SYSTEM FOR EXTRACTING A POWDER RICH IN CAFFEINE

Abstract

The present invention relates to a system for extracting/separating a caffeine-rich powder from the silverskin which surrounds the coffee seed/bean using an apparatus comprising at least one chamber for premixing distilled water and silverskin, an ultrasonic extraction cell comprising at least one module comprising at least one acoustic transducer and one acoustic radiation emitter, at least one mechanical separation tank, at least one drying unit and at least one apparatus monitoring/control unit, wherein the caffeine-rich powder is extracted/separated as a result of the breakdown of the silverskin molecular structure by the acoustic energy generated by the vibratory movement of the acoustic radiation emitter actuated by the acoustic transducer, and as a result of the chemical affinity of caffeine for distilled water.

Claims

1. (canceled)

2. An apparatus for extracting a caffeine-rich powder from the silverskin surrounding the coffee seed/bean, said extraction apparatus comprising: at least a chamber (1) which has at least one rotating blade (1a), an inlet valve (6), an acoustic transducer (8), an acoustic radiator (9), and an outlet valve (7); at least a variable-flow pump (10) with an electrovalve (11), and a flow meter/regulator (13); at least an extraction cell (2) comprising a module (2a, 2b) an acoustic transducer (14, 15) and one acoustic radiator (16, 17); at least a mechanical separation tank (3); at least a drying unit (4); and at least an apparatus monitoring/control unit (5), wherein the acoustic transducers (8), (14) and (15) operate in the frequency range of 19 to 21 kHz, preferably of 19.5 to 20.5 kHz, the acoustic radiators (9) and (16) emit axial waves while the acoustic radiator (17) emits radial waves, the acoustic radiator (9) has a cylindrical shape and flat top, with a diameter varying between 30 and 60 mm, preferably between 50 and 60 mm, and a variable wavelength in the range of 4 to 14 HWL (wavelength in mm), acoustic radiator (16) has a cylindrical shape and flat top, with a diameter of between 20 and 60 mm, and a variable wavelength ranging from 3 to 9 HWL (wavelength in mm), the acoustic radiator (17) has a cylindrical shape and spherical top, with a diameter between 20 and 60 mm, and a variable wavelength between 3 and 9 HWL (wavelength in mm), the acoustic intensity in the module (2a) is between 80 and 650 W/cm2 and the acoustic energy varying between 50 and 600 W/l from the acoustic transducer (14), and the working temperature and working pressure in the drying unit (4) is respectively under 50° C. and under 20 bar.

3. The apparatus of claim 2, wherein the acoustic radiator (16) a cylindrical shape and flat top, with a diameter between 50 and 60 mm,

4. The apparatus of claim 2, wherein the acoustic radiator (16) has a variable wavelength between 5 and 7 HWL (wavelength in mm).

5. The apparatus of claim 2, wherein the acoustic radiator (17) a cylindrical shape and spherical top, the cylindrical shape having a diameter between 50 and 60 mm.

6. The apparatus of claim 2, wherein the acoustic radiator (17), has a variable wavelength between 5 to 7 HWL (wavelength in mm).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0053] FIG. 1a is shown schematically and in simplified form an embodiment of the extraction system of the powder rich in caffeine and bioactive compounds according to the present invention.

[0054] FIG. 1b is shown schematically and in simplified form an embodiment of the extraction system of the powder rich in caffeine and bioactive compounds according to the present invention.

DETAILED DESCRIPTION

[0055] In FIG. 1a and FIG. 1b is shown schematically and in simplified form an embodiment of the extraction system of the powder rich in caffeine and bioactive compounds according to the present invention.

[0056] The silverskin caffeine-rich powder extraction system according to the present invention comprises a chamber for pre-mixing the distilled water and the silverskin 1, an ultrasonic extraction cell 2 comprising two modules 2a and 2b, a tank 3 with a mechanical separation system 3a, a drying unit 4 and an apparatus control unit 5.

[0057] Distilled water is introduced into the premixing chamber 1 via valve 6 and the silverskin, as obtained in the coffee roasting, i.e., without any prior processing including milling or grinding, is introduced by valve 7; premixing of the distilled water and silverskin is achieved by the action of a rotating blade 1a, an acoustic transducer 8 and an acoustic radiator 9 with mixing characteristics, namely of cylindrical shape and flat top, with a diameter varying between 30 and 60 mm, preferably between 50 and 60 mm, and a variable wavelength in the range of 4 to 14 HWL (wavelength in mm), preferably between 7 and 9 HWL.

[0058] The distilled water and silverskin premixture is pumped from chamber 1 into extraction cell 2 by means of a variable-flow pump 10.

[0059] The distilled water and silverskin premixture enters module 2a of extraction cell 2 via electrovalve 11 and passes to module 2b via electrovalve 12. Flow meter/regulator 13 allows for variation in the volume/time ratio of the distilled water and silverskin mixture exposed to the acoustic intensities generated by the two acoustic transducers 14 and 15 present in the modules 2a and 2b respectively.

[0060] In the first extraction module 2a the mixing/extraction of the distilled water and silverskin premixture is carried out using acoustic transducer 14 and acoustic radiator 16 having mixing/extraction characteristics, namely of cylindrical shape and flat top sonotrode), with a diameter of between 20 and 60 mm, preferably between 50 and 60 mm, and a variable wavelength ranging from 3 to 9 HWL (wavelength in mm), preferably between 5 and 7 HWL.

[0061] In the second extraction module 2b the extraction/homogenization of the distilled water and silverskin mixture from the extraction module 2a is effected using acoustic transducer 15 and acoustic radiator 17 having extraction/homogenization characteristics, namely of cylindrical shape and spherical top (sonotrode), with a diameter between 20 and 60 mm, preferably between 50 and 60 mm, and a variable wavelength between 3 and 9 HWL (wavelength in mm), preferably between 5 and 7 HWL.

[0062] The acoustic transducers 8, 14 and 15 operate in the frequency range of 19 to 21 kHz, preferably of 19,5 to 20,5 kHz; the acoustic radiators 9 and 16 emit axial waves while the acoustic radiator 17 emits radial waves.

[0063] In module 2a the mixture of distilled water and silverskin is exposed to an acoustic intensity of between 80 and 650 W/cm2 and to an acoustic energy varying between 50 and 600 W/l, dissipated axially and mainly through the top of the acoustic radiator 16, in hammer effect.

[0064] In module 2b the mixture of distilled water and silverskin is exposed to an acoustic power density of between 1 and 10 W/cm3 and a variable acoustic energy of between 50 and 600 W/l, dissipated radially over of the surface of the acoustic radiator 17.

[0065] Ultrasounds result in the breakdown of the molecular structure that makes up the silverskin, and the caffeine is isolated by dissolution into water, given the chemical affinities that the molecular structure of caffeine has for the molecular structure of water; this effect, obtained by a purely physical process, avoid the need for prior grinding of the silverskin in the present invention, and more importantly, avoid the need for the use of solvents, so making it a clean, non-effluent generating process.

[0066] After exposure to the acoustic effect produced by the acoustic radiators 9, 16 and 17, the aqueous solution of powder rich in caffeine and bioactive compounds passes via electrovalve 18 to the tank 3, through the mechanical separation device 3a in which the agglomerated particles are removed in the form of slurries, which are then transferred under pressure into filter press 19, by which they are withdrawn from the system.

[0067] The aqueous solution of caffeine-rich powder from tank 3 passes through electrovalve 20 into feed 21 of drying unit 4; the aqueous suspension of powder rich in caffeine is subjected to a water removal process in the drying unit 4; this removal should be carried out at a temperature not exceeding 50° C. and a pressure below 20 bar in order to allow drying of the aqueous solution and to obtain a concentrated powder rich in caffeine with unaltered qualities 22.

[0068] The control unit 5 enables automatic and continuous control of all process parameters, including flow-rates, time of exposure of the aqueous solution to acoustic radiation, and temperature monitoring.

[0069] The present invention has the following advantages: [0070] a. makes use of the silverskin, as a by-product of coffee roasting, which is usually discarded; [0071] b. avoid the need for milling or grinding of the silverskin, as a prior step of the extraction process; [0072] c. allows for the continuous extraction of a powder rich in caffeine and bioactive compounds through an extremely efficient solvent-free process which does not produce effluents that need to be treated, thus being environmentally clean, producing no solid residue other than that already produced during the full treatment of silverskin; [0073] d. maximizes the extraction of a powder rich in caffeine from the silverskin in a reduced number of steps and in an autonomous and continuous fashion, so reducing costs and production times; [0074] e. houses acoustic radiators and transducers in separate modules, which operate autonomously, providing different acoustic effects according to the geometries used.

Numerical References:

[0075] 1—Chamber

[0076] 1a—Rotating blade

[0077] 2—Ultrasonic extraction cell

[0078] 3—Tank

[0079] 3a—Mechanical separation device

[0080] 4—Drying unit

[0081] 5—Apparatus control unit

[0082] 6—Distilled water supply valve

[0083] 7—Silverskin supply valve

[0084] 8—Acoustic transducer

[0085] 9—Acoustic radiator

[0086] 10—Variable-flow pump

[0087] 11—Electrovalve

[0088] 12—Electrovalve

[0089] 13—Flow-meter

[0090] 14—Acoustic transducer

[0091] 15—Acoustic transducer

[0092] 16—Acoustic radiator

[0093] 17—Acoustic radiator

[0094] 18—Electrovalve

[0095] 19—Filter press

[0096] 20—Electrovalve

[0097] 21—Electrovalve

[0098] 22—Collection of caffeine-rich powder

Bibliography

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