Impregnated casing and method of making the same

The present invention relates to a casing which is impregnated with a high browning, low flavor liquid composition in order to impart a desirable brown color to a food contained in the casing without adding undesirable sensory characteristics to the food.

FIELD OF THE INVENTION 
The present invention relates generally to a casing impregnated with a high 
browning, low flavor liquid composition that imparts or adds a desirable 
brown, smoked color to an encased food. More particularly, the casing is 
impregnated with a liquid composition that browns an encased food but does 
not add a strong, smoked flavor to the food. A method of making 
impregnated casings is also within the scope of this invention. 
BACKGROUND OF THE INVENTION 
Using liquid solutions (often referred to as liquid smoke) as a replacement 
for conventionally smoking foods by direct contact with wood smoke has 
become a standard industry practice. One known liquid smoke solution for 
flavoring and coloring foods is an aqueous liquid smoke flavoring 
described by Hollenbeck in U.S. Pat. No. 3,106,473. Another useful 
solution for flavoring and coloring foods is obtained from a process for 
isolating the organic components of the fast pyrolysis of wood or 
cellulose described by Underwood et al. in U.S. Pat. No. 4,876,108. When 
such liquid solutions are applied to the surface of meats and other 
protein-containing foods, organic components in the solution give a food a 
characteristic smoke flavor and react with the proteins of the food to 
give a brown, smoked color typical of a conventionally smoked food. 
Surface appearance and flavor are important factors in the commercial and 
consumer acceptance of "liquid smoked" foods. A common feature of most 
varieties of such foods involves using various types of liquid solutions 
of wood-derived smoke constituents for imparting both characteristic 
flavor and color to the food. 
The application of a liquid smoke solution to a food is generally carried 
out in a variety of ways including: spraying or dipping a food during 
processing, incorporating the liquid smoke in the recipe itself, or 
treating a casing which contacts a food during processing. The 
conventional operations of spraying or dipping a casing have not been 
completely satisfactory due to an inability to treat or coat the encased 
food uniformly. In addition, treating a casing with a liquid smoke 
solution does not always provide a food having the desired surface 
appearance. For example, when a liquid smoke solution is applied to a meat 
the processor normally must give up browning in order to keep the flavor 
at a desired level because the flavor imparting ability of known liquid 
smoke solutions is generally too intense at a desired brown color. 
In addition, encased sausages treated by application of a conventional 
liquid smoke to a casing during processing have been found to yield (after 
peeling the casing from the sausage), sausages that are lacking in smoke 
color and that have poor color uniformity between sausages and batches of 
sausages. In addition to lack of uniformity of coloration when casings are 
treated with conventional liquid solutions, the surface of a treated 
sausage often may include light and dark streaks, light and dark blotches, 
uncolored spots or specks appearing at the ends of the sausage, dark 
surface discolorations or black spots appearing on the casing or on the 
sausage. 
Furthermore, applying a liquid smoke to encased food products, such as by 
spraying or dipping, also causes unwanted pollution and equipment 
corrosion problems for the food processor. 
It has also been reported that when a cellulosic casing, made from either 
fibrous or nonfibrous gel stock casing, is treated with a known highly 
acidic (pH of about 2.0 to 2.5), tar-containing, aqueous liquid smoke, 
tarry deposits accumulate on coating and squeeze rollers of conventional 
coating apparatus. These deposits cause the casing to stick to the rollers 
and eventually force a shutdown of the coating apparatus. 
One reported method to minimize some of these problems associated with 
imparting smoke color and flavor to foods uses a "tar-depleted" liquid 
smoke solution to coat the surface of a casing. For example, unwanted tars 
may be partially removed from conventional liquid smoke by neutralizing 
the liquid smoke with base to precipitate the tars. Use of such a 
neutralized, tar-depleted liquid smoke to treat a casing helps to prevent 
the tarry deposit accumulation problem. Unfortunately, the neutralizing 
method for forming a tar-depleted liquid smoke is not satisfactory. 
Tar-depleted liquid smoke solutions have a strong flavor but do not have a 
sufficient coloring ability because the coloring ability of a liquid smoke 
solution is typically known to decline with increasing pH. Further, the 
viscosity of a liquid smoke solution increases substantially when the 
solution is neutralized especially after concentration. These factors 
limit most applications, particularly where a high coloring ability is 
desired. 
Similarly, a solvent extraction process may be employed to make 
tar-depleted liquid smoke. Such a process is reported in U.S. Pat. Nos. 
4,505,939, 4,431,032, 4,431,033, 4,496,595, 4,525,397, 4,504,501, 
4,504,507, 4,657,765 and 4,717,576. In this process, a tar-containing 
liquid smoke solution is extracted with a nonreactive or reactive organic 
solvent which is immiscible in the liquid smoke solution under conditions 
sufficient to form a tar-enriched solvent fraction and a tar-depleted 
liquid smoke fraction. Using this solvent extraction method, it is 
possible to make a tar-depleted liquid smoke solution capable of imparting 
smoke color, odor, and flavor to foods. 
The tar-depleted liquid smoke solution made from the solvent extraction 
process, unless it is neutralized, is generally still highly acidic, and 
thus may degrade or interfere with the integrity of cellulosic casings. If 
a tar-depleted liquid smoke solution is partially neutralized, the 
coloring ability also typically declines with increasing pH without a 
corresponding decline in flavor. Thus, satisfactory coloring with 
extracted liquid smoke solutions requires adding a solution having too 
much flavoring capability. Similarly, if enough of a tar-depleted liquid 
smoke solution is added to a casing to impart satisfactory color, the 
amount of organic components in the casing becomes to great. These 
overloaded casings may become rubber-like and cannot be handled or 
shirred. In addition, the process of adding large amounts of a tar. 
depleted liquid smoke solution to casings is very difficult using 
conventional techniques. Although tar-depleted liquid smoke solutions 
address some of the problems of using these solutions to color encased 
foods, the undesirable sensory aspects have been a factor for the lack of 
commercial acceptance of these products. There is a need in the industry 
for impregnated casings having both good coloring or browning properties 
and acceptable flavoring properties. 
SUMMARY OF THE INVENTION 
The present invention provides a casing suitable to impart a brown color to 
food and provides a method of making a casing that includes contacting a 
casing with a high browning, low flavor liquid composition having a high 
ratio of browning index to the amount of soluble organic components in the 
composition (.degree. Brix). 
The ratio of browning index to the organic components is preferably 
selected to give a liquid composition that imparts a satisfactory brown, 
smoked color to a food contained in the casing without adding undesired 
sensory properties to the food. A preferred ratio of browning index to 
.degree. Brix is 0.9, and a more preferred ratio is 1.5. 
For specific organic components in the liquid composition, a preferred 
ratio of browning index to organic acids or salts thereof is greater than 
5.0, and a more preferred ratio is greater than 12.0. A preferred ratio of 
browning index to carbonyls is greater than 1.8, and a more preferred 
ratio is greater than or equal to 2.0. A preferred ratio of browning index 
to phenols is greater 8.5, and a more preferred ratio is greater than 
30.0. 
In addition, the viscosity of a preferred liquid composition, whether or 
not the solution is pH adjusted, is less than 300 cps, preferably less 
then 90 cps, and more preferably less than 10 cps. 
Cellulosic casings of the invention, both nonreinforced cellulosic casings 
and fibrous reinforced cellulosic casings, impregnated with a high 
browning, low flavor liquid composition have a low ratio of organic 
components to browning index density, as defined below. A preferred ratio 
of organic components to browning index density is less than 12.0, and a 
more preferred ratio of organic components to browning index is less than 
5.0. 
Cellulosic casings impregnated with a high browning, low flavor liquid 
composition also have a low ratio of phenols to browning index density, a 
preferred ratio of phenols to browning index density is less than 0.1. 
Furthermore, cellulosic casings impregnated with a high browning, low 
flavor liquid composition have a browning index density greater than 0.08 
and preferably the browning index density is in the range of 0.08 to 3.4.

DETAILED DESCRIPTION 
The present invention provides a casing and a method of making a casing in 
which the casing has higher browning capabilities and less intense flavor 
properties compared to previously reported food casings. 
As used herein the term "organic components" means components of a liquid 
composition, different than water, which are included in browning or 
liquid compositions suitable for application to a casing. Salts derived 
from neutralizing organic acids are included in this term as well as any 
inorganic components (although these inorganic components are, for 
practical purpose, very insignificant). The total percentage of organic 
components or total organics for a liquid composition are determined using 
the formula: 
100-(water content determined by the Karl Fisher titration method). 
The term "acids" means the total amount of organic acids plus alkaline 
salts produced during their neutralization and is a subgroup of the 
components included within the meaning of organic components. 
The term "Browning Index Density" (BID) is a measure of the browning 
ability of a casing per unit of area that is calculated by multiplying the 
following values: the amount of organic components added to the casing or 
organics load (ORGANICS IN CASING measured as mg/cm.sup.2); 100 divided by 
the percent of organic components in the added liquid (100/% ORGANICS IN 
LIQUID); and the browning index of the liquid composition divided by 1000 
(Browning Index/1000). Thus, BID values are determined using the formula: 
(ORGANICS IN CASING) (100/% ORGANICS IN LIQUID) (BROWNING INDEX)/1000). 
The amount of organic components which are added to a casing is calculated 
using the formula: 
(TOTAL WEIGHT)-(WATER)-(GLYCOL) (CELLULOSE) 
Casings suitable for use in the present invention include tubular casings, 
and preferably tubular cellulosic casings, that are prepared by any of the 
methods that are well known in the art. 
In earlier attempts to produce liquid smoke-containing cellulose casings, 
the only way to get acceptable coloring properties for the casings 
required loading the casings with substantial amounts of organic 
components (carbonyls, phenols, acids and salts thereof) derived from 
various liquid smoke solutions. Detrimentally, substantial portions of 
these solutions contained unnecessary organic components that had no 
beneficial properties or that even imparted unsuitable sensory properties 
to foods. Furthermore, very high amounts of organic components were needed 
on cellulose casings in order to give a satisfactory product. This 
overloading also detrimentally affected both the physical characteristics 
of the casings and the processes which were used to apply the solutions to 
the casings. Thus, the present invention provides a casing containing a 
minimum casing load of desired organic components from a desired liquid 
composition. 
In the past, the liquid smoke solutions that were typically applied to 
casings were most often obtained from products having high acid content 
and included acids that were difficult or impossible to remove and that 
had to be neutralized before these solutions were applied to cellulosic 
casings. When these conventional solutions were neutralized, however, the 
solutions eventually contained too many acid derived salts and the 
solutions became too viscous to be readily applied to casings in an easy 
straight forward way. Solutions which were too viscous also overloaded 
casings with undesired and unnecessary organic components. 
Practical processing conditions have established that low viscosity 
solutions are highly desirable when liquid compositions have to be applied 
to casings in order to impregnate them with adequate levels of coloring or 
browning components. If high viscosity compositions are used, they may 
also give an uneven distribution of organic components on casings because 
the application process becomes difficult. In addition, the absorption of 
high viscosity solutions into casings is slow and high speed coating 
methods cannot be used. Furthermore, in high viscosity solutions, organic 
components do not move freely in solution and diffusion processes of the 
solutions into casings are slow, making the impregnation process more 
difficult. 
The advantages of the cellulosic casings of the invention are due, in part, 
to three characteristics of the liquid compositions which are applied to 
the casings. Preferred liquid compositions have: 
i) low acid content (the ratio of browning index to total organic 
components is very high); 
ii) high levels of browning carbonyls (the ratio of browning index to 
carbonyls is higher than in reported liquid smoke solutions and results in 
food products having good coloring using casings treated with less 
solution); and 
iii) low levels of phenols (the high ratio of browning index to phenols 
gives a food with desirable brown color and less flavor). 
Two types of cellulosic casings, nonfibrous and fibrous, are within the 
scope of the invention. Such casings are either non-fibrous, flexible, 
thin-walled seamless casings formed of regenerated cellulose or cellulosic 
casings having a fibrous reinforcing web embedded in the wall of the 
casings. 
Any well known method may be used to contact suitable casings with a 
desired liquid composition. See, for example, the methods disclosed in 
U.S. Pat. Nos. 3,330,669 and 4,504,500. Suitable methods for contacting 
casings with a liquid composition are also described in U.S. Pat. 
application Ser. No. 07/416,963 filed Oct. 4, 1989, which is incorporated 
herein by reference. 
A liquid composition may be externally applied to a casing by passing the 
casing through a bath of the liquid composition. The liquid composition is 
generally allowed to soak into the casing for an amount of time sufficient 
for the casing to incorporate the desired amount of organic components 
into the casing before doctoring off any excess liquid, typically by 
passing the casing through squeeze rollers or wipers. The liquid 
composition may also be externally applied to the casing by methods other 
than dipping, such as spraying, brushing or roll-coating. In these types 
of applications, low viscosity liquid compositions are preferred. 
Another method of treating a casing with a liquid composition of this 
invention involves passing a flattened, tubular, cellulosic casing over 
guide rolls through a dip tank which contains the liquid composition. The 
casing passes over additional guide rolls after exiting the dip tank, and 
then passes between squeeze rollers which minimize any excess carryover of 
the liquid composition. The total contact time of the casing with the 
liquid composition in the dip tank, and with excess liquid composition on 
the casing passing over the guide rolls before the casing passes through 
the squeeze rollers, relates to the amount of organic components 
incorporated into the casing. 
After contact with the liquid composition the externally treated casing is 
then sent on to further conventional processing, including conventional 
humidification, as may be required, and conventional shirring. 
Alternatively, the liquid composition may be applied to the internal 
surface of a casing by any of several well-known procedures. These 
procedures include slugging or bubble coating, spraying, and coating while 
shirring. The slugging method for coating the inside of a casing involves 
filling a portion of the casing with the liquid composition, so that a 
slug of the composition generally resides at the bottom of a "U" shape 
formed by the casing. A continuous indefinite length of casing, keeping 
the slug confined within the casing, then moves past the slug and is 
coated on its inside wall by the liquid composition contained within the 
slug. 
Both externally or internally impregnated casings may be shirred by 
conventional methods or, before shirring, they may be dried or humidified 
to a water content suitable for shirring or further processing. The need 
for conventional drying or humidification after treatment with the 
composition depends on the water content of the casing after treatment and 
the type of casing. If the casing is a nonfibrous casing, a water content 
within the range of about 8-18 wt. % water immediately before shirring is 
typical, and for a fibrous casing a water content within the range of 
about 11-35 wt. % water immediately before shirring is typical, where 
weight percent is based on the total weight of casing including water. 
In the indirect application of the liquid composition to a food from a 
casing, the lack of a strong or an undesirable flavor is a notable, 
additional advantage. Conventional or known liquid smoke solutions such as 
tar-depleted liquid smoke solutions generally must be used at high 
concentrations to impart enough color or browning to an encased food. 
These high concentrations, however, typically have a flavor which may be 
more intense than desired. The use of the liquid compositions provided 
hereby on casings allows a processor to achieve a desired brown, smoke. 
like color without necessarily imparting too much flavor to a food. 
It is to be noted that the liquid composition which is impregnated in the 
casing, whether externally or internally applied, does not exist solely as 
a surface coating. Color and flavor components of the liquid composition 
which are coated on a casing penetrate the cellulosic structure of the 
casing as the cellulose absorbs the moisture of the composition. 
To obtain a suitable liquid composition, a fast pyrolysis process which 
uses hot particulate solids and/or inert gases to rapidly transfer heat to 
the wood feedstock in a reactor system is preferred. This process uses 
short vapor residence times (depending upon the reactor conditions) and 
results in very high gas or liquid yields from biomass. Char yields are 
from 0-15% depending upon the feedstock and reactor temperature. Maximum 
gas yields may be about 90% of the feedstock mass at 900.degree. C. and 
maximum liquid yields may be about 85% of the feedstock mass at 
600-650.degree. C. A suitable apparatus for this process is described in 
U.S. Pat. No. 4,876,108 and the related divisional U.S. Pat. No. 
4,994,297. This type of apparatus can be operated at temperatures between 
350.degree.-1000.degree. C. with vapor residence times between 0.03-3 
seconds. 
FIG. 1 illustrates an apparatus useful for the fast pyrolysis of a suitable 
feedstock by a rapid thermal process. Bin (40) stores a supply of the 
feedstock such as wood, cellulose, sugars, or polysaacharides in granular 
or powder form. The feedstock is removed from the bin (40) by an auger 
(42) and fed to the lower interior portion of the reactor (44) above a 
windbox (101) and a gird plate (43). The auger (42) may be water cooled at 
the inlet to the reactor to prevent premature pyrolysis, which can produce 
tarry materials. Alternatively, a solution or syrup of a 
carbohydrate-containing liquid feedstock may be injected into the reactor 
using a suitable well known injector apparatus. A heated storage tank 
(110) stores a supply of a liquid feedstock. The liquid feedstock is 
pumped from the storage tank (110) by a pump (112) through a clean 
jacketed conduit (114). The liquid feedstock enters the reactor (44) 
through an injector nozzle (116). The injector nozzle (116) may be cooled 
at the inlet in the reactor by a water-cooled jacket (118) to prevent 
premature pyrolysis of the liquid feedstock in the injector nozzle. 
A stream of recirculation gas transport fluid is fed by a conduit (100) 
into the windbox (101), through the grid plate (43) and into the lower 
portion of the reactor (44) containing a heat transfer medium such as sand 
(45). Rapid mixing and conductive heat transfer from the sand (45) to the 
sugar or starch feedstock occurs in the reactor (44). Pyrolytic conversion 
of the feedstock to a raw product vapor is initiated and continues through 
the reactor with upward flow into the primary cyclone separator (48). The 
pyrolysis stream comprising sand (45) and pyrolysis vapor is removed from 
the reactor (44) by conduit (46) and fed to primary cyclone separator 
(48). The hot sand (45) is removed from the product vapor stream in the 
separator (48) and recycled by means of a conduit (50) to the reactor 
(44). The recycled sand (45) is reintroduced into the lower portion of the 
reactor (44) at a point above the grid plate (43). Product vapor 
containing char is withdrawn from the primary cyclone separator (48) by a 
conduit (52) and fed to a secondary cyclone separator (54) which can be a 
high efficiency reverse flow cyclone separator. Char and solid sand fines 
are removed in the secondary cyclone and fed therefrom to a char catchpot 
(56) for disposal or further handling as desired. 
The hot product stream is withdrawn from the top of the secondary separator 
(54) through a conduit (58) which feeds the vapor comprising condensable 
and noncondensable components and some fine residual char and ash to the 
lower interior space of a baffled condenser (60) where the vapor is 
immediately quenched. The condenser (60) uses the product liquid as the 
quench medium. 
The condensed liquid product is withdrawn from the bottom of the condenser 
(60) through a conduit (62) and is fed to a pump (64) which pumps it to a 
heat exchanger (66) indirectly cooled by water. The cooled product liquid 
is removed from the heat exchanger (66) and returned by conduit (68) to 
the top of the condenser (60) as a spray. A conventional transparent 
vertical sight indicator (61) is mounted on the lower part of the first 
condenser (60). The sight indicator has high and low liquid level marks. 
When the volume of liquid in the condenser (60) reaches the high level 
mark raw pyrolysis liquid is withdrawn through a conduit (63) until the 
liquid level reaches the low level mark. Liquid is then accumulated in the 
condenser until it reaches the high level mark again when the raw 
pyrolysis liquid withdrawal step is repeated. 
Noncondensed product vapor is withdrawn from the top of the condenser (60) 
by conduit (70) and is fed to a packed second condenser column (72) where 
it is further cooled. Liquid is withdrawn by a conduit (74) from the 
bottom of the packed second condenser and fed to a pump (76) which pumps 
it through a water cooled heat exchanger (78). Cooled liquid product is 
removed from the heat exchanger (78) by conduit (80) and is fed to the top 
of the packed second condenser (72). The sight indicator has high and low 
liquid level marks. When the high level mark is reached raw pyrolysis 
liquid is withdrawn through conduit (75) until the liquid level reaches 
the low mark. 
A vapor stream is removed from the top of the packed second condenser 
column (72) by a conduit (82) and fed through a water cooled heat 
exchanger (84) which feeds it to a mist eliminator (88). The vapor is fed 
from the mist eliminator (88) to a conduit (90) which delivers the vapor 
to a filter (92). Liquid is removed from the bottom of the filter (92) by 
means of a conduit (102) and recirculated to the bottom portion of the 
second condenser column (72) above the level of liquid in the column. A 
portion of the resulting clean by-product gas stream is ducted from the 
filter (92) by a conduit (94) to waste while a further portion is taken 
from the conduit (94) and fed to conduit (96) which feeds into a gas 
recirculation blower (98). The recirculated gas is fed from the blower 
(98) to a conduit (100) which feeds into the bottom of the reactor (44). 
Suitable feedstocks for producing a high browning, low flavor liquid 
composition are generally a member of the group consisting of wood, 
sugars, cellulose, polysaacharides, other cellulosic biomass materials, 
and/or mixtures thereof. Such feedstocks include a variety of 
carbohydrate-containing materials including wood, cellulose, sugars or 
starches. For example, any mono., di., tri. or polysaccharide which 
contains glucose or glucose monomers many be used. Suitable saccharides 
include glucose, dextrose, invert sugar, lactose, malt syrup, molasses, 
starch hydrolysates and fractions therefore, sucrose, cellobiose, 
hemicellulose and cellulose. Wood also serves as a suitable feedstock 
although the presence of components in wood, in addition to cellulose, may 
provide an unduly complex pyrolysis mixture. Other suitable feedstock 
sources include plant derived material such as seed, leaf and fruit 
fibers, as well as plant derived syrups and extracts. 
After collecting the liquid pyrolysis materials from these feedstocks, it 
is generally advantageous to add sufficient water to dilute the pyrolysis 
materials to reduce the .degree. Brix value of the materials to about 
35.degree. Brix or lower, in order to ensure the complete separation of 
the desired water-soluble components from the undesired water-insoluble 
components. If the .degree. Brix value of the diluted pyrolysis solution 
is greater than about 35.degree. Brix, the separation of benzo(a)pyrene 
and tars from the aqueous layer may be incomplete. 
Furthermore, it is also desirable to ensure that the water-soluble liquid 
phase of suitable pyrolysis solutions be less than about 35.degree. Brix 
when subsequent extraction or other treatment steps are performed because 
these additional steps are less effective at higher .degree. Brix values, 
primarily due to the greater solvating effects of the organic components 
of the more highly concentrated solutions. 
Specifically, untreated water-soluble liquid pyrolysis solutions, desirably 
having a maximum .degree. Brix value of about 35, may be further improved 
by additional treatment to lower the amounts of unnecessary organic 
components in the solution. In one treatment, the liquid solution is 
extracted with a suitable water-insoluble organic solvent, such as 
methylene chloride, to remove phenols, flavoring materials, and other food 
flavoring organic components which provide smoke flavor and aroma, while 
retaining those organic components which provide browning. Generally, 
suitable extraction solvents include solvents having a proper range of 
hydrogen bonding parameters and an appropriate polarity index to 
solubilize the undesired flavoring organic components present in the 
water-soluble product. After extraction, the organic solvent is then 
separated from the aqueous phase to yield a suitable liquid solution which 
has less flavoring ability. 
The water-soluble liquid pyrolysis solution, with or without a prior 
extraction with methylene chloride or some other suitable organic solvent, 
may be treated with a nonionic resin, cationic resin or a combination of 
such resins, to also remove undesired contaminants and flavoring organic 
components. The resin treatment of liquid solutions produced by slow 
pyrolysis of wood is described in U.S. Pat. No. 4,959,232 which is 
incorporated herein by reference. The conditions disclosed therein are 
suitable for further processing the water-soluble liquid pyrolysis 
solution obtained from a suitable feedstock with or without a prior 
organic solvent extraction. The resulting liquid solution has little or 
substantially no flavoring ability. 
After suitable treatment the resulting liquid solution may be diluted with 
water or concentrated as appropriate depending on the type of application 
process for which it is to be used. 
EXAMPLES 
The following examples are presented to further illustrate the invention. 
In the examples, the concentration values for the organic components in 
the described liquids are given as .degree. Brix values or by weight as 
described above. The .degree. Brix values were obtained using standard 
refractory techniques which are well known in the sugar industry. Other 
typical analytical procedures are described in U.S. Pat. No. 4,876,108. 
EXAMPLE 1 
This example compares measurable differences of three liquid compositions, 
samples A, B and C that are useful in preparing a casing of the invention 
to a known tar-depleted solution, sample D. The measured differences 
indicate the suitability of the liquid compositions, A, B, and C, in 
making an impregnated cellulosic casing according to the invention. 
Table 1 lists the analytical data of the liquid composition samples A, B, C 
and D. 
Sample A was prepared from high dextrose corn syrup having 83.7% total 
solids and 16.3% moisture (62 D.E./44 Baume corn syrup, ADM Corn 
Sweetners, Cedar Rapids, Iowa) that was heated to about 150.degree. F. and 
then pumped through steam heated conduits into an upflow circulating 
fluidized bed reactor described above. The heated corn syrup entered the 
reactor through a nozzle having a 3/32 inch aperture. The reactor 
temperature was about 550.degree. C., the vapor residence was about 700 
msec, and the pressure was about 1.5 psi. The pyrolysis vapors were 
condensed and solubilized by direct contact with 20.degree. C. 
recirculating water to give a liquid product having about 30 .degree. 
Brix. The 30 .degree. Brix solution was extracted with methylene chloride 
(one volume methylene chloride to ten volumes solution) and then 
concentrated by evaporation under reduced pressure (-28.3 inches of 
mercury) at about 50.degree. C. to give a liquid composition of about 
45.degree. Brix. 
______________________________________ 
Sample A had the following composition: 
______________________________________ 
.degree.Brix 45 
Acids 2.7% 
Phenols 2.0 mg/ml 
Carbonyls 54.0% 
Browning Index 104.0 
Transmittance 82% 
Viscosity 4.98 cps 
Specific Gravity 1.174 g/m 
Color 27.5 
Hydroxyacetaldehyde 16.1% 
______________________________________ 
Sample B was prepared from powdered cellulose (Avicel pH-101, FMC Corp., 
Philadelphia, Pa.) that was pyrolyzed in a downflow transport reactor at 
550.degree. C. using an inert solid heat carrier. The vapor residence time 
was about 200 milliseconds and the vapors were condensed directly onto a 
cold water condenser. The raw pyrolysis liquid was found to be about 70 
.degree. Brix. About 4.2 kilograms of raw liquid were then added to about 
twenty liters of water and the resulting solution was passed through a 
column containing ten liters of XAD-4 non-ionic exchange resin (Rohm and 
Hass Corp., Philadelphia, Pa.). The resin treatment lowered the .degree. 
Brix of the solution from 14 to 9. The resin treated solution was then 
concentrated by evaporation under reduced pressure (-29 inches of mercury) 
to about 45 .degree. Brix at 50.degree. C. Sample B was found to have the 
following composition: 
______________________________________ 
.degree.Brix 45 
Acids 2.9% 
Phenols 7.3 mg/ml 
Carbonyls 22% 
Browning Index 44.0 
Transmittance 94% 
Viscosity 5.7 cps 
Specific Gravity 1.191 g/ml 
Color 3.0 
Hydroxyacetaldehyde 10.2% 
______________________________________ 
Sample C was prepared from about 1640 g of the high dextrose corn syrup 
liquid composition as described above as sample A which was added to about 
2360 g of a 40% aqueous solution of hydroxyacetaldehyde to give a combined 
mixture, sample C. 
The 40% aqueous solution making up part of sample C was prepared by adding 
water to about 800 g of solid hydroxyacetaldehyde (Red Arrow Products 
Company Inc., Manitowoc, Wis.) to give a final volume of about 2000 ml. 
After dissolution of the solids, the solution was filtered. The 
composition of this 40% solution was: 
______________________________________ 
.degree.Brix 28 
Acids &lt;0.2% 
Browning Index 94 
Hydroxyacetaldehyde 39.5% 
______________________________________ 
The combined mixture sample C was found to have the following composition: 
______________________________________ 
.degree.Brix 35 
Acids 2.0% 
Phenols -- 
Carbonyls 45.1% 
Browning Index 96.5 
Transmittance -- 
Viscosity 4.36 cps 
Specific Gravity 1.1326 g/ml 
Color -- 
Hydroxyacetaldehyde 28.4% 
______________________________________ 
for comparative purposes a tar-depleted liquid solution sample D, was 
prepared according to the description provided in U.S. Pat. No. 4,717,576. 
Accordingly, a conventional liquid smoke CHARSOL C-10 (Red Arrow Products 
Company Inc., Manitowoc, Wis.) having a .degree. Brix value of 24, acids 
value of 11%, phenols value of 16 mg/ml, carbonyls value of 12%, and 
browning index of 11 was extracted with three portions of methylene 
chloride equal to about 1/3 the total liquid smoke volume. The 
tar-depleted liquid smoke was then concentrated by evaporation under a 
vacuum (-29 inches of mercury) at 50.degree. C. to 45.degree. Brix. Sample 
D was found to have the following composition: 
______________________________________ 
.degree.Brix 45 
Acids 18.7% 
Phenols 8.6 mg/ml 
Carbonyls 22.8% 
Browning Index 27.5 
Transmittance 67 
Viscosity 5.7 
Specific Gravity 1.120 g/ml 
Color 14.0 
Hydroxyacetaldehyde 5.2% 
______________________________________ 
TABLE 1 
__________________________________________________________________________ 
COMPOSITION 
.degree.BRIX 
BI VISC 
CAR 
ACID 
PHEN 
BI/.degree.BRIX 
BI/CAR 
BI/ACID 
BI/PHEN 
__________________________________________________________________________ 
A 45 104 4.98 
54.0 
2.7 2.0 2.31 1.9 38.5 52.0 
B 45 44 5.7 22.0 
2.9 7.3 0.98 2.0 15.2 6.0 
C 35 96.5 
4.4 45.1 
2.0 -- 2.76 2.1 48.2 -- 
D 45 27.5 
5.7 22.8 
18.7 
8.6 0.61 1.2 1.5 3.2 
__________________________________________________________________________ 
BI browning index 
VISC viscosity (cps) 
CAR carbonyls (wt. %) 
ACID acids (wt. %) 
PHEN phenols (mg/ml) 
Two of the sample compositions A and C, have much higher browning 
capabilities when compared to sample D, as illustrated by the high 
browning index to .degree. Brix ratio compared to the low browning index 
to .degree. Brix ratio of sample D. 
Advantageously, samples A, B and C have very low levels of acids and 
substantially higher browning index values. These characteristics are 
preferred because acids may cause substantial degradation of the 
cellulosic casings when applied to nonfibrous reinforced cellulosic 
casings. It should also be noted that samples A, B and C have high 
browning index to carbonyl ratios compared to sample D which indicates 
that samples A, B and C have higher browning capabilities even if the 
amount of carbonyls is the same. 
Further, the high values for the ratio BI/PHEN indicate that samples A, B 
and C give a casing that does not impart an undesirable flavor. 
EXAMPLE 2 
In this example, two compositions useful to practice the present invention, 
samples A and B of Example 1, were first diluted and then partially 
neutralized by addition of sufficient amounts of solid sodium hydroxide to 
give samples designated A35, A35 N, B35 and B35-N, respectfully. Aliquots 
of sample A (500 g, 4.98 cps, browning index 104) and sample B (500 g, 5.7 
cps, browning index 44) from Example 1 were diluted with enough water to 
give a final browning index value of about 35 for both aliquots and were 
labeled as samples A35 and B35. Both diluted samples A35 and B35 were 
adjusted to a final pH value of about 5 by adding a sufficient amount of 
solid sodium hydroxide. During the addition of sodium hydroxide the 
temperature was maintained below 20.degree. C. by a water bath of ice and 
salt. The pH adjusted samples were labeled A35-N and B35-N. Viscosity 
values were obtained for the four samples; A35, B35, A35-N and B35-N. 
Viscosity values of the two neutralized samples were compared with the 
viscosity values of two tar-depleted products, G34 and G34-N reported in 
U.S. Pat. No. 4,717,576. Samples G34 and G34-N have nearly equal reported 
values of browning index when compared to samples A35 and B35. 
Table 2 shows browning index and viscosity for the diluted, neutralized 
compositions of the invention and known liquid smoke solutions. Large 
differences in viscosity are evident. 
TABLE 2 
______________________________________ 
Browning 
Product pH Index Viscosity* 
______________________________________ 
A35 3.0 35 1.3 
A35-N 5 35 1.5 
B35 2.9 35 3.3 
B35-N 5 34 3.7 
G34 2** 34** 95** 
G34-N 5** 34*** 197.5** 
______________________________________ 
*Values as cps at 25.degree. C. 
**Values from U.S. Pat. No. 4,717,576. 
***Values derived from U.S. Pat. No. 4,717,576. 
Known tar-depleted, concentrated, high acid content liquid smoke solutions 
exhibit a higher viscosity value after neutralization because of the 
presence of excessive amounts of alkaline salts of organic acids in the 
solutions. The high acid content of concentrated tar-depleted solutions 
prevents neutralizing those solutions to useful pH values and still retain 
acceptable viscosity values. For the liquid compositions, A35 and B35, no 
noticeable increment in viscosity was found after neutralization due to 
their low initial acid content. Thus, it is now possible to neutralize 
compositions having high browning index values without imparting 
undesirable high viscosity values to those compositions. 
Additional analytical data for neutralized liquid compositions useful to 
practice the invention are listed in Table 2A. To obtain the compositions 
listed in Table 2A enough base solution (50% sodium hydroxide) was added 
to the four samples of Example 1, samples A, B, C and D, to give a final 
pH value of 5.5.During neutralization the temperature was maintained below 
20.degree. C. After base treatment, the neutralized samples were adjusted 
to 35.degree. Brix by diluting with an appropriate amount of water. These 
samples were designated A35-N, B35-N, C35-N and D35-N and the properties 
of these samples are listed in Table 2A. 
TABLE 2A 
__________________________________________________________________________ 
COMP 
.degree.BRIX 
BI % CAR 
ACID 
BI/.degree.BRIX 
PHEN* 
BI/CAR 
BI/AC 
BI/PH 
__________________________________________________________________________ 
A35-N 
35 85.6 
43.4 2.2 2.45 1.07 2.0 38.9 
80.0 
B35-N 
35 32 15.4 2.4 0.91 3.62 2.1 13.3 
8.8 
C35-N 
35 93.1 
33.7 2.0 2.66 0.59 2.8 46.6 
158.0 
D35-N 
35 16.5 
12.5 12.5 
0.47 4.34 1.3 1.3 
3.8 
__________________________________________________________________________ 
BI browning index 
*PHEN phenols (mg/ml) 
CAR carbonyls (wt. %) 
ACID acids (wt. %) 
EXAMPLE 3 
Four nonfibrous frankfurter size gel stock cellulosic casings (1-4) were 
treated with four liquid compositions (A35-N, B35-N, C35-N and D35-N 
prepared in Example 2 having pH values of about 5.5) by applying these 
compositions to the external surface of the casings. The casings were 
passed through a tank containing each of the liquid compositions. The time 
of contact was regulated in order to control the amount of liquid 
composition absorbed into the casing. After dipping and doctoring off 
excess solution, the casings were dried and rehumidified to a water 
content of about 12 wt%. 
The four casings prepared were analyzed and the results are listed in Table 
3. 
TABLE 3 
______________________________________ 
Liquid Browning Organics 
Liquid 
Casing 
Composition Index Load Load BID 
______________________________________ 
1 A35-N 85.6 0.65 1.62 0.139 
2 B35-N 32 0.62 1.68 0.054 
3 C35-N 93.1 0.63 1.50 0.140 
4 D35-N 16.5 0.64 1.75 0.029 
______________________________________ 
Organics Load mg/cm.sup.2 
Liquid Load mg/cm.sup.2 
The results clearly illustrate that cellulosic casings treated with 
compositions A35-N, B35-N and C35-N of this invention have much higher 
values of BID than the casing prepared using the solution, D35-N, where 
all of the casings are loaded with essentially the same amounts of organic 
components. 
EXAMPLE 4 
This example shows additional advantages in casings treated with liquid 
compositions of the invention compared to casings treated with prior art 
liquid smoke solutions. A series of cellulose casings (5-8) were prepared 
using the liquid compositions A35-N, B35-N, C35-N and D35-N, prepared in 
Example 2 to give casing samples 5, 6, 7 and 8, respectively. The method 
of application was essentially similar to the method described in the 
Example 3 except that the time of contact of the liquid composition with 
the casings was regulated for each sample in order to get casings having 
essentially equal final BID values. Analytical data for the casings are 
listed in Table 4. 
These data illustrate that cellulosic casings of the invention, casings 
5-7, do not need to be loaded with excessive amounts of organic components 
to impart very good browning properties to the casings. The data also 
indicate that only about one-quarter to one-half of the load of organic 
components is needed to give approximately equal Browning Index Density 
values to the casings of the invention compared to casings treated with a 
known solution such as D35-N. This result is highly desirable because 
small casing loads do not detrimentally affect the physical properties of 
cellulose or cellulosic casings, but excessive loads may be detrimental. 
This advantage is believed to be related to two factors: the low amount of 
total acids; and the presence of more efficient browning carbonyls which 
are incorporated into the casing from the liquid compositions A35-N, B35-N 
and C35-N. This qualitative difference in the type of carbonyls of the 
exemplified liquid compositions provides the same or higher values of BID 
using lesser amounts of these compositions. 
Another advantage shown in this example is that the casings of this 
invention have an extremely high ratio of BID to phenols. Casings produced 
by this invention are very desirable when compared to casings treated with 
known liquid smoke solution because sausages prepared using casings 
treated with known liquid smoke solutions often have an undesired strong 
smoke flavor because of the high content of phenols in the casings. 
TABLE 4 
__________________________________________________________________________ 
CELLU- CAR/ 
PHEN/ 
ORG/ 
CAR/ 
ACIDS/ 
PHEN/ 
ORG/ 
Casing BID 
LOSE CAR 
ACID 
PHENOLS 
ORG BID BID BID CEL CEL CEL CEL 
__________________________________________________________________________ 
5 (A35-N) 
0.080 
2.88 0.22 
0.020 
0.0008 
0.37 
2.8 0.01 4.6 
0.08 
0.007 
0.0003 
0.13 
6 (B35-N) 
0.072 
2.91 0.25 
0.053 
0.0034 
0.83 
3.5 0.05 11.5 
0.09 
0.018 
0.0012 
0.29 
7 (C35-N) 
0.077 
2.83 0.22 
0.016 
0.0008 
0.35 
2.9 0.01 4.5 
0.08 
0.006 
0.0003 
0.12 
8 (D35-N) 
0.072 
2.98 0.52 
0.550 
0.0093 
1.59 
7.2 0.13 22.1 
0.17 
0.185 
0.0031 
0.53 
__________________________________________________________________________ 
Cellulose (mg/cm.sup.2) 
ACID acids (mg/cm.sup.2) 
BID browning index density 
CAR carbonyls (mg/cm.sup.2) 
ORG organics (mg/cm.sup.2) 
PHEN phenols (mg/cm.sup.2) 
EXAMPLE 5 
Sausages were produced with a casing of this invention or with a casing 
produced with another method. The sausages were prepared with the casings 
1, 2, 3 and 4 produced in Example 3. After the casings are dried, 
rehumidified and shirred, the four different casings were stuffed with a 
meat smulsion made using the formulation shown in Table 5. 
TABLE 5 
______________________________________ 
INGREDIENTS % (WEIGHT) 
______________________________________ 
Pork jowl 41 
Beef shoulder 40 
Sodium Nitrite and Nitrate 
0.024 
Salt 1.9 
Spices 0.5 
Water and Ice 16.6 
______________________________________ 
The casings were stuffed using conventional processes but without using a 
conventional smoking step. During the process, organic components 
transferred from the casing to the surface of the encased meat emulsion 
and these organic components reacted with proteins of the emulsion to 
develop a desired brown smoked color. After chilling the sausages, the 
casings were removed and the colorimetric parameters "L" (lighter color) 
and "a" (redder color) were determined for the resulting sausages using a 
DR. LANGE MICROCOLOR TRISTIMULUS colorimeter standardized with a white 
plate. For each of the different casings, 15 sausages were tested. Four 
colorimetric determinations were done on each sausage. A nonimpregnated 
cellulosic casing stuffed with the same meat emulsion and processed the 
same way was used as a control. The resulting data are listed in Table 5A. 
TABLE 5A 
______________________________________ 
L-L a-a 
Casing L (control) a (control) 
______________________________________ 
1 48.7 -9.9 19.0 6.1 
2 54.7 -3.9 15.2 2.3 
3 48.5 -10.1 18.5 5.6 
4 57.4 -1.2 13.6 0.7 
Control 58.6 -- 12.9 -- 
______________________________________ 
The data listed in Table 5A illustrate the advantages of this invention. 
Sausages prepared using casings of this invention (casings 1, 2 and 3) 
develop a very good brown color. Sausages prepared as described in the 
prior art (casing 4), although loaded with approximately the same amount 
of organics as included in the other casings, did not develop enough brown 
smoked color required to give an acceptable product. 
EXAMPLE 6 
It has been found that shirred nonfibrous cellulosic casings treated with a 
known liquid smoke solution prepared as reported in U.S. Pat. No. 
4,511,613 develop dark surface discolorations on the treated casing over 
time. The dark discolorations are appropriately called "black spots". 
These black spots represent a weakened area in the casing which is more 
susceptible to pinholing under stress as well as breakage during stuffing. 
It has been found that the areas of the black spots are contaminated with 
high levels of iron compared to the other areas of the casing. Casing 
deterioration may be experienced in a variety of stages from no visible 
damage to blister separation to actual holes at the site of these black 
spots. In addition, it has been observed that the black spots on the 
casing occasionally transfer to a food contained in the casing which 
adversely affects the aesthetic quality of the food. 
Various attempts have been made to prevent black spot formation when 
treating casings with liquid smoke solutions. Attempts have included 
careful processing conditions using cleaning devices for the various 
machinery process steps and solution cleaning using submicron filtration. 
These attempts to avoid or minimize iron contamination provide some 
improvement in reducing black spot formation during storage of liquid 
smoke treated casings, but they have not provided completely satisfactory 
results or eliminated black spot formation. Thus, there is a continuing 
need for a process and/or a composition to prevent the formation of black 
spots on liquid smoke treated food casings. 
To determine the propensity of cellulosic casings made by the invention for 
developing black spots, lengths of shirred casings were examined for the 
appearance of any discoloration after impregnation with the liquid 
composition of the invention compared to a known liquid smoke solution 
prepared as described in U.S. Pat. No. 4,717,576. Gel stock casings were 
passed through a tank containing each of the above solutions for a time 
period sufficient to provide adequate absorption of the solution into the 
casing. After dipping and doctoring off any excess solution, the 
impregnated casings were dried, rehumidified, rolled and shirred in a 
conventional shirring machine, Afterwards, five lengths of each of the 
impregnated casings were checked for black spots. The resulting data are 
listed in Table 6. 
TABLE 6 
______________________________________ 
Spots 
(average 
Liquid Load number/100 m 
Casing Comp. (mg/cm.sup.2) 
BID of casing) 
______________________________________ 
I A35-N 1.61 0.138 
0 
II D35-N 2.66 0.044 
35 
______________________________________ 
This example establishes that casings impregnated with a liquid composition 
according to the invention do not develop black spots, thus avoiding the 
likelihood of breaking during stuffing and the staining of a food 
contained in the casing.