CN1197857C

CN1197857C - Method for extracting tea polyhenols and tea pigment

Info

Publication number: CN1197857C
Application number: CN 03149378
Authority: CN
Inventors: 张守政
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-06-25
Filing date: 2003-06-25
Publication date: 2005-04-20
Anticipated expiration: 2023-06-25
Also published as: CN1480457A

Abstract

The present invention relates to a method for extracting tea polyphenol and tea pigment, which is characterized in that weakly acidic solution which can make the active phenol hydroxy of the tea polyphenol stable is added in extracting solution to regulate a pH value to 6.5 to 6.8, pectin and protein are superfiltered, water is taken off by using a reverse osmosis membrane to concentrate, theobromine is removed by using dichloromethane, tea polyphenol is extracted by using ethyl acetate, and the tea polyphenol is made from an extract phase through exsolution, dilution by deionized water and spray drying by low-temperature nitrogen gas. Vacuum flashing is carried out to an extract remaining phase after the tea polyphenol is extracted to recover solvent, the pH value is regulated to 7.0 to 7.5 by using alkalescent solution, and the solvent is oxidized by filling air and is dehydrated and concentrated by reverse osmosis and sprayed and dried at the low temperature to make the tea pigment. The tea polyphenol extracted by the present invention has the advantage of obvious oxidation resistance, and the added value of the tea is simultaneously raised.

Description

The extracting method of tea-polyphenol and tea pigment

Technical field the invention discloses a kind of method of extracting tea-polyphenol and tea pigment from tealeaves.

The background technology modern scientific research proves, catechin in the tealeaves (EGCG, EGC, ECG, EC) can be removed human free radical and improve immunizing power for the tea-polyphenol of main body (GTP), have medical health care functions such as anti-oxidant, anti-ageing, radioprotective, anticancer change, and successfully be applied to medicine, healthcare products, grease and food service industry.

From tealeaves, extract the method for GTP,, can reduce four classes at present: be i.e. solvent extraction method, ion precipitation method, resin adsorption method and supercritical carbon dioxide extraction method according to the domestic and international Searches of Patent Literature.The ion precipitation method of I patent publication No. CN1104621, with the tea-polyphenol purity height of this method extraction, but yield is low, and cost is also high; The solvent extraction process of publication exists the low shortcoming of functionality active component NVP-XAA 723 (EGCG) content; Resin adsorption method cost height, technology is loaded down with trivial details, is difficult to adapt to scale operation; Though supercritical carbon dioxide extraction method advanced technology, investment is big, and with regard to extracting tea-polyphenol definite method parameter is not arranged as yet, will be applied to still lack on the tea-polyphenol suitability for industrialized production maturity of technology and reliability in the recent period.The extracting method that the purpose of this invention is to provide a kind of tea-polyphenol and tea pigment.

The inventive method comprise effective constituent lixiviate, solid-liquid separation, fast cold filtration, ultrafiltration and reverse osmosis, caffein-free, solvent extraction, extraction phase solvent recuperation, deionized water dilution, low temperature N ₂Spraying drying, extracting phase solvent reclaim, alkaline oxygenated, reverse osmosis concentration and low temperature spray drying.Task of the present invention is finished by mode as described below, in the effective constituent lixiviate, adding citric acid solution accent pH value is 6.5-6.8, the active phenol hydroxyl oxidize that prevents catechin is dehydrogenated to quinones, extracting solution after solid-liquid separation and fast cold filtration removes pectin and protein with the membrane ultrafiltration of molecular weight cut off 5～100,000, be that 100～200 reverse osmosis membrane removes the moisture content major part in the extracting solution with molecular weight cut off again, the concentrated extracting solution of preparation methylene dichloride wash-out trimethyl-xanthine, the dealkalize extracting solution that makes, remove residual methylene dichloride through the heating vacuum flashing, use the ethyl acetate extraction tea-polyphenol then, to get the tea-polyphenol slurries after the extraction phase vacuum distilling recovery ethyl acetate, with the deionized water dilution, again with the dry elaboration tea-polyphenol that gets of nitrogen spray.Extracting phase heated add sodium carbonate solution after ethyl acetate is reclaimed in vacuum flashing, transfer pH value 7.0～7.5, fill atmospheric oxidation, get tea pigment with spraying drying behind the reverse osmosis membrane removal moisture of molecular weight cut off 100～200 again.

The invention has the beneficial effects as follows:

1, product purity height, (GTP 〉=98%), yield height (〉=10%), trimethyl-xanthine low (≤0.5%);

2, in the leaching process, add protective material, prevent the oxidational losses of catechin effective constituent;

3, remove pectin and protein effectively with ultra-filtration membrane, improve the quality of products, use the reverse osmosis concentration extracting solution, save the steam energy consumption;

4, use the nitrogen spray drying again with the dissolvent residual in the vacuum flashing removal material with the tea-polyphenol slurries of deionized water dilution precipitation, make the product no solvent residue;

5, product color is good, good water solubility, EGCG content height;

6, the permeate water of reverse osmosis is returned the tealeaves lixiviate, reduces no dried up turnout, reduces cost;

7, method is simple, and is easy to operate, with low cost, is suitable for industrialization and automatic production;

8, the whole process of extracting method does not have waste water, does not have waste residue, does not have waste gas, meets environmental protection requirement.

2,3,4 is the significance characteristics in the above advantage.Enforcement shows that extracting method of the present invention is suitable for industrialization and automatic production, and the tea-polyphenol that utilizes the present invention to extract has significant oxidation-resistance, is particularly suitable for food antioxidant and related drugs raw material, has also improved the added value of tealeaves simultaneously.

The present invention is further described below in conjunction with drawings and Examples for description of drawings.

Fig. 1 is the schema of extracting method of the present invention.

Embodiment is pressed the tea-polyphenol extraction step and is described in detail.

1, claim broken green tea (end) 1000 grams, add 10 liters of 85 ℃ of hot water and constant temperature, transfer pH value 6.5～6.8 with 5% aqueous citric acid solution, the vacuum vacuumizing, stirring and leaching 40 minutes is emitted extracting solution through solid-liquid separation, and speed is chilled to temperature below 35 ℃, so repeat lixiviate once, merge extracted twice liquid and get 18.6 liters of refining extracting solutions through 120～200 orders industry strainer filtering.Capable of using as feed after the isolating tea grounds drying.

2, described refining extracting solution removes pectin and protein with the ultra-filtration membrane of molecular weight cut off 5～100,000, reverse osmosis membrane with molecular weight cut off 100～200 is concentrated into 6～8 times with extracting solution again, 2.6 liters of spissated extracting solutions under operation use, also can reach proportion through the vacuum-evaporation reconcentration is 1.2 when above, makes the food grade tea-polyphenol with spraying drying.

3, described concentrated extracting solution volume ratio is 1: 0.8 a methylene dichloride wash-out trimethyl-xanthine, and the extracting solution behind the caffein-free supplies operation extraction tea-polyphenol down.In containing the methylene dichloride of trimethyl-xanthine, add volume ratio and be the ammoniacal liquor wash-out theophylline two times of 1: 1 5% concentration, the methylene dichloride distillation is reclaimed, the trimethyl-xanthine slurries, make trimethyl-xanthine 10.8 grams of purity 99.99% with vacuum-drying.

4, described dealkalize extracting solution volume ratio is that 1: 1.2 ethyl acetate is carried out dynamic extraction, ethyl acetate distillation recycling use with extraction phase, tea-polyphenol underflow liquid with being that the spraying drying of thermophore makes 112.3 gram elaboration tea-polyphenol in order to nitrogen after 2 times of the deionized water dilutions, purity 98.2%, yield 11.2%, trimethyl-xanthine 0.35%, the aqueous sodium carbonate that adds 5% concentration after the extracting phase heating vacuum flashing recovery ethyl acetate is transferred pH value 7.0～7.5, fill air in extracting phase, make the abundant oxidation of residue tea-polyphenol, remove moisture with reverse osmosis membrane again, get concentrated solution and make 62.8 gram tea pigments with the Cryogenic air spraying drying.

5, the permeate water of two road reverse osmosiss is that pure water returns and is used for the tealeaves lixiviate in the described operation.

Claims

1, the extracting method of a kind of tea-polyphenol and tea pigment, method comprise effective constituent lixiviate, solid-liquid separation, fast cold filtration, ultrafiltration and reverse osmosis concentration, caffein-free, solvent extraction, extraction phase solvent recuperation, deionized water dilution, low temperature N ₂Spraying drying, extracting phase solvent reclaims, the alkalescence atmospheric oxidation, reverse osmosis concentration and Cryogenic air spraying drying, it is characterized in that: add the stable weakly acidic solution of active phenol hydroxyl that can make tea-polyphenol in the extracting solution and transfer pH value 6.5～6.8, take off pectin and protein with ultrafiltration, concentrate with the reverse osmosis membrane dehydration, use the methylene dichloride caffein-free, use the ethyl acetate extraction tea-polyphenol, extraction phase is through precipitation, deionized water dilution and low temperature nitrogen spraying drying make tea-polyphenol, extracting phase behind the extraction tea-polyphenol is carried out vacuum flashing reclaim solvent, transfer pH value 7.0～7.5 with weakly alkaline solution again, fill atmospheric oxidation, concentrate with low temperature spray drying with the reverse osmosis dehydration and make tea pigment;

Weakly acidic solution adopts citric acid, oxalic acid and acetic acid, and weakly alkaline solution adopts yellow soda ash, sodium bicarbonate and ammoniacal liquor;

The optimal selection of weakly acidic solution is a citric acid, and the optimal selection of weakly alkaline solution is a yellow soda ash; Remove pectin and protein in the extracting solution with ultrafiltration, the optimal selection of ultra-filtration membrane is molecular weight cut off 5～100,000;

The extracting solution dehydration concentrates and uses reverse osmosis, the optimal selection of film is molecular weight cut off 100～200;

The solvent methylene dichloride of extracting solution caffein-free;

Make tea-polyphenol with nitrogen for the thermophore spraying drying, the nitrogen inlet temperature is 185 ℃ Celsius when dry, and the tea-polyphenol temperature out is 80 ℃ Celsius;

Transferring pH value with sodium carbonate solution in the extracting phase behind the extraction tea-polyphenol is 7.0～7.5, produces tea pigment with atmospheric oxidation.