Preparation method of dendrobium leaf-Kangpu tea

Abstract

The invention provides a preparation method of dendrobium leaf-Kangpu tea, which comprises the following steps: crushing dendrobium leaves, adding cellulase and pectinase for enzymolysis treatment, mixing with tea leaves and purified water, heating and boiling, cooling, filtering to remove residues to obtain a leaching solution, and fermenting with a kombucha solution to obtain the Kangpu tea. The obtained Kangpu tea is simple and efficient in processing and making method, unique in flavor, rich in bubbles and rich in nutrition, and can be put into industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and in particular relates to a method for preparing dendrobium leaf-kombucha. Background Art

[0002] Kombucha is a fermented tea beverage that is naturally fermented from the symbiotic culture of bacteria and yeast and the fermentation matrix of sugar tea. It has a history of more than two thousand years and is also known as "red tea fungus" or "Haibao". Kombucha contains three probiotics that are beneficial to the human body: yeast, acetic acid bacteria and lactic acid bacteria. It also contains rich digestive enzymes, organic acids, vitamin B group, antioxidants and trace minerals, which play a role in promoting digestion, enhancing the immune system, anti-oxidation and detoxification. At present, in the traditional method of making kombucha, black tea is used as the main raw material, and the tea is filtered and fermented. The products produced by this method have bad flavor problems such as sourness and irritation, resulting in uneven quality and poor consumer acceptance. Therefore, developing new kombucha flavors is an urgent problem to be solved.

[0003] Dendrobium candidum is a precious Chinese medicinal material. It is a perennial herb belonging to the genus Dendrobium of the Orchidaceae family. Its dried stems can be used as medicine. Due to its unique growth environment and medicinal effects, it is known as the first of the "Nine Immortal Grasses". With people's increasing attention to health and a new understanding of traditional medicinal materials, the application and research of Dendrobium candidum is also deepening. However, the current utilization of Dendrobium is mostly concentrated on Dendrobium stems, and the utilization rate of Dendrobium leaves is obviously insufficient. Dendrobium leaves are rich in health care ingredients such as polysaccharides and polyphenols, but they have a heavy green smell and high water content, and are poorly accepted by consumers. Therefore, it is of great significance to use the fermentation of kombucha to balance the flavor of Dendrobium leaves, make full use of Dendrobium candidum resources, and expand product categories.

[0004] Chinese patent publication number CN114794269A discloses a fruit-flavored kombucha beverage and a preparation method thereof, comprising: adding kombucha strain liquid to tea sugar water, fermenting and sterilizing to obtain a primary fermentation liquid; then adding pretreated fruit juice to the primary fermentation liquid, adding lactic acid bacteria seed liquid, fermenting to obtain a secondary fermentation liquid; finally, adding yeast seed liquid to the secondary fermentation liquid, fermenting to obtain the fruit-flavored kombucha beverage. Although this method emphasizes the conversion of phenolic compounds into free forms with more hydroxyls through step-by-step fermentation, thereby enhancing its antioxidant activity and nutritional value, and adding fruit juice and lactic acid bacteria to enhance the flavor and color, this method adds fruit juice, lactic acid bacteria, and yeast for step-by-step fermentation, which is complicated and cumbersome to operate, has a long production cycle, and is not conducive to centralized production.

[0005] Chinese patent publication number CN116998566 A discloses a fucoidan kombucha nutrient beverage and a preparation method thereof, wherein the raw materials include water, oligofructose, lychee concentrated juice, selenium-enriched black fungus peptide, fucoidan, calcium lactate, pectin, vitamin C, sodium hyaluronate, and instant black tea powder, and the above raw materials are homogenized, filtered, and sterilized, and then the kombucha fermentation liquid is added for homogenization and sterilization to obtain the product. Although the method significantly improves the stability, flavor, taste, aftertaste, and anti-fatigue indicators compared with the prior art, a large amount of exogenous excipients are added to the product, and the operation steps are complicated, which is not conducive to large-scale production. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a method for making Dendrobium officinale-kombucha through relevant research on Dendrobium officinale and Kombucha fermentation. The method adopts Dendrobium leaf pretreatment processing, optimizes the Dendrobium leaf-tea ratio, adds natural honey, and utilizes red tea fermentation to improve the flavor of Dendrobium officinale products and increase the content of beneficial ingredients. No additional auxiliary materials are added, thereby better meeting people's demand for natural health products.

[0007] To achieve the purpose of the invention, the present invention adopts the following technical solutions: A method for preparing dendrobium leaf-kombucha comprises the following steps: S1: Select fresh Dendrobium leaves without disease, rot or yellow leaves, rub and wash, remove dust and impurities, drain and spread, and then heat-kill after there is no water stain on the leaves; S2: The treated Dendrobium leaves were crushed and then enzymatically treated with cellulase and pectinase; S3: mixing the dendrobium leaves and tea leaves treated in S2 with purified water in a certain proportion and heating and boiling, filtering and removing residues after cooling to obtain an extract, and adding honey in a certain proportion to obtain a dendrobium leaf-tea-honey mixture; S4: preparing a kombucha fungus liquid, and activating the kombucha fungus to obtain a kombucha fungus liquid; S5: fermentation: the kombucha fungus liquid obtained in S4 is added to the mixed liquid of dendrobium leaves, tea leaves and honey obtained in step S3, and then mixed evenly, and then placed in a sterilized fermentation tank for static fermentation to obtain the kombucha tea.

[0008] Furthermore, the dendrobium leaves described in S1 are stir-fried at a temperature of 180-220° C. for high temperature sterilization, and are immediately spread out to cool after sterilization for 3-5 minutes.

[0009] Furthermore, the dendrobium leaves described in S2 need to be crushed, ground and homogenized, and 1-2% cellulase and 2-3% pectinase based on the weight of the dendrobium leaves are added and mixed before enzymolysis. The enzymolysis temperature is 40-60° C. and the enzymolysis time is 2-3 h. After enzymolysis, the mixture is sterilized and set aside.

[0010] Furthermore, the enzyme activity of the cellulase added in S2 is 50-100 U / mg; the enzyme activity of the pectinase added is 400-800 U / mg.

[0011] Furthermore, the tea leaves described in S3 are one or more of the six major types of tea.

[0012] Furthermore, the honey described in S3 is natural nectar, including but not limited to jujube honey, osmanthus honey, litchi honey, and multi-flower honey.

[0013] Furthermore, the mass ratio of the dendrobium leaves and tea leaves added in S3 is 0.25-1:1; the mass volume ratio of the dendrobium leaves-tea leaves to pure water is 1:100-200g / mL; and the amount of honey added in S3 is 10-20g per 100mL of the extract.

[0014] Furthermore, the kombucha activation step in S4 includes: inoculating the kombucha into a YPD liquid culture medium, pre-culturing at 37°C and 200 r / min for 12 h as a seed solution, and then inoculating into a shake flask containing a YPD liquid culture medium at an inoculum rate of 0.1-0.5%, culturing at 37°C and 200 r / min for 24 h, and the bacterial concentration is not less than 1.0×10 8 CFU / mL, the obtained bacterial liquid is the Kombucha bacterial liquid.

[0015] Furthermore, 5 to 10 mL of kombucha solution is added to every 100 mL of the dendrobium leaf-tea-honey mixture in S5.

[0016] Furthermore, the fermentation temperature described in S5 is 25-32° C.; and the fermentation time is 10-15 days.

[0017] Furthermore, the solution after the fermentation described in S5 is filtered and impurities are removed to obtain the Dendrobium leaf-kombucha.

[0018] Furthermore, the total sugar content of the dendrobium leaf-kombucha is between 23.32 and 78.83 mg / mL; and the pH value is lower than 4.0.

[0019] The invention provides a dendrobium-kombucha fermented product prepared by the method.

[0020] The invention provides the dendrobium-kombucha fermented product, and the fermented product includes a beverage and a health product.

[0021] In the Dendrobium-kombucha fermentation process, the present invention utilizes red tea fungus to improve the flavor quality of Dendrobium officinale, preserves the effective ingredients therein to the maximum extent, utilizes natural honey to provide a carbon source for the proliferation of fermentation bacteria while introducing a floral flavor, and simultaneously selects static fermentation that is beneficial to the stability of the tissue structure, and is also beneficial to the stable fermentation of the thick bacterial film floating on the upper layer of the fermentation liquid.

[0022] The beneficial effects of the present invention are embodied in: 1. Use red tea fungus to ferment dendrobium leaf kombucha to improve the flavor quality of dendrobium leaf and increase its effective ingredients; 2. The leaves of Dendrobium are thick and leathery, which is not conducive to the release of beneficial ingredients. The enzymatic hydrolysis of cellulase and pectinase can transform the insoluble cellulose of Dendrobium leaves into glucose, a carbon source that can be directly used by fermentation microorganisms, improve the fermentation effect, and promote the rupture of the cell wall of Dendrobium leaves, thereby increasing the release of beneficial ingredients and enhancing the health care effect. 3. Use natural honey to provide the carbon source for bacterial reproduction, which improves the flavor and increases the beneficial health care ingredients of honey. Avoid the unfriendly and monotonous flavor of processed carbon sources; 4. The present invention expands the utilization scope of Dendrobium officinale resources, avoids the waste of Dendrobium leaf resources, and enhances the effective utilization of Dendrobium leaves. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a graph showing the pH changes in Dendrobium leaf-Kombucha; Figure 2 This is a graph showing the changes in polyphenol content in Dendrobium leaf-Kombucha; Figure 3 This is a graph showing the changes in total sugar content in Dendrobium leaf-Kombucha; Figure 4 Different raw material ratios of Dendrobium leaf-Kombucha. DETAILED DESCRIPTION

[0024] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0025] Unless otherwise specified, the experimental methods used in the examples are all conventional methods; the materials and reagents used, unless otherwise specified, are all reagents and materials available from commercial sources.

[0026] To activate the kombucha, the kombucha was inoculated into YPD liquid culture medium, pre-cultured at 37°C and 200 r / min for 12 h to prepare a primary seed solution, and then inoculated into a shake flask containing YPD liquid culture medium at an inoculum rate of 0.1-0.5%, and cultured at 37°C and 200 r / min for 24 h. The bacterial concentration was not less than 1.0×108 CFU / mL, and the obtained bacterial solution was the kombucha bacterial solution. Example 1

[0027] The fresh dendrobium leaves without disease, rot and yellow leaves are preferably rubbed and washed, dust and impurities are removed, and the water is drained and spread. After the leaves show no water stains, they are stir-fried at 180-220°C, and the leaves are immediately cooled for 3-5 minutes, then crushed and ground into a homogenous slurry. 100g is taken, 1g of cellulase and 2g of pectinase are added, and the temperature is 40°C. After enzymolysis for 2 hours, sterilization is performed. It is mixed with black tea according to a mass ratio of 0.25:1, 100 times the volume of pure water is added, soaked and boiled to obtain a mixed leaching liquid; after cooling to room temperature, filtration and slag removal, osmanthus honey is added to obtain a dendrobium leaf-tea-honey mixed liquid, and the amount of honey added is 10g per 100mL of mixed leaching liquid; 5mL of red tea fungus liquid is added to each 100mL of dendrobium leaf-tea-honey mixed liquid, and the mixture is mixed evenly, and fermented for 10 days at 25°C in a sterilized fermentation tank, and the kombucha is obtained after filtering and removing impurities.

[0028] The enzyme activity of the added cellulase is 50-100 U / mg; the enzyme activity of the added pectinase is 400-800 U / mg.

[0029] The black tea in Example 1 can be replaced by green tea, oolong tea, yellow tea, dark tea, white tea or two or more thereof. Example 2

[0030] The fresh dendrobium leaves without disease, rot and yellow leaves are preferably rubbed and washed, dust and impurities are removed, and the water is drained and spread out. After the leaves are free of water stains, they are stir-fried at 180-220°C, cooled immediately after being sterilized for 3-5 minutes, and then ground into a homogenous slurry. 100g of the leaves are taken, 2g of cellulase and 3g of pectinase are added, and the temperature is 60°C. After enzymolysis for 3 hours, they are sterilized, and they are mixed with green tea in a mass ratio of 0.5:1, and 150 times the volume of pure water is added, and the mixture is soaked and boiled to obtain a mixed leaching liquid; after cooling to room temperature, filtration and slag removal, candied jujube nectar is added to obtain a dendrobium leaf-tea-honey mixed liquid, and the amount of honey added is 15g per 100mL of the mixed leaching liquid; 7.5mL of red tea fungus liquid is added to every 100mL of the dendrobium leaf-tea-honey mixed liquid, and the mixture is evenly mixed, and the mixture is fermented in a sterilized fermentation tank at 28°C for 12 days, and the kombucha is obtained after filtering and removing impurities.

[0031] The enzyme activity of the added cellulase is 50-100 U / mg; the enzyme activity of the added pectinase is 400-800 U / mg.

[0032] The green tea in Example 2 can be replaced by black tea, oolong tea, yellow tea, dark tea, white tea or two or more thereof. Example 3

[0033] The fresh dendrobium leaves without disease, rot and yellow leaves are preferably rubbed and washed, dust and impurities are removed, and the water is drained and spread. After the leaves show no water stains, they are stir-fried at 180-220°C, and the leaves are immediately cooled for 3-5 minutes, then crushed and ground into a homogenous slurry, 100g is added with 2.5g of cellulase and 2.5g of pectinase, and the temperature is 50°C, and the enzymolysis is sterilized after 3 hours. It is mixed with black tea in a mass ratio of 1:1, 200 times the volume of pure water is added, soaked and boiled to obtain a mixed leaching liquid; after cooling to room temperature, filtration and slag removal, litchi honey is added to obtain a dendrobium leaf-tea-honey mixed liquid, and the amount of honey added is 20g per 100mL of mixed leaching liquid; 10mL of red tea fungus liquid is added to each 100mL of dendrobium leaf-tea-honey mixed liquid, and the mixture is mixed evenly, and the mixture is fermented at 32°C in a sterilized fermentation tank for 15 days, and the kombucha is obtained after filtering and removing impurities.

[0034] The enzyme activity of the added cellulase is 50-100 U / mg; the enzyme activity of the added pectinase is 400-800 U / mg.

[0035] The dark tea in Example 3 can be replaced by black tea, oolong tea, green tea, dark tea, white tea or two or more thereof.

[0036] Comparative Example 1 Reference will be made to Example 1, except that the dendrobium leaves were not subjected to high temperature fixation.

[0037] Comparative Example 2 Reference will be made to Example 2, except that no honey was added to the mixed infusion.

[0038] Comparative Example 3 Reference will be made to Example 3, except that the mass ratio of dendrobium leaves to tea leaves is 0.1:1.

[0039] Comparative Example 4 Reference will be made to Example 3, except that the mass ratio of dendrobium leaves to tea leaves is 1.5:1.

[0040] The kombucha obtained in Examples 1 to 3 and Comparative Examples 1 to 4 was analyzed as follows: Ten volunteer judges (5 males, 5 females, aged 20-32 years old) were selected to conduct an overall sensory evaluation. The sensory evaluation indicators include: flavor, color, aroma, and mouthfeel. The score of each scoring indicator is set to 1-5 points. The higher the score, the better the quality. The sensory scores were averaged, and the results are shown in Table 1.

[0041] Table 1 Sensory scores of Dendrobium leaf-Kombucha tea with different treatments

[0042] According to the sensory score table in Table 1, the kombucha obtained in Examples 1 to 3 all achieved higher ratios in taste, aroma and color. Comparative Example 1 affected the aroma score due to the high green smell of the dendrobium leaf itself. Comparative Example 2 showed that the addition of honey significantly affected the taste, aroma and acceptance of kombucha. Since there was no energy carbon source directly from honey, the fermentation degree was insufficient and the overall score was low. The scores of Comparative Examples 3 to 4 showed that the ratio of dendrobium leaf to tea leaves significantly affected the taste, aroma and color of kombucha. In general, the judges had a high overall acceptance of dendrobium leaf-kombucha.

[0043] pH determination: Take 5 mL of sample and measure the pH of the solution using a calibrated pH meter. The results are shown in Figure 1 pH is an important evaluation index of Kombucha. The pH change caused by fermentation is mainly affected by the content of added Dendrobium leaf and honey. The pH value of Dendrobium leaf-Kombucha obtained was lower than 4, and the lowest pH value reached 2.76 when 10g of white sugar was added.

[0044] Polyphenol content detection method: Take 1.0 mL of fermentation broth, add 2.5 mL of Folin phenol reagent, shake well, add 2.5 mL of 15% Na2CO3 solution, add water to the scale, shake well. Place in a 40℃ water bath for 60 minutes, let stand and cool for 20 minutes, use an ultraviolet spectrophotometer to measure the absorbance value at a wavelength of 778nm, use gallic acid as the reference substance to develop a standard curve, and use the Folin phenol method to determine the polyphenol content. The results are as follows: Figure 2 The total amount of polyphenols in the obtained dendrobium leaf-kombucha is proportional to the content of the added dendrobium leaf, which is the key component of the flavor and nutritional quality of dendrobium leaf-kombucha. The polyphenol content ranges from 57.2 to 420.6 mg / L.

[0045] Total sugar content detection method: Pipette 500μL standard working solution and fermentation liquid, add 500μL 5% phenol solution, add 2.5mL concentrated sulfuric acid, mix well, react for 10-20min, measure the absorbance at 495nm with a UV spectrophotometer, and formulate a standard curve with glucose as the reference substance. The results are as follows: Figure 3 As shown. Dendrobium leaves are rich in polysaccharides. The total sugar content of kombucha is proportional to the content of dendrobium leaves and honey added. Honey, as the main energy source of kombucha, is the guarantee for the smooth fermentation. The total sugar content of dendrobium leaf-kombucha obtained is between 23.32 and 78.83 mg / mL.

[0046] Dendrobium leaf-kombucha processed by the process Figure 4 The dendrobium leaf-kombucha with different raw material ratios showed different colors. The kombucha had rich bubbles and a typical kombucha flavor.

[0047] The above research shows that fermenting the Dendrobium leaf-tea-sugar system with black tea fungi can improve its flavor, increase the content of its functional ingredients, and improve its nutritional value, showing extremely broad development prospects and practical application potential.

Claims

1. A method for preparing dendrobium leaf-kombucha, characterized in that: The steps include: S1: Select fresh Dendrobium leaves without disease, rot or yellow leaves, rub and wash, remove dust and impurities, drain and spread, and then heat-kill after there is no water stain on the leaves; S2: The treated Dendrobium leaves were crushed and then enzymatically treated with cellulase and pectinase; S3: mixing the dendrobium leaves and tea leaves treated in S2 with purified water in a certain proportion and heating and boiling, filtering and removing residues after cooling to obtain an extract, and adding honey in a certain proportion to obtain a dendrobium leaf-tea-honey mixture; S4: preparing a kombucha fungus liquid, and activating the kombucha fungus to obtain a kombucha fungus liquid: S5: fermentation: the kombucha fungus liquid obtained in S4 is added to the mixed liquid of dendrobium leaves, tea leaves and honey obtained in step S3, and the mixture is put into a sterilized fermentation tank for static fermentation after mixing, so as to obtain the kombucha tea.

2. The method for making Dendrobium leaf-kombucha according to claim 1, characterized in that: The dendrobium leaves described in S1 are stir-fried at a temperature of 180-220° C. to kill the green leaves, and then immediately spread to cool after killing the green leaves for 3-5 minutes.

3. The method for making Dendrobium leaf-kombucha according to claim 1, characterized in that: The dendrobium leaves described in S2 need to be crushed and ground into a homogenate, and 1-2% of the weight of the dendrobium leaves and 2-3% of the weight of the dendrobium leaves are added and mixed before enzymolysis. The enzymolysis temperature is 40-60° C. and the enzymolysis time is 2-3 hours. After enzymolysis, the mixture is sterilized for use.

4. The method for making Dendrobium leaf-kombucha according to claim 1, characterized in that: The enzymatic activity of the cellulase described in S2 is 50-100 U / mg; the enzymatic activity of the pectinase is 400-800 U / mg; the tea described in S3 is one or more of the six major tea categories; the honey described in S3 is natural nectar.

5. The method for making Dendrobium leaf-kombucha according to claim 1, characterized in that: The added mass ratio of the dendrobium leaves and tea leaves in S3 is 0.25-1:1; the mass volume ratio of the dendrobium leaves-tea leaves to pure water is 1:100-200g / mL; the amount of honey added in S3 is 10-20g per 100mL of the extract.

6. The method for making Dendrobium leaf-kombucha according to claim 1, characterized in that: The kombucha activation step in S4 includes: inoculating the kombucha into a YPD liquid culture medium, pre-culturing at 37°C and 200 r / min for 12 h as a seed solution, then inoculating into a shake flask containing a YPD liquid culture medium at an inoculum rate of 0.1-0.5%, culturing at 37°C and 200 r / min for 24 h, and the bacterial concentration is not less than 1.0×10 8 CFU / mL, the obtained bacterial liquid is the Kombucha bacterial liquid.

7. The method for making Dendrobium leaf-kombucha according to claim 1, characterized in that: In S5, 5 to 10 mL of kombucha solution is added to every 100 mL of the dendrobium leaf-tea-honey mixture; the fermentation temperature is 25 to 32° C.; the fermentation time is 10 to 15 days; after the fermentation is completed, the solution is filtered and impurities are removed to obtain the dendrobium leaf-kombucha.

8. The method for preparing Dendrobium leaf-kombucha according to any one of claims 1 to 7, characterized in that The total sugar content of the dendrobium leaf-kombucha is between 23.32 and 78.83 mg / mL; and the pH value is lower than 4.

0.

9. The Dendrobium-Kombucha fermented product prepared by the method according to any one of claims 1 to 8.

10. A beverage or health product containing the Dendrobium-Kombucha fermented product according to claim 9.

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