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CN-121991071-A - Preparation method for extracting caffeine

CN121991071ACN 121991071 ACN121991071 ACN 121991071ACN-121991071-A

Abstract

The invention discloses a preparation method for extracting caffeine, relates to the technical field of natural product extraction, and aims to solve the problems of low efficiency, more impurities, solvent residues, environmental pollution and the like of the traditional extraction method. The method comprises the steps of mixing tea powder with purified water, regulating pH, adding a compound enzyme preparation for enzymolysis, inactivating, centrifuging, drying to obtain a pretreated raw material, mixing a compound extraction solvent with the pretreated raw material, performing ultrasonic extraction, centrifuging to obtain a crude extract, adding petroleum ether into the crude extract for extraction and impurity removal, adding an antisolvent into a lower layer liquid to separate out a caffeine crude product, recrystallizing and purifying the crude product, and drying to obtain a caffeine finished product. The compound enzyme preparation contains enzyme and non-enzyme auxiliary agents, the compound extraction solvent is prepared by a specific process, the whole process has high extraction efficiency, high purity of finished products and less solvent residue, accords with the green production concept, and has good large-scale application potential.

Inventors

  • YUAN GUODONG
  • NING ZHEN
  • Deng Jiaji

Assignees

  • 云南悦然咖啡有限公司

Dates

Publication Date
20260508
Application Date
20260113

Claims (10)

  1. 1. The preparation method for extracting caffeine is characterized by comprising the following preparation steps: S1, mixing tea powder with purified water, regulating pH, adding a compound enzyme preparation for enzymolysis, inactivating, centrifuging and drying to obtain a pretreated raw material; s2, mixing the compound extraction solvent with the pretreatment raw materials, performing ultrasonic extraction, and centrifuging to obtain a crude extract; s3, adding petroleum ether into the crude extract to extract and remove impurities, and adding an antisolvent into the lower layer liquid to separate out a caffeine crude product; And S4, recrystallizing and purifying the crude caffeine product to obtain a multi-stage recrystallized crystal, and drying the multi-stage recrystallized crystal to obtain a finished caffeine product.
  2. 2. The method for preparing caffeine according to claim 1, wherein the mass ratio of the tea powder to the purified water to the complex enzyme preparation is 1:5-8:0.01-0.04.
  3. 3. The method for preparing caffeine according to claim 2, characterized in that the preparation method of the complex enzyme preparation comprises the following steps: Adding citric acid and chitosan into deionized water, stirring and dissolving, adding vitamin C, stirring uniformly to obtain non-enzyme auxiliary agent premix, adding cellulase and pectase into the non-enzyme auxiliary agent premix, and stirring uniformly to obtain the compound enzyme preparation.
  4. 4. The method for preparing caffeine extract according to claim 3, wherein the citric acid, chitosan, deionized water, vitamin C, cellulase and pectase are respectively 0.1-0.2 parts by weight of citric acid, 0.2-0.3 parts by weight of chitosan, 50-60 parts by weight of deionized water, 0.05-0.1 parts by weight of vitamin C, 1-3 parts by weight of cellulase and 1-2 parts by weight of pectase.
  5. 5. The method for preparing caffeine according to claim 1, wherein the enzymolysis temperature in S1 is 40-50 ℃ for 60-120 min, the inactivation temperature is 80-90 ℃ for 10-20 min, the centrifugation speed is 7000-9000 rpm for 15-25 min, and the drying temperature is 50-70 ℃ for 1-3 h.
  6. 6. The method for preparing caffeine according to claim 1, characterized in that the method for preparing the compound extraction solvent comprises the following steps: Adding choline chloride, D-sorbitol, betaine, glycerol and L-proline into deionized water, adding absolute ethanol, stirring at 80-85deg.C and 200-300 rpm for 30-50 min, and performing ultrasonic treatment at 100-150W for 5-8 min to obtain compound extraction solvent.
  7. 7. The method for preparing caffeine according to claim 6, wherein the choline chloride, the D-sorbitol, the betaine, the glycerol, the L-proline, the deionized water and the absolute ethyl alcohol are respectively 55-65 parts by weight of choline chloride, 18-22 parts by weight of D-sorbitol, 9-12 parts by weight of betaine, 4-6 parts by weight of glycerol, 2-3 parts by weight of L-proline, 55-70 parts by weight of deionized water and 8-24 parts by weight of absolute ethyl alcohol.
  8. 8. The method for preparing caffeine according to claim 1, wherein in the step S2, the mass ratio of the compound extraction solvent to the pretreated raw material is 25-35:10, the ultrasonic power is 200-400W, the extraction temperature is 60-70 ℃ for 15-25 min, and the centrifugal speed is 7000-9000 rpm for 10-20 min.
  9. 9. The method for preparing caffeine according to claim 1, wherein in the step S3, the volume ratio of petroleum ether to crude extract is 1:1-2, the extraction times are 2-4, the extraction time is 5min-15min each time, the volume ratio of antisolvent to lower layer liquid is 1.5-2.5:1, the dropping rate is 0.5mL/min-1.5mL/min, the standing time is 6h-10h, and the antisolvent is deionized water.
  10. 10. The method for preparing caffeine according to claim 1, wherein the specific method for recrystallization and purification in S4 is as follows: Primary recrystallization, namely adding the caffeine crude product into 70-80% ethanol water solution, stirring and dissolving at 75-80 ℃, filtering while the caffeine crude product is hot, cooling the caffeine crude product to 5-10 ℃ after filtering, and carrying out vacuum suction filtration to obtain primary recrystallization crystals; And (2) secondary recrystallization, namely adding 40-50% of ethanol water solution into the primary recrystallized crystal, stirring and dissolving at 75-80 ℃, filtering while the primary recrystallized crystal is hot, cooling the primary recrystallized crystal to 2-5 ℃ after filtering, and carrying out vacuum suction filtration to obtain the multistage recrystallized crystal.

Description

Preparation method for extracting caffeine Technical Field The invention relates to the technical field of natural product extraction, in particular to a preparation method for caffeine extraction. Background Caffeine is an important natural active substance, is widely applied to the fields of foods, medicines, beverages and the like, and is mainly extracted from natural products such as tea leaves, coffee beans and the like, wherein the tea leaves are rich in resources and low in cost, and become the preferable raw material for extracting the caffeine. At present, the extraction technology of caffeine in tea leaves has been developed to a certain extent, the traditional method mainly comprises a water extraction method and an organic solvent extraction method, the water extraction method is applied to a large number of small-scale production by virtue of the advantages of simplicity in operation and low cost, and the organic solvent extraction method improves the extraction efficiency by solvents such as chloroform, petroleum ether and the like, and is commonly used in the initial stages of pilot scale and industrial production. However, the prior art extraction techniques suffer from significant drawbacks. The traditional water extraction method is environment-friendly but low in extraction efficiency, the cell wall structure of tea is compact, caffeine is difficult to fully dissolve, the energy consumption is increased, a large amount of impurities such as tea polyphenol are dissolved out due to the fact that the extraction time is prolonged and the extraction temperature is increased, the subsequent purification difficulty is increased, the extraction efficiency can be improved by an organic solvent extraction method, but the used solvents are toxic, residues are easy to remain in products, the safety of food-grade and medical-grade caffeine is influenced, meanwhile, the solvent recovery process is complex, the waste liquid discharge is easy to cause environmental pollution, and the environment-friendly production concept is not met. Furthermore, there is still room for optimization in the prior art. The single enzymolysis method lacks the synergistic effect of non-enzyme auxiliary agents, the enzyme activity is easily affected by the oxidation of polyphenol substances in tea leaves, the cell wall breakage rate is limited, and the ultrasonic auxiliary extraction can strengthen mass transfer, but has insufficient selectivity on caffeine and can still dissolve out a large amount of impurities. Meanwhile, the compatibility of the existing compound extraction solvent formula is poor, partial solvent is difficult to match with the subsequent recrystallization process, so that the solvent recovery efficiency is low, the cost is high, a synergistic mechanism of enzyme and auxiliary agent is not formed in the compound enzyme preparation system, the enzymolysis effect is unstable, and the large-scale application of the caffeine extraction process and the product quality improvement are restricted. Therefore, in light of the limitations of the related art described above, there is a need to develop a method for preparing caffeine extraction. Disclosure of Invention Accordingly, the invention aims to provide a preparation method for extracting caffeine, which effectively solves the problems of low extraction efficiency, high energy consumption and more impurity dissolution in the traditional water extraction method, and the problems of residual solvent toxicity, easy environmental pollution and high solvent recovery difficulty in the organic solvent extraction method. The aim of the invention can be achieved by the following technical scheme: The invention provides a preparation method for extracting caffeine, which comprises the following preparation steps: S1, mixing tea powder with purified water, regulating pH, adding a compound enzyme preparation for enzymolysis, inactivating, centrifuging and drying to obtain a pretreated raw material; s2, mixing the compound extraction solvent with the pretreatment raw materials, performing ultrasonic extraction, and centrifuging to obtain a crude extract; s3, adding petroleum ether into the crude extract to extract and remove impurities, and adding an antisolvent into the lower layer liquid to separate out a caffeine crude product; And S4, recrystallizing and purifying the crude caffeine product to obtain a multi-stage recrystallized crystal, and drying the multi-stage recrystallized crystal to obtain a finished caffeine product. Further, the mass ratio of the tea powder to the purified water to the compound enzyme preparation is 1:5-8:0.01-0.04. Further, the preparation method of the complex enzyme preparation comprises the following steps: Adding citric acid and chitosan into deionized water, stirring and dissolving, adding vitamin C, stirring uniformly to obtain non-enzyme auxiliary agent premix, adding cellulase and pectase into the non-enzyme auxiliary agent premix, a