Note: Descriptions are shown in the official language in which they were submitted.
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CAT FOOD COMPOSITION OF IMPROVED PALATABILITY
BAC:KrR(>UND OF THE INVENTION
1. Field of the Invention - Pet animals
This invention generally relates to a pet food composition and
particularly a pet food having increased palatability to cats.
2. Prior Art
Pet foods provide a convenient and popular means for assuring proper
feeding. White the art is well aware of the nutritional requirements of pets
and
is experienced in making rations which are batanced to provide complete
nutrition when eaten, the foods must be made sufficiently palatable for the
pet
tb assure that the ration is readily consumed in the required amounts. This is
especially important in disease management diets. The pet must eat the food
to benefit from its nutritional value and the pet owner will not buy a second
package if it is initially rejected by the pet. This is especially true if the
pet is
suffering from a loss of appetite as one symptom of a disease or disorder, the
food will not be fully consumed and consequently less than the recommended
ration wilt be eaten.
Pet animals, particularly cats, are notoriously fickle in their food
preferences and require a high degree of palatability. Dry pet foods are
widely marketed for cats. Generally, commercially sold dry cat food products
have a relatively low moisture content of less than about 12% by weight and
provide excellent nutrition. The lower moisture content permits a higher
degree of nutritional balancing of ingredients. Typically, the dry pet food
product is produced by extrusion techniques and is generally well accepted by
the cat but has the drawback that the product is significantly lower in
palatability than canned or high moisture products that contain meat and have
a moisture content above 50% by weight. One solution to the problem of low
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palatability of dry cat foods is to add a palatability enhancer to the food so
that
the cat will more readily accept the dry food product. In the pet food
industry,
materials such as animal origin digests, organic acids and their salts, and
different types of meat proteins are commonly used to enhance the
palatability of pet foods for cats. In spite of the effectiveness of these
materials, a need has continually existed for additives or ingredients that
can
be added to cat food products to further enhance the palatability of the
product without reducing its nutritive properties.
SUMMARY OF THE INVENTION
The present invention provides a cat food composition of improved
palatability wherein a palatability enhancing amount of a choline compound is
incorporated within, or applied to the surface of, the cat food composition.
The use of choline compounds to enhance the palatability of cat food
compositions has been found to be applicable to a wide range of commercial
cat food products, and particularly dry cat foods.
2O Choline compounds have not been considered as palatability
enhancers in the pet food industry although choline chloride has been
included internally in pet foods at levels up to 0.24% by weight as a
nutrition
supplement. As will hereinafter be demonstrated, when included internally at
such concentration levels, choline chloride has little or no effect on
palatability
enhancement in cat food.
Various methods of adding the choiine compound to cat food
compositions may be employed in accordance with the practice of the present
invention including: applying the choline compound uniformly mixed with
other ingredients of the cat food during manufacture so r!r:at the choline
compound forms a part of the basal food or topically applying the choline
compound as a coating to the surface of the food product after its
manufacture. Regardless of the method of addition, the presence of the
choiine compound, at levels appropriate for the manner of addition, provides
the maximum degree of taste sensor response from cats resulting in a
statistically significant enhancement in palatability.
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I?ESCRIPTION OF THE PREFERRED EMBODIMENTS
Choline is the trivial designation for the compound,
2-hydroxy-N,N,N-trimethylethanaminium. The term "choline compound" as
used herein means choline containing compounds including choline or
structural analogs of choline in combination with various anions. These
anions may include among others, any of the halides (fluoride, iodide,
chloride
and bromide) bitartrate, dihydrogen citrate, bicarbonate, and salicylate and
mixtures thereof. Specific examples include butyryl choline chloride,
phosphoryl choline, calcium tetrahydrate acetyl choline chloride/bromide,
iodide, cholic acid, cholic acid sodium dehydrate, choline bicarbonate,
choline
bisuifite, choline chloride phosphate, choline hydroxide, choline iodide and
choline betartrate. In a preferred embodiment, the choline containing
compound is choline chloride. Choline chloride at doses of 60 mg/day is
recommended by small animal nutritionists as a structural component of fat
and nervous tissue.
The term "palatability", as used herein, encompasses within its
meaning all of the various properties of the food sensed by the cat such as
taste and smell. The cat food compositions and methods of enhancing the
palatability thereof to which the present invention is intended to apply
generally relate to cat food compositions of any moisture content but
preferably a cat food prepared from a nutritionally balanced mixture of
proteinaceous and farinaceous ingredients having a moisture content of less
than about 75% by weight. It is presently believed, however, that the
palatability enhancer of the present invention is especially important for use
with dry cat foods, that is, foods having a moisture content of less than
about
12% because of their relative need for some palatability enhancement.
' The term "cat food composition", as used herein, is generally intended
to apply to commercially sold, nutritionally balanced cat food compositions.
Cat food compositions meeting this definition are characterized by a minimum
protein content since there is a certain minimum protein level required when
the cat food composition provides the sole food intake for the cat.
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Commercially sold dry cat food compositions typically have a minimum
protein content that is dependent upon the age of the animal to which it is to
be fed, or if the animal is mature, whether or not it is involved in breeding.
Thus, while females involved in breeding, or kittens would require a minimum
protein content of at least about 28% by weight and preferably about 30-35%
by weight on a 90% dry matter basis in the composition, cats not in either of
the above two categories, e.g., mature cats not involved in reproduction,
would require a minimum protein level of at least about 20% by weight based
on a 90% dry matter basis in the composition. Preferably, the protein content
will be at least 25% by weight and more typically at least about 30% by weight
on a 90% dry matter basis in the cat food product.
The cat food compositions of the present invention to which the choline
compound is added are not intended to be restricted by any specific listing of
ingredients since these will be entirely dependent upon the nutritional
balance
of the ration desired as well as their availability to the pet food
manufacturer.
Generally, aside from the nutrition balancing additives such as vitamins and
minerals, or other additives such as preservatives, emulsifiers, included in
products of this type, commercial pet food compositions for the most part
consist of ingredients that may either be termed substantially proteinaceous
or ingredients that may be termed substantially farinaceous. Although the
following description should not be considered limiting for the purposes of
the
present invention, the proteinaceous ingredient may be defined as any
material having a protein content of at least about 15% by weight whereas the
farinaceous material may be defined as having a protein content below about
15% by weight and a major fraction of starchy or carbohydrate containing
materials.
Examples of proteinaceous materials typically used in commercial pet
foods are: vegetable protein meals such as soybean, cottonseed, and
peanut; animal proteins such as casein, albumen, and meat tissue including
fresh meat; as well as rendered or dried animal "meals" such as fish meal,
poultry meal, meat meal, bone meal, and the like. Other types of
proteinaceous materials include microbial proteins such as yeast and other
types of protein such as wheat gluten or corn gluten.
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Examples of typical farinaceous materials are grains such as corn, rice
and wheat and various other grains which are relatively low in protein.
The chofine compound may be applied in accordance with the practice
S of the present invention, after manufacture of the cat food, in a
palatability
enhancing amount, to the surface of the cat food composition generally in an
amount of about 0.06% by weight or more and preferably about 0.12 to about
0.60% by weight based on the weight of the food composition and most
preferably about 0.24 to about 0.30% by weight. This level of choline
compound provides a significant palatability improvement over cat food
compositions of identical formulation to which the choline compound has not
been topically applied to the food product surface.
When admixed with the other ingredients of the cat food during
manufacture and present internally therein palatability enhancement, an
amount of choline compound of at least about 0.25% by weight or within a
preferred range of about 0.30 to about 0.60% by weight is included in the food
composition. When so incorporated within the food composition, it is critical
that at least about 0.25% of the choline compound is present for as will
hereinafter be demonstrated, when the choline compound is present
internally in the food product in lesser amounts, little or no palatability
enhancement is observed.
Aiso in accordance with the practice of the present invention, the
choline compound may be used in combination with other known palatability
enhancers. For example, phosphoric acid, coated onto the surface of a dry
cat food, has been shown to be a palatability enhancer. U.S. Pat. No.
3,679,429 discloses a method for improving the palatability of dry cat food by
coating the food with fat and one of the following flavor enhancing acids:
hexamic, tartaric, fumaric and lactic acids, phosphoric and citric acids. U.S.
Pat. No. 3,930,031 discloses improving the palatability of semi-dry and dry
cat
food by coating the food with a mixture of phosphoric acid and citric acid
wherein the coating provides at least 0.5% by weight phosphoric acid.
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The added acid also provides a preservative or antimycotic action,
inhibits spoilage due to contamination and acts as an alkaline buffer whereby
the choline compound is stabilized to decomposition.
Insofar as the application of the palatability enhancing amount of the
choline compound as a coating applied topically to the surface of the cat
food,
it is preferred to apply the choline compound as a dispersion with a fat
material such as choice white grease in order to provide a uniform
distribution
of the choiine compound on the food composition surfaces, thereby assuring
maximum availability to the taste receptors of the cat.
In one means of effecting the application of the choline compound to
the surface of a cat food composition, according to the present method of
enhancing the palatability thereof, food particles such as those of the
extruded type are transported while in a somewhat heated condition on a
suitable conveyer to a spray chamber or mixing drum or vat. If a dry product
is desired, the particles are first dried to a moisture level of below about
12%
by forced air. A mixture of the choline compound and melted fat is separately
formed in a mixing tank or metering pump by blending the requisite level of
fat
and choline compound which is then introduced to the spray chamber or
mixing tank. The fat dispersion containing the choline compound is then
sprayed on, or mixed with, the food particles to provide the desired level of
fat
and a palatability enhancing amount of the choline compound on the cat food
particles. Following coating of the food particles, the coated particles are
collected and then transported, if desired, to a tumbling drum or similar
apparatus wherein the coated particles are tumbled repeatedly to improve the
uniformity of the coating. The coated food particles can then be removed
from the tumbling drum and cooled to ambient temperature.
If it is desired to incorporate the choline compound within the cat food
product admixed with the other food product ingredients, the choline
compound is merely admixed with the other ingredients of the food
formulation preparatory to the manufacturing process as, for example, by
extrusion, baking or canning processes.
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Application of the choline compound to a food composition in a
palatability enhancing amount either as a surface coating or intimately
admixed with the other food ingredients results in significant palatability
response from cats in comparison to the same cat food composition without
the choline compound. A significant improvement in cat food formulation is,
therefore, achieved by the application of the choline compound since the
palatability of the composition to the cat is usually a controlling factor in
the
commercial success of such compositions.
Pursuant to a better understanding of the present invention, the
following Examples describe illustrative but non-limiting embodiments thereof.
EXAMPLE 1
1 S Cat Food Composition Formulation
Containing Choline Chloride
Admixed With Other Food Ingredients
An extruded cat food composition having a protein content of about
31 % by weight on a 90% dry matter basis was prepared by mixing 0.30% by
weight choline chloride and major amounts of animal by-product meal, fish
meal, brewers rice and yellow corn and minor amounts of yeast, cellulose,
fiber, salt (sodium chloride), vitamins and minerals.
The choline chloride was completely admixed with the other
ingredients before being extruded. The choline chloride was a commercial
feed grade of choiine chloride (60% purity). The ingredient mixture was then
transferred to a steam preconditioner and subjected to steam and moisture in
order to adjust the moisture content to between about 20 and 40% by weight.
The conditioned mixture was then extruded under conditions of elevated
temperature and pressure to form a continuous strand of product that was
segmented into pieces or kibbles by a rotating cutting knife upon exit of the
strand from the extruder. The particles were then conveyed to a forced air
drying system and the moisture level reduced to below about 10% by weight.
The dried, extruded kibbles were placed in a small cement mixer for mixing
with choice white grease which was heated to about 122°F. This mixture
was
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stirred for about 5 minutes to achieve a uniform coating. The so coated cat
food was then placed in polyethylene-lined bags and stored at room
temperature for about two days before being tested for palatability.
For purposes of comparison, the procedure of Example I was repeated
with the exception that 0.24% by weight choline chloride was admixed with
the other ingredients used to prepare the extruded cat food product.
The palatability of the two cat food products containing respectively
0.24 and 0.30% by weight choline chloride was measured using a palatability
test which determined the extent to which cats may prefer one pet food diet
over another pet food diet. In this palatability test two pan comparisons with
a
panel of 30 cats were used. Each cat was presented with two pans of food,
each containing a measured amount of the test rations which were more food
than the animal was expected to consume. The test was run for two days.
The amount of food consumed was measured. A direct comparison of
consumption of the two rations gives a reliable indication of relative
palatability. The direct comparison or mean intake ratio, for all animals was
made based on the intake ratio for each animal as follows: A/(A+B) where A
is the sum of the weight consumed from Pan A containing pet food to which
choline chloride had been added and B is the sum of the weight consumed
from pan B containing a commercially available dry cat food sold for mature
cats containing about 0.24% by weight choline chloride as a nutritional
supplement, which served as a control.
The results of the palatability tests are recorded in Table I below. The
higher the food intake ratio the greater the palatability of the food to the
cats
which participated in the test.
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TABLE I
Wt. % Choline Chloride
Added to Food Preferring Food Intake
Composition %* Ratio
0.24 23 0.35
0.30 68 0.63**
* % of cats preferring the food containing choline chloride over
the commercial cat food product which served as a control..
** p < 0.01 (Data is statistically significant to a confidence
level of 99%).
The results recorded in Table I indicate that the palatability of dry cat
food is significantly increased as compared to a commercially available cat
food when the concentration of choline chloride is raised from 0.24% to 0.30%
by weight levels.
EXAMPLE 11
Cat Food Composition Containing Choline Chloride
Incorporated In White Grease Surface Coating
The procedure of Example 1 was repeated, except varying amounts of
choiine chloride were added to the choice white grease coating applied to the
surface of the food particles.
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A commercially available dry cat food containing 0.24% by weight
choline chloride as a nutrition supplement, served as the control. The results
are recorded in Table II below.
5
TABLE II
Wt.
Choiine Chloride Added Wt.
to Food Composition Choline Chloride
in
in Coating Food Composition Preferring %* Food
Intake Ratio
0.06 0.30 67 0.56
0.12 0.36 57 0.50
0.18 0.42 60 0.58
0.24 0.48 80 0.74**
0.30 0.54 75 0.66**
0.54 0.78 73 0.68**
IO * % of cats preferring food coated
with chofine chloride over
the control food.
** p < 0.01
The results recorded in Table II show that when choline chloride is
1 S applied to the surface of cat food at concentration levels of 0.06% by
weight
or more, a substantial enhancement in the palatability of the food to cats is
observed.
For purposes of contrast, the procedure of Example II was repeated
except the commercial cat food, which contained 0.2% sodium chloride, was
coated with choice white grease containing varying amounts of sodium
chloride salt.
c
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The commercial cat food without salt addition to the white grease
coating was used as a control. The results are recorded in Table III below.
TABLE III
Wt. % NaCI Added to
Food Composition in Wt. % NaCI in Food
Coating Composition Preferring Food Intake
%* Ratio
0.10 0.30 40 0.47
0.40 0.60 25 0.42
0.70 0.90 18 0.25**
1.00 120 29 0.34**
1.30 1.50 8 0.19**
* % of cats preferring food coated with sodium chloride containing
choice white grease over the control food.
** p < 0.01
The results recorded in Table III indicate that saltiness induced by
sodium chloride salt significantly decreased the palatability of the cat food.
Thus, the palatability enhancement obtained from the use of choline chloride
is not attributed to any saltiness of the compound.
a
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EXAMPLE 11!
The procedure of Example II was repeated except inorganic acid such
as phosphoric acid (75.0% solution) and organic acids such as malic acid '
powder (99.9% purity), fumaric acid powder (99.9% purity), and ascorbic acid
powder (99.9% purity) were included in the choice white grease coating. A
commercial cat food containing 0.24% by weight choline chloride as a
nutrition supplement served as the control. The results are recorded in Table
IV below.
TABLE IV
Wt. % Food
Choline ChlorideCholine ChlorideOrganic Acids Intake
in in in
Coating (Wt.%)Food CompositionCoating (Wt % Preferring*Ratio
%)
0.06 0.30 0.00 67 0.56
0.06 0.30 0.40 phosphoric100 0.96**
acid
0.18 0.42 0.00 60 0.58
0.18 0.42 0.10 malic acid65 0.67**
0.18 0.42 0.10 fumaric 67 0,61 **
acid
0.18 0.42 0.10 ascorbic 75 0.67**
acid
* % of cats preferring grease coated food product containing
palatability enhancing agent in the coating over the control food.
** p<0.01
The palatability data recorded in Table IV indicates that the food
composition surface with a combination of choline chloride and organic acids
or inorganic acid were preferred to a greater degree by cats than the food in
which organic acids were absent from the coating.
