Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
'769(~
1 --
TAR-DRPLET~D LIQUID STOKE SOLUTIONS
AND Method
FIELD OF THE INVENTION
This invention relate to: (a) a method for
preparing tar-depleted liquid smoke solution from
smote vapors, by tar-depleted liquid smoke
compositions, (c) tar-depleted, partially
neutralized liquid smoke compositions, (do food
casings colored and flavored with tar-depleted
liquid smoke compassion, (e) a method for making
ford casing colored and flavored with tar-deple~ed
liquid smoke composition, and (f) a method for
preparing a smote colored and flavored foodstuff
encased in a cawing.
BACKGROUND OF THE INVENTION
tubular cellulosic food casings are used
extensively for processing a great variety of meat
product and other food items. The food casings are
generally tunneled cubing of various diameter
prepared from reconstituted arterial such as
regenerated cellulose. Cellulosic food casings may
also be prepared with fibrous webs embedded in the
wall thereof, such casings commonly being referred
to a "fibrous food Congo."
The many different recipes and modes of
processing that are used by the prosody food
industry to suit different tastes, and even regional
preferences, generally necessitate the use of food
casings with a variety of characteristics. In Rome
instance, for example, food casings are required to
have multi functional use wherein they serve a
: '
- ~227~
-- 2 --
~ontainer6 during the processing of a food product
encased therein, and when Allah verve a a protective
wrapping for the finished product. It the processed
meat industry, however, the food Congo used it the
Reparation of many ye of meat products, such as
Yore types of assuage, such a fran~furter6,
bolognas and the like, beef rolls, hams and the
like, are frequently removed from about the
prosody meat product prior to slicing and/or final
packaging.
Surface appearance and flavor are important
factor in the commercial and consumer acceptance of
processed meat products, and a common feature of
~06t varieties of such product involves the use of
"smoking" for imparting oharacteri~tic flavor and
color thereto. The "smoking" of food product is
generally accomplished by the food processor
subjecting the food product to actual contact wit
smoke in a gaseous or cloud-like form. Such
"smoking" prowesses, however, have not been
considered completely satisfactory for a variety of
reason, including the inefficiencies and lacy of
uniformity of the smoking" operation. Because of
the 6hortcoming6 experienced, many meat packer now
employ various type of liquid aqueous 601utions of
wood-derived Moe constituents, commonly called
"liquid smoke ~olution6" what have been developed
and used commercially in the food processing
industry for the processing of many type of meat
and other food product. For convenience in this
specification, these commercially available "liquid
smoke" 601ution6 in their as-purcha6ed Tao will be
~L22'7~
frequently referred to herein a "aye" liquid
smote.
Example of prows for preparing as-is
liquid smoke are described in United States Patent
3,106,~73, issued October 8, 1963 to Hollenbeck, and
United States Patent 3,873,741, issued March 25,
1975 Jo Melter et at. The processes for making
liquid smote can be generally de~cribad as
comprising heating wood in an oxygen-controlled
atmosphere Jo effect the thermal decomposition of
wood and to generate smoke, and I contacting the
smoke with an aqueous solution to condense and to
recover the coloring and flavoring constituents of
the smoke. The condensed as-i& liquid smoke
601utions generally also contain various
tarry-sub6tance6, a well a organic acids such as
acetic acid.
The application of "liquid smoke solutions"
to meat product it generally carried out in a
variety of way, including spraying or dipping an
encased food product during the processing thereof,
or by incorporating toe "liquid smoke solution" in
the recipe itself. The actual operation of
"smoking" by spraying or dipping is not completely
satisfactory due to inability to treat the encased
product uniformly, and incorporation of "liquid
smoke solution" in the meat recipe doe not always
provide the desired surface appearance because of
dilution of smoke ingredients. Incorporation in the
recipe also reduce the stability of the meat
elan, and will adversely affect taste if high
concentrations are used. Application of liquid
~L22'7691)
smoke to encased food product by the Good
processor, such as by spraying or dipping, also
causes unwanted pollution and equipment corrosion
problem for the food processor. In addition,
encased sausages treated by application of the
liquid smoke during commercial processing have been
found to yield, after peeling the cawing from the
treated encased food product, sausages which are
lacking in smoke color uniformity between individual
sausage and batches of siege. Even more
undesirable is the lack of uniformity of coloration
which often appear on the surface of the individual
sausage, including light and dark streaks, light and
dark blotches, and even uncolored spots which
especially appear at the ends of sausages.
Several methods are known for coating
either the interior or the exterior of a food cawing
with various liquid substance designed to meet
particular processing requirements, as, for example,
substances that affect the adhesion properties of
the cawing. Some of the copings known in the art
contain a liquid smoke a a con~tituer.t thereof.
Known methods for coating an as-is type
liquid smoke solution internally in a cawing haze
been found to be costly and also to limit the speed
of a continuous high speed production line.
Renown method for coating the external
surface of a casing, particularly a cellulosic
gel-6tock cawing, wit assay type liquid smoke
solution, result in problems due to the tar context
of these smoke solutions. That is, during the
coating process, tarry deposits accumulate on the
~2~7~9~
carrier rolls and the squeeze roll of the treatment
unit which eventually forces shutdown of the
treatment swept.
One solution to the above-mentioned
problems of imparting smote color and flavor to a
foodstuff is to use "tar-depleted" liquid smoke
solutions to coax the interior or preferably tube
exterior surface of the cawing. However, until
recently, tar-depleted liquid move solutions were
unavailable, and methods for making the tame were
unknown. As indicated above, it has been found thaw
when a cellulosic food casing, made from a fibrous
or non-fibrous gel stock, is treated with a highly
acidic pi of about 2.0 eon 2.5) tar-containing,
aqueous liquid smoke, tarry deposits accumulate on
the carrier roll and the squeeze rolls of the smoke
treatment unit, keg the cawing to stick to the
rolls and eventually forcing shutdown of eke unit.
The acidity of the liquid smoke also may interfere
with peelabili~y of the casing by interfering with
the action of the peeling aid used, finch as, for
example carboxymethyl cellulose. Aqueous liquid
stoke solution are generally very acid, having a pi
of 2.5 or less and a titratable acidity of at least
3 weight percent.
It was found that tar could be removed from
the liquid smoke by neutralizing the aye liquid
Moe under controlled temperature conditions to
precipitate the tar, and the use of this
neutralized, tar-depleted liquid smoke to treat a
gel stock cawing would eliminate the problem of
tarry deposit. This process I disclosed and
69~
6 -
clad in Uni~ea Sue Pant ~pplicDtion serial
aurora ~17,î~2. filed I Satyr 19~. my I En.
N~chol~o~ . .
Caesar kiwi to rules Boyle he art O
gibe tar-~epletea liquid smoke till osseous
siqni~ica~t eye ~:olorillg capability. It bay been
generally believe that ye jars on a liquid ~rQolce
vainly contribute to gee coloring ability of the
liquid smoke. Err, ye aye recently been found
that tbi~ I jot toe cave, blot Swat otter
~on~titu~nt~ of the l~gui~ Melissa, Ballard is be
vainly Abe eaE~onyl~, Howe a Gore 6ignif inn role
I the coloring ability ox toe liquid Sue.
Another trod using "solvent
tractor prows cay be applied to Elk
*ar-~pleted l~guid emote. For example. such a
prows it clue sod clue in Utah State
Relent Number 4,431,033 issued
by 14, 1984 to I. D. ~iehol~on. hi pry
kippers (a contacting ~ar-eonta~ning guy
owe solution baying on abortive power ox it
Lowe tout 0. 25 at a Dave Lyon of byway 3~0 no,
Thea either nonreact~e or reactive organic lug
solvent which bd6 a hydrogen bonding volubility
parquetry of at Lotte about 2.7, an vacua 16
~mi~c~ble ED toe qu~ous Lou kiwi solution
under ~onaitions fount Jo form a ~ar-enric~ed
solvent fraction end tar-d~pletea lug smoke
rocket, an (b) separating toe Lowe joke
traction to o'er a tar-depleeea liquid zoo. Using
BUCK solvent xtr~ction method. it it pueblo to
Ike tar-d~pl~t~a ~lqui~ Mohawk solution ho g a
/, . .
~ZZ'76~
-- 7 --
high capability to impart smoke color odor, and
flavor, without requiring neutralization of the
tar-containing liquid smoke.
The tar-depleted liquid smoke made from the
solvent extraction process, unless it it
neutralized, it generally highly acidic, which may
also interfere with the action of the pee lability
agent, such as certain water soluble cellulose
ether, which may be used on the casing. To
alleviate this problem, the tar-depleted liquid
smoke may be partially neutralized. However, since
the coloration ability of the liquid stoke declines
with increasing phi the tar-depleted liquid smoke is
only "partially neutralized" Jo a degree such that
the peel~bility agent is not significantly affected
and the coloration ability of the smoke is
retained. the term "partially neutralized", a used
herein, is intended to refer to liquid smoke
compositions having a pi greater than about 3.
preferably having a pi within the range of from
about 3 to about 6.5, and even snore preferably
having a pi within the range of from about 3 to 5.
By providing a partially neutralized, tar-depleted
liquid smoke made from a solvent extraction process,
the problems due to acidity are avoided to a large
extent while a significant degree of the coloring
ability of thy original assay liquid smote is
retained.
The above described liquid smoke
compositions, whether aye or tar-depleted, have
been found suitable for use with fibrous cellulosic
food casing. When used with non fibrous casings,
~LZ2769~
however, it aye been one chat eye liquid smoke
solutions, in Tory uneo~central:e~ ~6-~a~ufactured
o'er part a Luke color, Odor an flavor to eye
ooastuf I, us owe on I quantity us iciest Jo be
acceptable for all eo~mercial application. Because
noaf~brous Cannes art thinner elan ~ibrou6 clunks.
tube liquid ~sDolce cannot lye on a practical manner
"coated on, plywood to, or incorporated on toe
casing Jo an extent sufficient Jo always impart toe
d~sirea joke color, odor and flavor so a
foods~uf~. Shea composition, therefore, cantos be
universally u6~d, King restrict vainly for use
web f~brou6 counsel.
It order to prove lug smoke owlish
having coloring Bills us iciently high to be
use on aon-fi~rous Congo. tar-depletea liquid
-stoke solution hove teen conceDltr~ed to form
tar-~epleted concener~t~a liquid stoke Utahan,
for example. a closed in United State Patent
Number 4,540,613 issued Stemmer in, 14~
to M. D. Nicbo loon end J . H .
BeckrDan. Tile triplet, concentrated liquid
eye solution Dave a Niger coloring ability.
~berefore, it it possible wren using casings costed
with replicated, concentrated, liquid owe
oiliness, Jo have su~ici~nt coloring ability to
- color lottery photo, oven whey u6~ng a
nonfibrou~ casing.
Tar-depl~t~a, e~ncentrated lieu a smoke
~olutlon6 eta be aye by a process Waco Cooper
roving on unneutr~lized, tar-depleted liquid
owe- composition jade Roy a solvent extraction
,J3L~ I
prows, and concentrating the unreleased
tar-depleted liquid smoke. The concentrated,
tar-depleted liquid smoke product ha ~urpri6ing and
advantageous physical properties, and it Jay be
optionally neutralized to provide a partially
neutralized, concentrated, tar-depleted liquid kiwi
composition.
The tar-depleted, concentrated liquid kiwi
solutions, described above, avoid the difficulties
inherent Zen an assay smoke is concentrated,
wherein there is an increased concentration of
undesirable chemical substance. for example tar,
and certain o'er constituents which are Doria,
or example phony, which contribute to the
luring ability, but cause an undesirably Strong
or "caustic" flavor in sigh concantration6.
One problem in ~oncentrati~q liquid smoke
solutions is that when a neutralized liquid smoke it
concentrated to a suitably high degree for coating
on non fibrous casings, there it a significant and
undesirable increase in viscosity, rendering toe
ruling concentrated, liquid smote unsuitable for
commercial use. The increase it viscosity of
neutralized, a and tar-depleted liquid smoke
solution which are concentrated is in large part
due to the presence of acids, mostly acetic acid, in
the liquid Sue. Upon neutralization of the acids
in toe liquid owe, salts of Neutralization of
these Audi are formed, and it is these salt that
are the substances which mainly contribute to the
high visc06ity. In non-concentrated smoke solution
which are neutralized, the concentration of these
I
-- 10 --
~lt6 us snarl not hug tough to cause a
~iffi~ulty. o'er, when ~eutral~2ea kiwi us
counterweighted the ¢oncen~rat~on of eye ~lt6
increases ~ropor~io~ally iota ye ~eqree of
~one2ntration, resulting in exile
concentration of those alto no thus, on
undesirably it viscosity.
It aye now been found by Nicholson and
Beckman as disallowed in the above-cited United States
4,540,613 : I, that wren
concentrating on unneutralized, tar-depletea, Lydia
kiwi, the acid content it not proportionally
increased Vito the degree of concentration of the
liquid smoke. That it, as the unneutralized,
tar-depleted smoke is concentrated, the acid
awing the viscosity difficulties are apparently
Yellowtail to a significant degree. Thus, it it
possible to wake concentrated liquid Moe
solutions, voile retaining a usably low
viscosity. The ~ar-deplete~ conoentr3tea liquid
Moe ~oapo~itions ox toe above iota Serial No.
4~5,924~ eke ox their lo total acid content,
haze a low ~i~co~ity when neutralized.
Additionally, thy are Allah tar-depletea, and
throb pry the processing advantages heretofore
fount only iota the ye of unconcentrated,
t~r-~epl~t~d liquid joke ~olut~on6. They also Dave
substantially increased owe coloring and flavoring
a ties over unconcentra~ed, tar-depleted liquid
Dow solution
There it alto an increase in the viscosity
I concan~ratea it smoke Solon. which Jay be
~l2276~C~
11 --
due in par to the presence of the high molecular
weight polymeric tar constituents in the liquid
smoke composition. The low amount of tars in the
tar-deple~ed concentrated liquid smoke composition
also contribute Jo the low viscosity of both the
unneutralized and partially neutralized forms.
The tar-depleted concentrated liquid smoke
solutions have many advantages. However, heretofore
they required additional processing of as-is liquid
smoke. The extra processing includes the treatment
to tar-deplete the as-is smoke and the processing to
concentrate the resulting tar-depleted liquid smoke,
when a concentrated liquid smoke is desired. This
extra processing of the as-is liquid smote to
prepare the concentrated and unconcentrated,
tar-depl~e~ed liquid smoke solutions requires
expensive processing equipment and extra labor
costs. It would be an advantage, therefore, to
produce tar-depleted liquid smoke solutions, having
the coloring ability of either concentrated or
unconcentrated liquid smote solutions, without extra
process Taipei beyond the condensation of the smoke
vapors to form a liquid smoke solution.
In United States Patent 4,359,481, issued
November 16, 1982 to Suits et at., is disclosed a
process for making a liquid smoke having reduced
tar-content by fractional condensation, i.e. by
cooling the smoke vapors in various stages. The
liquid smoke product of the Suits et at. it produced
for its flavoring ability, and is not shown to have
a high coloring ability.
I 2~12 -
An object of an aspect of the invention is,
therefore 3 to produce tar-depleted liquid smoke
solutions without the extra processing of as-is
liquid smoke.
An object of an aspect of the invention is
to provide a method for preparing tar-depleted
liquid smoke solutions, characterized by fewer
process steps and less expensive equipment than
heretofore possible.
An object of an aspect of the invention is
to provide a method to produce, from the condemn-
station of smoke vapors, tar-depleted liquid smoke
solutions having degrees of coloring ability,
equivalent to unconcentrated liquid smoke solutions.
An object of an aspect of the invention is to
provide a method to produce, from the condensation
of smoke-vapors, tar-depleted liquid smoke
solutions having degrees of coloring ability,
equivalent to concentrated liquid smoke solutions.
An object of an aspect of the invention is to
produce tar-depleted liquid smoke solutions having
a high content of carbonless.
An object of an aspect of the invention is to
produce tar-depleted liquid smoke solutions having
a high coloring ability.
An object of an aspect of the invention is to
produce a concentrated tar-depleted liquid smoke
with high coloring ability and low viscosity.
Other objects will become apparent in the
description that follows.
SUMMARY OF THE INVENTION
An aspect of the present invention is a
method for preparing a tar-depleted liquid smoke
solution which comprises (1) thermally decomposing
~L2;2~9~ .
- 13 -
wood in an oxygen-controlled atmosphere to generate
smoke vapors, (2) selectively vent extracting the
awry from the generated smoke vapors, and (3)
absorbing the smoke vapors into an aqueous medium to
provide a tar-depleted liquid smoke solution.
Another aspect of the present invention is
a method for preparing a tar-depleted liquid smoke
601ution which comprises (1) thermally decomposing
wood in an oxygen-oontrolled atmosphere to generate
smoke vapors, (2) contacting the smoke vapors, water
and an organic solvent having volubility parameter
greater than about 2.7, to form a tar-containing
liquid solvent phase and an aqueous liquid smote
phase, I separating the liquid smoke phase from
the the liquid solvent phase to provide a
tar-depleted liquid smoke 601ution.
Another aspect of the prevent invention is
an improvement in a method for preparing a
tar-depleted liquid smote 601ution which comprises
thermally decomposing wood in an oxygen-controlled
atmosphere to generate smoke vapors and condensing
the smoke vapors into an aqueous medium, the
improvement of selectively removing the tars from
the smoke vapor, by a process which comprises
contacting the smoke vapors with an organic solvent
having a volubility parameter greater than about 2.7.
Another aspect of the present invention is
any of the above methods wherein the smoke vapors
are contacted with water and a solvent in a single
contacting zone.
Another aspect of the present invention is
any of the above methods wherein the smoke vapor
~L22q~
- 14 -
are contacted with a solvent in a first contacting
zone and thereafter contacted with water in a second
contacting zone.
Another aspect of this invention is a tar-
depleted liquid smoke composition prepared by a
method which comprises (1) thermally decomposing
wood in an oxygen-controlled atmosphere to generate
smoke-vapors, (2) selectively solvent extracting
the tars from the generated smoke vapors, and (3)
absorbing the smoke vapors into an aqueous medium
to provide a tar-depleted liquid smoke solution.
Another aspect of this invention includes a
process for preparing a tar-depleted, partially
neutralized liquid smoke solution which comprises
preparing a tar-depleted liquid smoke by any of the
above defined methods and thereafter partially
neutralizing the tar-depleted liquid smoke to a pi
greater than about 3. preferably to a pi between
about 3 and about 6.5, and most preferably to a pi
between about 3 and about 5.
Another aspect of this invention includes
either an unneutralized or a partially neutralized
tar-depleted liquid smoke composition made from any
of the above processes.
Another aspect of this invention includes a
tar-depleted smoke colored and smoke flavored
tubular food casing which is made by contacting a
tubular casing wall with any of the above described
liquid smoke solutions.
Another aspect of this invention includes a
method for making a tar-depleted smoke colored and
smoke flavored tubular food casing by applying any
of the above described liquid smoke solutions to
a tubular casing.
~27~
- aye -
Another aspect of this invention includes a
method for preparing a smoke colored and smoke
flavored foodstuff which comprises stuffing the
above defined tubular casing with a foodstuff and
processing the resulting encased foodstuff under
f-~3
Jo
I
- 15 -
condition sufficient to transfer smoke color and
smoke flavor constant to thy encased foodstuff.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 it a flow diagram of a continuous
process for making a ~ar-depleted liquid smoke
according to the invention.
Figure 2 is a schematic view of a
laboratory apparatus for making a tar-depleted
liquid smoke according eon the invention.
Figure 3 it a schematic view of an
apparatus suitable for treatment of the external
surface of a food cawing with the liquid smote
composition manufactured by the method of this
invention.
Figure 4 is a 6chsmatic view of an
apparatus similar to and performing the save
functions as the apparatus of Figure 3, but with a
chamber fox partially drying the kink treated with
the liquid smoke composition of this invention to a
desired moisture content while in an inflated
condition.
Figure 5 is a schematic view of an
apparatus similar to and performing the tame
function a the apparatus of Figure I, but with
mean for partially drying of the casing treated
with the liquid smoke composition manufactured by
the method of this invention while in a flat
condition.
Figure 6 is a schematic view of tube
apparatus used in Example 5 for making tar-depleted
liquid smoke.
- -
7~igC~
- 16 -
DESCRIPTION OX THE INVENTION
As used in this specification and the
appended claims, the following terms are defined as
follows:
"Solution" is meant to encompass
homogeneous true solutions, as well as
emulsions, colloidal suspensions, and the
live.
"Smoke color, odor, and flavor
constituents", refers to the smoke color
odor and flavor constituents present in
natural liquid smoke solutions manufactured
by the condensation of smoke vapors
generated by the partial combustion of
hardwoods. Examples include liquid smoke
solutions in their as-is or present
commercially available Norm.
abrupt power" is a measure of the
coloring capability of the liquid move
solution. Absorptive power is measured by
placing 10 my of a liquid smoke solution Jo
be tested (either tar-containing liquid
smoke or tar-depleted liquid smote) in a
disposable vial, and 5 milliliters of
methanol is added thereto. The two
components are mixed by inverting the vial,
and the ultraviolet absorption value of the
mixture is then measured at a wavelength of
340 no. It should be noted what whereas
3Lz~7i69~
- 17
tar-content it a significant contributor to
thy absorptive power measurement, tar only
contributes to the staining of food in a
minor way if at all. Thus, in
commercially available assay smoke
solutions, absorptive power includes a
measurement of tar-content and the coloring
constituents such as carbonless, phenols and
acids. This means that absorptive power of
a smoke solutions and tar-depleted
smoke solutions may be used to rank them by
smoke coloring ability. However,
absorptive power of as-is liquid smoke
cannot be numerically compared with the
absorptive power of tar-depleted smoke
solutions used in this invention because of
the absorptive effect of tars.
"Absorptive index" is a measure of the
coloring ability of a easing treated with
the liquid smoke solution of the
invention. It is measured by cutting out 2
square inches (12.9 square centimeters) of
toe casing to be tested and placing the
cut-out portion in 10 milliliters of
methanol. After about 1 hour of soaking
tire, the methanol has extracted all of the
smoke components out of the casing, and the
ultraviolet absorption value of the
resulting smoke component-containing
methanol is determined at a wave length of
340 no.
~2~7~90 .
- 18 -
"Total acid content" refer to the
concentration of acid, principally acetic
acid, that are present in the liquid
smoke. Total acid content it measured by
the following procedure:
1. Leigh accurately 1 milliliter of
liquid smoke (filtered if necessary)
in a 250 milliliter beaker,
2. Dilute with 100 milliliter of
distilled water and titrate with
standard Own Noah to a pi of 8.15 (as
measured on a pi meter),
3. Calculate the total acid content
a weight percent of acetic acid
(Ha), using the following conversion;
-
1 I 0.1000 N Noah = 6.0 my Ha
This method can be used to measure total acid convent of tar-containing liquid smoke
601utions and tar-depleted liquid smoke
solutions that have not been neutralized.
"Light transmittance" is measured for
mixtures of liquid smoke solution and
water. This measured light transmittance
trelati~e topper water) is inversely
related to tar-content of the tested liquid
smoke, i.e. a high tar-content result in a
cloudy liquid withal light tran6mit~ance.
The procedure for measuring light
. .
. , . _ .. . .
27~
-- 19 --
transmittance is to thoroughly mix a 1
milliliter Alcott of the liquid smoke with
10 milliliter of water, and determine it
turbidity-tran~mittance on a 6pectrophoto-
Peter u6i~g a light wavelength of 590 no.
The higher the percent transmittance
reading, the lower the residual tar
concentration in the liquid smoke
company.
"Smoke Vapor" refer to the principally
gaseous product of the limited combustion
of wood. It comprises a complex mixture
of wood combustion products and varies
according to tube wood used and the burning
condition. Chile the smoke vapor is
principally Gus, it alto comprises a
colloidal suspension of various liquid and
solid material.
The smoke vapor in the process of ye
invention it generated by the incomplete combustion
of wood by limiting or controlling the amount of
atmospheric oxygen available or combustion. The
smoke vapor may be produced by any suitable method
known in the art. Suitable methods include the use
of externally heated retort provided with openings
for the controlled introduction of air, packing
house type kiwi generator, and indirect-heat
calciner6, which are essentially cylindrical retorts
rotating within a cylindrical furnace. Suitable
~ethod6 of generation of smoke vapor are disclosed
I
- 20 -
on the above-cited U. S. 3,106,473 and U. S.
3,873,741.
By practice of the invention, the tars,
which are mainly polycyclic aromatic hydrocarbons,
are selectively removed from the generated smoke
vapors by a method that selectively remove the tars
from eke vapor using a solvent that does not remove
the smoke color and flavor constituents. Suitable
methods for extracting the tars from the smoke vapor
include methods of contacting a gas and a liquid,
wherein the tars are removed through gas-liquid
absorption, Andre liquid-liquid extraction.
The solvent extraction ox the tar from the
smoke vapor may be achieved by contacting the smoke
vapor with an absorptive liquid, under conditions
wherein the tars are selectively removed from the
smoke vapor and absorbed into the absorptive
liquid. This can be accomplished by using known
methods and apparatus used to contact a liquid with
a gas phase. Suitable apparatus include plate
columns, having cross flow plates, such as sieve
plates, bubble-cap and valve plates, and counter
flow plates such as doleful plates, turbo grid
tray and ripple trays. Also suitable are packed
columns waving any of the known packings, such as
for examples ra~chig rings, tossing rings, bent
saddle, intalox waddles, tolerates, and pall
rings. Liquid dispersed contractors such as spray
columns, baffle-plate or shower deck columns, and
gas-in-liquid dispersed contractors suck as bubblers,
sparkers, big speed agitators, rotary disc
column, aerators, and the like, are also
~2Z~76~3
- 21 -
suitable, A general description of various method
suitable for use in the invention for contacting a
gas with a liquid it found in Chemical Engineers
handbook, Perry & Hilton, Fifty Edition, page 18-3
to 18-93.
The organic liquid solvent used in the
invention should ye immiscible in water and have a
hydrogen bonding volubility parameter in the
environment of the lockjaw contacting zone of
least about 2.7. The organic liquid ennui may be
either nonreactive with the smoke vapor or reactive
with the smoke vapor to form a derivative organic
liquid yenta. If reactive, the derivative solvent
should alto have the tame solvent properties as
described above.
The hydrogen bonding volubility parameter,
as used herein. can be calculated from known
literature or experimental vapor pressure data such
as the heat of vaporization at 25C. The total
volubility parameter IT) may be determined by
using the relation of Equation I
To 1 1/2 (1)
T l
where: aye = Heat of vaporization at 25C.
= Gas constant,
T = Temperature in degrees absolute,
d Density at 25C, and
M - Molecular weight.
:~L2;~7~0
The total syllable parameter value can be
separated into its hydrogen bonding Ho or
polar (up), and nonpolar (Sup)
concatenate. The following relationships are
useful for determining the hydrogen bonding
parameter value (OH).
Tub M
toga= 3.39066 T 0.15848 - log d I
H= IT (3)
where: a = Aggregation number,
Tub Boiling point in degrees absolute,
To s Critical temperature in degrees
absolute.
The theoretical basis for use of volubility
characteristics is discussed in the literature.
Tabulations of parameter have been published in
Lithe Three Dimensional volubility Parameter and
Solvent Diffusion Coefficient," Danish Technical
Press, 1967, Copenhagen, by C. M. Hansen. A list of
volubility parameters can be obtained from K. L.
Hoyt "Tables o Sealability Parameters", Union
Carbide Corporation, 1975, obtainable from Union
Carbide Corporation, River toad, Bound Brook, New
Jersey 08805.
Suitable organic solvents include halogen
dip or tri~ubstituted methanes, such as ethylene
dichlorides bromochloromethane, and the like;
~L22769~1
_ 23 -
chloroform, bromoform, and the like; acetophenone;
and alcohol liquids such as 2-ethylhexanol, the
phenol ether of ethylene glycol, the monohexyl ether
of ethylene glycol, n-octyl alcohol, n-~lexyl
alcohol, and n-butyl alcohol. The preferred solvent
is methylPne dichlorides ~dichloromethane).
The resulting tar-depleted smiles vapors
containing smoke flavor, odor, and color
constituents can be recovered, by known methods,
into an aqueous medium to form an aqueous,
tar-depleted smoke solution. These include those
described in the above-cited U. S. 3,106,473 and U.
S. 3,873,741. Also included is the use of the
gas-liquid contacting equipment listed above.
In a preferred practice of the invention
the smoke vapor is contacted with water and a
solvent in a single contacting means, that is the
color, flavor, and odor constituents are recovered
in an aqueous medium in the same contacting means as
that used for the contacting of the smoke vapor with
the solidity to extract the tar components. This is
accomplished by simultaneously introducing water and
the organic solvent into the gas-liquid absorption
jeans. The resulting product of the process are a
waste gas stream, containing some acetic acid that
was in the generated smoke vapor and a two phase
liquid product. In the two phase liquid product,
the kiwi phase contains eke the smoke flavor,
color and odor constituents, and is the tar-depleted
liquid smoke of this invention. The organic solvent
phase contains the tars that were in the generated
smoke vapor. Chile a single contacting means is
. . ._ _ _ . . . _ . .
~2~76~[)
- 24 -
preferred, separate vessel Gould be used for
contacting the solvent and the water with the smoke
vapor.
Toe condition of the sas-liquid contacting
are such thaw color, flavor and odor constituents
are tran6fsrred to the aqueous phase to form a
liquid smoke solution having sufficient coloring and
flavoring ability. In a continuous process, as
illustrated by Figure 1, the flow rates of the
smoke, waxer and solvent are regulated Jo that the
concentration ox the smoke color, odor, and if
avow constituent in the aqueous liquid smoke phase
is high enough to provide the desired coloring and
flavoring ability. It a batch process, such as
illustrated by Figure 2 and Example 1, the prows
it continued until the concentration of the color,
odor and flavor con~titueD~s it high enough to
provide the desired flavoring and coloring ability.
In calculating the amount of water introduced it
should be considered that water it sly introduced
as a gas in the smoke vapor. During the absorption
process this water will condense. Although it is
preferred to introduce additional water separately,
it it possible, due to this water in the smoke
vapor, to wake a tar-depleted liquid McKee of the
invention with minimal addition of waxer, relying on
the water condensed from the smoke vapor to form the
bulk of the aqueous phase to absorb the color,
flavor and odor constituent.
By Jo regulating the condition, a
described above, it is eyeball to make a
tar-depleted liquid smoke having the desired
- 25 -
concentration of color, flavor, and odor
constituent. Previously, tar-depleted liquid smoke
601utions were made from the commercially available
as-is liquid smoke solutions, which have only
limited concentrations of color, flavor and odor
constituent. None of Thea commercially available
assay liquid Moe solutions have concentrations
high enough Jo coat a casing in one application,
such that the casing will sufficiently color and
flavor certain food products, such a light colored
meats. Commercial liquid smoke 601utions have
limited concentrations due to problems involving
undesirably high concentrations of tars and phenols
whey assay smokes are made in a concentrated form.
Since tar depleted liquid smoke solutions have been
made from the low concentration, assay liquid smoke
solutions, such solutions also have inadequate
flavoring and coloring ability for some
applications, and it it necessary to subject these
tar-depleted liquid smoke solution to a further
concentration process to obtain the desired coloring
and flaYori~g ability. By practice of the
invention, it is possible to obtain tar-depleted
liquid smoke 601ution6 having coloring and flavoring
ability equivalent to either concentrated or
nonconcen~rated assay derived liquid smoke solutions
without further processing.
The aqueous tar-depleted liquid smoke
phase, and the tar-containing organic solvent phase,
are separated by known methods. These methods
include gravity decanting, liquid cycloning, and
centrifugal decanting, as well a the use of various
~LZ~:7Çi~
- 26 -
type of separation systems used in solvent
erection methods.
A preferred method of the invention for
making tar-depleted liquid smoke solution it
illustrated by Figure 1. In Figure 1, smoke vapors
are generated in a suitable smoke generator 51, The
generated smoke vapor it conveyed along line 52 to a
counter-current ga~-liquid absorption column 53,
such as, for example a packed column, plate column
or a spray column. An organic solvent and water are
introduced into the top of the column through lines
54 and 55, respectively. In the absorption column
53, the tar are absorbed into the organic solvent,
and the color, Flavor and odor con~tituentfi are
absorbed into the water, Jo form a two phase liquid
product leaving the column through line 56. The
remaining unabsorbed gaseous constituent of the
smoke vapor leave the column through line 57 a a
waste stream. The two phase liquid product
compare an aqueoufi, tar-depleted liquid Moe
phase 58, and a tar-containing liquid solvent phase
59, which are separated in any known separation
apparatus, such as a gravity settling tank 60, into
the tar-depleted liquid smoke of the invention which
leave through line 62, and the tar-containing
solvent which leave through line 61.
The tar-depleted liquid smoke of the
invention may be further concentrated. The
tar-depleted, liquid smoke of the invention may be
concentrated preferably under vacuum condition, a
a temperature of lest than about 70C, preferably
lets than about 50C. Other suitable concentration
769~
27 -
etude are ~iselosed toe abo~e-c~tea United
to Patent Number 4,540,613,
i~cluai~q frieze dry, spray drying or various
other evaporation technique us a YapOr~at~On by
owe temperature evaporate lo Baudot
environment, or the use of ~orced-~ircula~ion
aperture, long be vertical evaporator end
agitated evaporator
Tube ~ar-depletea joke solution jade by the
etude of ye ~nveneion I optionally partially
~eutral~2@a to on extent us that ye pi it wrier
Allah about 3. preferably between about 3 and about
6 . I, an core preferably between bout 3 and about
5. The temperature it preferably controlled Uruguay
the partial neutralization us thaw toe temperature
of tube llquia eye doe not rite above about OKAY,
Gore preferably sue Tao it woes not rise above
about 30~C.
The partial neutralization of the
unneutralized, ~ar-deplated. liquid stoke of the
invention Jay be accompli~hea by mixing either a
igloo ~lgaline solid with toe tar-aepleted liquid
evoke, or example Cole carbonate. sodium
bicarbonate, pota~ium bicarbonate. calcium
hydroxide, Dow carbonate, oddly, end dummy
hydroxide elite or kiwi, or by mixing the liquid
joke iota h pi liquid us a kiwi sodium
hydroxide sol~tio~. Although toe carbonate a the
bicarbonate produce violent owing high Jay
KIWI operational di~ficultia6. toe neutralization
faction no She acids on the liquid stoke wit
bicarbonate I Newark, awoke yo-yo irate ye
f ~:~
need for temperature control during the
neutralization.
The rate of addition of the neutralizing
material to the tar-depleeed liquid smoke depends on
the cooling gape fly of the mixing container as well
as toe efficiency of the mixing means, a will be
understood by those skilled in the art. The
coloring ability of the tar-depleted, partially
neutralized liquid smoke is not substantially
affected by temperature variations during the at 1
exact partial neutralization step, as long as the
temperature of the bull liquid is maintained below
about 40C, and preferably below about 30C.
The mixing container used for the partial
neutralization should be cooled by indirect meanfi,
as for example, brine circulating through immersed
coil in a closed-circuit refrigeration system. The
reason for indirect rather than direct contact
between the refrigerant and the tar-depleted liquid
smoke is to avoid contamination of the latter.
Another pueblo method for at least
partially neutralizing the tar-depleted liquid smoke
is by contacting the latter with an ion-exchange
material.
The method of the invention for making
tar-depleted liquid smoke solution has many
advantage over the prior art beyond that of reduced
c06ts. As described previously, by this invention
tar-depleted liquid smoke solution can be made to
have any desired concentration of flavor, color, and
odor constituents without undesirable concentrations
ox tars and phenols. Typically, the concentration
~.2~27!6,~90
2 9 --
of the colts ~nsti~uent~ corre6pon~ to from about
1 Jo bout yes the cc~centrat~on ox the Lowe it
a tar-dlepl~ quid smoke Elude by eke above
~i~6cribed lent traction prows Russell an isles
liquid eke hiving about a 12~ aye onto for
@xa~pl~ rl3o~ valuable prom Eyed Arrow
Pockets Cowan nitowcc, Wisconsin. an
advantage of tube invention is that the tar depleted
l~quia smiles Solon aye by if e proves of the
invention a toggle ~olorlng anility and high
carbonyl entreat rethought a correspondingly high
content ox ph~!nol6. Typically. tube content ox the
phenols is lets kiwi about 10 parent preferably not
greater ton 2 pureness, of tube content of the
~arbonyl6. toll 1.5 percent being achievable. The
phenol ye bevy to be ye 6ub6tances eye in
hug ~e~trat~o~s contribute vainly to the strong
or Roy flavor of some ~oneentrated liquid
owe owlish. By pry of the invention,
Luke smoke solution Jan ye aye that have the
equivalent coloring debility of highly concentrated
tar-~eplete~ liquid Sue solution derived prom an
as key hut a high eolori~g ability
it Tess trout an undesirable corresponding
increase on tube phenol content. As one by the
light ts~ns~ttan~e data Abe expel that
follow. rely ~11 of the tar were abeyant from the
Joy So epaulet Luke owe product produced
my the aye of toe invention. It it expected
that by rice of tube ln~ent~on. tar-aepleted
loud aye solution having a light tr~n~it~dnce `
of sty Lowe recent preferably at least 80
Z7~69~
- 30 -
percent, more preferably at least 90 percent, can be
produced. In addition, a portion of the acids, the
principal one being acetic acid, in the generated
smoke vapor remains in the waste gas stream, so that
the concentration of undesirable organic acids in
toe tar-depl~ted liquid smoke product may be reduced.
The tar-depletad, liquid smoke composition
of this invention, whether unneutsalized or
neutralized, is then applied to a food cawing. The
food casings that are suitable for use in the
invention are tubular casings, and preferably
tubular solely to casings, that are prepared by any
one of the methods well known in the art. Such
casings are generally flexible, thin-walled 6eamles~
tubing formed of regenerated cellulose, cellulose
ethers such as hydroxyethyl cellulose, and the like,
in a variety of diameter. also suitable are
tubular cellulosic casings haying a fibrous
reinforcing web embedded in the wall thereof, which
are commonly called "fibrous food casing", as well
as ~ellulosic casings without the fibrous
reinforcement, herein referred Jo as "non fibrous"
cellulosic casings.
Casings conventionally known as "dry stock
casing" may be used in the practice of this
invention. Such casings generally have a water
content within the range of from about 5 to about 14
weight percent water for non fibrous casings, or from
about 3 to about weight percent water for fibrous
casing, based on the total weight of the casing
including water.
. I , . .
- 31 -
Casings conYent~onally known as "gel stock
casings" are casings which have higher moisture
contents than the aforementioned casings wince they
have not been previously dried. such casings may
also be used in the practice of this invention. Gel
stock annex, whether fibrous or non-fibrous, are
the type exhibiting the aforementioned tarring
problem when treated by as-is, tar-containing liquid
stoke.
Toe tar-depleted liquid smoke solution of
the invention may be applied to the outer surface
of the tubular casing by passing the casing through
a bath of the liquid smoke solution. The liquid
smoke is allowed to soak into the casing prior to
doctoring off any excess liquid smoke by passing the
casing through squeeze rolls or wipers, and the
like, for an amount of time sufficient for the
cawing Jo incorporate the desired amount of smoke
coloring and smoke flavoring constituents. The
process of passing the casing through a treatment
bath, also referred to in tube art as a "dip bath" or
a "dip tank," may also be referred to in the art as
a "dipping" step. The liquid smoke of the invention
may alternatively be externally applied to the
cawing by method other than dipping, such as
spraying, brushing, roll-coating, and the like.
Alternatively, the tar-depleted, liquid
smoke composition of the invention may be applied to
the internal surface of the casing by any of several
well-known procedures such as those described in
United States Patent 4,171,3~1, issued October 16,
lg79 to Chit. These include slugging or bubble
issue
coating, spraying, and coating while shinning. The
slugging method for coating the inside of a casing
involves willing a portion of the cawing with the
coating material, Jo that the slug of coating
material generally resides at the bottom of a "U"
shape wormed by the cawing being draped over two
parallel rollers, and then moving the continuous
indefinite length of cawing so that the slug of
coating material remains confined within the casing,
while the casing moves past the 61ug and is coated
on its inside wall by the coaxing material contained
within the slug.
One method of treating the casing with the
smoke solution of the invention is shown in Figure
3. In Figure 3, a flattened, tubular, soliloquy
sausage casing 10 it externally treated with the
smote composition ox the invention during its
passage over lower and upper guide rolls 13 through
dip tank 11 which contains the liquid smoke solution
12 of the invention. The casing pauses o'er lower
and upper guide rolls 14 after exiting the dip tank,
and then passes between squeeze rolls ZOO which
minimize any excess carry-over ox the liquid smoke
composition. The total contact time of the casing
10 with the liquid smoke solution 12 will determine
the amount of smoke coloring and smoke flavoring
constituent of the tar-depleted, concentrated,
liquid smote composition that the casing will
incorporate. Tube total contact time it measured
from point A to point B in Figure 3. Aster the
casing passe through squeeze rolls 20, it passes
over guide roll 23 and is wound up on roll 24. The
;27~,9~
cawing is when sent on to further conventional
processing, including conventional humidification,
a may be required, and conventional whirring.
The embodiment illustrated in Figure 4
differs from that illustrated in Figure 3 in thaw in
Figure 4 the casing after pausing through squeeze
roll 20 is pasted into a heating and drying clamber
21, Byron it is dried to the proper moisture
content. The casing it inflated by a bubble of air
maintained in a relatively fixed position between
squeeze roll 20 and 22 by the sealing action of
rolls 20 and 22. The heating chamber 21 can be any
type of heating device, such a circulating hot air
chambers, which will dry the sausage casing to the
proper moisture content. After the cawing passes
out of the heating chamber 21 and through squeeze
rolls 22, it puffs over guide roll 23 and it wound
up on roll 24. The casing is then sent on to
conventional further processing, including
conventional humidification, as may be required, and
conventional whirring.
The embodiment illustrated in Figure 5
direr from that illustrated in Figure 4 in thaw in
Figure 5, the cawing is dried in a flat condition
while paying over guide rolls 25.
A preferred method for applying the
tar-depleted liquid smoke solutions manufactured by
the method of the invention it by a method wherein
the exterior wall of a cawing it coated by moving
tube cawing through an inner opening of a firs
flexible and resilient means which dipoles the
opening edge while liquid is applied by rubbing
3L~Z~6~3~
.
- I -
contact. The liquid coating it then smoothed by
move mint through the inner opening of a rotating
second flexible and resilient means. this method
and apparatus incorporating this method are
described in United States Patent 4,356,218 issued
on October 26, 1982, to Chit et at.
Therein the apparatus is described as an
apparatus for liquid coating the exterior wall of an
inflated flexible tubing during its longitudinal
movement comprising: pa) first flexible and
resilient mean with an inner circular opening
having slightly smaller diameter than the diameter
of the inflated flexible tubing exterior wall, the
first means being transversely positioned relative
to the tubing axis and arranged such that the
inflated flexible tubing may be moved in its
longitudinal direction through said inner circular
opening, so as to displace the circular opening edge
while maintaining rubbing contact therewith: by
means for supplying said liquid to said first means
tax for distribution thereby, so as to be applied to
the longitudinally moving inflated flexible tubing
exterior will during said rubbing contact: (c)
second flexible and resilient means with an inner
circular opening, the second means being rotatable
around the opening center and the opening having
slightly smaller diameter than the diameter of the
inflated flexible tubing exterior wall, said second
means being tran6ver6ely positioned relative to the
tubing axis and adjacent to, but spaced downstream
from the first means (a) with respect to the
longitudinally moving tubing such that the tubing
69~
with the coating on its external wall may be moved
through said inner circular opening of said second
means so as to displace the rotating circular
opening edge while maintaining rubbing contact
therewith for smooching the applied liquid on the
tubing exterior wall as a film of uniform thickness;
and (d) mean for rotating said second meanfi I
around the tubing axis during it longitudinal
movement through said second means so as Jo maintain
said rubbing contact while smoothing said liquid
into a continuous film of substantially uniform
thickness on the tubing exterior wall.
The method is described as a method for
coating the exterior wall of a longitudinally moving
inflated flexible tubing with liquid kippering the
steps of lea) continuously moving toe inflated
flexible tubing in the longitudinal direction along
a straight line; (b) providing first flexible and
resilient means with an inner circular opening of
slightly smaller diameter than the diameter of the
inflated tubing exterior wall: (c) supplying liquid
to said inner circular opening of the first means:
(d) moving said inflated tubing through said inner
circular opening of said first means and maintaining
rubbing contact with the opening edge Jo as to
displace said opening edge and simultaneously apply
said liquid to, and distribute toe applied liquid
around the inflated tubing exterior wall; (e)
providing second flexible and resilient means with
an inner circular opening of slightly smaller
diameter Han the diameter of the inflated tubing
exterior wall; (f) rotating said second mean around
....
I
- 36 -
it centerline axis: and (go moving said inflated
tubing with said liquid applied on it exterior wall
through the rotating second means inner circular
opening and maintaining rubbing contact with the
opening with the opening edge 80 a to displace said
opening edge while 6imultaneou~1y smoothing the
liquid coating as a continuous film of substantially
uniform thickness on the tubing exterior wall.
It it to be noted what the ~ar-depleted
liquid smoke company which it applied or
"coated" on the cawing surface, whether externally
or internally, doe not exist solely as a surface
moating. Smoke color, odor and Flavor contusions
which are coated on the surface penetrate the
cellulosic structure of the cawing as the cellulose
absorbs the smoke solution. Inspection of the
cross-section of the casing wall discloses a dolor
gradation across the casing wall, with the Moe
treated surface having a darker color than the color
on the surface on the opposite side of the cawing
Hall. Accordingly, as used, herein, the term
kowtowing or "coated" it meant to apply to a casing
wall that it not only coated with smoke constituents
but Allah impregnated with smoke con6tituent6.
The coated cawing may be whirred by
conventional methods, or prior to shinning, it may
be dried Andre humidified to a water content
suitable for whirring and/or further processing.
The need for conventional drying and/or
humidification after treatment with the liquid smoke
composition of this invention depends on the water
content of the cawing after treatment and the type
Lo 276~0
- 37 _
of casino. If the casing is a nonibrous casing, a
water content within the range of from about 11 to
about 13 weight percent water before whirring, and
between about 14 and 18 weight percent aster
whirring, is typical. For fibrous casings, a water
content within the range of from about 5 to about 7
weight percent water before shinning is typical, and
after shinning the water content is typically in the
range of from about I to 35 weight percent, where
the percentages are bayed on the total weight of
casing including water.
Thy liquid smoke compositions of the
invention may also contain otter ingredients which
may be suitably used in treatment of a tubular food
cawing, to which the smoke constituents are applied,
e.g., glycerine and/or propylene glycol, and the
like, which may be used as humectants or softening.
agent.
Other ingredients which are normally used
id the manufacture of, or for further treatment of
the food Congo, e.g. cellulose ether and mineral
oil, may also be prevent in the casing if desired.
and they may be used in the tame manner and amounts
as if the liquid smoke composition of the invention
Tad not been used.
In particular, agents for improving the
pee lability of the casings from food products such
as sausage, e.g. frankfurters, bolognas and the
like, may be optionally coated on the internal
surface of the Congo before or after the external
application of tar-depleted, concentrated, liquid
smoke composition to the casing and before or during
I
- 38 -
whirring. If the tar-depleted liquid smoke is
applied to the cawing internal surface, the
pee lability agent is preferably applied irrupt. Such
peelabiliey enhancing aqentC include, but are not
limited to, carboxy~ethyl cellulose, methyl
cellulose, and other water soluble cellulose ethers,
the use of which it disclosed in United State
Patent 3,898,348 issued August 5, 1975 Jo Chit, et
at.; "Aquapel", a trademarked product, made by
Hercules, Inc., ~ilmington9 Del., comprising alkyd
kitten divers, the use of which it further disclosed
in United States Patent 3,905,397 issued September
16, 1975 to Chit; and "Quilon", a trademarked
product, made by E. I. Dupont de Numerous Co.,
Wilmington, Del., comprising fatty acid Cromwell
chlorides, the use of which it further disclosed in
United States Patent 2,901,358 idea August 25,
1959 to I. F. Underwood et at.
The pee lability enhancing agent may be
applied to the internal surface of the tubular food
casings by using any one of a number of well known
methods. thus, or example, the pee lability
enhancing gent can be introduced into the tubular
cawing in the form of a ~slugll of liquid, in a
manner similar to that disclosed, for example, in
United States Patent 3,378,379 issued April 16, 196B
to Shiner et at. Advancing the casing past the
liquid slug coats the inner Ursa thereof.
Alternatively, the pee lability enhancing agent may
be applied to the internal surface of the casing
through a hollow mandrel over which the cawing it
Lot
- 39 -
advancing a, for example, a shinning machine
mandrel in a manner similar to that described in
United States Patent 3,451,827, issued June 24, 1969
to Bridge ford.
The method of this invention it Allah
suitable for producing a printed casing e.g., a
cawing having an insignia, trademark, lettering, and
eke like printed thereon, having smoke coloring and
smoke flavoring constituents incorporated therein.
Exemplary printed casings are disclosed in United
State Patent 3,316,189, issued April 25, 1967 to
Adams.
Casings prepared using the method of this
invention are also suitable for the processing of
what is conventionally known in the art as "dry
sausages." Unlike other ye of non fibrous and
fibrous casings which are preferably easy to peel
from the food product, either by the food processor
before sale Jo the cufitomer or by the consumer, "dry
sausage" cawing preferably adheres to huffed
product during and after prove King. "yeomen," a
trademarked product, made by Hercules, Inc., which
it a polyamide epichlorohydrin resin, the use of
which it further disclosed on United States Patent
3,378,379 issued April 16, 1968 to Shiner et at.,
may optionally be coated on the internal surface of
a casing treated with the smoke composition of the
invention to improve the adhesion of the casing Jo
food product processed therein.
The casings treated with toe liquid smoke
compositions of this invention can then be used in
conventional processes for the processing of
Lo 0
- 40 -
sausages and the Lowe and the smoke flavor and
color constituent are transferred to the food stuff
encased in the casing.
The aqueous tar-depleted liquid smoke
~olution6 of the invention can be used to maze a
smoke flavored cereal product, which can be used as
a additive to food. This is accomplished by
admixing the aqueous Sar~depleted liquid smoke with
a cereal, such as Walt, and drying the mixture. A
suitable method is di6clo~ed in United State Patent
3,177,077~ issued January 7, 1983 Jo Hollenbeck.
The aqueous tar-depleted liquid smoke
solutions of the inversion can be used to make a
smo~e-flavored edible oil. This is made by
contacting tube aqueous tar-deple~ed liquid smoke of
the invention with an edible oil and separating the
oil phase from the aqueous phase to form a
smoke-flavored edible oil. A suitable method it
disclosed in United States Patent 3,~80,446, issued
November 25, 1969 to Hollenbeck.
The invention will now be Gore clearly
understood by reference to the hollowing example
which art jet forth as being merely illustrative of
the invention and which are not intended, in any
manner, to be limitative thereof.
In the following examples, the phenols and
carbonyl content of liquid smoke were determined by
the following procedure. All the sample to be
evaluated were prepared by filtering them through a
Whitman No. 2 filter paper or equivalent, and
refrigerating them as soon as possible after
preparation to void possible polymerization. All
I
samples were diluted with distilled water it two
steps. In the first step 10 milliliters of the
sample were diluted to a total volume of 200
milliliters, and in the second step 10 milliliters
of the solution from the first step were further
diluted to a total volume of 100 milliliters. For
the determination of the phenols, 5 milliliters of
the solution from the second lop were further
diluted in a third step with distilled water to a
total volume of 100 milliliters. For carbonyl
determination, 1 milliliter of the second solution
was further diluted with carbonyl-free methanol to a
total volume of 10 milliliters.
The procedure for the determination of the
amount of phenols was a modified method for
detecting toe amount of phenols as
2,5-dimethoxyphenol bayed on the procedure described
by I. W. Tucker in "Estimation of Phenols in Meat
and Fat", JACAC, XXV.-779 (1942).
The reagents used for determination of the
phenols were
1. Boric acid-potassium chloride
buffer having a pi of 8.3, made by diluting
to 1 liter with distilled water
a. 125 milliliters of 0.4 Molar
boric acid solution,
b. 125 milliliter of 0.4 Molar
potassium chloride solution, and
c. 40 milliliters of 0.2 solar
sodium hydroxide solution,
2. 0.6 weight percent sodium
hydroxide solution,
I
- I -
3. Color reagent, aye my oiling
0.25 Roy ox N-2,6-triehloro_b~nzo~ui~one-
flown 30 lotteries of ~ath~ol end
Starr r~friqerator until use. and
4. 2,6~ et~o~yph~ol ( W )
Tudor a my Swahili a known
ought of DUMP it ova mount ox
distilled water to o'er solution ox
between 1 and 7 ~ierogra~s~illiliter.
the detonation of eye phenolfi aye o~pli~hed by
following toe 6~ep6 below in order;
1. 5 ~illiliter6 of liquid Sue
Apple, or 5 qrs DUMP arrowhead, or 5
~illlli~ar~ of distilled water (for use a
blown ore aided to 5 aillili~er6 of pi
.3 far
2. The OH aye audited to I unyoke
itQr ox sodium Dydroxiae solution.
3. Just before us 1 milliliter of
Abe dolor reagent aye tea to lo
~llliliter6 with it'll water and 1
alter of toe allotted color reagent Way
Dow Jo toe text sample.
4. She color was allowed to develop
for 25 nuts it root temperature.
5. The bourbons us determined at
Dave l~nqt~ of I em in 1 I
~olori~eter tube. the spectrophoto~eter
was S~ctroni~M20, Dva~lable prom aye
end Lob, Rochester. New York.
6. A nerd curve Wow prepared
Roy the area of the WIPE standard with
Jo
. ~2~7~g~
- I -
absorbency as the abscissa and
concentrations of the tendered a the
ordinate. The equivalent concentration of
phenol a DUMP in the liquid smoke applies
were interpolated from this curve.
7. The amount of phenol a DUMP
concentration in mg/ml in the liquid smoke
ampule were calculated by using the
equation,
ppm DUMP (from to curve DO X 0.001
- - = DUMP gone.
vol. fig. smoke sample I
where "DO" in the above equation it toe sample
dilution factor (400), and "0.001" it a factor to
convert ~icrogram6 to milligram To calculate the
my of phenol a DUMP in a gram of liquid smoke,
divide the above result by the weight of 1
milliliter of liquid smoke.
The procedure for calculating carbonyl
compound was a modified Lappan-Clark method for
determining the equivalent amount of 2-butanone
based on the procedure described in their article
"Calorimetric Method for Determination of Tess of
Carbonyl Compounds", Anal. Chum. 23, 541-542
(1959). The reagents used were
1. Carbonyl-free methanol, prepared
by adding 5 g of 2,4-dinitrophenylhydrazine
(DIP) to 500 milliliter of methanol and a
few drop of Hal, refluxing for three
hour, and then distilling,
. .
.... . . . .. _ . . . . . .
~2~69i~
- I -
2. DIP 601ution, made by disallowing
twice recrystallized DIP in carbonyl-free
methanol to form a saturated solution
(Solution way stored in refrigerator and
prepared fresh every two week. It was
prewarmed before use to insure saturation.),
3. KOCH solution, made by dissolving
10 g KOCH in 20 milliliters of distilled
water and diluted to 100 milliliter with
carbonyl-free methanol, and
4. 2-butanone (methyl-ethyl-ketone)
(ME standard solutions, prepared by
adding known amount between 3.0 Jo 10 my
of ME in 100 milliliters of carbonyl-free
methanol tusked to make standard curve).
The procedure used for determining the amount of
carbonyl compounds was as follow:
1. To 25 milliliter volumetric
flask containing 1 milliliter of DIP
reagent add 1 milliliter of diluted liquid
smoke solution, or 1 milliliter of standard
R 601ution, or 1 milliliter of methanol
(for reagent blank),
2. Add 0.05 milliliter of
concentrated Hal to all 25 milliliter
flask, mix content of each, and place in
a water bath at 50C for 30 minutes,
3. Cool to room temperature and add
5 milliliter 6 so KOCH solution Jo each,
4. Dilute contents of each flask to
25 milliliters with carbonyl-free methanol,
~2~g~
- 45 -
5. Using a Spectronic 20
6pectrophotometer, available from Bausch
and Lomb, Rochester, New Yore, and 0.5 4
inch (1.27 10.2 cm) cuve~tes, calibrate
the ~peceropho~ometer by reading at a Dave
length of 480 no against the methanol blank
and jetting the absorbency at 0.
6. Using data for MCKEE. ploy
ab~orban~e Years ME concentration for
standard curve,
7. Interpolate concentration of ME
equivalent in diluted liquid McKee
solutions from this curve,
8. Calculate the carbonless
concentration as my ~EK/lOOml liquid smoke
by the following equation;
my From to curve DO go ME per
= 100 I fig. smoke
100 ml
where "DO" it the sample dilution factor (200). To
calculate carbonyl6 a my UæK/g liquid smoke, divide
the result of toe above equation by the
weight yin gram of 100 milliliters of the smoke
being tested.
The Color frowning Index way determined as
follows:
I Prepare a phthalate buffer 601ution
(pi 5.5) by diluting to 1000 milliliters
~ieh distilled water, 500 milliliters of
0.1 potassium hydrogen phthalate and 76
milliliters of 0.5 H Noah;
.. .
lz~6g~
(2) Prepare a 2 percent Gleason buffer
solution by dissolving 2 Russ of Gleason
in 100 milliliter of the pi 5.5 ~hthalate
buffer;
(3) Add 10 milliliters of the phthalate
buffet solution to a 20~150 mm test tube;
(~) Add 10 milliliters of the Gleason
buffer solution to another 20~150 mm test
tube;
US) Add 1.0 milliliter of distilled water
and 10 milliliter of Gleason to serve as a
reagent blank;
(6) Cap the tubes wit marbles and warm
the tubes in a boiling water bath for 5
minutes:
~73 Dilute toe liquid smoke solution to be
tested with methanol at a ratio of 1 part
liquid smoke to 50 part methanol;
o the tube containing the Gleason
buffer (reaction sample) and the phthalate
buffer only tunreacted control) add 1.0
milliliter of the diluted liquid smoke;
(9) Allow the color reaction to proceed at
100C for exactly 20 minutes, after which
the tubes are removed from the boiling
water bath and cooled in an ice bath for 2
minute;
(10) Using a ~pectrophotometer with
cuvette~ 0.5 inches (12.7 mm) diameter or
equivalent, determine the optical density
of the reaction sample and the unrequited
control at a wave length of 400 no, by
~227G9~
-- I _
rod Ann the glycine-water plank jet
at optical density of O.
(11~ From e optical eons ox the
r~3c~d lapels (OUR) and the opSi~al
Nat ox Lowe reacted control (ODE)
~eter~lne the Color Brovninq Peg t~BI )
grow toe following formula:
t:BI - 1 (OUR - ODE) O. lo ] DO So O. 65 .
whose UP is tile salDple ablution factor (JO).
Lowe Color Browning Index it azure of toe
quantity ox potential color forming substances
profanity per us of liquid owls.
Toe color etrlc Rowley "L" an aye or
sausage surfaces were obtainer using a aaraner~xL-23
Tris~i~ult~6 Calorimetry to a 1 centimeter
aperture s~tasldardizea iota write plate, all in
accordance it the tenured operating priors
~escribea in Use instruction manual or the aaraner
~L-23 Tr1fitl~ulus Calorimeter. Webb Jo commonly
Sue on to industry for ye ~ea~urefflent of dolor.
Five frankfurter frond each liquid Dallas treated
sample worry eta. ~qea6uralDent~ were aye Bout
2.5 eenti~D2ter~ from act end ox tube franls~urter~
and it tube idyll. Tube 15 Yule obtained for the
AL" Noah I" Yule were a~rer~ged together to obtain
the isle ire. L" value represent
liQ~tn~ss no arcane. eke sigher tube AL" value the
lighter thy color. The a" .ralue~ r~preljent
wryness, thy Hebrew to a value Sue rudder the
oily .
I~LWLE I
This zeta onstrates the Roy of
toe inv~t~on 1:18~ batch prows. The apparatus
. .
69~
- 48 -
used it illustrated it Figure 2. Hardwood audit
available from Franz Company hardwood Sawdust,
Milwaukee, Wisconsin, way thermally decomposed Jo
generate Moe vapor by placing 775 grams of sawdust
in a kiwi generator 71 comprising a 6 liter metal
container capable of being sealed and heated. The
metal container way heated over a Bunsen burner 72,
and the generated smote vapors were led from the
generator via stainless steel tubing 73 to an
abrasion vessel 74. The abrasion vessel 7g
comprised a one liter Erlenmeyer flask 75 . The
Moe vapor entered the absorption vessel 74 through
a wintered glass sparg2r 76. the absorption vowel
74 was f tiled with 600 ml ethylene dichlorides
~dichloromethane) and 100 ml water, and way stirred
throughout the abrasion to increase the gas-liquid
contact. The Moe generation way continued as long
as the kiwi generator 71 was capable of generating
Moe (about six Herr. A the smoke vapors were
generated, tube pressure forced them into the
abrasion vessel 74. The organic solvent,
ethylene dichlorides phase 77 in the absorption
vowel 7q absorbed eke tarry hydrocarbon components,
becoming darker in color as the absorption prows
proceeded. The aqueous phase 78 absorbed the color,
flavor, and odor constituents of the vapor. The
absorption vessel was equipped with a glass water
cooled condenser snot shown) to recondense
evaporated water and ethylene dichlorides vapor.
During the abrasion process, the temperature of
the organic phase 77 way at about 40C, and aqueous
phase 78 way Allah at about 40C. The exit gay from
~L;2;Z~69~1
- 4g -
the absorption vessel was found Jo have no odor and
was colorless. This procedure way repeated on two
subsequent day with a fresh charge of sawdust on
each day, but the original charge of ethylene
dichlorides and water was retained in flask I during
all three days. The aqueous phase 78 was separated
from the ethylene dichlorides phase 77 by
recantation to give a measured 200 milliliters of
aqueous tar-depleted liquid smoke.
A sample of the tar-depleted liquid smoke
aye made and analyzed. The results of the analysis
are summarized in Table A. Also shown in Table A
are the typical value of an as-is liquid smoke
coarsely C-12) for comparison.
TABLE A
Invention As-Is
CBI 11.0 10.5-12
Light Transmittance So) 100 0
Phenol mug 1 13-20
Acids (~) 11.3 11.5-12.5
The visual color of the tar-depleted liquid
smote was a very light amber color. The light
transmittance was 100 percent, indicating a total
depletion of tar constituents. The coloring ability
a shown by the CBI it comparable to an as-is liquid
smoke and the content of the phenols is
significantly less.
This example demonstrates that the method
of this invention may be used to prepare a
~2%~69i~)
-- so --
tar-depleted liquid smoke solution having coloring
ability comparable to commercially available as-is
liquid smoke solution also demonstrate the
low phenol content and the low tar-content, as shown
by the fight Transmittance, of the liquid smoke
solution of the invention as compared with assay
liquid smoke solution.
EMPLOY II
The tar-depleted liquid smoke of Example I
was applied to a casing and the cawing was used to
make a sausage product. The tar-depleted liquid
smoke way partially neutralized at a temperature of
about 18C to a pi of about 5 and was applied to a
nonfibrou~ gel stock easing using the method and
apparatus described in the above-cited U. S.
4,356,216. The casing way dried, shinned and then
stuffed and processed by conventional Taipei of
cooking, cold water showering, and chilling, but
without the conventional step of smoke treatment.
In Table B is shown the meat formulation used.
TABLE B
Inqredient6 Weiqhtfk~)
Beef Chuck 22.7
Regular Pork Trim 22.7
attires 9.1
Salt lo
Spice 0.5
Prague Powder (Sodium Nitrite) 0.13
.. . . ..
go
- so -
Sue Elro~s~siDg ennui were ~u~fic~e~t Jo Sue
thy trainer of Nikko color, odor Noah Lowry
~o~titue~ Prune the Congo to the riced
usage The aye were pull my conventiollal
ethos and eoloriLmetr~c Allah wore obeainea.
These ye ~u~ar~zed blow in Table C. Alto Boone
in Table C ore values obtained frond sausages treated
bit an aye l~guia joke (Charlie C-12), a
tar-a~pleted lug smoke jade from an liquid
joke ~Ctlar601 ~-12i u6~ng the solvent extraction
prows disclosed on the above-~itea U. 5. Ser. No 4,431,033
(501. lot ), and an ull~moked control, using
on untreated cawing. The toe liquid stoke Lyle on
produced by the solvent extraction prows was
partially neutralized to a pi of about 4 at a
temperature less than about ~0C.
TABLE C
a, a
Invention 15 . 65
Assay 49.~6 14.B9
ct.S0.09 15.24
Control ~0.~5 1~.57
Tubs exafflple ooze that the tar-depleted
loud joke of Tao invention i~part6 color to a
owe Rudy ho is æub6tantially equivalent to
that parted by assay liquid kiwi end tar-aeple~ed
liquid Sue aye from on I liquid woks by a
~ol~nt extraction process.
69~
EXAMPLE III
The purpose ox this example it to compare
the chemical characteristics of the tar-depleted
liquid smoke produced in accordance with this
invention with whose of liquid moves produced by
other ~ethod6.
Using the apparatus and method described in
Example I, two text run were made. In a run
according to the invention, the absorption vessel 74
contained 700 grams of ethylene dichlorides and 100
grams of water. In a comparative run, the
abrasion vowel 74 contained 700 grams of water
and no ethylene dichlorides weft used. Smoke
generation was conducted in each text for about 3.5
hours.
For the run according Jo the invention
(Inanity, the ethylene dichlorides layer ab60rbed
the tar components of the smoke vapor and the awry
layer absorbed the color, flavor and odor
constituent of the vapor. The temperature of the
two liquid layer in the abortion Ye Mel 74 was
about 40C. The aqueous layer was separated from
the ethylene dichlorides layer by recantation and
the resulting ear-depleted liquid smoke (220 trams)
was analyzed.
In the comparative control run, the smoke
vapors produced during the smoke ~eneraeion procefis
were only ab60rbed by the water, resulting in an
aqueous mixture of tarry hydrocarbon con~eituent~
and smoke color, flavor and odor constituents. the
temperature of the aqueous layer was about 100C.
The tarry constituents beetled out and the aqueous
~L~Z769C!
- 53 -
layer containing the liquid smoke constituents was
separated by recantation and then analyzed (Coup.
A). Since this liquid smoke was v rye dilute
compared to the tar-depleted liquid smote produced
according to the invention, it was concentrated Jo a
concentration weight ratio ox 2.5:1 by evaporating
it at a temperature of 50C at a pressure of 20 mm
Hug. The resulting 220 grams of concentrated liquid
smoke was analyzed (Coup. B). The results of the
analysis is shown in Table D. Also shown in Table D
are values typically found or as-is liquid smoke
solution and the values for the liquid move as
disclosed in the examples of the above cited U. S.
blue, to Suits, et at. (Suits).
TABLE D
Sample CBI Light Trans. Curb. Phenols Acids
percent) mug mug I%)
_______________________._________________________
Invent. 9.8 95.9~6.3 1.514.9
Coup. A 6.0 98.072.5 5.65.6
Coup. B 7.3 97.5103.3 8.09.6
swept - - 25 - 81 1.6-2.3 2-6.4
As-Is 10.5-12 070 -100 13-2011.5-12.5
The data of Table D demonstrates the
advantages of the tar-depleted liquid smoke
solution of the invention as compared to other
liquid smoke solutions.
. .
I
- 54 -
The liquid smoke 601utions made by the
prior art process, wherein smoke vapor it absorbed
into an aqueous medium, (Coup. A, Coup. I, and
As-Is) all show a significantly higher convent of
phenols than the liquid smoke of the invention.
This low content of phenols on the invention was
achieved in addition to the achievement of a
favorably high content of the carbonless. The high
content of the earbonyls in relation to the content
of the phenols Allah eo~pares Favorably with the
liquid smoke concentrates disclosed in Suits, et at.
The percent of the phenols in the composition of the
invention was only 1.6 percent of the content of the
carbonyl~ (1.5 mug phenols mug carbonless).
This it equivalent to a ratio of carbonless So
phenols of 65:1 on a 2-butanone/DMP basis which it
84:1 on an acetone/phenol basis. This how
significant improvement over the compositions
disclosed in Suits, et at. which have a carbonyl to
phenol ratio of (17-~7):1 on an acetone/phenol
basis. This example demonstrates what a desirable
high content ox the carbonyl coloring constituents
can be achieved without necessarily resulting in a
corresponding undesirable it content of the
finlike flavoring constituents.
Increased coloring ability does not
necessarily correspond to increased flavoring
ability. However, the process of the invention
produces a liquid smoke solution highly effective
for its coloring capability, and although it has a
low finlike content, its flavoring ability is
sufficient for commercial applications.
- 55 -
Typically, liquid smoke ~olution6 produced
commercially by the prior art process of absorbing
smoke appear into an aqueous medium, and which have
a carbonyl content comparable to Coup. A and Coup.
B, hove a very low light transmittance. This it
shown by comparable commercially available assay
liquid smoke solution which have a light
transmittance of I The samples Coup. A and Coup.
B would normally be expected to also have a very low
light transmittance. However, due to a limitation
of the cooling capacity of the condenser, the prior
art process of Coup. A and Coup. B was run at a
higher than normal temperature of 100C. In
prowesses of this kind an abrasion temperature
between about 20C and about 45C is normally
desired. The higher temperature of this example
caused a higher proportion of organic acids Jo be
lost by evaporation, as shown by the lower then
expected acid content of Coup. A and Coup. B. The
acids in a liquid smoke 601ueion syllables the tars
in the liquid Moe 601u~ion. In Coup. A the acid
content was insufficient to 601ubilize the tar, and
the main portion of the tars jell out of 601ution
before analysis of Coup. A. Thirty trams of solid
precipitated tars were removed before the the
analysis of Sample Coup. A and the 6ub~equent
concentration of Sample Coup. A to form Sample Coup.
B.
A was shown above, the tar-depleted liquid
smoke produced in accordance with the present
invention had coloring ability, a shown by the CBI,
comparable to that of commercially available as-is
liquid smote.
~L~2~69~
- I -
EMPLOY IV
In this example, a non fibrous cawing having
a flat width of about 30.0 mm to about 31.8 mm was
dipped in eke liquid smoke solution of Example III
for 30 seconds. About 10 milligrams of liquid smoke
was absorbed per square inch of casing surface (1.55
milligrams per square centimeter). The treated
casing was dried and stuffed by conventional methods
with an egg albumin emulsion and cooked for 2 hours
at 100C in a laboratory oven. The egg albumin
emulsion contained about 35 wt.% powdered egg white
albumin (Raft, Ionic, about 12 White of a commercial
powdered cellulose (Solfaflock, Brown Co.). and
about 53 White water. The consistency was that of a
thick pave, similar Jo typical meat emulsions. The
color transferred to the egg albumin emulsion it a
measure of the coloring ability of Cue liquid smoke
solution for protein substances. Upon visual
inspection of the final product, very good smoke
color way exhibited by the products processed in the
casings treated with the liquid smoke of the
invention (Invent.) and the concentrated liquid
smoke solution made by a prior art prows (Coup.
By. The sample made by the prior art process (Coup.
A) exhibited only iota smoke color when compared
with the white control sample.
EMCEE V
This example demonstrates an embodiment of
the invention using a pilot scale process. The
apparatus used is illustrated in Figure 6. Sawdust
vat fed into a conventional smoke generator snot
shown), essentially the same as that as described in
~.2;2~
- 57 -
United States Patent 3,106,473. The generated smoke
way conducted through a duct 101 into the bottom of
a counter-current absorption unit 102, and was then
drawn wick a blower (not shown) upwardly and out of
the absorption unit 102 through duct 103. The
absorption unit 102 was a column about 1 meter high
and 15 centimeters in diameter and it contained a
bed 104 of packed bent saddles. ethylene chloride
was introduced into the top of the absorption unit
102 through conduit 105, and then through a spray
nozzle 106, after which it flowed downward and
countercurrent to the upward flow of the smoke
pausing thrush the absorption unit 102. While the
smoke vapor was flowing upwardly through the
absorption unit, water in toe smoke vapor condensed
from the smoke vapors and also Plowed downwardly
through the absorption unit 102, countercurrent to
the smoke vapor, thereby absorbing color, flavor,
and odor constituents from the smoke vapor as it
progressed. The ethylene chloride, also flowing
counter currently to the smoke vapors, extracted tar
from the smoke vapors and tars which may have been
absorbed in the condensed waxer. The condensed
water and the liquid ethylene chloride then passed,
as separate foe, out of the column through
conduit 107. From conduit 107 the two phase liquid
paused into a separator 108 in which the liquid
separated into a less dense phase 109 comprising an
aqueous liquid smoke, containing mainly smoke color,
flavor and odor constituents, and a denser phase 110
of ethylene chloride, containing mainly smoke
tars. the ethylene chloride pasted from the
LO I
- 58 -
separator 108 through conduit 111 Jo a color 112,
and recycled via conduit 113, 105 and pump 114 into
the absorption unit 102. Lone 111, 113, 105 were
inlaid tunnels steel pipe. The aqueous liquid
smoke 109 left the operator 108 by way of a
overflow 115 and collected as a jar depleted liquid
smoke product of the invention.
Twenty-four pound (10.9 kg) of maple
audit were continuously fed to the smoke generator
with the strew fed during the test. The temperature
of the smoke vapor entering the abrasion unit
through duct 101 way about 250F (120C) at the
beginning of the test and rove to about 3754F
t190C) at the end of the test. About 65 pound
(29.5 kq) of dry ice were used in eke cooler 112, to
maintain the temperature of the ethylene chloride
at between about 30F (-1C) and about 44F (7C) a
it entered the absorption unit from line 105.
Initially there were 16 liters of Mullen chloride
in the system. During the run, ethylene chloride
was periodically added to make up for ethylene
chloride vapor lout to the atmosphere through duct
103. A total of 24 liter of ethylene chloride
wore used with 9.4 liter recovered at the end ox
the run. The remaining 14.6 liter were 105~ a
vapors through duct 103. The total amount of
aqueous tar-depleted liquid Moe condensate
obtained through overflow 115 way 2830 ml.
The text way begun by first starting pump
114 and equilibrating the temperature of the
ethylene chloride to about 33F (1C). The smoke
vaporfi were then admitted through duct 101 into toe
~2Z76~
- 59 -
adsorption unit 102. Ethylene chloride was added
in 2 liter increments 45 minutes, 70 minutes, 100
minutes and 110 minutes after the smoke Vapors were
admitted. Samples of the overflow of the aqueous
tar depleted liquid smoke product of 400 ml, 900 ml,
and Z50 ml were taken 45 minutes, 90 minutes and 125
minutes, respectively, after the smoke vapors were
admitted. The samples were combined into one sample
tin-) and analyzed. Part of the combined sample
was concentrated (Cone.) to a weight ratio of 2:1 by
evaporation at a temperature of 50C and at a
pressure of 20 mm Hug, and the concentrated product
was then analyzed. The results of the analysis are
shown in Table E. the values not shown for the
concentrated sample were not measured.
Table E
In. Cone.
Light Trans. (~) -60
Casbonyls mug 152 180
Phenols my 5 21.7
Acid (wt. I) 9
CBI 20 46.~
The above tar-depleted liquid smoke products (In.
and Cone.) were applied to a cawing and the casing
was stuffed as in Example II. The "L" and "a"
values were measured for the food product stuffed in
each casing as well as the "L" and "a" values for a
food product stuffed in a control casing thaw was
not treated with liquid smote. The results of the
measurements are shown in Table F.
~22~
- 60 -
Table F
L a
Ivy. Sly 1~.3
Cone. 46.6 lB.9
Cont. 55.5 17.0
This example shows how tar-depleted liquid smoke of
the invention having good coloring ability can be
produced in a continuous process. Also shown the
absence of tar in the tar-depleted liquid smoke a
shown by the light transmittance values.
