Monascus fermented sweet tea and preparation method thereof
By optimizing the fermentation conditions and parameters of sweet tea fermented by Monascus, the problems of unstable microbial growth and metabolism during the fermentation process were solved, the biological activity and appearance quality of the sweet tea were improved, and a controllable production process was formed.
Patent Information
- Application Number
- CN202510814436.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-18
- Publication Date
- 2025-09-19
AI Technical Summary
The existing Monascus fermentation sweet tea technology has imprecise control of fermentation conditions, which affects microbial growth and metabolism, resulting in insufficient extraction and conversion of sweet tea's active ingredients. There is a lack of systematic research and optimization of key parameters, and the post-fermentation processing process is not perfect.
The method of fermenting sweet tea with Monascus purpureus is adopted, and the humidity and temperature are controlled, fermentation is carried out in the dark, and fermentation parameters such as bacterial liquid concentration, inoculation amount, fermentation time, etc. are optimized. Combined with drying treatment, the Monascus purpureus fermented sweet tea is prepared.
The biological activity and appearance quality of sweet tea are improved, the bitter taste is reduced, the color of the tea leaves is reddish, the taste is sweeter, and the soup color is bright, forming an adjustable production process to ensure product quality.
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Figure CN120660771A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of fermented tea and medicine, in particular to sweet tea fermented by Monascus and a preparation method thereof. Background Art
[0002] Sweet tea, grown from the leaves of Lithocarpus litseifolius (Hance) Chun, a plant of the Fagaceae family, combines the functions of medicine, tea, and sugar. Lithocarpus litseifolius boasts health benefits such as "one health booster, one moisturizer, and one wake-up call (stomach invigoration, lung moistening, and hangover sobering)"; "three preventative measures (preventing coronary heart disease, arthritis, and colds)"; "three anti-oxidants (anti-cancer, anti-allergy, and anti-oxidation)"; and "four lowering measures (lowering blood pressure, blood sugar, blood lipids, and cholesterol)" and is known as the "cordyceps growing on a tree." In my country, Lithocarpus litseifolius is abundant in wild resources and is found in Jiangxi, Guangxi, Hunan, Yunnan, Sichuan, and Chongqing. Chongqing, in particular, boasts high yields and excellent quality, making it the primary production area for sweet tea. Lithocarpus litseifolius leaves have a distinct sweetness, hence the name "sweet tea."
[0003] Microbial fermentation is not only energy-saving and environmentally friendly, but also preserves the healthy properties of the tea itself to the greatest extent. Fermented tea usually has a mellower taste and a special aroma. Fermented tea is also gentler on the gastrointestinal tract than unfermented tea, and will produce new active substances that are beneficial to the human body. Monascus pigment is a natural pigment synthesized by fermentation of filamentous fungi of the genus Monascus. Monascus pigment has special physiological functions in the metabolic process of Monascus and can be used as an energy storage substance. Monascus can assimilate the pigment and delay cell aging and autolysis. Monacolin K is an active substance isolated from Monascus that inhibits cholesterol synthesis.
[0004] Therefore, Monascus is selected as the fermentation bacteria for Duoshuike sweet tea. During its growth and reproduction process, it can produce Monascus pigments with multiple biological activities, which can not only improve the appearance quality of Duoshuike sweet tea, but also increase the biological activity of sweet tea, thus obtaining a health product with better functionality.
[0005] The existing Monascus fermentation technology for sweet tea still has some shortcomings. First, the control of fermentation conditions is not precise enough, which leads to adverse effects on the growth and metabolism of microorganisms during the fermentation process, thereby affecting the extraction and conversion of the effective ingredients of sweet tea. Secondly, there is a lack of systematic research and optimization of key parameters in the fermentation process (such as fermentation temperature, time, inoculation amount, humidity, etc.). In addition, the existing technology pays insufficient attention to the post-fermentation processing process. How to effectively separate and purify the active ingredients in the fermentation product is also an important factor restricting the further development of sweet tea fermentation products.
[0006] The present invention will provide a new solution for the deep processing of sweet tea; at the same time, it establishes the process parameters for fermenting sweet tea, which will provide guidance for the industrial production of fermented sweet tea products; and also lay a good foundation for the advent of sweet tea-related functional products. Summary of the Invention
[0007] The purpose of the present invention is to solve the shortcomings of the prior art and to provide a monascus fermented sweet tea and a preparation method thereof.
[0008] In order to achieve the above object, the present invention adopts the following technical solutions:
[0009] The invention discloses a sweet tea fermented by monascus. The raw materials of the sweet tea fermented by monascus include sweet tea and monascus.
[0010] A monascus fermented sweet tea and a preparation method thereof. The method for preparing the monascus fermented sweet tea comprises the following steps: inoculating monascus into the sweet tea, controlling the humidity and temperature, and fermenting in the dark to obtain the monascus fermented sweet tea.
[0011] Preferably, the tea leaves of the sweet tea are sterilized at 121° C. for 15-20 minutes before inoculation.
[0012] Preferably, in the preparation method, the fermentation humidity is controlled by adding sterile water, wherein the volume of the sterile water is 5%-20% of the dry weight of the sweet tea leaves.
[0013] Preferably: the concentration of the Monascus bacteria solution is not less than 3.0×10 8 CFU / mL.
[0014] Preferably, the inoculation amount of the Monascus bacterial solution is controlled in such a manner that the volume of the added bacterial solution is 5%-20% of the dry weight of the sweet tea leaves.
[0015] Preferably, the fermentation temperature is 30-39° C., and the fermentation time is 8-14 days.
[0016] Preferably, the Monascus purpureus is used, with a preservation number of CICC 40942, which is deposited in the China Industrial Microbiology Culture Collection Center.
[0017] Preferably, the preparation method further comprises drying the Monascus fermented sweet tea at a temperature of 40-55° C. for 10-12 hours before obtaining the Monascus fermented sweet tea.
[0018] A monascus fermented sweet tea is prepared by the monascus fermented sweet tea preparation method.
[0019] The beneficial effects of the present invention are:
[0020] 1. The present invention can not only improve the appearance quality of the multi-sui ke sweet tea, but also increase the biological activity of the sweet tea, thereby obtaining a health-care product with better functionality; the bitter taste of the fermented tea obtained by the present invention is reduced, the color of the tea leaves is reddish, the overall taste is more fresh, sweet and refreshing, and the soup color is brighter; the Monascus fermented sweet tea produced by this method retains the advantages of the freshness and sweetness of traditional sweet tea, and at the same time incorporates the nutritional components of Monascus, combines Monascus and sweet tea, further improves the flavor quality of the sweet tea, forms a good production process, and at the same time explores the formation mechanism of its flavor quality, thereby ensuring that the quality of the product is adjustable and controllable. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a schematic diagram showing the effect of the bacterial liquid inoculation amount on the total flavonoid content of sweet tea;
[0022] Figure 2 This is a schematic diagram showing the effect of fermentation temperature on the total flavonoid content of sweet tea according to the present invention;
[0023] Figure 3 This is a schematic diagram showing the effect of humidity on the total flavonoids content of sweet tea according to the present invention;
[0024] Figure 4 This is a schematic diagram showing the effect of fermentation time on the total flavonoid content of sweet tea according to the present invention;
[0025] Figure 5 Schematic diagram showing the effect of the interaction between humidity and bacterial inoculation amount on the total flavonoids content of fermented sweet tea of the present invention;
[0026] Figure 6 Schematic diagram showing the effect of the interaction between temperature and bacterial inoculation amount on the total flavonoids content of fermented sweet tea of the present invention;
[0027] Figure 7 This is a schematic diagram showing the effect of the interaction between time and bacterial liquid inoculation amount on the total flavonoids content of fermented sweet tea of the present invention;
[0028] Figure 8 Schematic diagram of the effect of the interaction between temperature and humidity on the total flavonoids content of fermented sweet tea of the present invention;
[0029] Figure 9 This is a schematic diagram showing the effect of the interaction between time and humidity on the total flavonoid content of fermented sweet tea of the present invention;
[0030] Figure 10 Schematic diagram of the effect of the interaction between time and temperature on the total flavonoids content of fermented sweet tea of the present invention. DETAILED DESCRIPTION
[0031] The technical solution of the present invention will be further described in detail below in conjunction with specific implementation methods.
[0032] Example 1:
[0033] Fermented tea with increased content of effective ingredients in sweet tea fermented by Monascus
[0034] The fermented tea with increased effective component content of sweet tea by Monascus fermentation is made from the following raw materials: sweet tea and Monascus (CICC 40942, China Industrial Microorganism Culture Collection Center).
[0035] in:
[0036] Sweet tea: Origin: From the leaves of Lithocarpus litseifolius (Hance) Chun, a plant of the Fagaceae family. The leaves are sweet and rich in various amino acids and essential trace elements, making them a popular beverage. Used as a medicinal herb, they nourish the liver and kidneys, clear away heat and toxins, reduce inflammation, promote fluid production and moisten the lungs, and relieve coughs and sore throats.
[0037] Monascus (Monascus purpureus Went.), also known in Chinese as red yeast rice, red malt, and red rice, is a genus of ascomycetes in the Aspergillus family, part of the order Eurotiales. Monascus pigment is a natural pigment synthesized by fermentation from filamentous fungi of the genus Monascus. Monascus pigment has a unique physiological function in the metabolic process of Monascus, acting as an energy storage substance. Monascus can assimilate the pigment, slowing cell aging and autolysis. Monacolin K is an active substance isolated from Monascus that inhibits cholesterol synthesis. This active substance has the ability to lower cholesterol and blood pressure, as well as prevent and treat other diseases.
[0038] The Monascus bacterial liquid is prepared as follows: purple Monascus on a PDA plate previously stored in the laboratory is inoculated onto the PDA plate, cultured at 30°C for 2-3 days, and then the purple Monascus is inoculated into a YPD liquid culture medium, cultured at a shaker at 120 r / min and 30°C for 3-5 days, and then taken out and counted using a hemocytometer.
[0039] Example 2:
[0040] Fermented tea with increased content of effective ingredients in sweet tea fermented by Monascus
[0041] The method for preparing fermented tea by increasing the content of effective ingredients in sweet tea through Monascus fermentation comprises the following steps:
[0042] S1: First, a single-factor experiment was conducted on the fermentation process of sweet tea: the total flavonoids content of sweet tea was used as the corresponding indicator, and the fermentation temperature, fermentation time, inoculation volume, and humidity were used as single-factor variables. The concentration of the bacterial solution was not less than 3.0×108 CFU / mL, and other factors were fixed for the experiment.
[0043] S2: Adjust the bacterial concentration by mixing the cultured bacterial solution and taking 10 μL for counting. Count the cells in the counting chamber of a hemocytometer. Count the cells in the five middle grids of each counting chamber. Average the results from the upper and lower counting chambers to obtain the count result. For cells located on a grid, only the upper and right grid lines are counted. Count the cells three times, take the average, and calculate the result using the following formula:
[0044] S3: Under the conditions of fermentation time 10d, fermentation temperature 30℃ and humidity 10%, set the inoculation liquid volume to 5%, 10%, 15% and 20%; under the conditions of inoculation liquid volume 10%, humidity 10% and fermentation temperature 30℃, set the fermentation time to 8d, 10d, 12d and 14d; under the conditions of inoculation liquid volume 10%, fermentation temperature 30℃ and fermentation time 10d, set the humidity to 5%, 10%, 15% and 20%; under the conditions of inoculation liquid volume 10%, humidity 10% and fermentation time 10d, set the fermentation temperature to 30℃, 33℃, 36℃ and 39℃.
[0045] S4: Select the optimal conditions from the single-factor experiment and perform a Box-Behnken experimental design using Design Expert 13 software. A four-factor, four-level experimental design was developed with fermentation temperature, fermentation time, inoculum volume, and humidity as the four factors, and sweet tea total flavonoids content as the corresponding value.
[0046] S5: Determination of total flavonoids content in sweet tea: First, draw a standard curve. Preparation of rutin standard: accurately weigh 2.48 mg of rutin standard in a 5 mL volumetric flask, add 55% ethanol to dilute, and make up to volume to prepare a 496 μg / mL rutin standard solution.
[0047] S6: Pipette 0, 0.05, 0.1, 0.2, 0.25, and 0.4 mL of rutin standard into 5 mL centrifuge tubes respectively, add 55% ethanol to dilute the final volume to 1 mL; add 0.1 mL of 5% NaNO2 solution, mix well, and react at room temperature for 6 minutes; add 0.1 mL of 10% Al(NO3)3 solution, mix well, and react at room temperature for 6 minutes; add 1 mL of 4% NaOH solution, add distilled water to dilute to 2.5 mL, mix well, and let it stand at room temperature for 15 minutes.
[0048] S7: Measure absorbance at 510 nm using a Shimadzu UV-1780 spectrophotometer. Repeat twice and take the average value. Plot a standard curve with the rutin standard concentration (X, μg / mL) as the abscissa and the absorbance (Y) as the ordinate. The standard curve equation is: Y = 0.0044X - 0.0019 (r² = 0.9975).
[0049] S8: Preparation of sweet tea fermentation sample: Accurately weigh 1.0 g of sweet tea fermentation sample into a 100 mL conical flask, add 25 mL of 55% ethanol, seal tightly, weigh, soak at room temperature for 20 min, ultrasonically treat at 30°C water temperature (power 200 W, frequency 40 kHz) for 1 h, cool, weigh again, make up for the weight loss with 55% ethanol, shake well, filter, and save the filtrate.
[0050] Example 3:
[0051] Effect of single factor experiment of fermented tea in Example 1 on the total flavonoid content of sweet tea
[0052] Under the conditions of fermentation time 10d, fermentation temperature 30℃ and humidity 10%, the inoculation liquid volume was set to 5%, 10%, 15% and 20%; under the conditions of inoculation liquid volume 10%, humidity 10% and fermentation temperature 30℃, the fermentation time was set to 8d, 10d, 12d and 14d; under the conditions of inoculation liquid volume 10%, fermentation temperature 30℃ and fermentation time 10d, the humidity was set to 5%, 10%, 15% and 20%; under the conditions of inoculation liquid volume 10%, humidity 10% and fermentation time 10d, the fermentation temperature was set to 30℃, 33℃, 36℃ and 39℃.
[0053] The effect of bacterial inoculum volume on the total flavonoid content of sweet tea is that as the inoculum volume increases, the total flavonoid content of sweet tea gradually increases and then shows a downward trend. When the inoculum volume reaches 20%, it shows an upward trend again, but it does not exceed the total flavonoid content when the inoculum volume is 10%, which is 30.73μg / mL. The 10% bacterial inoculum volume is determined to be the appropriate inoculum volume. Figure 1 shown.
[0054] The effect of fermentation temperature on the total flavonoid content of sweet tea. As the fermentation temperature gradually increases, the total flavonoid content of sweet tea increases first and then decreases. When the fermentation temperature is 33℃, the total flavonoid content reaches the highest, which is 28.93μg / mL. Therefore, the fermentation temperature of 33℃ is determined to be the appropriate fermentation temperature. Figure 2 shown.
[0055] The effect of humidity on the total flavonoid content of sweet tea. As the humidity increases, the total flavonoid content of sweet tea increases first and then decreases. The maximum total flavonoid content is 30.64μg / mL at a humidity of 10%. 10% humidity is determined to be the most suitable environmental humidity for fermentation. Figure 3 shown.
[0056] The effect of fermentation time on the total flavonoid content of sweet tea. As the fermentation time increases, the total flavonoid content of sweet tea reaches its highest on the 10th day. After the 10th day, the total flavonoid content decreases. On the 10th day, the total flavonoid content is 33.45μg / mL. In summary, it can be determined that 10 days of fermentation time is the most suitable fermentation time; Figure 4 shown.
[0057] Example 4
[0058] Response surface optimization experiment of fermented tea in Example 1
[0059] According to the results of the single-factor experiment, the response surface was used to optimize the design of the four factors of bacterial inoculum volume, humidity, fermentation temperature, and fermentation time. The experimental design factor levels and codes are shown in Table 1 below:
[0060] Table 1 Factor levels and coding
[0061]
[0062] Based on the data in Table 1, a four-factor, four-level Box-Behnken experimental design was performed in DesignExpert 13 software, resulting in 28 experimental schemes. Fermentation experiments were designed based on each experimental scheme, with three replicates set up for each experiment. The absorbance values were measured and the total flavonoid content was calculated. The experimental conditions and corresponding total flavonoid contents for the 28 groups are detailed in Table 2:
[0063] Table 2 Box-Behnken experimental design and total flavonoid content
[0064]
[0065] DesignExpert13 software was used to analyze and fit the data in Table 2 to test the validity of the regression model. The variance analysis is shown in Table 3:
[0066] Table 3 Analysis of variance of regression equation
[0067]
[0068]
[0069] Note: * indicates significant difference (P<0.05); ** indicates extremely significant difference (P<0.01).
[0070] The quadratic regression equation of the total flavonoids content of sweet tea on A, B, C, and D is: Y = 33.42-1.13A-1.1B-0.1515C-1.46D-0.8523AB+1.43AC-3.96AD+1.28BC-1.61BD-1.48CD-3.53A 2 -2.17B2 -5.64C 2 -1.94D 2 Linear terms A, B and D, interaction term BD, quadratic term A 2 、B 2 、C 2 、D 2 The effects were extremely significant (P<0.01); the interaction terms AC, BD and CD had significant effects (P<0.05). This showed that the inoculation amount, humidity and fermentation time had significant effects on the total flavonoids content of sweet tea.
[0071] As shown in Table 3, the model is extremely significant (P < 0.0001), and the model lack of fit term P = 0.4326 is not significant (P > 0.05), which is favorable to the model. As shown in Table 4 below, the model R2 = 0.9538, indicating that the model fits well and the experiment is relatively stable, which can be used to predict and analyze sweet tea fermentation conditions.
[0072] Table 4 Fitting data
[0073]
[0074]
[0075] The effects of the interaction of various factors on the total flavonoids content of fermented sweet tea, such as Figure 6-7 shown.
[0076] The optimal fermentation conditions obtained by analysis with DesignExpert13 software were: bacterial inoculation volume 10.889%, humidity 9.712%, fermentation temperature 33.229℃, fermentation time 8.873d, and the predicted response value of total flavonoids content was 33.759μg / mL.
[0077] Based on the fermentation conditions obtained by response surface analysis and taking into account the actual conditions, the final optimal fermentation conditions were obtained as follows: bacterial liquid inoculation amount 11%, humidity 10%, fermentation temperature 33°C, fermentation time 9 days, and the final total flavonoid content was 33.167±0.441μg / mL.
[0078] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.
Claims
1. A sweet tea fermented by Monascus, characterized in that The raw materials of the monascus fermented sweet tea include sweet tea and monascus.
2. A method for preparing sweet tea fermented by Monascus, characterized in that: The method for preparing the monascus fermented sweet tea comprises the following steps: inoculating monascus into the sweet tea, controlling the humidity and temperature, and performing fermentation in the dark to obtain the monascus fermented sweet tea.
3. The method for preparing sweet tea fermented by Monascus according to claim 2, characterized in that: The tea leaves of the sweet tea are placed in a stationary state for sterilization before inoculation, and the sterilization conditions are: sterilization at 121° C. for 15-20 minutes.
4. The method for preparing sweet tea fermented by Monascus according to claim 2, characterized in that: In the preparation method, the fermentation humidity is controlled by adding sterile water, wherein the volume of the sterile water is 5%-20% of the dry weight of the sweet tea leaves.
5. The method for preparing sweet tea fermented by Monascus according to claim 2, characterized in that: The concentration of the Monascus bacterial solution is not less than 3.0×10 8 CFU / mL.
6. The method for preparing sweet tea fermented by Monascus according to claim 5, characterized in that: The inoculation amount of the Monascus bacterial solution is controlled in the following manner: the volume of the added bacterial solution is 5%-20% of the dry weight of the sweet tea leaves.
7. The method for preparing sweet tea fermented by Monascus according to claim 2, characterized in that: The fermentation temperature is 30-39° C., and the fermentation time is 8-14 days.
8. The method for preparing sweet tea fermented by Monascus according to claim 2, characterized in that: The monascus used is purple red yeast rice Monascus purpureus.
9. The method for preparing sweet tea fermented by Monascus according to claim 2, characterized in that: The preparation method further comprises drying the Monascus fermented sweet tea at a temperature of 40-55° C. for 10-12 hours before obtaining the Monascus fermented sweet tea.
10. A sweet tea fermented by Monascus, characterized in that The Monascus fermented sweet tea is prepared by the preparation method of Monascus fermented sweet tea according to any one of claims 2 to 9.