CN85102970A - The production technology of decaffeination tea - Google Patents

Abstract

The invention provides a kind of technology of producing decaffeination tea with carbon dioxide extraction method, aspect pressure and temperature, be supercriticality, there is moisture to exist, tealeaves is deployed into and contains 15% to 50% of water accounts weight, at first between 350 crust, extract at pressure 260 crust with saturated carbon dioxide down at 50 ℃ to 70 ℃, in identical pressure limit, caffeine is extracted from the carbon dioxide that contains caffeine then with activated carbon, then noncaffein carbon dioxide is recycled use on stripped tealeaves, with tealeaves by separating in the carbon dioxide and oven dry.

The present invention also provides a kind of device that carries out this technology.

Description

The production technology of decaffeination tea

The method of known various tealeaves decaffeinations, the opinion with the coffee decaffeination, available fresh coffee beans is made raw material.When the tealeaves decaffeination, must begin by fermented product, this practice is very crucial to keeping fragrance, and just extracts coffee thereby opinion, this is disadvantageous usually.

The various technologies of known decaffeination, all with an organic solvent, but all solvents all have shortcoming, and promptly most fragrance is also sloughed, and is difficult to solvent is removed from tealeaves fully.

Germany patent right specification has illustrated a kind of technology of tealeaves decaffeination for No. 2127642, the first step of its technology is with dry supercritical carbon dioxide, from stem tea, remove spices, second step was with saturated supercritical carbon dioxide slective extraction caffeine subsequently, dry tealeaves later on again, and the spices of separating in the first step extraction process is flooded.Should carry out at 40 to 60 ℃ with this method extraction, suffer a loss, only after the spices extracting goes out, just use high temperature for avoiding spices.The extraction of caffeine is depressed at 200 to 250 crust gas and is carried out.Then temperature and pressure is dropped to below the critical zone, by separating caffeine in the carbon dioxide.

The shortcoming of this technology maximum is that spices must be earlier extracts under gentle as far as possible condition, then could under comparatively harsh separation condition caffeine be extracted.Other shortcoming of this technology is to need the twice operational sequence.Separate caffeine with decompression with cooling at last and require great effort equally very much,, just can make carbon dioxide enter critical range once again because must consume lot of energy later on.

According to No. 2637197, Germany patent specification, once attempted to overcome the latter's shortcoming and will use ion-exchanger, separate caffeine from the carbon dioxide of subcritical range, the two procedures of known tea extraction still keeps the end and becomes, and the condition of use is 40 ℃ and 200 crust.

One object of the present invention provides the tealeaves that a step operation of in fact more simplifying is produced decaffeination, and this method just extracts caffeine selectively, and does not extract the spices in the tealeaves simultaneously.When being extractant, do not need temperature and pressure between overcritical and subcritical, to change with carbon dioxide yet.

Therefore a kind of technology proposed according to the present invention, produce the tealeaves of decaffeination with carbon dioxide extraction method, its pressure and temperature is critical, water is deployed into water content with tealeaves and accounts for 15% to 50% of weight, extract in pressure 260 to 350 crust, 50 ℃ to 70 ℃ conditions of temperature with saturated carbon dioxide, optimum temperature is at 60 ℃ to 70 ℃ next time.In the pressure limit of regulation, with activated carbon caffeine is separated from the carbon dioxide that contains caffeine, the noncaffein carbon dioxide recirculation that obtains thus is used in the tealeaves of decaffeinated, and tealeaves takes out the back oven dry.

The present invention is based on this wonderful discovery promptly tieing up under above-mentioned specified pressure and the temperature under the temperature-resistant situation of tealeaves, only extracts caffeine selectively and is actually possible.The dipping again of the separating and extracting of spices and decaffeinated tea can save like this.Although used high temperature, the spices that surprisingly has sensitiveness in fact also produces any substantial variation in the end, and tealeaves is in fact still keeping its former flavoursome and fragrance.So on the basis of this slective extraction method, also can use low-cost activated carbon without ion-exchanger, caffeine with extraction from carbon dioxide extracts, although the Germany patent specification advises that people do not use activated carbon for No. 2637197, because its selectivity is not high.

As for technology according to the present invention, be generally used for tealeaves, add water capacity 15% to 50%(that water is formulated to regulation in advance by weight).The allotment of water capacity can be finished very easily, is placed on the tealeaves that suitably whisks in the machine and whisks as long as the water of specified quantity added, and makes uniformity of temperature profile.It is good that the tealeaves water content is transferred to 25% to 40% of weight, accounts for 28% to 35% best results with wet weight.

As mentioned above, carbon dioxide uses under super critical condition and saturation state.As above-mentioned, pressure must be at 260 crust between 350 crust, and it is good clinging to 300 with 260 crust, and the best is that 270 crust are to 290 crust.The set point of temperature scope is critical-temperature for 50 ℃ to 70 ℃.As be lower than 50 ℃ lower limit, and caffeine extraction total amount will sharply descend, and make very uneconomically of this technology behaviour, and the extraction cycle of needs is long.Surpassing under 70 ℃ of situations of the upper limit, fragrance can play bad variation.

The consumption of carbon dioxide is decided by the total amount of extraction caffeine in the tealeaves.Because under the pressure and temperature condition of regulation, approximately the per kilogram carbon dioxide can extract 0.2 gram caffeine.The every gram caffeine of extraction is good to use about 2～20 kilograms of carbon dioxide from tealeaves, and optimum amount is about 3～10 kilograms.

Extraction was carried out about 2～10 hours usually, kept the pressure and temperature in the prescribed limit later on, will be full of the carbon dioxide of caffeine, and input is separated with activated carbon and touched, and being good with the activated carbon form of bio-carrier, so caffeine is inhaled in the feeding activated carbon.Carbon dioxide is sloughed after the caffeine under extracting pressure, and recirculation is used for stripped tealeaves, feeds the moisture of the similar equivalent amount that brings out because of extraction then again to there.This technology preferably uses several extraction autoclaves to carry out, in parallel or series connection all can, and can from process cycles, single separation use.After recirculation stopped, content of caffeine reduced greatly in the wet tealeaves of making, and in fact its flavour content does not change, and this tealeaves is preferably under 60 ℃ to the 80 ℃ temperature and dries, and just can directly drink later.

Be adsorbed on the activated carbon aspect as for caffeine, preferably keep 50 ℃ to 70 ℃ of temperature.Carbon dioxide to stripped tealeaves recirculation use simultaneously with its humidification, carrying out to good, and with best between 60 ℃ to 70 ℃ 50 ℃ to 70 ℃ scopes.

Contain the activated carbon useable solvents extraction of caffeine, spices is separated from caffeine, spices is added in the stripped tealeaves again gone with the salt forming method.

The extraction of tealeaves can be carried out in the autoclave of routine, fills up tealeaves in the still, and carbon dioxide longitudinally flows through tealeaves.For well, the draw ratio of standard is about 3: 1 to 8: 1 to this extraction autoclave with cylindrical shape.This extraction autoclave simple structure treats that by the lid that can open extract is easy to be loaded.

We find the like this extraction autoclave of structure, and the bad material caking phenomenon of dosing usually takes place, and the reason that produces this phenomenon is the adhesive force that the shape of particle of tealeaves and other natural materials has height.Technological parameter such as temperature, carbon dioxide volume flow, compression ratio and liquid flow volume changes in flow rate all might make material produce caking in addition.

Loose when dosing material and beginning to lump, flow through the pressure loss of dosing material and strengthen, thereby to cause further caking, result be to form air flue, this has just caused on the cross section of autoclave and the inhomogeneities of extraction on aspect the height, thereby has prolonged necessary extraction cycle widely.

The concrete device of being recommended according to the present invention, these shortcomings can overcome, its method is to treat that extract is that tealeaves is arranged according to hollow garden tube mode, extraction is carried out in the concentric shafts mode, introduce undersaturated carbon dioxide by garden tube surface, at another surface aggregation of cylinder, saturated carbon dioxide passes through the activated carbon carbon dioxide by there again, the outside of main cylinder is introduced the most favourable, because the shape of hollow cylinder is suitable, this just might be placed on activated carbon the inner chamber of hollow garden tube, flox condition advantageous particularly there.

According to the radius flow method of recommending, change continuously to another surface emissivity flow cross section by this surface of hollow garden tube, circulation is inevitable to be carried out towards this direction.Here the comparing it by the outside with the garden tubular autoclave of general axial radius flow to the concrete device of inner radius flow and dose the suffered gas in material surface and impact and want big 15 to 20 times of special recommendation, and the surface of last inner chamber is subjected to gas and impacts and want big 5 times, and this depends on the size of the diameter of inner chamber.Blank pipe gas speed and duct gas speed are all relatively low between adjacent particles, because average residence time is constant in autoclave, the contact cycle of each independent particle greatly increases.

Dose the mechanical stress that thing is subjected to and also significantly reduce in this concrete device, the known pressure loss becomes with blank pipe speed square and directly is directly proportional with the flowing through channel of liquid.Since the flowing through channel of the carbon dioxide of radius flow extraction only approximately be the axial radius flow of autoclave the carbon dioxide flowing through channel 1/10th, therefore dose the pressure that material is subjected to and also can avoid.

The special superiority of radiant flux dynamic formula extraction shows, introduce the extraction fluid by the outer cover of garden tube, another advantage is can place activated carbon in the hollow lumen of hollow garden tube, the pressure loss in the pipeline is avoided between extraction autoclave and the separation autoclave like this, and best mode of operation just becomes possibility.

Be to carry out concrete device that the radiant type extraction process uses as shown in the figure according to the present invention, for example accompanying drawing 2, comprise garden tube autoclave 1, extractant inlet 2, lid 3 and be installed on extractant extractor 4 in the autoclave, garden cartridge type extract container 5, attached sieve aperture cover 6 and be placed in sieve aperture extractant surge drum 7 on the tube axis of garden docks with the extractant extractor.Sieve aperture extractant surge drum 7 can be tubular.When the extraction fluid needs to collect, when directly flowing to another separation autoclave that is filled with activated carbon through extractant extractor 4, adopt the surge drum advantageous particularly of this form by the extraction autoclave.Yet according to the special performance of device of the present invention, extractant surge drum 7 is filled with activated carbon, adorn in addition a separation autoclave just become unnecessary.Extract container 5 can have a ring cover 8, passes it and stretches out extractant surge drum 7.

According to device of the present invention, the flow on the filler to be extracted is even.

The container 5 for the treatment of extract can be fixed in the autoclave, also can be by there dismounting, and according to this structure, could be after having only this container 5 to pull down to garden tubular autoclave charging.The rational structure of extractant surge drum 7 is, when dosing the thing filler, it can disassemble from this device, and so just tube has been changed the material discharging process of dosing, upgrade again dose material before, again pipe is inserted.Yet this surge drum also can fixedly mount.

Concrete device of technology of the present invention and device are treated extract and are used the radius flow method, can be used for the material of dosing of any kind of in principle, and they can bear with the extractant resemble the carbon dioxide and carry out high pressure extraction.

For example purpose is for the present invention will be described below, can consult accompanying drawing, wherein:

Fig. 1 is the schematic diagram of an apparatus according to the invention, and detailed explanation is arranged in example,

Fig. 2 is the schematic diagram of the radius flow extraction kettle according to the present invention.

Example

10 kilograms of Ceylon's mixed type tealeaves contain moisture that accounts for weight 5.9% and the caffeine that accounts for weight 3.3%, use water-soaked in whisking device, put into subsequently in the extraction autoclave (E).Add 7 kilograms of activated carbon in the absorber (A).By pump P1 carbon dioxide is pumped by liquefaction basin (V), extraction autoclave and absorber are under 200 bar pressures, afterwards, the pump P1 in the flow process is turned off.Start after the pump P2, carbon dioxide circulates through extraction autoclave and absorber, and temperature is heated to 63 ℃ by heat exchanger W1 in the extraction autoclave, gets 290 crust of autoclave internal pressure.Absorber is in pressure 280 crust and 61 ℃ of operations of temperature, and after 2.5 hours, extraction is ended, and discharges the carbon dioxide in the extraction autoclave, up to the co 2 liquefaction basin in pressure balance, discharge later on and enter atmosphere.By taking out tealeaves 70 ℃ of oven dry down in baker in the extraction autoclave.The residual content of caffeine that the moisture content of weight of accounting for 4.5% is arranged and account for weight 0.08% of tealeaves after the extraction that is obtained.

Claims (19)

1, produces the technology of decaffeination tea with carbon dioxide extraction method, aspect pressure and temperature, be postcritical, and there is moisture content to exist, water allotment tealeaves, its water content accounts for 15%～50% of weight, at first under 50 ℃～70 ℃, with saturated carbon dioxide, under pressure 260 crust～350 crust situations, extract, in same pressure limit, from the carbon dioxide that contains caffeine, extract caffeine with activated carbon then, afterwards, the carbon dioxide recirculation of removing caffeine is used in stripped tealeaves, tealeaves is separated from carbon dioxide and dries.

2, according to claim 1 described technology, wherein before extraction, tealeaves is deployed into water content and accounts for 20%～40% of weight.

3, according to claim 2 described technologies, wherein before extraction, tealeaves is deployed into water content and accounts for 28%～35% of weight.

4, according to claim 1 described technology, wherein pressure carbon dioxide remains on 260 crust～300 crust.

5, according to claim 4 described technologies, wherein carbon dioxide keep-ups pressure at 270 crust～290 crust.

6,, wherein extract between 60 ℃～70 ℃ of temperature and carry out according to claim 1 described technology.

7, according to claim 1 described technology, wherein by extracting caffeine in the tealeaves, every gram caffeine uses 2～20 kilograms carbon dioxide.

8,, wherein 3～10 kilograms of carbon dioxide have been used by the every gram caffeine of extraction in the tealeaves according to claim 7 described technologies.

9, according to claim 1 described technology, wherein contain the activated carbon solvent extraction of caffeine, with forming method with caffeine by separating in the spices, spices is added in the stripped tealeaves more then.

10, according to the described technology of above-mentioned any claim, wherein tealeaves is put into hollow cylinder, extract, by a unsaturated carbon dioxide that introduce on the surface of cylinder in the concentric shafts mode, collect saturated carbon dioxide on the drum surface over there, feed in the activated carbon.

11, according to claim 10 described technologies, wherein carbon dioxide is introduced by the outer surface of cylinder and is assembled in the cylinder upper plenum.

12, according to claim 11 described technologies, wherein activated carbon is put in the inner chamber of hollow cylinder.

13, according to the production technology of claim 1 to 12 described decaffeinated tea, in fact according to preceding method and for example, and produce the tealeaves of decaffeination with reference to accompanying drawing.

14, the decaffeination tea of producing according to described any one the technology of claim 1 to 13.

15, finish the device of claim 1 described technology, comprise cylindrical shape autoclave band extractant inlet, lid and be placed on extractant extractor in the autoclave, band sieve aperture cover cylinder type extract container, be installed in the sieve aperture extractant surge drum on the cylinder axis in addition, this surge drum docks with the extractant extractor.

16, according to claim 15 described devices, wherein sieve aperture extractant surge drum is made cast.

17, according to claim 16 described devices, wherein be filled with activated carbon in the extractant surge drum.

18, according to claim 15 to 17 described devices, wherein the extract container has ring-like lid, and the extractant surge drum is by wherein stretching out.

19, according to claim 15 described devices, example was described and enumerated in the front in fact, and with reference to accompanying drawing.

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