Tea leaf stabilizer, application thereof and tea leaf product

Abstract

The invention provides a tea stabilizer. The tea stabilizer comprises the following raw materials in parts by weight: 0.03-0.16 part of nutritional yeast powder; and 0.03 to 0.10 part by weight of zinc-enriched yeast powder. The zinc-rich yeast achieves the color protection effect through the ion color protection principle, the nutritional yeast powder serving as yeast thalli has a certain adsorption effect on pigments and active ingredients, the nutritional yeast powder and the yeast thalli are matched to achieve a synergistic effect, and the color protection effect of the zinc-rich yeast is better than that of current zinc-rich yeast raw materials when the zinc-rich yeast is applied to tea beverages. And the taste of the tea beverage can be improved by reducing astringency.

Description

Technical Field

[0001] This invention relates to the field of microbial technology, and in particular to a tea stabilizer, its application, and a tea product. Background Technology

[0002] Tea is one of the world's three major traditional beverages, widely favored by consumers for its unique flavor, profound cultural heritage, and rich nutritional components. The chemical composition of tea infusion, obtained by steeping tea leaves in water, is complex, containing many substances beneficial to human health, such as tea polyphenols, flavonols, and amino acids. This contributes to the weight loss, blood pressure lowering, and blood sugar lowering functions of tea infusion. Tea beverages are liquid drinks made from tea extracts or their concentrates, tea powder, etc., with or without the addition of small amounts of sugar and / or sweeteners, processed to retain the original flavor of the tea.

[0003] The evaluation indicators for tea beverage quality mainly include taste, flavor, and color. The strong bitterness of tea beverages affects people's appetite and consumption choices. At the same time, tea beverages are susceptible to color deterioration due to changes in processing and storage conditions, which also restricts the healthy development of the tea beverage industry. Consumers' demands for tea beverages are constantly shifting towards "health," "natural," and "delicious." Optimizing processes and formulas using tea leaves as raw materials to develop nutritious tea beverages with excellent taste and color not only meets consumer demands but also provides new ideas for expanding the tea beverage market.

[0004] Existing technology CN114766564A relates to a method for color protection in beverages, including the preparation of a metallic yeast solution and the preparation of green plant extracts. Metallic yeast is added during the production of the green plant beverage. The metallic yeast can mitigate the discoloration reaction of chlorophyll molecules caused by the replacement of magnesium with hydrogen atoms, resulting in brown pheophytin. This alleviates the discoloration reaction of chlorophyll during the production and storage of the extract, thus achieving a color-protecting effect. However, this method is only applicable to green plants such as green tea, matcha, and seaweed. It is not suitable for tea varieties of other colors that do not contain chlorophyll, thus limiting its applicability.

[0005] Therefore, it is essential to provide a tea stabilizer that has a wide range of applications and good color protection. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a tea stabilizer. The tea stabilizer provided by the present invention has good color protection effect, can maintain the color value stable during the shelf life and reduce bitterness.

[0007] This invention aims to solve the problems of color deterioration in tea beverages during processing and storage, as well as the bitter taste and strong metallic flavor caused by the addition of color-protecting agents.

[0008] This invention provides a tea stabilizer, comprising the following raw materials in parts by weight:

[0009] Nutritional yeast powder 0.03~0.16 parts by weight;

[0010] 0.03~0.10 parts by weight of zinc-enriched yeast powder.

[0011] This invention provides a method for preparing nutritional yeast powder:

[0012] 1. Shake-flask seed culture: Two loops of BH3 bacterial culture were inoculated into a shake flask containing 1 L of liquid culture medium. The liquid culture medium consisted of: 100 g / L sucrose, 20 g / L yeast extract, 1.0 g / L KH₂PO₄, 0.5 g / L MgSO₄, pH 5.0–5.5. The culture conditions were: 30℃, 200 rpm, for 24 h.

[0013] 2. Pond's Tank Seed Fermentation: The shake flask seed culture was inoculated into a Pond's tank containing 7L of liquid culture medium. The liquid culture medium composition was: 700g / L sucrose, 140g / L yeast extract, 7.0g / L KH2PO4, 3.5g / L MgSO4, pH 5.0–5.5. The culture conditions were: 30℃, 500rpm, for 24h.

[0014] 3. Primary seed fermentation: Inoculate the Pond's tank seed culture with a solution containing 3 mg / L. 3 The liquid culture medium in the fermenter consisted of: 180 g / L sugarcane molasses (based on reducing sugar), 20 g / L ammonium sulfate, 4 g / L NH4H2PO4, 30 g / L Na2CO3, and 0.004 g / L zinc sulfate, with a pH of 5.0-5.5. All nutrients were fed-batch during fermentation. The culture conditions were: 30℃, aeration rate of 0.1-5.0 L / (L×min), and a culture time of 24 h.

[0015] 4. Secondary seed fermentation: Inoculate the primary seed culture with a solution containing 100 mg / L. 3 In the fermenter, the liquid culture medium consisted of: 180 g / L sugarcane molasses (calculated as reducing sugar), 20 g / L ammonium sulfate, 4 g / L NH4H2PO4, and 0.004 g / L zinc sulfate, with a pH of 3.5-6.0. Nutrients were fed-batch during fermentation. The culture conditions were: 30℃, airflow 0.1-5.0 L / (L×min), and culture for 24 h. After fermentation, the yeast was separated and concentrated using a separator to a wet weight of over 600 g / L, yielding the secondary seed fermentation broth.

[0016] 5. Commercial fermentation: Inoculate the secondary seed fermentation broth into a 100m³ solution. 3In a fermenter containing liquid culture medium, the wet weight of yeast after inoculation was 52 g / L. The liquid culture medium consisted of: 150 g / L carbon source (cane molasses: starch hydrolysate = 1:1) (based on reducing sugar), 10 mL / L 20% ammonia, 4 g / L NH4H2PO4, 0.004 g / L zinc sulfate, and pH 4.0-7.0. All nutrients were supplied via a fed-batch method during fermentation. The culture conditions were: 30℃, aeration rate of 0.1-5.0 L / (L×min), and a culture time of 16 h.

[0017] 6. Separation: Separate twice with a separator and collect the heavy phase solution.

[0018] 7. Sterilization: Sterilize the double phase solution at 90℃ for 60 minutes.

[0019] 8. Spray drying: The inactivated solution is spray dried at an inlet temperature of 160℃ and an outlet temperature of 85℃, with a feed rate of 300L / h. After drying, the dried powder is collected to obtain nutrient yeast powder.

[0020] The present invention does not limit the source of the above-mentioned nutritional yeast and zinc-enriched yeast, as long as it is known to those skilled in the art.

[0021] The tea stabilizer provided by the present invention comprises 0.03 to 0.16 parts by weight of nutrient yeast powder; preferably, it comprises 0.03 parts by weight, 0.04 parts by weight, 0.05 parts by weight, 0.06 parts by weight, 0.07 parts by weight, 0.08 parts by weight, 0.09 parts by weight, 0.10 parts by weight, 0.11 parts by weight, 0.12 parts by weight, 0.13 parts by weight, 0.14 parts by weight, 0.15 parts by weight, or 0.16 parts by weight; or any value within the range of the above two.

[0022] The tea stabilizer provided by the present invention includes 0.03 to 0.10 parts by weight of zinc-enriched yeast powder; preferably including 0.03 parts by weight, 0.04 parts by weight, 0.05 parts by weight, 0.06 parts by weight, 0.07 parts by weight, 0.08 parts by weight, 0.09 parts by weight, and 0.10 parts by weight; or any value within the range of the above two.

[0023] In a preferred embodiment of the present invention, the tea stabilizer comprises the following raw materials in parts by weight:

[0024] Nutritional yeast powder 0.03~0.16 parts by weight;

[0025] 0.03~0.05 parts by weight of zinc-enriched yeast powder.

[0026] In a preferred embodiment of the present invention, the tea stabilizer comprises the following raw materials in parts by weight:

[0027] Nutritional yeast powder 0.04~0.15 parts by weight;

[0028] 0.04 parts by weight of zinc-enriched yeast powder.

[0029] In a preferred embodiment of the present invention, the tea stabilizer comprises the following raw materials in parts by weight:

[0030] 0.15 parts by weight of nutritional yeast powder;

[0031] 0.04 parts by weight of zinc-enriched yeast powder.

[0032] In a preferred embodiment of the present invention, the tea stabilizer comprises the following raw materials in parts by weight:

[0033] 0.15 parts by weight of nutritional yeast powder;

[0034] 0.05 parts by weight of zinc-enriched yeast powder.

[0035] In a preferred embodiment of the present invention, the tea stabilizer comprises the following raw materials in parts by weight:

[0036] 0.16 parts by weight of nutritional yeast powder;

[0037] 0.05 parts by weight of zinc-enriched yeast powder.

[0038] The zinc ion content of the zinc-enriched yeast powder of the present invention is 5000~20000ppm; specifically, it can be 5000 ppm, 8000 ppm, 10000 ppm, 12000 ppm, 14000 ppm, 16000 ppm, 18000 ppm, 20000ppm; or any value between the above two.

[0039] This invention provides the application of the tea stabilizer described in any of the above technical solutions in maintaining the color value of tea products stable and / or reducing bitterness during the shelf life of the tea products.

[0040] The preparation method provided by this invention can maintain the stability of the color value of tea beverages during their shelf life. Using a combination of nutritional yeast powder and zinc-enriched yeast powder as a stabilizer for tea beverages results in a better color-protecting effect than using zinc-enriched yeast powder alone; the two components have a synergistic effect. This stabilizer is not only suitable for green tea but also for oolong tea, jasmine tea, and other tea beverages.

[0041] This invention adds a stabilizer during the tea extraction process to inhibit the partial extraction of caffeine, reduce the bitterness of the tea beverage, and thus improve its taste.

[0042] The method for detecting colorimetric values ​​in this invention: The laboratory uses a CS-821N high-stability benchtop colorimeter to test samples, applying the Hunter-Lab colorimetric system, using a standard C light source and a 1~4° small field of view to measure the three color components L, a, and b. Where L represents lightness; a larger L value indicates a brighter color. a represents red-green hue; a positive value indicates a degree of red, and a negative value indicates a degree of green. b represents yellow-blue hue; a positive value indicates a degree of yellow, and a negative value indicates a degree of blue. The derived index -a / b from L, a, and b represents the overall color of the tea infusion; a larger value indicates a greener color, better color saturation, and superior visual appeal. The average overall colorimetric value of the tea beverage during its shelf life is the average of the sum of the overall colorimetric values ​​at each acceleration time point, which can comprehensively evaluate the differences in the overall colorimetric changes of tea beverages during the acceleration phase between different samples. The color difference value of the sample is ΔE (ΔE = [(ΔL)]). 2 +(△a) 2 +(△b) 2 ] 1 / 2 () indicates the magnitude of the color difference between the same sample before and after acceleration, and is an indicator used to quantify color difference. Three samples are measured in each group, and the average value of the results is taken.

[0043] This invention provides a tea product, comprising:

[0044] 0.1~0.5 parts by weight of tea powder;

[0045] Tea stabilizer: 0.06~0.1 parts by weight;

[0046] Acidity regulator: 0.02~0.06 parts by weight;

[0047] Antioxidant 0.01~0.08 parts by weight;

[0048] water to 100;

[0049] The tea stabilizer is the tea stabilizer described in any one of claims 1 to 2.

[0050] The tea product provided by this invention includes 0.1 to 0.5 parts by weight of tea powder; specifically, it can be 0.1 parts by weight, 0.2 parts by weight, 0.3 parts by weight, 0.4 parts by weight, 0.5 parts by weight; or any value between the above two.

[0051] The tea product provided by this invention includes 0.06 to 0.1 parts by weight of a tea stabilizer; specifically, it can be 0.06 parts by weight, 0.07 parts by weight, 0.08 parts by weight, 0.09 parts by weight, or 0.10 parts by weight; or any value within the range of the above two. The tea stabilizer is the tea stabilizer described in any one of claims 1 to 2.

[0052] The tea product provided by the present invention includes 0.02 to 0.06 parts by weight of acidity regulator; preferably including 0.02 parts by weight, 0.03 parts by weight, 0.04 parts by weight, 0.05 parts by weight, and 0.06 parts by weight; or any value between the two above.

[0053] The acidity regulator described in this invention is sodium bicarbonate.

[0054] The tea product provided by the present invention includes 0.02 to 0.08 parts by weight of antioxidant; preferably including 0.02 parts by weight, 0.03 parts by weight, 0.04 parts by weight, 0.05 parts by weight, 0.06 parts by weight, 0.07 parts by weight, and 0.08 parts by weight; or any value between the two above.

[0055] The antioxidant described in this invention is sodium ascorbate.

[0056] The tea powder is one of black tea, flower tea, oolong tea, or green tea; the tea products include, but are not limited to, tea beverages.

[0057] In a preferred embodiment of the present invention, the tea product includes:

[0058] Nutritional yeast 0.16 parts by weight;

[0059] 0.05 parts by weight of zinc-enriched yeast;

[0060] 0.5 parts by weight of tea leaves;

[0061] 0.05 parts by weight of acidity regulator;

[0062] Antioxidant 0.01 parts by weight;

[0063] water to 100;

[0064] In a preferred embodiment of the present invention, the tea product includes:

[0065] Nutritional yeast 0.15 parts by weight;

[0066] 0.05 parts by weight of zinc-enriched yeast;

[0067] 0.5 parts by weight of tea leaves;

[0068] 0.05 parts by weight of acidity regulator;

[0069] Antioxidant 0.01 parts by weight;

[0070] water to 100;

[0071] In a preferred embodiment of the present invention, the tea product includes:

[0072] Nutritional yeast 0.15 parts by weight;

[0073] 0.04 parts by weight of zinc-enriched yeast;

[0074] 0.5 parts by weight of tea leaves;

[0075] 0.05 parts by weight of acidity regulator;

[0076] Antioxidant 0.01 parts by weight;

[0077] water to 100;

[0078] This invention provides a method for preparing a tea product, comprising the following steps:

[0079] A) After pulverizing the tea leaves, mix them with a tea stabilizer, add water to extract, and obtain the turbid liquid after extraction;

[0080] B) Filter and centrifuge the extracted turbid liquid to obtain the supernatant;

[0081] C) Mix the supernatant, water, acidity regulator, and antioxidant, then sterilize and package.

[0082] The present invention provides a method for preparing a tea product. First, the tea leaves are crushed and then mixed with a tea stabilizer. Preferably, a number of whole tea leaves are crushed, and the crushed tea leaves are weighed after passing through a 40-mesh sieve and mixed with the weighed stabilizer.

[0083] The tea powder used in this invention includes various types of tea such as black tea, flower tea, oolong tea, and green tea.

[0084] After mixing, water is added for extraction to obtain a turbid extract. The mass ratio of tea leaves to water in this invention is 1:1000 to 1:200; specifically including 1:200, 1:300, 1:400, 1:500, 1:600, 1:700, 1:800, 1:900, and 1:1000.

[0085] The extraction temperature described in this invention is 90~100℃, specifically 90℃, 95℃, or 100℃; the extraction time is 10~20min; or any value between the two mentioned above. Specifically, it can be 10min, 15min, or 20min; or any value between the two mentioned above.

[0086] The extracted turbid liquid is filtered, centrifuged, and the supernatant is obtained. The extracted turbid liquid is transferred to the surface of a 300-mesh filter cloth to separate the tea residue from the liquid. The filtered liquid portion is then centrifuged.

[0087] The filtration described in this invention uses a 300-mesh filter cloth, and the centrifugation conditions are 3000~5000 r / min for 5~8 min.

[0088] Take the supernatant from the centrifuged sample and mix it with water, acidity regulator and antioxidant.

[0089] The components and proportions described above have been clearly described in this invention and will not be repeated here.

[0090] After stirring, sterilize and package. Nitrogen purging is applied to the gaps in the filled packaging bottles. The sterilization temperature is 130-150℃, the sterilization time is 10-50 seconds, and the bottles are cooled to 25-30℃ after sterilization.

[0091] This invention provides a tea stabilizer comprising the following raw materials in parts by weight: 0.03-0.16 parts by weight of nutritional yeast powder; and 0.03-0.10 parts by weight of zinc-enriched yeast powder. The zinc-enriched yeast of this invention achieves color protection through the principle of ion-based color protection. The nutritional yeast powder, as yeast cells, has a certain adsorption effect on pigments and active ingredients. The combination of the two has a synergistic effect, and its application in tea beverages is superior to the color protection effect of current zinc-enriched yeast raw materials. Furthermore, it can improve the taste of tea beverages by reducing astringency. Attached Figure Description

[0092] Figure 1 The comprehensive color values ​​of jasmine tea in Examples 1-3 and Comparative Examples 1-3 are shown.

[0093] Figure 2 The comprehensive color values ​​of oolong tea in Examples 4-6 and Comparative Examples 4-6 are shown.

[0094] Figure 3 The comprehensive color values ​​of green tea in Examples 7-9 and Comparative Examples 7-9;

[0095] Figure 4 The results show the caffeine content of jasmine tea in Examples 1-3 and Comparative Examples 1-3.

[0096] Figure 5 The results for the caffeine content of oolong tea in Examples 4-6 and Comparative Examples 4-6 are as follows;

[0097] Figure 6 The results of green tea caffeine content in Examples 7-9 and Comparative Examples 7-9 are shown in the figure. Detailed Implementation

[0098] This invention provides a tea stabilizer, its application, and a tea product. Those skilled in the art can refer to this document and appropriately modify the process parameters to achieve the desired results. It is particularly important to note that all similar substitutions and modifications are obvious to those skilled in the art and fall within the scope of this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can clearly modify or appropriately alter and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0099] It should be understood that the expression “one or more of…” individually includes each of the objects described after the expression, as well as various different combinations of two or more of the described objects, unless otherwise understood from the context and usage. The expression “and / or” combined with three or more described objects should be understood to have the same meaning, unless otherwise understood from the context.

[0100] The terms “including,” “having,” or “containing,” including the use of their grammatical synonyms, should generally be understood as open-ended and non-restrictive, for example, not excluding other unstated elements or steps, unless otherwise specifically stated or understood from the context.

[0101] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0102] It should be understood that the order of the steps or the order in which certain actions are performed is not important as long as the invention remains operational. Furthermore, two or more steps or actions can be performed simultaneously.

[0103] The use of any and all instances or exemplary language such as “e.g.” or “including” in this document is merely intended to better illustrate the invention and is not intended to limit the scope of the invention unless the claims are made. No language in this specification should be construed as indicating that any unclaimed element is essential to the practice of the invention.

[0104] Furthermore, the numerical ranges and parameters used to define the present invention are approximate values, and the relevant values ​​in the specific embodiments have been presented as precisely as possible. However, any value inevitably contains standard deviations due to individual test methods. Therefore, unless explicitly stated otherwise, it should be understood that all ranges, quantities, values, and percentages used in this disclosure are modified with the word "approximately". Here, "approximately" generally means that the actual value is within plus or minus 10%, 5%, 1%, or 0.5% of a specific value or range.

[0105] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0106] To further illustrate the present invention, the following describes in detail, with reference to embodiments, a tea stabilizer, its application, and a tea product provided by the present invention.

[0107] The nutritional yeast described in this embodiment of the invention is prepared according to the following method.

[0108] 1. Shake-flask seed culture: Two loops of BH3 bacterial culture were inoculated into a shake flask containing 1 L of liquid culture medium. The liquid culture medium consisted of: 100 g / L sucrose, 20 g / L yeast extract, 1.0 g / L KH₂PO₄, 0.5 g / L MgSO₄, pH 5.0–5.5. The culture conditions were: 30℃, 200 rpm, for 24 h.

[0109] 2. Pond's Tank Seed Fermentation: The shake flask seed culture was inoculated into a Pond's tank containing 7L of liquid culture medium. The liquid culture medium composition was: 700g / L sucrose, 140g / L yeast extract, 7.0g / L KH2PO4, 3.5g / L MgSO4, pH 5.0–5.5. The culture conditions were: 30℃, 500rpm, for 24h.

[0110] 3. Primary seed fermentation: Inoculate the Pond's tank seed culture with a solution containing 3 mg / L. 3 The liquid culture medium in the fermenter consisted of: 180 g / L sugarcane molasses (based on reducing sugar), 20 g / L ammonium sulfate, 4 g / L NH4H2PO4, 30 g / L Na2CO3, and 0.004 g / L zinc sulfate, with a pH of 5.0-5.5. All nutrients were fed-batch during fermentation. The culture conditions were: 30℃, aeration rate of 0.1-5.0 L / (L×min), and a culture time of 24 h.

[0111] 4. Secondary seed fermentation: Inoculate the primary seed culture with a solution containing 100 mg / L. 3 In the fermenter, the liquid culture medium consisted of: 180 g / L sugarcane molasses (calculated as reducing sugar), 20 g / L ammonium sulfate, 4 g / L NH4H2PO4, and 0.004 g / L zinc sulfate, with a pH of 3.5-6.0. Nutrients were fed-batch during fermentation. The culture conditions were: 30℃, airflow 0.1-5.0 L / (L×min), and culture for 24 h. After fermentation, the yeast was separated and concentrated using a separator to a wet weight of over 600 g / L, yielding the secondary seed fermentation broth.

[0112] 5. Commercial fermentation: Inoculate the secondary seed fermentation broth into a 100m³ solution. 3 In a fermenter containing liquid culture medium, the wet weight of yeast after inoculation was 52 g / L. The liquid culture medium consisted of: 150 g / L carbon source (cane molasses: starch hydrolysate = 1:1) (based on reducing sugar), 10 mL / L 20% ammonia, 4 g / L NH4H2PO4, 0.004 g / L zinc sulfate, and pH 4.0-7.0. All nutrients were supplied via a fed-batch method during fermentation. The culture conditions were: 30℃, aeration rate of 0.1-5.0 L / (L×min), and a culture time of 16 h.

[0113] 6. Separation: Separate twice with a separator and collect the heavy phase solution.

[0114] 7. Sterilization: Sterilize the double phase solution at 90℃ for 60 minutes.

[0115] 8. Spray drying: The inactivated solution is spray dried at an inlet temperature of 160℃ and an outlet temperature of 85℃, with a feed rate of 300L / h. After drying, the dried powder is collected to obtain nutrient yeast powder.

[0116] Examples 1-3 and Comparative Examples 1-3: Application of stabilizers in jasmine tea:

[0117]

[0118] Examples 4-6 and Comparative Examples 4-6: Application of stabilizers in oolong tea:

[0119]

[0120] Application of stabilizers in green tea in Examples 7-9 and Comparative Examples 7-9:

[0121]

[0122] The samples from Examples 1-9 and Comparative Examples 1-9 were placed in an accelerated stability test chamber (test conditions: temperature and humidity 40℃±2℃, 75%RH±5%RH) for three months as the shelf life test period, to investigate the changes in color value and caffeine content of the tea beverage during the accelerated process.

[0123] Verification Example 1

[0124] 1. Colorimetric Value Detection Method: The laboratory used a CS-821N high-stability benchtop colorimeter to test the samples, applying the Hunter-Lab color system, using a standard C light source and a 1~4° small field of view to measure the three color components L, a, and b. L represents lightness; a larger L value indicates a brighter color. a represents red-green hue; a positive value indicates a degree of red, and a negative value indicates a degree of green. b represents yellow-blue hue; a positive value indicates a degree of yellow, and a negative value indicates a degree of blue. The derived index -a / b from L, a, and b represents the overall color of the tea infusion; a larger value indicates a greener color, better color saturation, and superior visual appeal. The average overall colorimetric value of the tea beverage during its shelf life is the average of the sum of the overall colorimetric values ​​at each acceleration time point, which can comprehensively evaluate the differences in overall colorimetric changes between different samples during the acceleration phase. The color difference value of the sample is ΔE (ΔE = [(ΔL)]). 2 +(△a) 2 +(△b) 2 ] 1 / 2 The color difference () represents the magnitude of the color difference between the same sample before and after acceleration, and is an indicator used to quantify color difference. Three samples were measured in each group, and the average result was taken. Test results are shown below. Figure 1-3 Table 1-2.

[0125] Figure 1 The graph shows the trend of the overall color value of jasmine tea during the accelerated extraction process. Compared with Comparative Example 3 (without added yeast), the addition of zinc-enriched yeast or nutrient-enriched yeast at 0 months can both protect the color of the extracted tea, but cannot maintain the stability of the overall color value during the shelf life; the color will decay to varying degrees. The overall color values ​​of Examples 1, 2, and 3 are all higher than those of the Comparative Example, and the trends of each example are relatively stable during the accelerated extraction process. This indicates that the addition of a certain proportion of nutrient-enriched yeast and zinc-enriched yeast can enhance the overall color value and stabilize the overall color value during the extraction process and shelf life of the tea beverage. Figure 2 , Figure 3 The trend charts of the overall color values ​​of oolong tea and green tea can further confirm that the stabilizer has the same color-protecting and stabilizing effect in their tea beverages.

[0126] Table 1

[0127]

[0128] *Different letters in the table indicate significant differences at the 0.05 level according to SAS statistics.

[0129] Table 1 shows the average comprehensive color values ​​of the comparative examples and the examples for each tea beverage. Based on the results of the application of stabilizers in jasmine tea, it can be concluded that: there are significant differences between Examples 1-3 and Comparative Examples 1-3, indicating that the application of stabilizers can significantly improve the color value of jasmine tea beverages, demonstrating a clear color-protecting effect; there are significant differences between Examples 1 and 3, and the comprehensive color value of Example 3 is better than that of Example 1, proving that Example 3 has a better color-protecting effect; there are no significant differences between Comparative Examples 2 and 3, indicating that the effect of adding zinc-rich yeast during the acceleration process is consistent with that of not adding it.

[0130] Based on the results of the application of stabilizers in oolong tea, the following conclusions can be drawn: There are significant differences between Examples 4-6 and Comparative Examples 4-6, indicating that the application of stabilizers can significantly improve the color value of jasmine tea beverages, and its color protection effect is obvious; There are significant differences between Examples 4 and 6, and the overall color value of Example 6 is better than that of Example 1, proving that the color protection effect of Example 6 is better; There are significant differences among Comparative Examples 4, 5, and 6, and the overall color values ​​are all negative, indicating that the colors have all undergone abrupt changes, and the changes are all quite obvious.

[0131] Based on the results of the application of stabilizers in green tea, the following conclusions can be drawn: Examples 7-9 show significant differences from Comparative Examples 7-9, indicating that the application of stabilizers can significantly improve the color value of green tea beverages, demonstrating a clear color-protecting effect; Example 9 shows significant differences from Examples 7 and 8, and the overall color value of Example 9 is better than that of Examples 7 and 8, proving that Example 9 has a better color-protecting effect; Comparative Examples 7, 8, and 9 show significant differences, and the overall color values ​​of Comparative Examples 7 and 9 are both negative, indicating that color mutations have occurred and the changes are quite significant, while Comparative Example 8 has a positive value, indicating that zinc-rich yeast also has a certain color-protecting effect in green tea.

[0132] Table 2

[0133]

[0134] Table 2 shows the color difference values ​​of different tea beverages during their shelf life. Based on the magnitude of the color difference value, we can determine the following: When ΔE is between 0 and 1, the color difference is indistinguishable to the naked eye. If ΔE is between 1 and 2, the human eye can detect it slightly, but if the color difference sensitivity is low, it is still impossible to distinguish and judge. If ΔE is between 2 and 3, the color difference between substances can be distinguished more clearly, but it is still not very obvious. Once ΔE reaches between 3.5 and 5, a significant color difference is achieved.

[0135] The color difference values ​​of Examples 3, 6, and 9 were all below 1, indicating that a 5:1 ratio of nutritional yeast to zinc-enriched yeast, when applied to jasmine tea, oolong tea, and green tea, can maximize the preservation of the initial color of the tea infusion. The color values ​​of Examples 1, 2, 4, 5, 7, and 8 were in the range of 1-2, confirming that stabilizers at a ratio of 1:1 or 2:1 can also have a certain color stabilizing effect; slight color differences occurred in the accelerated coloring of the tea beverages. The color difference values ​​of Comparative Examples 2, 5, and 8 were all between 2 and 3, while the other comparative examples were all above 3, confirming that zinc-enriched yeast plays a positive role in reducing color differences during the accelerated coloring process of tea beverages, but the effect is limited.

[0136] Verification Example 2

[0137] Caffeine determination method: Refer to GB5009.139-2014 Determination of caffeine in beverages. Three samples were tested in each group, and the average value of the results was taken. Test results are shown below. Figure 4-6 .

[0138] Depend on Figures 4 to 6 It can be seen that compared with tea beverages without stabilizers, the addition of stabilizers can inhibit the release of caffeine during the tea extraction process, while the caffeine content in each group remains stable during the acceleration process. Reducing the caffeine content in tea beverages can effectively reduce the bitterness of the tea soup and improve the taste of the tea beverage.

[0139] Verification Example 3

[0140] Sensory evaluations were conducted on the tea beverages obtained in Examples 1-6 and Comparative Examples 1-6. The evaluation criteria are shown in Table 3, and the evaluation results are shown in Table 4.

[0141] Table 3 Evaluation Criteria

[0142]

[0143] Table 4 Evaluation Results

[0144]

[0145] As can be seen from Table 2, the scores of Examples 1-9 are all above 80, while the scores of Comparative Examples 1-9 are all below 60. The total sensory evaluation scores of the Examples are all better than those of the Comparative Examples, indicating that the method of preparing tea beverages with added stabilizers improves the sensory quality of the tea beverages.

[0146] In summary, this application's method of adding a stabilizer during tea extraction enhances the color of the tea liquor and maintains stable color values ​​during accelerated extraction. It also inhibits partial extraction of caffeine, reduces bitterness in tea beverages, and improves their taste, effectively enhancing the color, aroma, and flavor scores of tea beverages and improving their overall quality. This method is applicable not only to green tea but also to the preparation of tea beverages from various other tea types, such as oolong tea and jasmine tea. The preparation method is simple, easy to operate, and suitable for industrial production.

[0147] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A tea stabilizer, comprising the following raw materials in parts by weight: Nutritional yeast powder 0.03~0.16 parts by weight; 0.03~0.10 parts by weight of zinc-enriched yeast powder.

2. The tea stabilizer according to claim 1, wherein the method for preparing the nutritional yeast powder comprises: yeast, The zinc-rich yeast powder was prepared by fermentation, separation and washing, inactivation and spray drying, and the zinc ion content was 5000~20000ppm.

3. The application of the tea stabilizer according to any one of claims 1 to 2 in maintaining the color value of tea products stable and / or reducing bitterness during the shelf life of the tea products.

4. A tea product, characterized in that, include: 0.1~0.5 parts by weight of tea powder; Tea stabilizer: 0.06~0.1 parts by weight; Acidity regulator: 0.02~0.06 parts by weight; Antioxidant 0.01~0.08 parts by weight; water to 100; The tea stabilizer is the tea stabilizer described in any one of claims 1 to 2.

5. The tea product according to claim 3, characterized in that, The acidity regulator is sodium bicarbonate; the antioxidant is sodium ascorbate. The tea powder is one of black tea, flower tea, oolong tea, or green tea; the tea products include tea beverages.

6. A method for preparing a tea product, characterized in that, Includes the following steps: A) After pulverizing the tea leaves, mix them with a tea stabilizer, add water to extract, and obtain the turbid liquid after extraction; B) Filter and centrifuge the extracted turbid liquid to obtain the supernatant; C) Mix the supernatant, water, acidity regulator, and antioxidant, then sterilize and package.

7. The preparation method according to claim 6, characterized in that, Step A) The tea leaves are pulverized and then passed through a 40-mesh sieve; the tea powder is one of black tea, flower tea, oolong tea or green tea.

8. The preparation method according to claim 6, characterized in that, The mass ratio of tea leaves to water is 1:1000 to 1:200; The extraction temperature is 90~100℃, and the extraction time is 10~20min.

9. The preparation method according to claim 6, characterized in that, Step B) The filtration is performed using a 300-mesh filter cloth, and the centrifugation conditions are 3000~5000 r / min for 5~8 min.

10. The preparation method according to claim 6, characterized in that, Step C) The sterilization temperature is 130~150℃, the sterilization time is 10~50s, and the temperature is cooled to 25~30℃ after sterilization.

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