Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Description
METHOD FOR AROMATIZING FOOD PRODUCTS
Technical Field
The present invention pertains to aroma-
05 tized particles of vegetable material such as coffee,cereal grains and/or chicory material.
Background Art
Soluble beverage powders such as spray-
dried coffee products are relatively devoid of aroma
as compared to their source or parent material-
namely, roasted and ground coffee. Low aroma in-
tensity also exists in certain types of roasted
coffee material such as most decaffeinated coffees
and the compressed roasted coffee materials des-
cribed in U.S. Patents Nos. 1,903,362 to McKinnis,
3,615,667 to Joffe and 3,801,716 to Mahlmann et al.
These low-aroma beverage products have an initially
low ~uantity of aroma, suc~ that upon the initial
opening of the product by the consumer only low
aroma impact is detected, and whatever amount of
aroma is present in the product is rapidly given up
after initial opening of the container, such that
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subsequent openings of the container during a typical
in-use cycle for the product evolve little or no
aroma.
It should be noted that the term "coffee product"
05 as used in this invention is meant to refer to not
only those materials consisting of 100% coffee but
also to substitute or extended coffees which may
contain roasted grain (e.g. wheat), chicory or other
vegetable ~aterial either alone or in combination
with coffee.
To date most efforts to add natural aroma
to food products have focused on the addition of
roasted coffee aroma to soluble coffees such as
spray- or freeze-dried coffee. Understandably then
the thrust of the present invention is in the area
of aromatizing coffee products; however, the appli-
cation of this invention for the aromatization of
other food products is contemplated.
At the present time, virtually all commercial
soluble coffees are combined with coffee oil such as
by spraying the soluble coffee prior to packaging
with either a pure or an aroma-enriched coffee oil.
In this manner the soluble coffee material will have
an aroma more akin to non-decaffeinated roasted and
ground coffee. The addition of oil is usually
effected by the well-known oil plating technique
(shown in U.S. Patent No. 3,148,070 to Mishkin et
al.) or by oil injection (shown in U.S. Patent
No. 3,769,032 to Lubsen et al.). At the present
time, commercial roasted coffee products do not
eontain any added aroma, all attempts at producing a
more aromatie product being directed to preserving
the aromaties contained within the freshly roasted
coffee beans.
Coffee oil with or without added aromas
has been the preferred medium employed to aromatize
coffee material since such products could still be
designated as being pure coffee; however, techniques
05 developed for the production of coffee oil (see
Sivetz, Coffee Processing Technology, Vol. 2, Avi
Publishing Company, 1963, pages 21 to 30) such as
solvent-extracting or expelling coffee oil from
roasted coffee are not particularly desirable since
the manufacturer is left with either solvent-
containing roasted coffee or expelled cake, both of
which must be either further processed or discarded.
~he addition of oil to a coffee product has a]so
proven troublesome in that, undesirably, oil drop-
lets can appear on the surface of the liquid beverageprepared from the oil-containing product. Thus, it
would be advantageous if processes for aromatizing
coffee products were developed which employed all
coffee or other vegetable materials, but which did
not require the production or addition of coffee oil
or other glyceride material.
Disclosure of Invention
Particles of vegetable material having an
essentially insoluble cellular structure and a
natural oil content of at least 1% and preferably at
least 3% by weight, such as coffee, grain (e.g.
wheat) or chicory material and which particles may
be in the form of roasted whole coffee beans or
subdivided particles of roasted coffee, wheat or
chicory including ground or colloidally milled
particles are employed as the carrier for coffee
aroma. The particles could be obtained from
compressed roasted coffee or even spent roasted
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coffee grounds, such as the waste grounds from
soluble coffee manufacture. These particles are
contacted with volatile aromatic compounds such that
the aromatics are entrapped or adsorbed in an amount
05 in excess of 0.1% by weight. ~lthough it would be
theoretically possible -to adsorb aromatics in an
amount up to about 5% by weight, in actual practice
levels in excess of 1% are difficult to achieve.
Conventional roasted and ground coffee material to
which no aromatics have been added contain aromatics
in an amount below 0.05% by weight. Preferably the
aromatized particles of this invention will contain
aromatics at a level of 0.2% or more, typically
about 0.5%. This aromatized roasted material is
combined with low-aroma coffee products at an
appropriate weight level in order to provide a
desirable aroma. A level of about 0.05% to 2% of
added particles is used when the insoluble or only
partially soluble particles are combined with a
soluble powder in order to limit the amount of
sediment in the reconstituted product. An aromatic
level within the particle of only 0.1% by weight
would typically require the addition of more then 5%
of these particles to the low-aroma coffee product.
When the aromatized particles are combined with an
insoluble material, it would of course be possible
to employ a higher level, say up to 10% by weight.
When it is desired to obtain particles
smaller than 200 microns cryopulverization techniques
such as that disclosed in U.S. Patent No. 3,965,267
to Davis have proven quite useful. Conventional
soluble coffee material, such as spray-dried or
freeze-dried coffee has not proven to be a useful
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carrier when employed in the process of this in-
vention. Soluble coffee powder has not been found
to either adsorb, retain or stabilize aromatics to
the same extent or in the same manner as the roasted
05 coffee, grain or chicory materials which are em-
ployed in this invention.
The method of contacting the roasted
particles with aromatics for the purpose of en-
trapping aroma within the particles can be many and
varied. The use of high pressure and/or low particle
temperatures may be employed in order to maximize
pick-up of aroma or shorten the period of time
required to achieve a desired level of aromatization;
however, such conditions are not required. It will
usually be desirable, however, to minimize the
amount of moisture which comes into contact with the
particles both before, during and after aromatization.
The moisture content of and amount of the material
supplying aromatics to the roasted particles should
be controlled so that the moisture content of the
particles is kept below about 15% by weight. Suit-
able condensation, vaporization, sweeping and/or
other separation techniques may be employed to
separate moisture and aromatics contained in aroma-
bearing gas streams, aroma frosts or liquid aromaticcondensates. It may also be desirable to separate
aromatics from any carrier gas (e.g. CO2) in which
they are entrained. Among the techniques useful for
adsorbing aromatics into the roasted particles are:
(1) placing a mi~ture of the roasted particles and a
condensed CO2 aroma frost in a vented vessel, prefer-
ably above -40C, and permitting the CO2 portion of
the frost to sublime off, (2) enclosing both the
roasted particles and a condensed aroma frost in one
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or two connected pressure vessels and then raising
the temperature within the frost containing vessel
to vaporize the frost and provide an elevated pressure,
(3) combining a highly concentrated aqueous aroma
05 condensate with the roasted particles at a level at
which it does not unduly moisten the particles, (4)
condensing aromatics onto chilled roasted particles,
(5) passing a stream of aroma-bearing, low-moisture -
gas through a bed or column of roasted partices.
The aromatics which may be used for this
invention may be derived from any of the many sources
well-known to those skilled in the art. Depending
on the method of contact to be employed, the aromas
may be present as a component of a gas, a liquid
condensate or a condensed frost. Among the aromas
which may be used are coffee oil aromas, as described
in U.S. Patent No. 2,947,634 to Feldman et al.,
aromas obtained during the roasting of green coffee,
as described in U.S. Patent No. 2,156,212 to Wendt,
aromas obtained during the ~rinding of roasted
coffee, as described in U.S. Patent No. 3,021,218 to
Clinton et al., steam-distilled volatile aromas
obtained from roasted and ground coffee, as
described in U.S. Patents Nos. 2,562,206 to Nutting,
3,132,947 to Mahlmann, 3,244,521 to Clinton et al.,
3,421,901 to Mahlamnn et al., 3,532,507 to Cascione
and 3,615,665 to White et al., and the vacuum
distilled aromas obtained from roasted and ground
coffee, as described in U.S. Patents Nos. 2,680,687
to Lemonnier and 3,035,922 to Mook et al. It would,
of course, also be possible to employ volatile
synthetic chemical compounds which duplicate or
simulate the aromatic compounds naturally present in
roasted coffee. As will be recognized by those
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skilled in the art, the addition of volatile
aromatic compounds to food products will, along with
providing the desired aroma enhancement, also
provide a flavor effect to the presence of an amount
05 of these compounds in the food product at the time
of consumption.
According to one embodiment of this in-
vention, a coffee aroma gas containing a high carbon
dioxide level, preferably above 80% by weight, is
obtained from a source such as commercial coffee
grinding equipment. This gas is preferably passed
through a first condenser where it is cooled to
between 2C and 10C and where most of the moisture
contained in the gas is condensed. This gas is then
fed to a condenser, such as a jacketed, scraped-wall
heat e~changer, cooled by means of a liquid gas
refrigerant such as liquid nitrogen, where the gas
is condensed to the form of a carbon dioxide frost.
The frost is then placed in a pressure
vessel where it is warmed, such as by means of a
surrounding water jacket, to at least -29C and
preferably between about 2C and 65C. The amount
of frost and the pressure vessel are sized so that a
gaseous pressure of at least 6.8 at~ospheres will be
developed within the vessel or vessels. As the
temperature of the frost increases above about
-56.6C, the solid carbon dioxide contained in the
frost is converted to an aroma-bearing li~uid phase
and/or saturated vapor phase.
The aroma-bearing carbon dioxide vapor is
then permitted to contact roasted coffee, wheat
and/or chicory material, this contact taking place
either in the same vessel in which the frost is
vaporized or in a second vessel which is fed with
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the aroma-bearing carbon dioxide vapor. As will be
apparent to those skilled in the art, when two or
more vessels are employed, the total volume of all
of the vessels and the connecting ducts will be
05 inversely proportional to the pressure developed
within the system.
After the desired period of contact, the
vessel containing the low aromatized roasted ad-
sorbent will be isolated if necessary and then
cooled, usually to a temperature below 0C and
preferably below -45C, before it is vented. This
cooling step will cause additional coffee aromatics
to be adsorbed by virtue of the adsorption power/
capacity of the adsorbent (i.e., capillary con-
densation with the microporous structure). Itwould, of course, be possible to maximize this
additional adsorption by cooling to the point where
a frost is reformed. At this point, the pressure
within the vessel would approach atmospheric and it
will usually be desirable to then heat and vent the
vessel in order to remove carbon dioxide and raise
the temperature of the contents above 0C.
When separate vessels are used for the
frost and the adsorbent material, it will be possible ~~
to recover a portion of the aromatics which might be
vented from the adsorbent-containing vessel along
with carbon dioxide. This can be effected by iso-
lating the frost vessel and cooling it to recondense
carbon dioxide to a frost. If this cooled frost
vessel is then connected to the adsorbent vessel
vent line, the vented vapors will pass to the frost
vessel where they will ~e condensed and available
for aromatizing additional roasted coffee, wheat
and/or chicory material.
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The specific particle size of the roasted
coffee, wheat and/or chicory material to be aroma-
tized according to this invention has not been found
to be critical. The use to which the aroma-bearing
05 particles will be put may dictate the size parameter.
For instance, it may be desired (1) to aromatize
whole coffee beans, a few of which could be in-
corporated into a container of roasted and ground or
soluble coffee product givin~ a product with unique
appearance, (2) to aromatize roasted coffee, wheat
and/or chicory particles the size of which will
match the roasted and ground product with which they
are to be blended, and (3) to aromatize particles of
a size 20 (U.S. Standard Screen) mesh (840 microns)
or less for incorporation into a soluble coffee
product. Finely ground roasted material having a
particle size below 200 microns and preferably about
25 microns can be advantageously obtained following
the cryopulverization technique of the aforementioned
Davis patent. Colloidal sized particles can also be
used.
The oil content of the roasted particles
- of at least 1%, preferably at least 3%, is believed
to enhance the ability of the cellular particles to
entrap aromatics. This enhancement may be evidenced
by adsorption of a higher quantity of aromatics
and/or a broader spectrum of aromatics. It has also
been found that this oil component can also serve a
useful purpose when an aromatized powdered food
material produced in accordance with this invention
is pac~aged in glass jars, since even minute amounts
of oil contained within the packaged product will
prevent small particles of material from adhering to
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the inside of the glass jar, thus producing a possible
unsightly appearance.
The moisture content of the starting
roasted coffee, wheat and/or chicory material should
05 be below about 7% in order to avoid stability problems
in the fixed aromatics, especially during the period
before the aroma-bearing adsorbent is combined with
the low-aroma coffee product. Once the combina-tion
is effected, excess moisture that may be present in
the aroma-bearing adsorbent will migrate to the
low-aroma product which has been previously dried to
a stable moisture content. Since the aromatized
adsorbent may be added at a level below about 2% by
weight of the low aroma material, the total amount
of moisture transferred may be insignificant.
Best Mode for Carrying Out the Invention
This invention is further described but
not limited by the following Examples.
Example 1
300 grams of roasted and ground coffee
were placed in a CO2-flushed, 2-liter Parr Bomb. A
second Parr Bomb containing 200 grams of grinder gas
frost was placed in a 50C water bath causing the
frost to sublime and produce an internal temperature
of about 24C and a maximum pressure of about 62.2
atmospheres. Using a high pressure tube connection,
the two Parr Bombs were then maintained at room
temperature for three hours. The bomb containing
the roasted and ground coffee was isolated and then
cooled and maintained at about -70C for 10 hours.
Thereafter this bomb was vented and warmed to 0C.
The resulting aromatized roasted and ground coffee
possessed an intense aroma of fresh roasted coffee.
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Example 2
200 grams of grinder gas frost and 300
grams of regular grind roasted coffee (average
particle size 860 microns) were placed and sealed in
05 a 2-liter Parr Bomb under a C02 atmosphere. Three
layers of paper towels were placed between the frost
and coffee as an adsorbent in order to pick up
moisture from the frost component and minimize
caking of the roasted coffee. The contents of the
bomb were then warmed to room temperature (24C)
over three hours where a pressure of about 41.8
atmospheres was developed and these conditions were
maintained for an additional hour. Using dry ice,
the bomb was cooled for up to 20 hours until the
internal pressure was reduced to atmospheric. Then,
applying an ice bath, the Parr Bomb was warmed to
0C and about 14.6 atmospheres; C02 was then slowly
vented out of the system. Under a C02 atmosphere,
the Parr Bomb was opened and the aromatized roasted
coffee removed and combined with agglomorated spray-
dried coffee powder at a level of 0.58% by weight (1
gram per 6 oz. (170 gms) of powder) and sealed in a
glass jar under a CO2 atmosphere.
Example 3 ~
The procedure of Example 2 was repeated
using fine grind (average particle size 620 microns)
roasted and ground coffee and whole beans in place
of regular grind coffee. The sealed jars of each of
these three variants were evaluated periodically,
both organoleptically and with a carbon gas chromato-
graph (GC) and compared to a control sample aromatized
by adding a grinder gas aroma-enriched (1~8:1 frost
to oil ratio) coffee oil into a 6 ounce (170 grams)
jar of agglomerated spray-dried coffee at a 0.2%
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level. The aromatized coffee oil was prepared in
accordance with the high-pressure decanting technique
of commonly-assigned U.S. Patent No. 4,119,736 to
Howland et al. Thus, the quantity of grinder gas
05 frost consumed in the preparation of all samples was
at a comparable level ~0.67 vs. 0.61 grams per jar).
Table I su~marizes the relative quantity of the
total volatile hydrocarbon compounds present in 1 cc
of the headspace in the sealed jars as a function of
time at 35C storage.
TABLE I
35C Storage Stability of Aromatized Soluble Coffee
Average GC Counts in Millions (~10%)
Regular
Grind Fine Grind
Aroma Coffee Oil Roasted Roasted Roasted
Carrier Control Whole Beans CoffeeCoffee
Storage
Time
(in wks.)
0 1.75 1.10 4~30 2.00
2 1.81 1.15 3.60 2.20
4 1.75 1.13 - 1.80
6 1.60 1.00 3.10 1.90
8 1.50 1.15 ~.10 2.00
1.40 1.20 3.10
Examination of Table I shows that soluble
coffee aromatized with the different sized particles
of aromatized roasted coffee held up very well in
terms of headspace counts regardless of initial
aroma level. Organoleptic evaluations confirm the
above data.
28
In conjunction with GC measurements,
periodic organoleptic evaluations were carried out
on each sample by a panel of skilled coffee tasters.
Briefly, a typical organoleptic evaluation consists
05 of two segments. First, the oxygen content of the
sealed jar is determined using a Beckman Oxygen
Analyzer, Model C2. The oxygen content should be
under 4 percent. The seal of the jar is then broken
and the relative quality, intensity and nature of
the aroma in the headspace is recorded, by three to
five experienced panelists, each with their own set
of samples. The jars are then commonly ranked
according to their relative intensities (impact) on
a scale of 1 (nil) to 9 (very intense) and accord-
ing to their relative qualities on a scale of 1(extremely poor) to 9 (excellent). The second
phase of the evaluation involves the preparation of
a brewed cup of the soluble coffee and a deter-
mination of each cup's relative "flash" aroma and
flavor. Finally, a visual inspection of each cup's
surface appearance was made noting the presence of
any oil, roasted coffee or other matter. In addition,
for these samples, the cups were carefully decanted
and the presence of sediment was noted. In general,
a rough approximation indicated that 40 percent of
the cups prepared with the regular grind sample had
one to five specks on the surface and/or a perk-like
sediment in the bottom of the cup. For the fine
grind sample, about 30 to 40 percent of the prepared
cups contained a light perk-like sediment after
decanting the brew. The surfaces of all the variant
samples were totally oil-free. The coffee oil
control sample produced cups having noticeable
surface oil.
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Table II and III relate the average opinions
of the panelists for jar aroma impact and quality,
respectively, as a function of storage time.
TABLE II
05 Effect of 35C Storage on Jar Aroma Impact Rating
(Impact Ratin~ on a Scale of 1 to 9)
Time Coffee Whole Regular Fine
(weeks) oil Beans Grind Grind
0 7.5 6.5 6.5 7.0
2 6.0 5.0 6.0 6.5
4 5.5 4.5 6.0 6.0
6 5.7 5.0 6.0 6.0
8 6.0 5.0 6.0 5.5
6.0 6.0 6.0
TABLE III
Effect of 35C Storage on Jar Aroma Quality Rating
(Quality Rating on a Scale of 1 to 9)
Time Coffee Whole Regular Fine
(weeks) Oil Beans Grind Grind
0 7.0 6.5 7.0 7.0
2 5.7 5.0 7.0 6.5
4 5.0 4.0 6.5 5.5
6 6.0 4.0 5.5 5.5
8 6.0 5.0 6.0 5.0
6.0 6.0 6.0
As can be seen from the foregoing results,
the aroma impact and quality of the tested variants
are comparable to the aromatized oil control. The
gas chromatograph of the variants all showed a very
similar headspace composition to that of the control.
After ten weeks of storage at 35~C, sealed
jars were evaluated in a in-use test which reflects
a simulation of actual consumer use day by day. The
05 results of this study showed all three variants to
possess comparable aroma impact and quality to the
oil control.
Example 4
Spent coffee grounds were dried to 7% (by
weight) moisture and 300 grams of the grounds were
placed in a 2-liter Parr Bomb containing a bottom
layer of 200 grams of grinder gas frost and a layer
of paper toweling. The Bomb was then sealed, warmed
to room temperature (about 59 atmospheres) and after
3 hours the Bomb was then cooled by dry ice to
reduce the internal pressure to atmospheric. The
Bomb was then inserted into an ice bath; warmed to
0C and then vented. The aromatized spent grounds
were then blended with soluble coffee powder at a
level of 0.5%. After storage under inert conditions,
the resulting product was characterized as having a
pronounced and pleasant coffee-like aroma with
slightly more green notes than the products of
Examples 2 and 3.
ExamPle 5
Dark roasted Colombian coffee beans are
cryopulverized using liquid nitrogen as the cryo-
genic fluid. The ground particles possessed an
average size of 125 microns and were kept under a
dry atmosphere. Subsequently the particles were
well mixed with coffee grinder gas frost at a weight
ratio of 1.2:1. The mixture was then transferred to
a prechilled, pinhole vented jar and stored at -8C
overnight. Thereafter the aromatized particles are
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combined with spray dried coffee agglomerate at a
level of 0.2% by weight and packaged in glass jars
under an inert atmosphere. Upon prolonged storage,
the jars are found to contain a pleasant headspace
aroma.
