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CN-122004320-A - Tea powder with high aroma, low bitterness and tea red element enrichment, and preparation method and application thereof

CN122004320ACN 122004320 ACN122004320 ACN 122004320ACN-122004320-A

Abstract

The application relates to tea powder with high aroma, low bitterness and tea red element enrichment, and a preparation method and application thereof, wherein the preparation method comprises the following steps of adding crushed black tea leaves into water, and stirring to obtain tea fine powder suspension; adding a compound enzyme preparation into the tea fine powder suspension, carrying out enzymolysis and enzyme deactivation to obtain an enzymolysis tea liquid, carrying out constant-temperature extraction on the enzymolysis tea liquid at a first temperature, then carrying out constant-temperature extraction at a second temperature, filtering and centrifuging to obtain a gradient extract, introducing nano bubbles into the gradient extract for oxidation, controlling a reaction end point by monitoring an index reflecting the composition change of an oxidation product to obtain an oxidation tea liquid, and carrying out adsorption, nanofiltration concentration and spray drying on the oxidation tea liquid to obtain the high-aroma low-astringency high-thearubigin tea powder. The preparation method realizes the beneficial effect of improving the content of thearubigins in the tea powder through the technology coupling of multienzyme compound synergy, low-temperature gradient extraction and nanobubble controllable oxidation.

Inventors

  • FU LIQI
  • XU XIAOXIANG
  • LI JUNWEN
  • SHANG JINGYI

Assignees

  • 统一企业(中国)投资有限公司昆山研究开发中心
  • 统一企业(中国)投资有限公司

Dates

Publication Date
20260512
Application Date
20260209

Claims (10)

  1. 1. A preparation method of tea powder with high aroma, low bitterness and tea red element enrichment is characterized by comprising the following steps: raw material pretreatment, namely crushing black tea leaves, adding the crushed black tea leaves into water, and stirring to obtain tea leaf fine powder suspension; Adding a compound enzyme preparation into the tea fine powder suspension for enzymolysis and enzyme deactivation to obtain an enzymolysis tea liquid, wherein the compound enzyme preparation comprises at least two of cellulase, tannase, beta-glucosidase, alpha-L-rhamnosidase and alpha-galactosidase; Gradient extraction, namely extracting the enzymolysis tea liquid at a first temperature for 20-50min at a constant temperature, heating to a second temperature, extracting for 20-50min at a constant temperature, filtering and centrifuging to obtain a gradient extract, wherein the first temperature and the second temperature are both less than 70 ℃; Oxidizing, namely introducing nano bubbles into the gradient extract liquid to oxidize, and controlling a reaction end point by monitoring an index reflecting the composition change of an oxidation product to obtain oxidized tea liquid; Refining and drying, namely adsorbing, nanofiltration concentrating and spray drying the oxidized tea liquid to obtain the high-aroma low-astringency high-thearubigin tea powder.
  2. 2. The method for preparing tea powder with high aroma, low bitterness and rich thearubigins according to claim 1, wherein in the raw material pretreatment process, the water content of black tea leaves is less than or equal to 8%, the black tea leaves are crushed to 40-60 meshes, then the black tea leaves and deionized water are mixed according to the mass ratio of 1:15-1:20, the pH of the system is regulated to 4.5-5.5, the temperature is raised to 30-50 ℃, and the temperature is kept and stirred for 8-25min, so as to obtain tea fine powder suspension.
  3. 3. The method for preparing tea powder with high aroma, low bitterness and tea red enrichment according to claim 1, wherein the compound enzyme preparation comprises the following components, by mass, 0.5-2 parts of cellulase, 1-3 parts of tannase, 0.5-3 parts of beta-glucosidase, 1-3 parts of alpha-L-rhamnosidase and 1-3 parts of alpha-galactosidase in an enzymolysis process.
  4. 4. The preparation method of the tea powder with high aroma, low bitterness and tea red element enrichment according to claim 1, wherein the addition amount of the compound enzyme preparation is 0.03% -0.20% of the mass of black tea leaves, the enzymolysis condition is that the temperature is 30-50 ℃, the pH is 4.5-5.5 and the time is 40-60min, and the enzyme deactivation condition is that the temperature is raised to 80-95 ℃ and the temperature is kept for 5-15min.
  5. 5. The method for preparing tea powder with high aroma, low bitterness and tea red enrichment according to claim 1, wherein in the gradient extraction process, the first temperature is 25-35 ℃, the second temperature is 45-55 ℃, the stirring speed during extraction is 100-300r/min, the filtering is 150-250 mesh filter cloth, and the centrifugal condition is that the rotating speed is 4500-5500r/min, and the time is 8-20min.
  6. 6. The method for preparing tea powder with high aroma, low bitterness and rich in thearubigins according to claim 1, wherein in the oxidation process, the average particle size of the nano bubbles is 100-200nm, the concentration of dissolved oxygen is 15-20mg/L, and oxidation is carried out at 25-30 ℃; the oxidation endpoint met the following conditions: (1) The absorbance at 460nm wavelength reaches 90% -98% of its maximum; (2) The absorbance ratio at 380nm to 460nm wavelength is 0.55-0.90; (3) The absorbance ratio at wavelengths of 540nm to 460nm is not greater than 0.35.
  7. 7. The method for preparing tea powder with high aroma, low bitterness and rich in thearubigins according to claim 6, wherein the oxidation endpoint satisfies the following conditions: (1) Absorbance at 460nm wavelength reaches 95% ± 1% of its maximum; (2) The absorbance ratio at 380nm to 460nm wavelength is 0.60-0.85; (3) The absorbance ratio at wavelengths of 540nm to 460nm is not greater than 0.3.
  8. 8. The preparation method of the tea powder with high aroma, low bitterness and tea red essence enrichment according to claim 1, wherein in the refining and drying process, diatomite is adopted, the adding amount of the diatomite is 0.1-0.2% of the mass of the oxidized tea liquid, the adsorption time is 10-20min, the molecular weight cut-off of nanofiltration concentration is 800-1200Da, the solid content after concentration is 15-20%, the air inlet temperature of spray drying is 160-170 ℃, and the air outlet temperature is 70-80 ℃.
  9. 9. A tea powder with high aroma, low bitterness and tea red element enrichment is characterized in that the tea powder is prepared by the preparation method of the tea powder according to any one of claims 1-8, wherein the tea red element content in the tea powder is more than or equal to 5%, the light transmittance under ice water condition is more than or equal to 95%, and the total terpene substance content is more than or equal to 25 mug/g.
  10. 10. The use of a tea powder with high aroma, low bitterness and enriched thearubigins, characterized in that the tea powder of claim 9 is used for preparing cold-brew black tea beverage, baked food additive or functional health product.

Description

Tea powder with high aroma, low bitterness and tea red element enrichment, and preparation method and application thereof Technical Field The application relates to the technical field of tea fine and further processing, in particular to tea powder with high aroma, low bitterness and tea red element enrichment, a preparation method and application thereof. Background The tea is used as a traditional medicine and food homologous crop in China, the instant tea powder of a deep processing product is increasingly widely applied to the fields of beverages, baking, health care products and the like due to convenience and portability, and the instant black tea powder becomes one of main market products by virtue of unique flavor and color. At present, the traditional preparation process of the instant black tea powder mainly adopts the conventional processes of hot water leaching, normal pressure oxidation and spray drying, and the process has a plurality of technical bottlenecks: The fragrance defect is that more than 90% of fragrance substances in the tea exist in a glycoside bonding state, the bonding state fragrance precursor is not subjected to targeted hydrolysis by the traditional process, only a small amount of free fragrance substances can be extracted, the conventional hot water extraction (the temperature is more than or equal to 80 ℃) easily damages the thermolabile volatile fragrance such as linalool, nerol and the like in the tea, the fragrance of the final product is light, and even the fresh and refreshing flavor is lost due to the generation of 'cooked soup flavor' at high temperature. The bitter taste is prominent, the traditional process can not effectively degrade tea polyphenol (especially ester catechin) and soluble tannin which cause bitter taste in tea, and the finished product has heavy bitter taste and strong astringency, is easy to generate rough mouthfeel due to the combination of tannin and protein, and limits the application of the tea in low-astringent beverage. The traditional oxidation process is mostly normal-pressure air oxidation, the oxidation process is uneven and uncontrollable, and partial peroxidation is easy to generate a large amount of theabrownins, so that the tea powder soup color is dull and brown, the theabrownin content (generally less than 1%) with smooth mouthfeel and bright color is greatly reduced, and the product quality is influenced. The problem of turbidity after cold is remarkable, and the traditional instant black tea powder is easy to generate turbidity and sediment due to aggregation of substances such as pectin, macromolecular tea polyphenol and the like under the low-temperature or ice water environment, so that the requirements of cold tea beverage on clarity cannot be met. To solve the above problems, the prior art has attempted some improvements such as single enzyme treatment with addition of tannase or beta-glucosidase only, medium temperature extraction, ozone oxidation, etc., but all have limitations. For example, single enzyme treatment can only improve a certain index, such as that tannase only reduces astringency, beta-glucosidase only improves aroma, multi-index cooperative optimization cannot be realized, medium-temperature and constant-temperature extraction is difficult to extract aroma components with different molecular weights, ozone oxidation is too strong, aroma components are easy to be damaged excessively, and the risk of theabrownin generation is increased. In summary, the existing preparation process of instant black tea powder is difficult to realize multi-dimensional quality improvement of 'high thearubigin, low bitter and astringent taste, strong aroma, no muddy color after cooling and bright color', and development of a novel integrated and synergetic preparation process is needed. Disclosure of Invention In order to overcome the defects, the application provides the preparation method of the tea powder with high fragrance and low bitterness and enriched thearubigins, which realizes the beneficial effects of improving the thearubigins content in the tea powder, eliminating the bitterness and astringency and enriching the fragrance through the technology coupling of multi-enzyme compounding and synergism, low-temperature gradient extraction and controllable oxidization of nano bubbles. The technical scheme adopted by the application for solving the technical problems is as follows: a preparation method of tea powder with high fragrance, low bitterness and rich thearubigins comprises the following steps: raw material pretreatment, namely crushing black tea leaves, adding the crushed black tea leaves into water, and stirring to obtain tea leaf fine powder suspension; Adding a compound enzyme preparation into the tea fine powder suspension for enzymolysis and enzyme deactivation to obtain an enzymolysis tea liquid, wherein the compound enzyme preparation comprises at least two of cellulase, tannase, beta-glucosidase, alpha-L-rham