U.S. patent application number 14/056126 was filed with the patent office on 2014-02-13 for mocha-making apparatus with separating of steam fraction.
This patent application is currently assigned to ILLYCAFFE' S.P.A.. The applicant listed for this patent is ILLYCAFFE' S.P.A.. Invention is credited to Bruno DELLAPIETRA, Luca MASTROPASQUA, Luciano NAVARINI, Furio SUGGI LIVERANI.
Application Number | 20140044845 14/056126 |
Document ID | / |
Family ID | 34971600 |
Filed Date | 2014-02-13 |
United States Patent
Application |
20140044845 |
Kind Code |
A1 |
NAVARINI; Luciano ; et
al. |
February 13, 2014 |
MOCHA-MAKING APPARATUS WITH SEPARATING OF STEAM FRACTION
Abstract
An apparatus for preparing a coffee beverage inducing the
passage of an extraction fluid through a dose of coffee by heating
said fluid, includes a separating device arranged to separate a
fraction of said beverage obtained with a prevalently liquid phase
of said fluid from a further fraction of said beverage obtained
with a prevalently steam phase of said fluid; an apparatus for
preparing a coffee beverage by imbibing a dose of coffee with an
extraction fluid driven by heating through said dose, includes an
inhibition device arranged to inhibit said imbibing when said fluid
contains a substantial steam phase; a method for obtaining a coffee
beverage includes heating an extraction fluid so as to induce the
passage of said extraction fluid through a dose of coffee to obtain
said beverage and separating a fraction of said beverage obtained
with a prevalently liquid phase of said extraction fluid from a
further fraction of said beverage obtained with a prevalently steam
phase of said extraction fluid is provided for.
Inventors: |
NAVARINI; Luciano; (Trieste,
IT) ; MASTROPASQUA; Luca; (Trieste, IT) ;
DELLAPIETRA; Bruno; (Duino Aurisina (TS), IT) ; SUGGI
LIVERANI; Furio; (Trieste, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ILLYCAFFE' S.P.A. |
Trieste |
|
IT |
|
|
Assignee: |
ILLYCAFFE' S.P.A.
Trieste
IT
|
Family ID: |
34971600 |
Appl. No.: |
14/056126 |
Filed: |
October 17, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13242877 |
Sep 23, 2011 |
8590444 |
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14056126 |
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11632954 |
Feb 7, 2007 |
8053012 |
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PCT/EP2005/006045 |
Jun 6, 2005 |
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13242877 |
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Current U.S.
Class: |
426/433 |
Current CPC
Class: |
A47J 31/30 20130101;
A47J 31/303 20130101; A47J 31/002 20130101 |
Class at
Publication: |
426/433 |
International
Class: |
A47J 31/30 20060101
A47J031/30 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 30, 2004 |
IT |
MO2004A000202 |
Claims
1. Method for obtaining a coffee beverage comprising heating an
extraction fluid so as to induce the passage of said extraction
fluid through a dose of coffee to obtain said beverage, wherein it
is provided for separating a fraction of said beverage obtained
from a prevalently liquid phase of said fluid from a further
fraction of said beverage obtained from a prevalently steam phase
of said fluid, said separating being provided after said beverage
has been obtained.
2. Method according to claim 1, wherein said separating comprises
conveying said fraction to a designated container by means of a
conveying conduit element.
3. Method according to claim 1, wherein said separating comprises
further conveying said further fraction to a tank of an apparatus
for making coffee beverages by means of a conduit element.
4. Method according to claim 1, and further comprising pouring said
extraction fluid to be heated into a suitable containing
device.
5. Method according to claim 4, and further comprising inhibiting
said passage of said extraction fluid through said dose of coffee
to avoid the formation of said further fraction of beverage.
6. Method according to claim 5, wherein said inhibiting comprises
detecting the temperature of said fluid inside said containing
device.
7. Method according to claim 6, wherein said detecting the
temperature comprises adjusting the temperature of said extraction
fluid inside said containing device within a desired range of
values.
8. Method according to claim 7, wherein said adjusting the
temperature comprises maintaining the temperature of said fluid
inside said containing device within values comprised between
approximately 60.degree. C. and 120.degree. C.
9. Method according to claim 5, wherein said inhibiting comprises
detecting the level of said fluid inside said containing
device.
10. Method according to claim 5, wherein said inhibiting comprises
detecting the pressure of said fluid inside said containing
device.
11. Method according to claim 5, wherein said inhibiting comprises
further maintaining the pressure inside said containing device
within a desired range of values by safety a relief valve
element.
12. Method according to claim 11, wherein said further maintaining
comprises maintaining the relative pressure in said containing
device by means of a safety valve element within a range of values
comprised between approximately 0.01 bar and 5 bar.
13. Method according to claim 5, wherein said inhibiting further
comprises transmitting warning signals to a user.
14. Method according to claim 13, wherein said transmitting signals
comprises transmitting acoustic signals.
15. Method according to claim 13, wherein said transmitting signals
comprises transmitting visible signals.
16. Method according to claim 5, wherein said inhibiting further
comprises stopping said heating.
17. Method according to claim 5, wherein said inhibiting further
comprises appropriately regulating the power absorbed during said
heating.
18. Method according to claim 1, wherein said heating comprises
absorbing heat from an electric resistance device arranged to
generate said heating.
19. Method according to claim 1, and further comprising the use of
coffee in powder or anyway minced form.
20. Method according to claim 1, and further comprising the use of
capsules, portions or cartridges containing desired preset
quantities of coffee powder.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser.
No. 13/242,877, filed Sep. 23, 2011, now allowed, which is a
divisional of U.S. application Ser. No. 11/632,954, filed Feb. 7,
2007, now U.S. Pat. No. 8,053,012, which is the U.S. national phase
of International Application PCT/EP2005/006045, filed Jun. 6, 2005,
which designated the U.S. and claims priority of Italian Patent
Application No. MO2004A000202, filed Jul. 30, 2004, the entire
contents of each of which are hereby incorporated by reference in
its entirety.
DESCRIPTION
[0002] The invention relates to improved methods and apparatuses
for obtaining coffee-based beverages, in particular to be prepared
with steam-pressure coffee machines.
[0003] Different types of steam-pressure coffee machines are known
that are used above all for domestic use, in which the steam
generated inside a boiler exerts a pressure that thrusts the water
contained in the boiler to pass through a panel of coffee powder,
producing to the coffee beverage.
[0004] Such steam-pressure coffee machines shall hereinafter be
referred to as "Mocha".
[0005] The "Mocha" coffee machines in the embodiment shown in FIG.
10a comprise two receptacles that can be hermetically tightened
together: a first receptacle acts as a boiler formed in such a way
as to contain water to be heated and to be itself heated by a
suitable source of energy, and is provided with a relief valve that
is suitably calibrated and arranged to prevent the pressure inside
the boiler from exceeding a set limit value, a second receptacle
that acts as a tank in which the produced beverage is
collected.
[0006] "Mocha" coffee machines furthermore comprise a filtering
funnel interposed between the boiler and the tank and formed in
such a way as to receive a set quantity of coffee powder, and a
duct for conveying the produced coffee beverage to the tank.
[0007] When it is desired to prepare the coffee, a desired quantity
of water is poured into the boiler and a desired quantity of coffee
is poured into the filtering funnel container and the water of the
boiler is heated to take it to boiling point.
[0008] As known to those skilled in the art, heating produces
increased pressure inside the boiler that thrusts the water therein
to pass through the filtering funnel, to go through the coffee
powder, thereby imbibing it and giving rise to the coffee beverage,
which passes through a second filter provided at the base of the
collection tank, rises up the duct provided inside the tank and
emerges at the top part of the duct so collecting in the collection
tank.
[0009] To generate heating of the water of the boiler, different
heat sources can be used, for example the flame of a common gas
stove, or an electric plate.
[0010] In another type of steam-pressure coffee machines, such as
the one shown in FIG. 10b, the collection tank of the coffee
beverage is missing and the duct is so shaped as to convey the
produced beverage directly to suitable containers, for example one
or more cups of a user that can be placed at an outlet portion of
the duct.
[0011] The duct can be provided with an upper cover shaped in such
a way as to identify on a side surface of the duct suitable outlet
orifices for the exit of the beverage and be arranged to prevent
the beverage, thrust by high pressure, from spurting outside the
tank.
[0012] In a further type of steam-pressure coffee machines shown in
FIG. 10c, there is provided a boiler of the autoclave type inside
which the water to be heated is poured, the boiler is electrically
heated and following heating into the boiler there is generated
steam that pushes the water through a panel of coffee placed on a
filter holder from which the produced beverage exits that is
collected in suitable containers, for example one or more cups of
users, which are located at the filter holder.
[0013] The filter holder is shaped in such a way as to be similar
to those used in espresso coffee machines in order to simulate the
preparation of espresso coffee.
[0014] In order for coffee machines to correctly simulate espresso
preparation, they have to deliver the coffee beverage in a
reasonably short time, so that the temperature in the boiler has
values that are significantly greater than 100.degree. C., and
these values are reached in a particularly short time.
[0015] A drawback of steam-pressure "Mocha" coffee machines like
those disclosed above, is that the beverage produced has
organoleptic features that are inferior to those of beverages
obtained by infusion, or with "espresso" coffee machines, in which
extraction is not achieved by steam pressure but by a pump that
drives the hot water into contact with the coffee powder.
[0016] This is due to the particular temperature and pressure
conditions that are generated within such coffee machines during
the extraction process.
[0017] A further difference between extraction by infusion or
pressure percolation achieved with "espresso" coffee machines and
the extraction in the steam pressure coffee machines is that in the
latest part of the coffee drink is obtained by making water in the
form of steam pass through the coffee powder.
[0018] In order to overcome this problem, EP0607765 provides for
making a coffee machine comprising two distinct boilers into which
to pour the water: a first boiler to be placed in contact with a
heat source and a second boiler interposed between the first boiler
and a filter containing the coffee powder.
[0019] When the water of the first boiler is brought to boiling
point, it exerts thrust pressure against a piston interposed
between the first and the second boiler that forces the water of
the second boiler, which is hot but at temperature below boiling
point, towards the coffee powder. In this way, the coffee beverage
is obtained by imbibing the coffee powder at a temperature between
75.degree. and 95.degree. C.
[0020] Providing two different boilers for water, one with water to
bring to boiling point and one with water to imbibe the coffee
powder, is also known from EP0148982.
[0021] The presence of the second boiler for water makes the coffee
machines seen above constructionally more complex and above all
considerably more bulky than common coffee machines.
[0022] Furthermore, such coffee machines consume more energy than
common coffee machines because a greater quantity of water has to
be heated and they need more time to make the coffee beverage.
[0023] Cooling the water and/or the steam that is thrust up from
the boiler by the thrust of the pressure generated inside the
boiler by the heating of the water is furthermore known, for
example from WO94/07400 or IT1245706.
[0024] The journey of the water and/or the steam towards the coffee
powder is varied in such a way as to provide, before the passage
through the coffee powder, the passage through exchanger elements
in which the water cools and any steam that may be present
condenses.
[0025] U.S. Pat. No. 6,161,469 relates to an espresso machine,
wherein water in the boiler (1) is superheated and kept at a
temperature above 100.degree. C. for producing steam to be supplied
to a dispenser nozzle (10), which superheated water is mixed with
cold water at a mixing station (12), to obtain hot water having a
temperature below 100.degree. C., supplied to the coffee brewing
unit (13) and to the dispenser nozzle (10). According to the
invention, the coffee brewing unit (13) is attached to the lower
side of the boiler (1) and is connected to the mixing station (12)
by means of a feed pipe (14), which is at least partly housed in
the boiler (1). In the pipe (4) for feeding cold water to the
boiler (1), a non return valve (16) is provided, which opens in the
direction of flow into the boiler and is situated downstream from
the branch point of the pipe (11) for feeding cold water to the
mixing station (12).
[0026] FR 2 347 014 describes a coffee machine for preparing
espresso coffee beverage, in particular for home use, provided with
a heating water container arranged for containing the water with
which the coffee powder has to be imbibed, and a reservoir for
containing cooling water into which a serpentine is provided. Into
the serpentine flows steam coming from the heating container that
pour after being cooled by the cooling water in the reservoir into
the coffee filter, so producing the coffee beverage.
[0027] WO94/07400 describes a low temperature pressurized coffee
machine comprises a lower body (1) for receiving water from an
intermediate heat-diffusing body consisting of a spiral coil, and
an upper body (5) for receiving coffee. The water is brought to the
boil by a heat source, whereupon it passes through the coil under
the effect of pressure, losing several degrees centigrade. The hot
but not boiling water then passes through a section containing
ground coffee, thereby extracting the coffee aroma without the
bitterness.
[0028] These solutions nevertheless have numerous drawbacks, in
fact the presence of the exchanger element makes these coffee
machines more complex and bulkier than common coffee machines.
[0029] Furthermore, maintenance and cleaning operations are more
delicate and require greater time and care than are necessary with
common coffee machines.
[0030] Such coffee machines furthermore consume more energy than
common coffee machines as all the water in the boiler is first
heated and is then cooled before coming into contact with the
coffee powder.
[0031] An object of the invention is to provide improved methods
and apparatuses for producing coffee beverages.
[0032] Still another object is to provide simple and cheap
apparatuses that enable a coffee beverage to be obtained with great
organoleptic features.
[0033] A further object is to supply simplified methods and
apparatuses that enable a coffee beverage to be obtained using
water that is not in a steam state.
[0034] In a first aspect of the invention a method is provided for
obtaining a coffee beverage comprising heating an extraction fluid
such as to induce the passage of the extraction fluid through a
dose of coffee to obtain said beverage, wherein separating a
fraction of said beverage obtained with a prevalently liquid phase
of said fluid from a further fraction of said beverage obtained
with a prevalently steam phase of said fluid is provided for.
[0035] In a second aspect of the invention, an apparatus is
provided for preparing a coffee beverage by inducing the passage of
an extraction fluid through a dose of coffee by heating said fluid,
wherein the apparatus further comprises a separating device
arranged to separate a fraction of said beverage obtained with a
prevalently liquid phase of said fluid from a further fraction of
said beverage obtained with a prevalently steam phase of said
fluid.
[0036] In a third aspect of the invention a method is provided for
obtaining a coffee beverage comprising heating an extraction fluid
to induce said fluid to pass through a dose of coffee, wherein this
passing through is prevented when said fluid contains a substantial
steam phase.
[0037] In a fourth aspect of the invention, an apparatus is
supplied to prepare a coffee beverage by imbibing a dose of coffee
with an extraction fluid driven through said dose by heating,
wherein the apparatus further comprises an inhibition device
arranged to inhibit imbibing when said fluid contains a substantial
steam phase.
[0038] In an embodiment, said inhibition device comprises stop
elements arranged to block said heating.
[0039] In another embodiment, said inhibition device comprises a
monitoring system arranged to monitor the heating in such a way as
to inhibit the formation of said steam phase in said extraction
fluid.
[0040] The inhibition device may comprise a pressure-adjusting
device arranged to adjust the pressure inside a tank containing the
fluid by keeping it within a desired range of values; in a
particular embodiment, the pressure-adjusting device enables the
pressure to be maintained within a range between approximately 0.01
and 5 bar, these values are relative pressure values, assuming that
the atmospheric pressure value is 0 bar.
[0041] The above-said inhibition device may further comprise a
temperature-adjusting element for adjusting the temperature inside
a tank containing the fluid, keeping it within a desired range of
values; in a particular embodiment, the temperature-adjusting
element enables the temperature to be kept within a range comprised
between approximately 60.degree. C. and 120.degree. C.
[0042] In some embodiments, the inhibition device cooperates with
sensors such as for example level-sensors, or pressure, or
temperature sensors.
[0043] Owing to these aspects of the invention, it is possible to
obtain a beverage by imbibing a set quantity of coffee only with
water, i.e. preventing the coffee from being imbibed by a fluid
containing steam.
[0044] The coffee can be in powder or anyway minced form to promote
the extraction, or can be in the form of capsules, portions or
cartridges containing desired preset quantities of coffee
powder.
[0045] In this way it is possible to obtain a beverage with high
organoleptic features and which is comparable to that obtained with
"espresso" coffee machines.
[0046] The inhibition device and/or the separating device can be
connected, by means of suitable modifications, to a "Mocha" coffee
machine of any known type that can thus be used to obtain a
high-quality coffee beverage.
[0047] The invention will be better understood and implemented with
reference to the attached drawings that show an embodiment thereof
by way of non-limitative example in which:
[0048] FIG. 1 is a graph that shows the flow rate [g/min] over time
[sec] of a coffee beverage in an extraction procedure that provides
for the use of an electric three-cup "Mocha" machine according to
the state of the art;
[0049] FIG. 2 is a graph that shows the flow rate [g/min] over time
[sec] of a coffee beverage obtained with three distinct
coffee/water ratios in a procedure according to the one in FIG.
1;
[0050] FIG. 3 is a graph that shows the pH values of subsequent
fractions of coffee beverage obtained with the procedure according
to FIG. 1;
[0051] FIG. 4 is a graph that shows the dry residue values [g] of
subsequent fractions of coffee beverage obtained with the procedure
according to FIG. 1;
[0052] FIG. 5 is a graph that shows the variation of the refraction
index in subsequent fractions of coffee beverage obtained with the
proceeding according to FIG. 1;
[0053] FIG. 6 is a graph that shows the concentrations of some
aromatic substances in the coffee beverage obtained using the
procedure according to FIG. 1;
[0054] FIG. 7 is a graph that shows the average excellence
indicator of the body of the coffee beverage obtained with the
procedure according to FIG. 1;
[0055] FIG. 8 is a lateral schematic section of a "Mocha" coffee
machine according to the invention;
[0056] FIG. 9 is an enlarged detail of FIG. 8;
[0057] FIGS. 10a, 10b and 10c are schematic representations of
different types of known steam-pressure coffee machines.
[0058] The graphs set out in FIGS. 1-7 were obtained using a
three-cup electric Mocha machine that has been suitably adapted to
facilitate the experimental tests.
[0059] By varying the coffee machine used and/or the value of one
or more experimental parameters, such as for example the
coffee/water ratio, the geometry of the coffee machine, the
granulometry and/or the type of coffee powder used, the blend of
coffee used, graphs are obtained with point values that are
different from those shown in FIGS. 1-7 but with the same
qualitative trend.
[0060] The considerations that follow with reference to the
attached Figures therefore have general validity and can be
extended to experiments using values other than the experimental
parameters. The production dynamics of a coffee beverage with a
traditional "Mocha" type coffee machine is explained with the help
of the graph in FIG. 1 that shows on the Y axis the flow values
[g/min] of a coffee beverage produced and on the X axis shows the
time [sec], and in which I indicates the average flow calculated on
the quantity of beverage collected in the first 6 seconds from the
moment of the appearance of the first drop of beverage.
[0061] In the process of preparation of the coffee beverage 4
phases can be distinguished: [0062] an imbibing phase, indicated by
A in FIG. 1, in which the water that is driven towards the coffee
powder by an increase in the pressure in the boiler imbibes the
initially dry powder and starts extraction of the coffee beverage.
This phase is characterised by progressively decreasing values over
time of the flow of produced beverage because the water imbibing
the coffee powder causes it to swell and compact. In this phase the
beverage is extracted with water in liquid state; [0063] an
extraction phase, indicated as B in FIG. 1, in which the flow
values of the produced beverage remain almost constant over time
and in which the beverage is produced by extraction from the coffee
powder with water in liquid state; [0064] a transition phase,
indicated by C in FIG. 1, in which the flow values of the produced
beverage increase rapidly over time until they reach a maximum
value indicated as M and then decrease just as rapidly. In this
phase the water changes from liquid state to steam state; [0065] a
further extraction phase, indicated as D in FIG. 1, characterised
by decreasing flow values of the produced beverage, in which
extraction of the coffee beverage occurs through contact between
the coffee powder and a mixture of water and steam.
[0066] In phase A and B, the coffee beverage is produced by
extraction with water, a solid-liquid extraction, whereas,
substantially at the maximum flow value M, extraction with a
mixture of water and steam, a solid-liquid-steam extraction,
starts. This phase is accompanied by gurgling noise that is typical
of "Mocha" steam-pressure coffee machines.
[0067] The graph in FIG. 1 was obtained by pouring into the coffee
machine 15 g coffee powder and 150 ml of water in a coffee/water
ratio of 1/10 g/ml.
[0068] By varying the values of the coffee/water ratio, flow/time
curves are obtained with different point values from the one shown
in FIG. 1, but with unvaried quality, as can be seen from the
analysis of the graph in FIG. 2 showing the flow of the beverage
obtained over time with coffee/water values that are respectively
15/150, 13/150 and 17/150.
[0069] The three curves of FIG. 2 show an identical qualitative
development, the four phases of the preparation process of the
beverage can in fact be identified and, in each curve the point M,
namely the moment of maximum flow of produced beverage, can be
distinctly identified with different coordinates.
[0070] By repeating the process of production of the coffee
beverage with a three-cup electric "Mocha", suitably modified to
facilitate sampling, for each production cycle 10 fractions of
coffee beverage of equal weight are taken weighing 11 g that are
subjected to different chemical-physical and sensorial analyses in
order to investigate their qualities and properties.
[0071] An analysis of the aspect of the obtained fractions has
shown that the first four fractions are particularly transparent
and have an intense reddish brown colour, the subsequent fractions
become progressively cloudier and with a less intense colouring and
the last two fractions are cloudy and with a very intense dark
brown colour and have oily particles dispersed over the
surface.
[0072] FIGS. 3 to 5 show respectively the pH values, the dry
residue and the refraction index of the different fractions of
beverage. An analysis of the graph in FIG. 3 shows that the pH
value decreases slightly from the first to the fourth fraction and
then increases more decisively from the fifth to the ninth fraction
and then suddenly falls at the tenth fraction.
[0073] FIG. 4 shows the quantity of dry residue [g] in the
different fractions of beverage obtained from 25 ml of each
fraction. As can be seen from the graph, the quantity of dry
residue of each fraction diminishes constantly in the subsequent
fractions from the first to the ninth, reaches the minimum value in
the ninth fraction and then grows from the ninth to the tenth
fraction.
[0074] FIG. 5 shows the trend of the refraction index in the
beverage fractions obtained by Illycaffe protocol. The refraction
index has values of approximately 1.34 in the first five fractions
and reaches the minimum values of approximately 1.334 in the eighth
and ninth fractions.
[0075] The 10 fractions of beverage obtained were further
subjected, after SBSE extraction (Stir Bar Sorptive Extraction), to
chromatographic analyses to determine the quantity of the volatile
aromatic substances contained therein.
[0076] FIG. 6 shows, in terms of area, the quantities of the
aromatic substances found in the first and second combined
fractions, and in the ninth and tenth combined fractions and the
average quantities of these substances in the non-fractioned
beverage.
[0077] These values are also set out, if available, in Table 1,
respectively in columns 3, 4, 5; column 1 of this table shows the
aromatic substances.
TABLE-US-00001 BEVERAGE FRACTIONS FRACTIONS COMPOUND AVERAGE 1 + 2
9 + 10 2-methylbutanal 684261 3617450 118003 3-methylbutanal 283392
1294385 37559 2,3-butandione 28469 435045 19346 2,3-pentandione
74388 4774112 n.a. dimethyl sulphide n.a. 29132 n.a. 2-acetylfuran
1854707 3099263 66507 2-ethyl-3,5- 1027553 621688 134626
dimethylpyrazine 2-ethyl-3,6- 2847963 2385983 517735
dimethylpyrazine 2,3-diethyl-5- 806350 596872 272601 metylpirazine
3-isobutyl-2- 147320 85330 67340 methoxypyrazine 4-hydroxy-2,5-
n.a. n.a. n.a. dimethyl-3(2H)- furanone 2(5)-ethyl-4- n.a. n.a.
n.a. hydroxy-5(2)-methyl- 3(2H)-furanone 3-hydroxy-4,5- n.a. n.a.
n.a. dimethyl-2(5H)- furanone (E)-.beta.-damascenone 193042 58413
135298 Guaiacol 898993 676585 109555 4-ethylguaiacol 3475261
1192214 1222443 4-vinylguaiacol 11843980 4685742 7058276
Phenylethanol 89277 101096 n.a.
[0078] An analysis of the graph of FIG. 6 and/or Table 1 shows that
different volatile substances such as for example 2-methylbutanal,
3-methylbutanal, 2,3 butandione are more heavily present in the
first two fractions than in the last two fractions of beverage;
whereas other different aromatic substances such as for example
vinyl-guaiacol and ethyl-guaiacol beta-damascenone are present in
greater quantities in the last two fractions of beverage than in
the first.
[0079] It should therefore be noted that the first two combined
fractions of produced coffee beverage have different aromatic
substances from those that are present in the last two combined
fractions.
[0080] The fractions of beverage were finally subjected to an
organoleptic analysis with which the overall assessment, or
excellence indicator, of the coffee and the appreciation of the
beverage was investigated on the basis of different descriptors of
the quality of the beverage itself, as for example the body, the
excellence indicator of the beverage in the different fractions is
shown by way of example in the graph in FIG. 7.
[0081] The first three fractions of beverage have been judged in a
generally very favourable rating, this rating decreases from the
fourth fraction onwards; from the sixth fraction onwards foreign
aromas (off-flavour), or aromas that are not typical of coffee
beverage are noted, in particular, for example, the sixth fraction
is characterised by a taste of wet paper, the seventh and eighth by
a metal taste, the ninth by an unpleasant heavily metallic taste,
the tenth by an extremely unpleasant bleach taste.
[0082] In general, the appreciation of the fractions is very great
when the fractions are obtained by solid-liquid extraction,
progressively decreases until it disappears where the fractions are
produced by solid-liquid-steam extraction.
[0083] For this reason, it is necessary to separate the last
fractions of beverage from the others to prevent the organoleptic
properties of the entire obtained beverage from being lowered, or
it is necessary to maintain the process of preparation of the
coffee beverage within conditions of solid-liquid extraction.
[0084] FIGS. 8 and 9 show a general model of coffee machine 1 of
the "Mocha" steam-pressure type, but the subsequent considerations,
when it is not explicitly declared, may apply to any other desired
coffee machine of the "Mocha" pressure-steam type, and may
furthermore extend, if necessary simple dimensional modifications
can be made, to coffee machines suitable for obtaining different
quantities of coffee beverage, or a different number of cups of
coffee for each operating cycle.
[0085] In particular, the ranges specified below for the parameters
of FIG. 9 were identified following laboratory tests as possible
variation ranges of the above parameters relatively to coffee
machines that produce 1 to 12 cups, but with simple scale changes
further values of the parameters can be obtained to use with coffee
machines with different productive capacity.
[0086] Furthermore, in order to apply the invention, coffee
machines can be used to be connected to any source of energy, such
as gas stoves, or electric plates, or microwave ovens, or also
coffee machines with incorporated electrical resistances.
[0087] The coffee machine 1 comprises a boiler 2 into which the
water to be heated is poured, which is placed in contact with a
source of heat and which is provided with a safety valve 4 arranged
to prevent pressure inside the boiler 2 exceeding a given maximum
value, and an upper portion 3 that is tightened during use onto the
boiler 2.
[0088] A funnel container 5, comprising a containing cavity 6 that
is delimited at the bottom by a filtering surface 6a and inside
which a desired quantity of coffee powder indicated by W is poured,
and a duct 7 projecting from the containing cavity 6, is inserted
inside the boiler 2 in such a way that the duct 7 is projected from
the containing cavity 6 towards the bottom of the boiler 2.
[0089] The upper portion 3 comprises a lower filtering surface 8, a
tank 9 in which the produced coffee beverage is collected and which
is connected to the lower surface 8 by a hollow conduit 10, a grip
11 for facilitating a user's grasp of the coffee machine 1, a side
surface 12 provided with a projecting portion 13 spout shaped
through which the beverage is poured, and a removable lid.
[0090] The hollow conduit 10 comprises a substantially frustum
conical portion 20 arranged on the lower surface 8 and a conveying
portion 21 connected to the frustum conical portion 20 by a
connecting zone 22 have a circular section with a diameter
indicated as D in FIG. 9 that can be comprised between 3 and 15
mm.
[0091] The frustum conical portion 20 conveys the coffee beverage
that exits from the lower surface 8 to the conveying portion 21,
extending from the connecting zone 22 to an upper surface 10a of
the hollow conduit 10, the coffee beverage runs into the hollow
conduit 10 and is then discharged through its upper surface 10a.
The conveying portion 21 may have a cylindrical shape or a shape
that is slightly funnelled upwards.
[0092] The hollow conduit 10 has an overall longitudinal extent,
defined as the distance between the lower filtering surface 8 and
the upper surface 10a, indicated as H in FIG. 9, that can be
comprised between 10 and 150 mm, and is shaped in such a way as to
offer the least possible resistance to the exiting of the beverage
obtained by extraction with steam in order to facilitate, as shall
be seen below, the separation between the fraction of beverage
obtained with a prevalent liquid phase from the fraction obtained
with a prevalent steam phase.
[0093] In particular, the conduit 10 is provided with an upper
surface 10a from which the coffee beverage exits that is obtained
with a completely free outlet section, i.e. the portions that
partial cover the upper surface 10a are not provided that are on
the other hand provided in the state of the art.
[0094] Inside the tank 9 a conveying conduit 15 is inserted
comprising an end 16 that is inserted inside the conduit 10, a
portion 17 that extends partially inside the tank 9 and partially
outside it and that is arranged in such a way as to be tilted in
relation to a vertical direction Y by an angle a comprised between
0.degree. and 90.degree., and an outlet portion 18 having an almost
vertical extent and terminating with an outlet end 18a.
[0095] The end 16 of the conveying conduit 15 can be inserted into
the conduit 10 at a distance from the filtering surface 6a
indicated by H1 in FIG. 9 comprised between 0 and 50 mm.
[0096] In particular, when the value of H1 is the same as 0 mm, the
conveying conduit 15 is arranged at the same height as the lower
surface 8, thereby terminating in the frustum conical portion 20
and receiving the coffee beverage produced directly by the lower
surface 8.
[0097] The section of the conveying conduit 15 is almost circular
with a diameter, indicated as D1 in FIG. 9, with a value that can
be comprised between 1 and 10 mm; the tilted portion 17 of the
conveying conduit 15 has an extent indicated by L in FIG. 9 the
value of which can be comprised between 0 and 150 mm.
[0098] In order to prepare a coffee beverage, a suitable quantity
of water is poured inside the boiler 2, a suitable quantity of
coffee powder is poured into the funnel container 5 that is
inserted inside the boiler 2, the upper portion 3 is tightened on
the boiler 2 and the coffee machine 1 is then subjected to a heat
source.
[0099] The water in the boiler 2 is heated, causing a pressure
increase that thrusts part of the water of the boiler 2 to rise up
through the duct 7 until it comes into contact with the coffee
powder, imbibing it and extracting the coffee beverage therefrom,
the coffee beverage passes through the lower filtering surface 8,
rises up through part of the conduit 10 until it reaches the end 16
at which it leaves the conduit 10, flows through the conveying
conduit 15 and is finally discharged through the outlet end 18a
into a collection container for containing the fraction of beverage
subsequently called "approved", which is located at the outlet end
18a.
[0100] Through the effect of the heat and the subsequent increase
of pressure and temperature inside the boiler 2, after a certain
lapse of time, extraction of the coffee beverage occurs through
solid-liquid-steam extraction.
[0101] During this extraction phase the flow of produced beverage
decreases over time but the thrust pressure increase, in other
words the produced beverage is subjected to a thrust pressure in
its ascent in the conduit 10 that is greater than that of the
solid-liquid extraction phase, so the beverage produced runs
through the entire conduit 10, emerges from the upper surface
thereof 10a and is collected in the tank 9.
[0102] In this way, it is avoided that the fraction of beverage
obtained by solid-liquid-steam extraction mixes with the fraction
of beverage obtained by solid-liquid extraction and inside the tank
9 a beverage is obtained with inferior organoleptic features, said
fraction of beverage being subsequently called as "rejected".
[0103] By varying the tilt of the portion 17 of the conveying
conduit 15, it is possible to vary the ratio between the fraction
of approved beverage and the fraction of rejected beverage
collected inside the tank 9.
[0104] Laboratory tests have indicated an angle comprised between
0.degree. and 90.degree., or comprised between 50.degree. and
85.degree., in relation to the vertical, as an acceptable tilt
value, this value being confirmed as acceptable also with different
models of coffee machines on which the laboratory tests were
conducted.
[0105] With the coffee machine 1 disclosed above, it is possible to
obtain in a simple and economical manner a coffee beverage with
pronounced organoleptic features by simply separating the fraction
of beverage with an unpleasant taste from the fraction of beverage
with a pleasant taste.
[0106] Alternatively, the solid-liquid-steam extraction of the
coffee beverage for obtaining a coffee beverage with pronounced
organoleptic features can be avoided.
[0107] In particular, coffee machines can be provided provided with
temperature and/or pressure sensors, and/or water level sensors
appropriately calibrated and connected to acoustic or visual
elements in such a way that when certain values of said parameters
are detected, acoustic or visual signals are emitted. In this way,
a user is warned that solid-liquid-steam extraction is about to
start and can decide whether to continue this extraction process or
arrest it by acting on the heat source to have a beverage with
pronounced organoleptic features.
[0108] Furthermore, in the electric coffee machines provided with
an internal electric resistance, the sensor elements can be
connected to on/off switches in such a way that when certain values
of said parameters are detected that indicate the start of
solid-liquid-steam extraction, the coffee machine is switched off,
and production of a beverage with an unpleasant taste is thus
automatically avoided.
[0109] Alternatively, in the electric coffee machines provided with
an internal electric resistance the sensor elements may be
connected to control elements for controlling the supplied power,
in such a way that the electric power delivered is such as to
prevent solid-liquid-steam extraction.
[0110] In another embodiment, it is further possible to suitably
calibrate the safety valve with which the coffee machines are
provided on a set pressure value, so as to prevent steam being
generated inside the boiler, in such a way that when the set
pressure value is reached in the boiler the safety valve opens to
discharge the pressure inside the boiler, warning the user of the
advisability of acting on the heat source.
[0111] In Table 2 attached below the results of experimental tests
on different types of "Mocha" steam-pressure type coffee machines
are set out, column 1, loaded with different quantities of coffee
and water, column 2. Column 3 shows the quantity of approved
beverage [g], columns 4 and 5 respectively show the average
refraction index and the pH of the approved beverage, column 6
shows the quantity of rejected beverage [g], columns 7 and 8
respectively show the average refraction index and the pH of the
rejected beverage, column 9 shows the residual quantity of water
[g] in the boiler.
[0112] The results shown in lines 1-4 and 10-12 were obtained with
coffee machines of the type schematically represented in FIGS. 10a,
and 10b, modified like the coffee machine in FIG. 8, i.e. with
coffee machines provided with a beverage separator, the results
given in lines 5-9 were obtained with coffee machines of the type
schematically shown in FIGS. 10a, and 10c, in which it is provided
to stop in different ways the extraction of the coffee beverage, in
particular: the results given in lines 5, 6 were obtained with
coffee machines provided with level sensors, the results given in
line 7 with manual intervention at the start of the
solid-liquid-steam extraction phase, the results given in lines 8,
9 by stopping heating upon respective reaching of relative pressure
in the boiler 2 amounting to 0.7 and 0.5 bar.
[0113] The results shown in lines 1-9 were obtained with a
coffee/water ratio value of 0.1, whereas the results of lines 10-12
with a coffee/water ratio value of approximately 0.113.
TABLE-US-00002 Type Approved beverage Rejected beverage of Coffee/
Weight Weight Residual Mocha water [g] RI (30.degree. C.) PH [g] RI
(30.degree. C.) pH water TYPE 1 12/120 88.45 1.33981 5.423 3.22
1.33410 na 9.10 TYPE 2 15/150 97.93 1.34000 5.483 28.25 1.33539
6.104 3.27 TYPE 3 15/150 90.35 1.34096 5.426 32.48 1.33491 6.006
2.88 TYPE 4 15/150 65.93 1.34384 5.436 55.07 1.33421 6.171 5.43
TYPE 5 15/150 79.40 1.34257 5.314 na na na 46.70 TYPE 6 15/150
66.33 1.34012 5.275 na na na 59.30 TYPE 7 10/100 41.00 1.34465 na
33.00 1.33448 na na TYPE 8 15/150 98.47 1.34100 5.359 na na na na
TYPE 9 15/150 95.00 1.34101 5.380 na na na na TYPE 2 17/150 86.45
1.34144 5.376 35.88 1.33488 6.07 4.05 TYPE 3 17/150 89.3 1.34194
5.349 36.5 1.33492 5.909 1.00 TYPE 4 17/150 71.4 1.34506 5.391 18.6
1.33544 5.902 18.0
* * * * *