Fermented tea drink capable of protecting gastric mucosa and preparation method of fermented tea drink

Abstract

The invention discloses a fermented tea drink capable of protecting gastric mucosa and a preparation method thereof, and the preparation method comprises the following steps: S1, adding tea leaves into distilled water, heating to boiling, preserving heat, and cooling to room temperature to obtain tea soup; s2, uniformly mixing radix puerariae, poria cocos and lily bulbs, then performing freeze crushing, then adding the crushed materials into deionized water, then adding cellulase and pectinase, performing enzymolysis, and after enzymolysis is completed, performing enzyme deactivation, extraction, filtration and concentration so as to obtain a plant extracting solution; s3, adding a carbon source, a plant extract, pomegranate juice and polyglycerol fatty acid ester into the tea soup, uniformly stirring and mixing, and sterilizing to obtain a fermentation substrate; and S4, inoculating the mixed bacteria into a fermentation substrate, then performing fermentation, and after fermentation is completed, performing filtration and sterilization to obtain the fermented tea drink. The fermented tea drink has good stability, flavor and taste, also has the efficacy of assisting in protecting gastric mucosa, promotes intestinal health, and has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of tea beverages, and in particular relates to a fermented tea beverage capable of protecting gastric mucosa and a preparation method thereof. Background Art

[0002] Kombucha, also known as red tea, is a tea beverage with a unique flavor that is made by mixing tea, sucrose and water in a certain proportion and fermented by microorganisms. Kombucha originated in my country, and the types of tea used mainly include green tea and black tea. In addition, fruit and vegetable juice, plant extracts and milk can be added to the sugar tea, or the above substances can be directly used as raw materials for fermentation.

[0003] Kombucha is rich in a variety of acetic acid bacteria and yeasts. At present, the yeasts that have been isolated from kombucha mainly include Saccharomyces, Schizosaccharomyces, Brettanomyces, Candida, Zygosaccharomyces, Pichia and Torulina, etc. Most of the bacteria are acetic acid bacteria, mainly including Acetobacter, Acetobacter pasteurianus, Acetobacter azotobacter, Gluconobacter oxydans and Bacillus fowleri, etc. In addition, some kombucha also contains a small amount of lactic acid bacteria, mainly Lactobacillus. During the fermentation process, the above-mentioned mixed microorganisms can metabolize carbohydrates and other components in raw materials such as sugar tea to produce a unique flavor. The chemical composition of the fermented product is complex, containing organic acids, vitamins, active enzymes, polyphenols, glucuronic acid, D-glucaric acid-1,4-lactone and trace nutrients. Many studies have shown that these active substances have the functions of regulating gastrointestinal health, promoting digestion, refreshing, anti-cancer, lowering blood sugar, lowering blood lipids and protecting the liver, preventing cardiovascular diseases, improving immunity, and relieving rheumatism, gout and hemorrhoids.

[0004] Chinese patent CN116998566A discloses a fucoidan kombucha nutrient beverage and a preparation method thereof, which belongs to the field of food processing. The raw materials of the fucoidan kombucha nutrient beverage include water, oligofructose, lychee concentrated juice, kombucha fermentation broth, selenium-enriched black fungus peptide, fucoidan, calcium lactate, pectin, vitamin C, sodium hyaluronate, instant black tea powder, and taurine; the invention also provides a method for preparing a fucoidan kombucha nutrient beverage. The fucoidan kombucha nutrient beverage has significantly improved stability, flavor, taste, aftertaste and anti-fatigue compared with the prior art. However, the patent is mainly formulated by flavor substances, and the maximum nutritional value (including antioxidant) of fruits is not brought into play. At the same time, it contains various additives, the ingredients are not natural enough, and the health care function is unclear.

[0005] However, in my country, kombucha is still mostly produced at home, so there are some problems that need to be solved urgently: (1) The production form is extensive and the production capacity is low; (2) The non-standard production environment cannot effectively suppress the number of bacteria, resulting in poor quality and unsafe kombucha; (3) The quality of kombucha fermented products on the market is still unstable, such as the composition and taste of the fermented products are unstable, and there is a certain gap with traditional fermented products. Products fermented with kombucha can optimize their original flavor and improve their nutritional value, but at present there are not many kombucha products, with weak market competitiveness and low market share.

[0006] At present, some studies on kombucha mainly focus on the effects of carbon sources in the fermentation matrix and fermentation strains on the flavor and taste of kombucha, but there are few reports on the changes in the biofilm during the fermentation process. In the industrial production process, the formation of biofilm will affect the production efficiency. At the same time, since the formation of biofilm requires the consumption of nutrients in the fermentation liquid, it may lead to a reduction in functional ingredients in kombucha, which is not conducive to industrial production.

[0007] Therefore, there is an urgent need in the art to develop a fermented tea beverage that can protect the gastric mucosa and a preparation method thereof. Summary of the invention

[0008] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a fermented tea beverage that can protect the gastric mucosa and a preparation method thereof. The fermented tea beverage has good stability, flavor and taste, and also has the effect of assisting in protecting the gastric mucosa, promoting intestinal health, and has good application prospects.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A method for preparing a fermented tea drink capable of protecting gastric mucosa comprises the following steps:

[0011] S1. Add tea leaves to distilled water, heat to boiling, keep warm, filter, and cool to room temperature to obtain tea soup;

[0012] S2, mixing kudzu root, poria cocos and lily evenly and then freezing and crushing to obtain mixed plant powder, then adding the mixed plant powder into deionized water, followed by adding cellulase and pectinase to perform enzymolysis, inactivating the enzyme after the enzymolysis, extracting, filtering, and concentrating the filtrate under reduced pressure to 1 / 4 of the volume to obtain a plant extract;

[0013] S3, adding the carbon source, plant extract, pomegranate juice, and polyglycerol fatty acid ester to the tea soup in step S1, stirring and mixing evenly, and sterilizing at 115° C. for 15 min to obtain a fermentation base;

[0014] S4, inoculating the mixed bacteria into the fermentation base in step S3, followed by fermentation, filtering and sterilizing after the fermentation is completed to obtain the fermented tea beverage.

[0015] Preferably, the tea leaves in step S1 are one or more of black tea, green tea, white tea and oolong tea; and the mass ratio of the tea leaves to distilled water is 10-15:1000.

[0016] Preferably, the insulation time in step S1 is 20-30 minutes.

[0017] Preferably, in step S2, the mass ratio of Pueraria root, Poria cocos and Lilium bulbs is 10-13:5-8:3-6, and the temperature of the freeze-crushing is -30 to -50°C.

[0018] In the present invention, kudzu root is the tuberous root of vine plant kudzu, which is widely distributed in Hubei, Guangdong, Guangxi, Hunan and Jiangxi and other places, and belongs to the authentic medicinal materials of Guangxi. Kudzu root is sweet and spicy, cool in nature, lung and stomach meridian, and has the effects of relieving muscle and reducing fever, clearing rash, promoting body fluid and quenching thirst, and raising yang and stopping diarrhea. Kudzu root is rich in various chemical components, including (iso) flavonoids, terpenes, steroids, coumarins, kudzu phenolic glycosides and benzopyrans, etc., with pharmacological activities such as improving cardiovascular and cerebrovascular system, anti-oxidation, hypoglycemic, antipyretic, anti-inflammatory, alcohol detoxification and liver protection, estrogen-like effect, anti-osteoporosis and immune regulation. Kudzu root can affect the content of superoxide dismutase activity and malondialdehyde in mouse gastric mucosa, thereby playing a protective effect on gastric mucosa.

[0019] Poria cocos is the dried sclerotium of the fungus Poria cocos, which is derived from the Polyporaceae family. It often parasitizes on the roots of Masson pine and Pinus densiflora. Poria cocos contains a variety of ingredients, including triterpenes, polysaccharides, sterols, diterpenes, proteins, amino acids, organic acids and their esters, flavonoids and trace elements. Among them, polysaccharides and triterpenes are the main active ingredients that exert their medicinal effects. Polysaccharides are the main ingredients in Poria cocos, which have a variety of health benefits such as immunomodulation, diuresis, anti-inflammatory, liver protection, and calmness, and have certain nutritional properties.

[0020] Lily is an important yin-nourishing medicine in traditional Chinese medicine with a long history of use. It is also a nutritious food ingredient. Lily contains a variety of compounds such as polysaccharides, saponins, phenols, alkaloids, flavonoids, etc., which have biological activities such as antitussive and expectorant, sedative and hypnotic, immune regulation, antioxidant, antidepressant, anti-tumor, anti-inflammatory, and hypoglycemic effects.

[0021] Preferably, the mass ratio of the mixed plant powder, deionized water, cellulase and pectinase in step S2 is 50-60:800-1000:0.5-0.8:0.2-0.5, the temperature of the enzymatic hydrolysis is 40-50°C, and the time is 30-40min; the temperature of the extraction is 60-70°C, and the time is 1-2h.

[0022] In the present invention, polysaccharides and active ingredients in the three plant raw materials can be extracted by enzymatically hydrolyzing Pueraria root, Poria cocos and lily and then extracting them, thereby improving the protective effect of fermented tea on gastric mucosa.

[0023] Preferably, the carbon source in step S3 is composed of sucrose, lactose and inulin in a mass ratio of 5-7:3-5:2-3; based on the volume of the tea soup, the added amount of the carbon source is 70-80 g / L, the added amount of the plant extract is 20-30 g / L, the added amount of the pomegranate juice is 50-60 g / L, and the added amount of the polyglycerol fatty acid ester is 1-2 g / L.

[0024] In the present invention, the addition of a specific carbon source can, on the one hand, provide important nutrients for the growth of the composite strain and energy for microbial activity; on the other hand, the added inulin, as dietary fiber, can synergistically act with active substances such as polysaccharides in the plant extract, and the inulin and polysaccharides that are not completely consumed after fermentation enable the fermented tea to have the effect of regulating intestinal flora; the added polyglycerol fatty acid ester, as a surfactant, can change the surface tension of the fermentation liquid, thereby slowing down the formation of biofilm. Since the formation of biofilm requires the consumption of nutrients in the fermentation liquid, the added polyglycerol fatty acid ester can reduce the amount of biofilm generated, thereby improving the yield and efficacy of the fermented tea.

[0025] Preferably, the preparation method of the pomegranate juice in step S3 is as follows: fresh pomegranates and an equal weight of water are added into a juicer, crushed for 20-25 minutes, and filtered through a 100-mesh filter cloth to obtain the pomegranate juice.

[0026] In the present invention, pomegranate juice is rich in nutrients such as carbohydrates, amino acids, polyphenols, flavonoids, etc., and has high medicinal and edible value in traditional medicine. Pomegranate has multiple functions such as anti-oxidation, anti-inflammatory, antibacterial, and prevention of cardiovascular, diabetes and nervous system diseases. Fermenting pomegranate juice with tea soup together can not only improve the flavor of fermented tea, but also improve the conditioning function of fermented tea on the gastrointestinal tract, which is helpful to protect gastric mucosa and regulate intestinal health.

[0027] Preferably, the mixed bacteria in step S4 are composed of yeast, acetic acid bacteria, and Lactobacillus delbrueckii subspecies bulgaricus, and the mass ratio thereof is 10-15:10-15:5-10; and the inoculation amount of the mixed bacteria is 0.1-0.2% of the mass of the fermentation substrate.

[0028] In the present invention, by adding Lactobacillus delbrueckii subspecies bulgaricus, competition with acetic acid bacteria can be achieved, thereby reducing the production of bacterial film. At the same time, Lactobacillus delbrueckii subspecies bulgaricus can utilize inulin and polysaccharides in plant extracts to produce a large amount of beneficial substances such as short-chain fatty acids, thereby promoting the growth of Lactobacillus delbrueckii subspecies bulgaricus and increasing the acidity of fermented tea, thereby improving fermentation efficiency.

[0029] Preferably, the fermentation temperature in step S4 is 22-25° C., and the fermentation time is 7-9 days; during the fermentation process, ultrasonic treatment is performed every 12 hours, the ultrasonic treatment power is 200-300 W, and the time is 50-60 minutes.

[0030] In the present invention, by performing intermittent ultrasonic treatment during the fermentation process, not only can the materials in the fermentation liquid be mixed more evenly and the fermentation efficiency be improved, but the formation of the biofilm can also be interrupted, the thickness of the biofilm during the fermentation process can be reduced, and the yield of the fermented tea beverage can be increased.

[0031] The present invention also protects a fermented tea drink capable of protecting gastric mucosa and prepared by the method as described above.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The method for preparing a fermented tea beverage capable of protecting gastric mucosa provided by the present invention comprises adding a small amount of polyglycerol fatty acid ester as a surfactant to the raw materials, thereby changing the surface tension of the fermentation liquid, which may affect the formation of a biofilm. Meanwhile, the fermentation liquid is treated with ultrasound intermittently during the fermentation process, temporarily interrupting the biofilm formation process without affecting the overall fermentation, thereby further reducing the thickness of the biofilm and reducing the loss of nutrients in the fermentation liquid, thereby increasing the yield of the fermented tea beverage and the content of functional ingredients in the fermented tea beverage, and being suitable for industrial production.

[0034] (2) The fermented tea beverage capable of protecting gastric mucosa provided by the present invention is prepared by adding a carbon source in a specific ratio. By adding a certain amount of inulin as a fermentation substrate, it can not only synergistically enhance the proliferation of Lactobacillus delbrueckii subspecies bulgaricus with the polysaccharides in the plant extract, but also the large amount of short-chain fatty acids produced during the fermentation process increase the acidity of the fermented tea beverage and improve the fermentation efficiency.

[0035] (3) The fermented tea drink capable of protecting gastric mucosa provided by the present invention has pomegranate juice added thereto, which contains a large amount of nutrients such as polyphenols and flavonoids, and can repair gastrointestinal mucosal damage induced by external stimulation. In addition, flavonoids have anti-inflammatory effects and can regulate the normalization of inflammatory factors in the stomach and intestines. Thus, the prepared fermented tea drink has the effect of assisting in protecting gastric mucosa and promoting intestinal health, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is the fermented tea beverage product prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] In the present invention, the yeast is Kluyveromyces marxianus, purchased from Ruichu Biotechnology (Jiangsu) Co., Ltd. (strain number SHBCC D13658); the acetic acid bacteria is Acetobacter pasteurianus, purchased from Ruichu Biotechnology (Jiangsu) Co., Ltd. (CGMCC 1.1810); the Lactobacillus delbrueckii subspecies bulgaricus was purchased from Shanghai Collection Biotechnology Center (ATCC11842).

[0039] Example 1

[0040] A method for preparing a fermented tea drink capable of protecting gastric mucosa comprises the following steps:

[0041] S1. Add 13 g of green tea leaves into 1000 g of distilled water, heat to boiling, keep warm for 25 min, filter, and cool to room temperature to obtain tea soup;

[0042] S2, 12g of Pueraria root, 7g of Poria cocos, and 5g of lily were mixed evenly and then frozen and crushed at -40°C to obtain a mixed plant powder, and then 55g of the mixed plant powder was added to 900g of deionized water, followed by adding 0.7g of cellulase and 0.3g of pectinase, and enzymolysis was performed at 45°C for 35min. After the enzymolysis was completed, the enzyme was inactivated at 105°C, and the mixture was extracted at 65°C for 1.5h, filtered, and the filtrate was concentrated under reduced pressure at 20kPa to 1 / 4 of the volume to obtain a plant extract;

[0043] S3, adding 75g of carbon source, 25g of plant extract, 55g of pomegranate juice, and 1.5g of polyglycerol fatty acid ester to 1L of tea soup in step S1, stirring and mixing evenly, and sterilizing at 115°C for 15min to obtain a fermentation base;

[0044] S4. Inoculate the mixed bacteria into the fermentation base in step S3 at 0.15% of the mass of the fermentation base, and then ferment at 23°C for 8 days. Perform ultrasonic treatment every 12 hours during the fermentation process. The ultrasonic treatment power is 250 W and the time is 55 minutes. After the fermentation is completed, filter and sterilize to obtain the fermented tea.

[0045] Wherein, the carbon source in step S3 is sucrose, lactose, and inulin in a mass ratio of 6:4:2.5; the preparation method of the pomegranate juice is as follows: fresh pomegranates and water of equal weight are added to a juicer, crushed for 25 minutes, and filtered through a 100-mesh filter cloth to obtain the pomegranate juice;

[0046] The mixed bacteria in step S4 are composed of yeast, acetic acid bacteria, and Lactobacillus delbrueckii subspecies bulgaricus in a mass ratio of 13:13:8.

[0047] Example 2

[0048] A method for preparing a fermented tea drink capable of protecting gastric mucosa comprises the following steps:

[0049] S1. Add 12g of white tea leaves into 1000g of distilled water, heat to boiling, keep warm for 25min, then filter, and cool to room temperature to obtain tea soup;

[0050] S2, 11g of Pueraria root, 6g of Poria cocos, and 4g of lily were mixed evenly and then frozen and crushed at -40°C to obtain a mixed plant powder, and then 55g of the mixed plant powder was added to 900g of deionized water, followed by adding 0.6g of cellulase and 0.4g of pectinase, and enzymolysis was performed at 45°C for 35min. After the enzymolysis was completed, the enzyme was inactivated at 105°C, and the mixture was extracted at 65°C for 1.5h, filtered, and the filtrate was concentrated under reduced pressure at 25kPa to 1 / 4 of the volume to obtain a plant extract;

[0051] S3, adding 75g of carbon source, 25g of plant extract, 55g of pomegranate juice, and 1.5g of polyglycerol fatty acid ester to 1L of tea soup in step S1, stirring and mixing evenly, and sterilizing at 115°C for 15min to obtain a fermentation base;

[0052] S4. Inoculate the mixed bacteria into the fermentation base in step S3 at 0.15% of the mass of the fermentation base, and then ferment at 24°C for 7 days. Perform ultrasonic treatment every 12 hours during the fermentation process. The ultrasonic treatment power is 250 W and the time is 55 minutes. After the fermentation is completed, filter and sterilize to obtain the fermented tea.

[0053] Wherein, the carbon source in step S3 is sucrose, lactose, and inulin in a mass ratio of 6:4:2.5; the preparation method of the pomegranate juice is as follows: fresh pomegranates and water of equal weight are added to a juicer, crushed for 20 minutes, and filtered through a 100-mesh filter cloth to obtain the pomegranate juice;

[0054] The mixed bacteria in step S4 are composed of yeast, acetic acid bacteria, and Lactobacillus delbrueckii subspecies bulgaricus in a mass ratio of 12:12:6.

[0055] Example 3

[0056] A method for preparing a fermented tea drink capable of protecting gastric mucosa comprises the following steps:

[0057] S1. Add 10 g of black tea into 1000 g of distilled water, heat to boiling, keep warm for 25 min, then filter, and cool to room temperature to obtain tea soup;

[0058] S2, 10g of Pueraria root, 5g of Poria cocos, and 3g of lily were mixed and then frozen and crushed at -30°C to obtain a mixed plant powder, and then 50g of the mixed plant powder was added to 800g of deionized water, followed by adding 0.5g of cellulase and 0.5g of pectinase, and enzymolysis was performed at 40°C for 40min. After the enzymolysis was completed, the enzyme was inactivated at 105°C, and the mixture was extracted at 60°C for 2h, filtered, and the filtrate was concentrated under reduced pressure at 20kPa to 1 / 4 of the volume to obtain a plant extract;

[0059] S3, adding 70g of carbon source, 20g of plant extract, 50g of pomegranate juice, and 1g of polyglycerol fatty acid ester to 1L of tea soup in step S1, stirring and mixing evenly, and sterilizing at 115°C for 15min to obtain a fermentation base;

[0060] S4. Inoculate the mixed bacteria into the fermentation base in step S3 at 0.1% of the mass of the fermentation base, and then ferment at 22°C for 9 days. Perform ultrasonic treatment every 12 hours during the fermentation process. The ultrasonic treatment power is 200 W and the time is 60 minutes. After the fermentation is completed, filter and sterilize to obtain the fermented tea.

[0061] Wherein, the carbon source in step S3 is sucrose, lactose, and inulin in a mass ratio of 5:3:2; the preparation method of the pomegranate juice is as follows: fresh pomegranates and water of equal weight are added to a juicer, crushed for 20 minutes, and filtered through a 100-mesh filter cloth to obtain the pomegranate juice;

[0062] The mixed bacteria in step S4 are composed of yeast, acetic acid bacteria, and Lactobacillus delbrueckii subspecies bulgaricus in a mass ratio of 10:10:5.

[0063] Example 4

[0064] A method for preparing a fermented tea drink capable of protecting gastric mucosa comprises the following steps:

[0065] S1. Add 15 g of oolong tea leaves to 1000 g of distilled water, heat to boiling, keep warm for 30 min, then filter, and cool to room temperature to obtain tea soup;

[0066] S2, 13g of Pueraria root, 8g of Poria cocos, and 6g of lily were mixed evenly and then frozen and crushed at -50°C to obtain a mixed plant powder, and then 60g of the mixed plant powder was added to 1000g of deionized water, followed by adding 0.8g of cellulase and 0.2g of pectinase, and enzymolysis was performed at 50°C for 30min. After the enzymolysis was completed, the enzyme was inactivated at 105°C, and the mixture was extracted at 70°C for 1h, filtered, and the filtrate was concentrated under reduced pressure at 25kPa to 1 / 4 of the volume to obtain a plant extract;

[0067] S3, adding 80g of carbon source, 30g of plant extract, 60g of pomegranate juice, and 2g of polyglycerol fatty acid ester to 1L of tea soup in step S1, stirring and mixing evenly, and sterilizing at 115°C for 15min to obtain a fermentation base;

[0068] S4. Inoculate the mixed bacteria into the fermentation base in step S3 at 0.2% of the mass of the fermentation base, and then ferment at 25°C for 7 days. Perform ultrasonic treatment every 12 hours during the fermentation process. The ultrasonic treatment power is 200 W and the time is 50 minutes. After the fermentation is completed, filter and sterilize to obtain the fermented tea.

[0069] Wherein, the carbon source in step S3 is sucrose, lactose, and inulin in a mass ratio of 7:5:3; the preparation method of the pomegranate juice is as follows: fresh pomegranates and water of equal weight are added to a juicer, crushed for 25 minutes, and filtered through a 100-mesh filter cloth to obtain the pomegranate juice;

[0070] The mixed bacteria in step S4 are composed of yeast, acetic acid bacteria, and Lactobacillus delbrueckii subspecies bulgaricus in a mass ratio of 15:15:10.

[0071] Comparative Example 1

[0072] A method for preparing a fermented tea drink capable of protecting gastric mucosa comprises the following steps:

[0073] S1. Add 13 g of green tea leaves into 1000 g of distilled water, heat to boiling, keep warm for 25 min, filter, and cool to room temperature to obtain tea soup;

[0074] S2, 12g of Pueraria root, 7g of Poria cocos, and 5g of lily were mixed evenly and then frozen and crushed at -40°C to obtain a mixed plant powder, and then 55g of the mixed plant powder was added to 900g of deionized water, followed by adding 0.7g of cellulase and 0.3g of pectinase, and enzymolysis was performed at 45°C for 35min. After the enzymolysis was completed, the enzyme was inactivated at 105°C, and the mixture was extracted at 65°C for 1.5h, filtered, and the filtrate was concentrated under reduced pressure at 20kPa to 1 / 4 of the volume to obtain a plant extract;

[0075] S3, adding 75g of carbon source, 25g of plant extract, and 55g of pomegranate juice to 1L of tea soup in step S1, stirring and mixing evenly, and sterilizing at 115°C for 15min to obtain a fermentation base;

[0076] S4. Inoculate the mixed bacteria into the fermentation base in step S3 at 0.15% of the mass of the fermentation base, and then ferment at 23°C for 8 days. Perform ultrasonic treatment every 12 hours during the fermentation process. The ultrasonic treatment power is 250 W and the time is 55 minutes. After the fermentation is completed, filter and sterilize to obtain the fermented tea.

[0077] Wherein, the carbon source in step S3 is sucrose, lactose, and inulin in a mass ratio of 6:4:2.5; the preparation method of the pomegranate juice is as follows: fresh pomegranates and water of equal weight are added to a juicer, crushed for 25 minutes, and filtered through a 100-mesh filter cloth to obtain the pomegranate juice;

[0078] The mixed bacteria in step S4 are composed of yeast, acetic acid bacteria, and Lactobacillus delbrueckii subspecies bulgaricus in a mass ratio of 13:13:8.

[0079] Compared with Example 1, this comparative example does not add polyglycerol fatty acid ester in step S3.

[0080] Comparative Example 2

[0081] A method for preparing a fermented tea drink capable of protecting gastric mucosa comprises the following steps:

[0082] S1. Add 13 g of green tea leaves into 1000 g of distilled water, heat to boiling, keep warm for 25 min, filter, and cool to room temperature to obtain tea soup;

[0083] S2, 12g of Pueraria root, 7g of Poria cocos, and 5g of lily were mixed evenly and then frozen and crushed at -40°C to obtain a mixed plant powder, and then 55g of the mixed plant powder was added to 900g of deionized water, followed by adding 0.7g of cellulase and 0.3g of pectinase, and enzymolysis was performed at 45°C for 35min. After the enzymolysis was completed, the enzyme was inactivated at 105°C, and the mixture was extracted at 65°C for 1.5h, filtered, and the filtrate was concentrated under reduced pressure at 20kPa to 1 / 4 of the volume to obtain a plant extract;

[0084] S3, adding 75g of carbon source, 25g of plant extract, 55g of pomegranate juice, and 1.5g of polyglycerol fatty acid ester to 1L of tea soup in step S1, stirring and mixing evenly, and sterilizing at 115°C for 15min to obtain a fermentation base;

[0085] S4. Inoculate the mixed bacteria into the fermentation base in step S3 at 0.15% of the mass of the fermentation base, and then ferment at 23° C. for 8 days. After the fermentation is completed, filter and sterilize to obtain the fermented tea beverage.

[0086] Wherein, the carbon source in step S3 is sucrose, lactose, and inulin in a mass ratio of 6:4:2.5; the preparation method of the pomegranate juice is as follows: fresh pomegranates and water of equal weight are added to a juicer, crushed for 25 minutes, and filtered through a 100-mesh filter cloth to obtain the pomegranate juice;

[0087] The mixed bacteria in step S4 are composed of yeast, acetic acid bacteria, and Lactobacillus delbrueckii subspecies bulgaricus in a mass ratio of 13:13:8.

[0088] Compared with Example 1, this comparative example did not perform ultrasonic treatment in step S4.

[0089] Comparative Example 3

[0090] A method for preparing a fermented tea drink capable of protecting gastric mucosa comprises the following steps:

[0091] S1. Add 13 g of green tea leaves into 1000 g of distilled water, heat to boiling, keep warm for 25 min, filter, and cool to room temperature to obtain tea soup;

[0092] S2, adding 75g of carbon source, 55g of pomegranate juice, and 1.5g of polyglycerol fatty acid ester to 1L of tea soup in step S1, stirring and mixing evenly, and sterilizing at 115°C for 15min to obtain a fermentation base;

[0093] S3. Inoculate the mixed bacteria into the fermentation base in step S2 at 0.15% of the mass of the fermentation base, and then ferment at 23°C for 8 days. Perform ultrasonic treatment every 12 hours during the fermentation process. The ultrasonic treatment power is 250 W and the time is 55 minutes. After the fermentation is completed, filter and sterilize to obtain the fermented tea.

[0094] Wherein, the carbon source in step S2 is sucrose, lactose, and inulin in a mass ratio of 6:4:2.5; the preparation method of the pomegranate juice is as follows: fresh pomegranates and water of equal weight are added to a juicer, crushed for 25 minutes, and filtered through a 100-mesh filter cloth to obtain the pomegranate juice;

[0095] The mixed bacteria in step S4 are composed of yeast, acetic acid bacteria, and Lactobacillus delbrueckii subspecies bulgaricus in a mass ratio of 13:13:8.

[0096] Compared with Example 1, in this comparative example, no plant extract was added in step S2.

[0097] The biofilm thickness, polyphenol, alkaloid, total acid and lactic acid content of the fermented tea drinks in Examples 1-4 and Comparative Examples 1-3 were measured, wherein the detection method of tea polyphenols was referenced to GB / T 31740.2-2015 "Tea Products Part 2: Tea Polyphenols", the detection method of alkaloids was referenced to GB / T 8312-2013 "Determination of Tea Caffeine", the detection method of total acid was referenced to GB 12456-2021 "Determination of Total Acid in Foods of National Food Safety Standard" and the detection method of lactic acid was referenced to GB 5009.157-2016 "Determination of Organic Acid in Foods of National Food Safety Standard", and the results are shown in Table 1 below. The results are shown in Table 1 below:

[0098] Table 1 Biofilm thickness and content of various components in different groups of fermented tea drinks

[0099]

[0100]

[0101] As can be seen from Table 1 above, the total acid content of the fermented tea prepared in Examples 1-4 is not much different from that of the fermented tea prepared in Comparative Examples 1-2, indicating that the addition of polyglycerol fatty acid esters and ultrasonic treatment during the fermentation process have little effect on the fermentation, but the biofilm thickness in Examples 1-4 is significantly smaller than that in Comparative Examples 1-2, and the polyphenol content and alkaloid content are higher than those in Comparative Examples 1-2, indicating that the method for preparing fermented tea provided by the present invention can significantly reduce the formation of biofilm, thereby increasing the content of functional ingredients in the fermented tea.

[0102] The fermented tea prepared in Example 1 and Comparative Examples 1-3 was subjected to a mouse test to verify its gastric mucosal protective effect, as follows:

[0103] Experimental animals: 60 SPF SD rats, male, weighing 180-220 g.

[0104] Experimental method: Rats were randomly divided into 6 groups, 10 rats in each group, including a blank control group, a model control group, an example 1 group, a comparative example 1 group, a comparative example 2 group, and a comparative example 3 group. The example 1 group was gavaged with the fermented tea prepared in example 1, the comparative example 1 group was gavaged with the fermented tea prepared in comparative example 1, the comparative example 2 group was gavaged with the fermented tea prepared in comparative example 2, and the comparative example 3 group was gavaged with the fermented tea prepared in comparative example 3, and the gavage volume was 15mL / d. The blank control group and the model control group were given the same volume of purified water. After the last administration of the test substance, all animals were strictly fasted but not watered for 24h. Except for the blank control group, the animals in the other groups were gavaged with anhydrous ethanol, and the gavage volume was 1.0mL / kg.bw. After 1h, the rats were anesthetized by intraperitoneal injection of 20% ulanose solution at 6mL / kg.bw body weight, and bled to death. The whole stomach was exposed, the pylorus was ligated, and an appropriate amount of 10% formaldehyde solution was perfused (it was appropriate to fill the stomach with formaldehyde solution), fixed for 20 minutes, and then cut open along the greater curvature of the stomach, the contents were washed, the gastric mucosa was unfolded, and the length and width of the bleeding point or bleeding band were measured with a vernier caliper under a stereoscopic dissecting microscope or with the naked eye. Because the width represents the severity of the injury much greater than the length, double the points were scored. The scores were scored according to the standards in Table 2, and the results are shown in Table 3:

[0105] Table 2 Gross observation scoring criteria for acute anhydrous ethanol injury

[0106]

[0107] Observation indexes: The degree of gastric mucosal injury in each experimental group was expressed by injury incidence (%), injury score index and injury inhibition rate (%). Injury incidence (%) = number of rats with bleeding or ulcers in a group / number of rats in the group × 100%; injury score index = total injury score of the group / number of animals in the group; injury inhibition rate (%) = (AB) / A × 100% (A and B are the injury scores of the model group and the experimental group, respectively).

[0108] Table 3 Effects of fermented tea on gastric mucosal damage induced by anhydrous ethanol

[0109] Group Number of animals Damage Points Injury incidence % Damage inhibition rate % Blank control group 10 - - - Model control group 10 <![CDATA[35.2±9.6 # ]]> 100 - Example 1 Group 10 16.4±6.2** 100 53.4 Comparative Example 1 10 20.6±7.5** 100 41.5 Comparative Example 2 10 19.1±7.3** 100 45.7 Comparative Example 3 10 26.7±8.1* 100 24.1

[0110] Note: # indicates significant difference compared with the normal control group (P<0.01); ** compared with the model control group P﹤0.01, * compared with the model control group P﹤0.05

[0111] As shown in Table 3, compared with the blank control group, the injury score of the model control level increased significantly (P<0.01), indicating that the model was successfully established; compared with the model control group, the acute alcohol injury score of the rat gastric mucosa in the Example 1 group and the Comparative Example 1-2 group decreased significantly (P<0.01), indicating that the fermented tea prepared by the present invention has a significant protective effect on the gastric mucosal injury of rats caused by anhydrous ethanol. And the injury inhibition rate of the Example 1 group is higher than that of the Comparative Example 1-3 group, indicating that the preparation method of the present invention makes the fermented tea drink have a better effect.

[0112] After the naked eye scoring is completed, pathological histological observation and scoring are performed: the most severely damaged part of the gastric mucosa of each rat is cut off (normal tissue is slightly retained around it), fixed in 10% formaldehyde solution, routinely prepared, stained, and observed. The scoring method for this project is: the degree of congestion, bleeding, and mucosal cell degeneration and necrosis in the entire mucosal epithelial layer is divided into 5 levels, with congestion weighted as 1, bleeding weighted as 2, and epithelial cell degeneration and necrosis weighted as 3. The scoring criteria and the total score formula of the lesion are shown in Table 4, and the results are shown in Table 5:

[0113] Table 4 Scoring criteria for histopathological examination of acute gastric mucosal injury

[0114]

[0115] Table 5 Scoring results of histopathological examination of acute gastric mucosal injury

[0116]

[0117]

[0118] Note: # indicates significant difference compared with the normal control group (P<0.01); ** compared with the model control group P﹤0.01, * compared with the model control group P﹤0.05

[0119] As can be seen from Table 5, compared with the blank control group, the injury score of the model control level was extremely significantly increased (P<0.01), indicating that the model was successfully established; compared with the model control group, the total score of pathological histological lesions of acute alcohol injury to gastric mucosa of rats in Example 1 group and Comparative Example 1-2 groups was extremely significantly reduced (P<0.01), indicating that they had obvious improvement effects on gastric mucosal injury, and the total score of lesions in Example 1 group was lower than that in Comparative Example 1-3 groups, indicating that the fermented tea prepared by the present invention has better effects.

[0120] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a fermented tea drink capable of protecting gastric mucosa, characterized in that: The following steps are involved: S1. Add tea leaves to distilled water, heat to boiling, keep warm, filter, and cool to room temperature to obtain tea soup; S2, mixing kudzu root, poria cocos and lily evenly and then freezing and crushing to obtain mixed plant powder, then adding the mixed plant powder into deionized water, followed by adding cellulase and pectinase to perform enzymolysis, inactivating the enzyme after the enzymolysis, extracting, filtering, and concentrating the filtrate under reduced pressure to 1 / 4 of the volume to obtain a plant extract; S3, adding the carbon source, plant extract, pomegranate juice, and polyglycerol fatty acid ester to the tea soup in step S1, stirring and mixing evenly, and sterilizing at 115° C. for 15 min to obtain a fermentation base; S4, inoculating the mixed bacteria into the fermentation base in step S3, followed by fermentation, filtering and sterilizing after the fermentation is completed to obtain the fermented tea beverage.

2. The preparation method according to claim 1, characterized in that: The tea leaves in step S1 are one or more of black tea, green tea, white tea and oolong tea; the mass ratio of the tea leaves to distilled water is 10-15:1000.

3. The preparation method according to claim 1, characterized in that: The insulation time in step S1 is 20-30 minutes.

4. The preparation method according to claim 1, characterized in that: In step S2, the mass ratio of kudzu root, poria cocos and lily is 10-13:5-8:3-6, and the temperature of the freezing and crushing is -30 to -50°C.

5. The preparation method according to claim 1, characterized in that: The mass ratio of the mixed plant powder, deionized water, cellulase and pectinase in step S2 is 50-60:800-1000:0.5-0.8:0.2-0.5, the temperature of the enzymolysis is 40-50°C, and the time is 30-40min; the temperature of the extraction is 60-70°C, and the time is 1-2h.

6. The preparation method according to claim 1, characterized in that: The carbon source in step S3 is composed of sucrose, lactose and inulin in a mass ratio of 5-7:3-5:2-3; based on the volume of the tea soup, the added amount of the carbon source is 70-80g / L, the added amount of the plant extract is 20-30g / L, the added amount of the pomegranate juice is 50-60g / L, and the added amount of the polyglycerol fatty acid ester is 1-2g / L.

7. The preparation method according to claim 1, characterized in that: The preparation method of the pomegranate juice in step S3 is as follows: fresh pomegranates and water of equal weight are added into a juicer, crushed for 20-25 minutes, and filtered through a 100-mesh filter cloth to obtain the pomegranate juice.

8. The preparation method according to claim 1, characterized in that: The mixed bacteria in step S4 are composed of yeast, acetic acid bacteria, and Lactobacillus delbrueckii subspecies bulgaricus, and the mass ratio thereof is 10-15:10-15:5-10; and the inoculation amount of the mixed bacteria is 0.1-0.2% of the mass of the fermentation substrate.

9. The preparation method according to claim 1, characterized in that: The fermentation temperature in step S4 is 22-25° C., and the fermentation time is 7-9 days. During the fermentation process, ultrasonic treatment is performed every 12 hours, the ultrasonic treatment power is 200-300 W, and the time is 50-60 minutes.

10. A fermented tea drink capable of protecting gastric mucosa prepared by the method according to any one of claims 1 to 9.

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