).

Choose a large fine strain (diameter 17-20cm) to make a big altar (diameter 17-20cm).

Make a big altar with small plants, and you will die if you don't move them.

Third, the choice of raw materials. It is best to use some untreated natural tea leaves, and glucose is the best sugar. The survival rate is extremely high and the culture speed is fast. Don't use honey, honey is impure and contains many impurities.

Fourth, the amount of sugar, tea and water. The important ratio of sugar, tea and water is 5: 0. 1-0.4: 100 (5 to 0.1 to 0.4 to 100). Just put less tea with some pigment. If more tea leaves restrict the growth of bacteria, the strong bacteria in tea leaves will die. Sugar is a little sweet, so put less water the first time. The largest 17 cm can hold two kilograms of water, and other strains can hold three ounces of water. If you put too much water, the bacteria will not move, and with experience, you can double it for the second time.

Fifth, ventilation. Ventilation is necessary to prevent other miscellaneous bacteria from surviving. Ventilation is very important, because ventilation can effectively reduce the concentration of other miscellaneous bacteria in the incubator, so that other bacteria can not parasitize on the film of black tea fungus.

Six, please pay attention to the unit when buying strains. Because 80% of the strains of black tea fungus are water, so don't buy strains by weight, because the strains are all water at home. It looks like a lot of grams, but it's all water. It is good to choose some strains with large diameter, good quality, good thickness and good origin, such as Russian strains planted in the former Russian Caucasus. (from ★ I love black tea fungus net ★ from "I love black tea fungus net" by Feng Xiaolong) The first time I cooked tea, there was only a little color in the tea and a little sweetness in the sugar. The ratio of sugar, tea and water is 5:0. 1-0.4: 100. (5 to 0. 1 0.4 100)

Black tea fungus is a traditional folk acidic beverage with a long history, which can be traced back to the ancient Qin Dynasty in China. In addition to China, Japan, South Korea and other Southeast Asian regions, black tea fungus is widely spread in Central and Eastern European countries, where people use sour tea wine (that is, black tea fungus) as a refreshing drink to treat indigestion and arteriosclerosis. From the early 1990s to the present, black tea fungus has spread widely in Germany, the United States, Canada and other western countries, becoming a fashion. Sugar tea is co-fermented by various microorganisms such as acetic acid bacteria, yeast and lactic acid bacteria. The liquid of Kombucha contains some tea extracts, living microorganisms and their metabolites, mainly including gluconic acid, acetic acid, glucose, fructose, protein, amino acids, vitamins, trace elements, tea polyphenols, caffeine, ethanol and carbon dioxide. Black tea fungus has always been regarded as a kind of healthy drink with many health-care effects on human body. Its health care functions include: cleaning the stomach, preventing constipation and hemorrhoids; Help digestion; Can be used for preventing and treating cardiovascular diseases, such as hypertension, hyperlipidemia, arteriosclerosis and diabetes; Avoid all kinds of stones; Help the body eliminate toxins in time, prevent cancer and enhance the body's immunity. It can be said that it is a good health drink. Although Kombucha has a long history in China, its scientific research started late. In 18+0, Fang, a famous microbiologist in China, published the article "What is a sea treasure" in the fifth issue of the Yellow Sea magazine, which is the first scientific paper on black tea fungus in China. In this paper, it is considered that the main microbial species of black tea fungus are acetic acid bacteria and yeast, and it is pointed out that there is more than one kind of acetic acid bacteria in black tea fungus, but it is mainly membrane vinegar bacteria. From the late 1970s to the early 1980s, kombucha beverage was very popular in China. A large number of articles introduced the efficacy and production methods of kombucha. In recent years, there have been some studies on the bacteriostasis of Kombucha in China, but there are few studies on the strain and its mechanism. The research on kombucha abroad began in the early 20th century. From the early to the middle of the 20th century, some doctors and scholars have reported the role and function of black tea fungus in treating various diseases. From the mid-20th century to now, there have been literature reports on the microbial composition, interaction, fermentation conditions, bacterial liquid composition and mechanism of action of black tea fungus. 1 strains of kombucha and their relationships. Acetobacter and yeast are the main strains used in the fermentation culture of Kombucha, and some Kombucha have a small amount of lactic acid bacteria [mainly Lactobacillus boulardii]. Up to now, Acetobacter, Acetobacter xylinum, Acetobacter xylinum, Gluconobacter and Acetobacter ketoacidogenes have been isolated from various black tea fungi. Acetobacter weakly oxidized, Gluconobacter liquefied, Acetobacter aceti and Acetobacter pasteurella, among which Acetobacter xylinum is the most important. Yeast includes Saccharomyces cerevisiae, inconspicuous yeast, Ludwig II, Schizosaccharomyces pombe, Candida tropicalis, candidate yeast, Dbaly II, Brettanyomyces, Kloeckera, Zygosaccharomyces bailii, etc. The strains that ferment black tea fungus are composed of the above-mentioned one or more acetic acid bacteria and the above-mentioned one or more yeasts, and some of them are lactic acid bacteria. Different strains have different kinds and quantities of metabolites in their liquid. Yeast and Acetobacter are mutually beneficial in black tea fungus. At the initial stage of fermentation, because acetic acid bacteria can't directly use sucrose or the speed of using sucrose is very slow, saccharomycetes degrade sucrose into glucose and fructose and further ferment to produce ethanol. After glucose, fructose and ethanol are in the culture medium, acetic acid bacteria begin to grow and multiply in large numbers, glucose and fructose are oxidized to produce metabolites such as gluconic acid and acetic acid, and ethanol produced by saccharomycetes is oxidized to produce acetic acid. Some data show that ethanol produced by yeast can stimulate the growth of acetic acid bacteria and produce more cellulose films and acetic acid, while acetic acid produced by acetic acid bacteria can stimulate yeast to produce ethanol. The existence of acetic acid and ethanol can protect acetic acid bacteria and yeast from infection by other microorganisms.

Study on fermentation conditions of 2

Mi-Ae-Choi (1994) and others studied the effects of different temperatures (5 ~ 45℃) and carbon sources (sucrose, glucose, fructose and corn syrup) on the pH and total acid of Kombucha. The results showed that the optimum temperature for acid production by fermentation was 30℃, and the organic acids produced by sucrose and fructose, glucose and corn syrup were similar. The metabolic rate of fructose is much faster than that of glucose, while the metabolic rate of fructose and glucose is faster than that of sucrose. Jürgen Reiss( 1993) used different carbon sources (sucrose, fructose, lactose and glucose) with different concentrations to treat the metabolites (ethanol and lactic acid) of Kombucha (a strain composed of Acetobacter xylinum, Acetobacter pseudoxylophilus, Glucobacterium, Schizosaccharomyces pombe, Rhodotorula, etc.) at the fermentation temperature of 20 ~ 22℃, and sucrose could increase the yield. Martin Sievers et al. (1995) studied the fermentation of two strains of Kombucha (including different yeast species). They cultured Kombucha at room temperature (20 ~ 22℃) for 60 days and tested its fermentation process. Results Different yeasts have different utilization rates of glucose and fructose and different metabolic processes. Yeast plays a decisive role in the utilization of sugar, and different yeasts use sugar in different ways. Matin Sievers and others also pointed out that the Acetobacter xylinum they used can metabolize lactic acid, so they did not detect lactic acid like Jürgen Reiss.

Analysis of three components of black tea fungus

Some scholars have analyzed the components contained in the liquid of black tea fungus. Different data have different results because of different strains, culture conditions, analysis methods and analysis emphasis. German Gü nther W. Frank (1991) thinks that black tea fungus contains glucuronic acid, gluconic acid, acetic acid, alcohol, lactic acid, amino acids, protein, folic acid, lichenic acid, Vc and various B vitamins [14]. Liu et al. (1995) analyzed two species of black tea fungus from Taiwan Province province by HPLC. The results showed that the black tea fungus contained glycerol, acetic acid and ethanol. Michael R. Roussin of the United States (1996) reported that 9 samples of/kloc-0 from the United States and other parts of the world were analyzed by HPLC/MS/PDAD. Results glucuronic acid, which was almost recognized as a functional factor before, was not found, and the contents of various vitamins were few, but many were detected. They detected more than 40 chemicals from 19 species of black tea fungus. How these substances work after entering the human body needs further scientific research. Biljanabauer-Petrovska (1998) analyzed the minerals and soluble vitamins in black tea fungus by atomic absorption chromatography and thin layer chromatography. The results show that the contents of zinc, copper, iron, manganese, nickel and cobalt beneficial to human body are higher than those of unfermented tea, while the contents of lead and chromium harmful to human body are very few and far lower than those of tea. This shows that microorganisms can increase beneficial elements and reduce harmful elements.

Study on the mechanism of action of 4

So far, the beneficial mechanism of tea fungus to human health has not been fully understood, but experts and scholars at home and abroad have preliminarily expounded its mechanism from the nature and composition of tea fungus through research.

4. 1 Clean the stomach, help digestion, inhibit harmful bacteria, prevent gastrointestinal diseases and prevent the occurrence of colon cancer. Black tea fungus can reduce the pH of the stomach, and acidification of the upper digestive tract is very beneficial to health. It has antagonistic effect on harmful bacteria in gastrointestinal tract, such as Helicobacter pylori closely related to gastritis, gastric ulcer and gastric cancer, and can also prevent the occurrence of colon cancer. Kim et al. (1994) found that the activities of glucosidase and glucuronidase in intestinal bacteria increased with the increase of pH, and the activities at pH7 were 5~ 10 times higher than those at pH6. They think that high pH environment will induce the activity of these two enzymes, which will lead to the occurrence of colon cancer.

4.2 Drinking black tea fungus can maintain the normal pH value of blood. Medical research shows that the blood pH of cancer patients is 7.56, while that of normal people is below 7.5. The serological test of venous blood showed that kombucha beverage can significantly maintain the normal pH value of blood, which is of great significance to study the causes of kombucha preventing and treating early cancer.

4.3 Acetic acid, the main component of black tea fungus, is very beneficial to health. Modern medicine has proved that acetic acid has the functions of eliminating fatigue, stimulating appetite, helping digestion, preventing and treating hypertension and arteriosclerosis, and also has certain anti-tumor and anti-obesity effects, so that calcium can be easily absorbed by the human body, keeping the elasticity of bones, and moistening muscles and rejuvenating skin.

4.4 Many people think that glucuronic acid is one of the detoxification and anticancer functional factors of Kombucha, and Kombucha is one of the most important detoxification substances in human liver. Glucuronic acid can be combined with exogenous toxins or endogenous toxic substances produced by human metabolism to become water-soluble glucuronide, which can be excreted together, so that toxins that may cause various pathological changes or have occurred in the body can be removed in time, and good results can be achieved in preventing and treating diseases.

4.5 Glucoside 1 4 lactone in black tea fungus can greatly reduce the damage of heparin, hyaluronic acid, sulfated mucopolysaccharide and glucuronic acid, help the body expel toxins more effectively, prevent cancer, and relieve discomfort caused by functional decline of related tissues such as arthritis, gout and asthma.

4.6 The gluconic acid in black tea fungus can combine with heavy metals to form a water-soluble complex, which helps the human body to excrete harmful heavy metal elements. Studies have shown that the content of heavy metals in urine of people who drink black tea newly increases.

4.7 Kombucha contains a variety of tea extracts, and the health care function of these extracts can not be ignored. According to ancient and modern research, tea has more than 30 kinds of health care functions, among which the main ones are exciting nerves, enlarging the heart, exciting breathing, anticoagulation, lowering blood fat, preventing coronary heart disease, diuresis, helping digestion, detoxification and antibacterial, cancer prevention and radiation resistance. Tea polyphenols have anti-mutation function and are natural antioxidants, which can delay human aging. Chlorogenic acid, catechin, VC and VE in tea all have the function of skin care. There are many known or unknown health-promoting components in black tea fungus. The reason why it is beneficial to health is not the single action of a substance, but the result of the joint action of many beneficial ingredients. Its health care function to human body is also various. In recent years, some countries in Europe and America have made further research on the clinical application effect of black tea fungus. For example, 1998, Yoram Azrad of the United States reported the clinical effect of drinking black tea fungus for 6 months in AIDS patients. The results showed that the patient's clinical condition had been greatly improved, and no possible infection occurred during this period.

5 concluding remarks

To sum up, black tea fungus is a traditional folk acidic beverage with a long history, which has many health care functions and is a natural microbial fermentation product with great utilization value. However, the mechanism of the fitness function of black tea fungus is very complicated, so far, it has not been fully understood and needs further in-depth study. At the same time, we should also strengthen its applied research to make it serve human health more fully. (From ★ I Love Kombucha Net ★ From "I Love Kombucha Net" by Feng Xiaolong)