Note: Descriptions are shown in the official language in which they were submitted.
lZ931 ~8
METHOD FOR THE DECAFFEINATION OF ROASTED
COFFEE_EXTRACTS AND THE PRODUCTS THEREOF
05
TECHNICAL FIELD
The present invention relates to a method for
decaffeinating aqueous roasted coffee extracts and
the products of such method. More particularly, the
invention involves loading an organic caffeine
solvent with hydrolyzed coffee solids, contacting a
roasted coffee extract with the loaded organic
caffeine solvent and separating the coffee extract
from the then caffeine-containing organic caffeine
solvent.
BACKGROUND ART
Numerous decaffeination techniques are known in
the art. One widely practiced decaffeination method
is disclosed in U.S. Pat. No. 2,309,092 to Berry et
al. Green coffee beans are moistened and subsequently
extracted with a caffeine-deficient green coffee
extract, with the extraction typically taking place
in a countercurrent extraction battery. Caffeine-
laden extract withdrawn from the extraction battery
3~
is then decaffelnated by contact with a caffeine
solvent. While the method of Berry et al. is quite
effective, it is only applicable to the decaffeination
of green coffee beans and is not suitable for the
05 decaffeination of extracts of roasted coffee.
The art has generally continued to progress
along lines of decaffeination of green extracts.
Relatively little progress has been made in technology
looking toward the direct decaffeination of the
extract of roasted and ground coffee. To be sure,
certain patents like that to Adler et al.,
U.S. 2,933,395 issued April 9, 1960, have offered to
the art workers the approach of decaffeinating the
extract of roasted and ground coffee; but such arts
have not materially advanced until recently to the
point of providing a brew quality equal to or exceeding
that recoverable by decaffeination of green beans.
Thus, techniques are known for decaffeinating
roasted coffee extracts, but the methods are not
without certain drawbacks. Belgian Patent Disclosure
865,488 of Bolt et al. describes a process in which
roasted coffee extract is first decaffeinated with
the solvent, the solvent is then contacted with
water to transfer the caffeine and unavoidably some
non-caffeine solubles, the decaffeinated solvent is
returned to the coffee extract and subsequently
stripped therefrom; and the caffeine is crystallized
from the water phase, which is then discarded. The
water phase unavoidably contains an amount of non-
caffeine solubles which would contribute importantflavor notes but which are instead discarded. The
particular flavor notes which are lost with the
discarded water phase are the "body" notes which
contribute to the overall balance of coffee extract
flavor. Without these body notes, the coffee extract
~Z93~4~
and the soluble coffee made therefrom are typically
characterized as weak and thin.
A similar though supposedly improved decaffein-
ation method is disclosed in U.S. Pat. No. ~,409,253
05 to Morrison et al. The improvement is said to be in
recycling the water phase from which the caffeine
has been crystallized back to the incoming caffeine-
containing extract. It appears that the water phase
cannot be combined with the decaffeinated extract
because of the substantial amounts of caffeine
remaining in the water after crystallization. This
inefficient recycling of the water phase, with the
corresponding increase in the amount of caffeine to
be removed, would appear to increase the volume of
extract to be decaffeinated, inflating operating
costs.
Accordingly, it is an object of the present
invention to provide an efficient method for decaf-
feinating aqueous roasted coffee extracts.
Another object of the invention is to provide a
method of decaffeinating aqueous roasted coffee
extracts which minimizes the amount of flavor notes
lost during decaffeination.
Such improvements as have been noted in the
production of decaffelnated extract produced from
roasted and ground coffee leave much to be desired
from the standpoint of flavor. It would be desirable
to provide a decaffeination process which uses
roasted and ground coffee, instead of green; is
relatively applicable to current processing techniques;
and yields a product that can match or exceed the
quality extracts derived from decaffeinated green
beans. The present invention relates to just such a
product.
3~
-- 4 -
DISCLOSURE OF THE INVENTION
It has now been found that the objects of the
invention are met by a method for decaffeinating
roasted and ground coffee extracts which involves
05 "loading" an organic caffeine solvent such as methylene
chloride with hydrolyzed coffee solids; contacting a
non-decaffeinated roasted and ground coffee extract
with the loaded caffeine solvent to effect decaffeina-
tion; and separating the decaffeinated extract from
the then caffeine-containirlg organic caffeine solvent.
In excess of 96% by weight of the caffeine initially
present in the roasted coffee extract can be removed
by such methods.
One of the essential features of the present
invention is "loading" the organic caffeine solvent
with essentially hydrolyzed coffee solids. The term
"essentially hydrolyzed coffee solids" is intended
to refer to those coffee solids and compounds obtained
from roasted coffee grounds after the coffee grounds
have been at least thoroughly atmospherically extracted.
Such atmospheric extraction, which is well-known to
a worker skilled in the art, typically involves
extracting between 20% and 25% by weight of the
roasted and ground coffee at atmospheric pressure
and at about 212F. Nearly all of the caffelne is
atmospherically extracted so it is not a concern
that caffeine will be loaded in the solvent inhibiting
subsequent decaffeination of the roasted coffee
extract. Further extraction of the coffee grounds
provides what is meant by "essentially hydrolyzed
coffee" solids which encompasses both coffee solids
and addit:ional compounds, such as coffee oil, tars
and the like, that are not "solids" in the strictest
sense but are obtained from the coffee grounds along
with the solids.
3~8
It has surprisingly been found that the hydro-
lyzed coffee solids loaded in the organic caffeine
solvent prevent the loss of important flavor notes,
particul'arly body notes, during subsequent decaffeina-
05 tion of a separate extract of roasted and groundcoffee. This is so, even though the compounds
initially present in the roasted coffee extracts
prior to decaffeination responsible for the body
notes are not thought to be similar to the hydrolyzed
coffee solids. It is believed, without being limited
to any given theory, that the essentially hydrolyzed
coffee solids in the organic caffeine solvent retard
the transfer of the compounds responsible for the
body notes from roasted coffee extract to the solvent
during decaffeination. Thus, in an experiment in
which hydrolyzed coffee solids were added to an
extract that was decaffeinated by an unloaded solvent
as a control, the resulting extract was found not to
have the desirable body notes. Such a result suggests
body notes found in the decaffeinated extract of the
present invention are not transferred from the
loaded organic caffeine solvent but are instead
retained in the roasted coffee extract in which they
were already present.
The essentially hydrolyzed coffee solids may be
loaded in the caffeine solvent by any of alternative
means. According to one embodiment, the organic
caffeine solvent is contacted with a hydrolyzed
coffee extract prepared from coffee that has been at
least atmospherically extracted; the term "at least"
impliès that in addition to the atmospherically
extracted solids, solids recovered when the roasted
and ground coffee are exposed to a superatmospheric
pressure and at temperatures greater than ~12F are
likewise advantageous recovered in a decaffeination
~Z93~'~8
process. Contact of the organic caffeine solvent
and hydrolyzed coffee extract may be in any manner
providing good liquid-liquid contact. For instance,
the caffeine solvent may be contacted with the
05 hydrolyzed coffee extract in an agitated batch tank.
Most preferably, the organic caffeine solvent and
hydrolyzed coffee extract are contacted in a continuous
liquid-liquid column such as a Karr column or rotating
disk contactor column. For the continuous column,
the caffeine solvent is continuously fed to one end
of the column and withdrawn from the opposite end
and the hydrolyzed coffee extract is continuously
fed to the second end of the column and typically
maintained as the dispersed phase within the column,
being withdrawn from the opposite end to which it is
fed. The particular liquids fed to the top and
bottom o the column depend on the relative densities
of the two liquids, with the heavier one being fed
to the top of the column.
The hydrolyzed coffee extract used to load the
organic caffeine solvent may be obtained from any of
numerous sources. Autoclaved coffee solids are an
example of a suitable hydrolyzed coffee extract.
Autoclaved coffee solids are defined as those coffee
solids which are extracted above 212F and above
atmospheric pressure after the coffee charge has
been atmospherically extracted. For instance, an
extract of autoclave coffee solids may be the secondary
extract obtained from a spli-t-extraction percolation
system as described, for example, in U.S. Pat.
No. 3,79~689 to Pitchon et al. on February 5, 1974.
Alternatively, the hydrolyzed coffee extract may be
obtained by hydrolyzing spent coffee grounds in the
presence of an acid catalyst (as described in U.S.
Pat. No. 4,508,945 to Fulger et al.) or by thermal
~293~8
means without the incorporation of an acid catalyst
The hydrolyzed coffee extract may also be obtained
from a waste stream such as from the blow down
liquor pressed from spent grounds discharged from an
05 extraction battery.
Alternately, it is possible to load the organic
caffeine solvent by direct contact with spent coffee
grounds to transfer hydrolyzed coffee solids into
the solvent.
After contact with the caffeine solvent to load
it, the hydrolyzed extract may be stripped of residual
solvent and retained for later combination with the
decaffeinated roasted coffee extract. The contacted
hydrolyzed extract may also be recycled to load
additional organic caffeine solvent.
Important parameters for the loading of the
organic caffeine solvent, that is, the transfer of
the essentially hydrolyzed coffee solids to the
solvent, include the weight ratio of solvent to
hydrolyzed coffee extract, the concentration of the
hydrolyzed coffee solids in the extract, the temper-
ature of the contact between the organic caffeine
solvent and hydrolyzed coffee extract and the effi-
ciency of the contact. The efficiency of the contact
is largely determined by the amount of agitation of
the two liquids, with the greatest agitation short
of forming an emulsion or flooding a continuous
column being desirable. It has been found to be
most preferable to load the organic caffeine solvent
with the essentially hydrolyzed coffee solids at a
level of from about 0.1% to 1.0% by weight coffee
solids. In order to do so, :it is desirable to
contact the caffeine solvent with the hydrolyzed
coffee extract in a weight ratio of from 1:1 to 10:1
organic caffeine solvent to aqueous hydrolyzed
coffee extract. The preferred aqueous hydrolyzed
coffee extract concentration for such a weight ratio
range is from 10% to 40% by weight essentially
hydrolyzed coffee solids. The temperature of the
05 contact is preferably between about 70F and 180F,
with a lower temperature often leading to the forma-
tion of undesirable emulsion. If the boiling point
of the organic caffeine solvent is less than the
loading temperature, the contact must be at a pressure
greater than atmospheric. Operation of the liquid-
liquid contactor within the described conditions
will load the organic caffeine solvent to the desired
0.1% to 1.0% by weight essentially hydrolyzed coffee
solids level.
In an alternative embodiment, the organic
caffeine solvent is loaded with the hydrolyzed
coffee solids by contact with spent coffee grounds
that have been at least atmospherically extracted.
Most preferably, the grounds have had about 20% to
55% of the starting weight of the roasted and ground
coffee previously extracted with most of the caffeine
also being extracted. Contact of the caffeine
solvent and spent coffee grounds may be carried out
in any vessel providing good solid-liquid contact.
For instance, the grounds may be slurried in a solvent
such as methylene chloride in a batch tank for a
period of time sufficient to load the solvent to the
desirable hydrolyzed coffee solids level. Alternatively,
spent coffee grounds may be placed as a fixed bed in
an elongated vessel with the caffeine solvent being
recirculated through the bed until the preferred
coffee solids level has been reached.
As it is preferable to load the organic caffelne
solvent with the hydrolyzed coffee sollds at a level
of from about 0.1% to 1.0% by weight coffee solids,
~293~48
the important parameters for the loading of the
solvent include the weight ratio of organic caffeine
solvent to spent coffee grounds and the temperature
of the contact of the solvent and spent grounds.
05 The spent coffee grounds are preferably (~ntacted
with the organic caffeine solvent at a weight ratio
~dry basis spent grounds) of from 1:1 to 10:1 organic
caffeine solvent to spent coffee grounds. The
preferred temperature range of the contact is between
about 70F and 180F. The 180F temperature is the
preferred uppermost limit to prevent chemical break-
down of the hydrolyzed coffee compounds. Contacting
of the spent coffee grounds with the caffeine solvent
according to the conditions set forth provides for
the desired loading of the caffeine solvent at the
preferred 0.1% to 1.0% by weight hydrolyzed coffee
solids level.
Regardless of the embodiment chosen, the organic
caffeine solvent is preferably one of the organic
solvents which are known in the art to be good
decaffeination solvents. The acetates, such as
ethyl or butyl acetate, freons, triglycerides and
the halogenated hydrocarbon solvents are all useful.
Most preferably, the caffeine solvent is methylene
chloride which has long been known to be an effective
solvent. Methylene chloride is widely available,
relatively inexpensive and has been approved for use
in decaffeinating coffee. It is desirable to load
the methylene chloride at a temperature somewhat
below the hereinbefore indicated 180F. Moreover,
methylene chloride has a specific gravity of about
1.4 so it is preferable to feed the caffeine solvent
to the top of any continuous liquid-liquid contactor.
Once the organic caffeine solvent has been
loaded with the desired level of hydrolyzed coffee
solids, the loaded caffeine solvent may be used to
~:9;~3L41~
- 10 -
decaffeinate a roasted coffee extract. The roasted
coffee extracts intended for use herein are those
extracts typically obtained by the operation of a
commercial coffee extraction system. Such a commercial
05 extraction system most often comprises a countercurrent
extraction battery of approximately 6 to 8 sections
containing roasted coffee with varying degrees of
extra.ction. Feed water at approximately 350F is
fed to the section containing the most extracted
coffee and the roasted coffee extract is withdrawn
from the section containing the freshest coffee.
Periodically, the section containing the spent
coffee is isolated, a section containing fresh
roasted and ground coffee is added to the battery
and the flow is adjusted. Alternatively, the coffee
extract may be the extract withdrawn from the first
stage extraction column of a split-extraction perco-
lation system described in, for example, U.S. Pat.
No. 3,790,689. The resultant coffee extract after
evaporation contains anywhere from 10% to 50% by
weight total coffee solubles and from 0.1% to 5% by
weight caffeine. The extract also contains much of
the volatile and non-volatile flavor and aroma
compounds initially present in the roasted coffee.
While loading the organic caffeine solvent
according to the method of the present invention is
effective in preventing the loss of the non-volatile
body notes, the organic caffeine solvent tends to
remove the volatile flavor and aroma compounds and
so it is desirable to strip the volatile compounds
from the extract prior to decaffeination. Such
stripping of the volatile compounds may be carried
out by any of the techniques known in the art. Most
preferably, the roasted coffee extract is stripped
with steam so as to remove substantially all of the
~Z93~L~8
volatile flavor and aroma compounds therefrom. The
evolving steam containing the volatile compounds can
be collected by known techniques for eventual addition
to the decaffeinated coffee extract. For instance,
05 the steam may be trapped as a frost or condensed in
water-cooled heat exchangers to provide an aqueous
condensate. The aqueous condensate may be added to
the decaffeinated coffee extract as is or may be
fractionated into specific aroma fractions according
to known techniques. Certain of the aroma fractions
are then added to the decaffeinated extract as
desired to provide an extract having principally
those flavor notes of the fractions added,
Although it is preferable to strip the volatile
flavor and aroma compounds from the extract prior to
decaffeination, it is by no means necessary to do
so. However, since the major utility of the present
invention resides in an aromatized roasted decaffeinated
extract, it is preferred to strip the volatile
aromas prior to extract decaffeination and thence
collect and add same back, as previously mentioned.
In any event, a roasted coffee extract, whether
stripped or not, is contacted with the loaded organic
caffeine solvent so as to remove at least a portion
of the caffeine initially present in the roasted
coffee extract. It will be appreciated that virtually
any level of decaffeination may be achieved, from
less than 10% by weight of the caffeine initially
present to better than 98% by weight of the caffeine
initially present. It is typically desirable to
remove at least 50% by weight of the caffeine initially
present. Commercial applications most often require
better than 97% by weight decaffeination of the
coffee extract.
lZ~3~
The degree of decaffeination is related to the
parameters for the contact of the loaded organic
caffeine solvent and the roasted coffee extract.
. The important parameters include the weight ratio of
05 the loaded caffeine solvent to the non-decaffeinated
coffee extract, the concentration of coffee solids
in the extract, the temperature of the contact and
the efficiency of the contact. It has been found
that the weight ratio in the liquid-liquid contactor
is most preferably from about 1:1 to 10:1 loaded
organic caffeine solvent to roasted coffee extract.
The preferred roasted coffee extract concentration
is from 10% to 40% by weight coffee solids. The
temperature is desirably maintained between about
70F and 180F, with a temperature much in excess of
180F tending to damage the flavor of a coffee
extract. Of course, if the boiling point of the
loaded organic caffeine solvent is below the decaf-
feinatio-n contact temperature, the decaffeination of
the extract takes place at a pressure greater than
atmospheric. Thus these conditions match those
employed substantially in the initial loading of the
solvent, set forth hereinabove. The efficiency of
the contact is again largely determined by the
degree of agitation of the two liquids, with the
greatest agitation short of forming an emulsion or
flooding a continuous column being most preferable.
Roasted coffee extract from which at least a
portion of the caffeine has been removed is eventually
withdrawn from the liquid-liquid contactor. Inasmuch
as the decaffeinated extract will usually contain
residual organic caffeine solvent, it is desirable
to strip the residual solvent therefrom before
processing the extract into a finished soluble
cofee. Hence, the residual solvent is stripped
.
~ Z~ 3
- 13 -
from the extract and the extract can then be dried
into a decaffeinated soluble coffee.
Drying of the extract, whether or not the
volatile flavor and aroma compounds have been added
05 back, may be by any of the means known in the art.
Spray drying and freeze drying are particularly
preferred methods.
.The organic caffeine solvent withdrawn from the
liquid-liquid contactor during decaffeination may be
treated further to recover the caffeine therein.
One well known method of recovering the caffeine
involves adding the caffeine-containing solvent to a
tank of hot water so as to evaporate the solvent and
transfer whatever is dissolved therei.n to the water.
The organic caffeine solvent is most preferably
condensed and recycled for further use in accordance
with the method of the present invention. The
caffeine transferred to the water is conveniently
crystallized therefrom by techniques apparent to a
" 20 worker skilled in the art.
The following examples are intended to illustrate
certain embodiments of the present invention. The
examples are not meant to limit the invention beyond
what is claimed below.
EXAMPLE 1
Methylene chloride was "loaded" with autoclaved
coffee solids and the loaded methylene chloride was
employed to decaffeinate an aqueous roasted coffee
extract.
I. Solvent Pretreatment
Pure methylene chloride was treated with auto-
claved coffee solids to produce a decaffeination
medium which was rich in non-caffeine coffee solids
but substantially free of caffeine as follows.
~ 29 3
- 14 -
Methylene chloride at 110F was fed into the
top of a two inch diameter Karr column. A 26.55%
aqueous solution of autoclaved coffee solids at
110F was fed into the bottom end of the column.
05 The autoclaved coffee solids solution was obtained
as follows. A two column train was extracted for
flavor and caffeine by atmospheric extraction and
the extract was preserved as a quality brew but not
for use in the present process: a 300F fresh water
charge to the bottom of the first of the two columns
was withdrawn at 245F and circulated upwardly into
the second column Erom which it was withdrawn at
230F, cooled to 100F and stored; this atmospheric
extract had 11.5% coffee solids; the extract had
0.4% caffeine.
The atmospherically spent coffee column was
thereafter introduced to the process of the present
invention. Four conventional columns of the spent
co~fee were subjected to sequential autoclaving;
fresh water at 365F was charged to the bottom of
the first column and recovered at the top, processed
through the three remaining columns in like manner
at progressively lowered temperature, and recovered
at 290F from the top of the fourth such column,
whereupon the extract was cooled to 100F; it possessed
7% soluble solids and 0.023% caffeine; the temperature
drop across the four columns was fairly uniform.
The extract recovered represented the autoclaved
coffee solids solution to be processed further in
accordance with this invention~ the solution comprised
78.5% (d.b.) carbohydrates, 15.8% measured as total
sugars (Kjeldahl), 2.1% chlorogenic acid (d.b.), and
0.2% potassium.
The autoclaved e~tract (the hydrolyzed coffee
extract) was concentrated in a centritherm evaporator
to the aforesaid 26.55% solution. This solution
1 ~ 9 3
- 15 -
contains some solids that will be transferrable to
the methlylene chloride but whose presence will
prevent flavor losses that would otherwise occur
during decaffeination. The coffee solids solution
05 was agitated (120 spm at l" stroke length) in the
Karr column and the column exhibited the following
pressure profile; 22 psig at the top, 25 psig in the
middle, and 27 psig at the bottom. The Karr column
had an effective length of contact of eight feet,
the column itself having an overall length of
twelve feet to include a separation zone at the top
and a solvent collection zone at the bottom. The
methlylene chloride had a downward flow rate of
120 cc per minute and the solution of autoclaved
solids was fed upwardly through the unit at a flow
rate of 25 cc per minute. The thus treated and
"loaded" methylene chloride had an approximate
level of 0.17% soluble hydrolyzed coffee solids and
a neglible level of below approximately 0.015%
caffeine. The solvent recovered at the bottom of
the Karr column represented the loaded methylene
chloride for use in decaffeination; the processed
autoclaved stream recovered at the top of the Karr
column ~ay be stripped of residual methylene chloride
by conventional methods and the solids recovered for
recombination with the previously saved atmospheric
extract, all of which forms no part of the present
invention.
II. Decaffeination
-
An aqueous extract of roast and ground coffee
of approximately 12% solids was first stripped of
any volatile flavor and/or aroma compounds by passing
the extract through a centitherm before decaffeination,
the inlet to the centitherm being at about 90F and
- 16 -
the outlet at about 130F, the extract being concen-
trated to 55% solids; the solids solution was
thereafter diluted to about 20% soluble solids and
contained about 0.8% caffeine. The flavor compounds
05 were collected and processed by conventional means
for later addition to the decaffeinated extract
prior to spray drying. The loaded methylene chloride
produced in Section I. of this example was utilized
to decaffeinate the extract to achieve an average
percent decaffeination of 96.3%. The extract operating
conditions during decaffeination were as follows: the
2" Karr column as above was employed and the column
was agitated at 120 spm at a 1" stroke length; the
extract for decaffeination and the solvent were both
fed at llO~F to the Karr column; the pressure profile
was the same as in Section I. of this example above.
The extract flowed upwardly through the column at
25 cc per minute and the loaded methylene chloride
flowed downwardly at 120 cc per minute; this resulted
in a derivable solvent/extract ratio of 4.8/1 by
volume and 5.8/1 by weight. The decaffeinated
extract was further processed to remove residual
solvent and constituted the useful product of the
present invention; thus, the extract drawoff was
stripped of methylene chloride by passage through a
flash evaporation to achieve methylene chloride
levels in the decaffeinated extract of less than
50 p.p.m. and thereafter spray dried.
This extract could be tasted as extract or
spray dried and tasted upon reconstitution. In
either event, the decaffeinated coffee extracts
compared favorably against a similar decaffeinated
coffee extract produced in a similar process with
the one difference being that the methylene chloride
was not "loaded" with hydrolyzed coffee solids as in
1293~ 4~
- 17 -
Section I of this example. The decaffeinated coffee
produced according to the present invention was
preferred in that it was perceived as being more
flavorf~li and possessed more body notes, namely
05 those that would be typically associated with product
produced by conventional green bean decaffeination
methods of the prior art. The flavor comparisons
are shown in the columnar description identified as
Table A below.
BI,E A
COMPARISON OF TREATED AND
UNTREATED SOLVENT DECAFFEINATION
SAMPLE PREFERENCE EVALUATION/COMMENTS
Extract 4.0 Bland, washed out, thin,
Decaffeinated with stripped
Untreated MeCl2
Extract 5.5 Good body, slight
Decaffeinated with caramel flavor, good
Treated MeCl2 mouthfee], smoother
PREFERENCE SCALE
9 = Like extremely
8 = Like very much
7 = Like moderately
6 = Like slightly
5 = Like nor dislike
4 = Dislike slightly
3 = Dislike moderately
2 = Dislike very much
1 = Dislike extremely
Of greatest use in accordance with this inven-
tion, however, will be decaffeinated coffee extracts
to which the stripped aromas and flavor values have
been added and the solids recovered from the caffeine-
rich methylene chloride. Thus, the volatile flavor
and aromas which were stripped from the extract were
recovered, concentrated and added to the decaffeinated
~ Z9 3 ~ 4
- 18 -
extract of the present invention along with flavor
components recovered from the caffeine rich methylene
chloride e~iting the top of the Karr column in II.
above. The latter solids are typically recovered in
05 accordance with the process set forth in U.S. Patent
No. 4,505,940 to Jones et al., dated March 19, 1985,
ref. col. 8, line 5 et seq. of said patent. The
aromatized excract produced by addition of these
recovered aromatic and flavor constituents can
thereafter be spray dried and again compared to a
conventional "green bean" decaffeination product
representative of those presently marketed as Sanka~
Decaffeinated coffee. Most significantly, such a
product compares very favorably as indicated by the
tabulations in Table B below.
TABLE B
COMPARISON OF INSTANT SANKA VERSUS
DECAFFEINATED PRODUCT USING SOLVENT PRETREATMENT
S.~MPLE PREFERENCE EVALUATION/COM~ENTS
Instant Sanka 6 Cereal, slightly green,
slight burnt caramel
Elavor
Product 6 Slight cereal flavor,
Decaffeinated with good body, balanced,
Treated MeCl2 slightly caramel,
(Includes recovered slightly acidic
volatile and non-
volatile flavor streams)
EX~MPLE II
An alternate source of hydroly~ed coffee solids
can be derived from the direct contact of spent
ground coffee with methylene chloride to provide a
similar "loaded" decaffeination solvent.
~ ~9 3 1 ~8
- 19 -
I. Solvent Preparation.
14 pounds of spent grounds derived from a
commercial percolation system, approximately 50%
solids removal, containing 50% water, were placed in
05 an elongated vessel. 15 gallons of methylene chloride
at room temperature and 1~ psig were pumped through
the elongated bed at 350 cc/minute, for 5 hours.
The methylene chloride was present in a sealed
system which was recycled during this time. This
produced a loaded methylene chloride having an
approximate level of 0.42% soluble solids and a
negligible level of caffeine.
II. Decaffeination
An aqueous extract of roast and ground coffee
was first stripped of any volatile flavor and/or
aroma compounds by passing the extract through a
centritherm before decaffeination. On analysis,
prior to decaffeination, the stripped extract was
found to contain 0.9% caffeine, and about 25% soluble
solids. The loaded methylene chloride produced in
Section I of this Example above was utilized to
decaffeinate the extract to achieve an average
percent decaffeination of 9g.~%. The extract oper-
ating conditions during decaffeination were as
follows:
Operating Conditions: 2" Karr column
Agitation: 120 SPM at 1 inch stroke length
Temperature: extract feed 110F
solvent feed 110F
Pressure: top 22 psig
middle 25 psig
bottom 27 psig
Extract Flowrate: 30 cc/min
3L~9~
- 20 -
Solvent Flowrate: 130 cc/min
Solvent/Extract: 4.3/1 by volume (5.2/1 by
weight)
So~vent Carryover
05 in Extract Drawoff: 30~/O by volume
The extract drawoff was stripped of methylene
chloride by passing throug:h a flash evaporator as in
Example I. The extract was then aromatized and
spray dried.
