CA1144808A - Pet food of improved acceptability - Google Patents

Abstract

PET FOOD OF IMPROVED ACCEPTABILITY ABSTRACT The object of the invention is to provide a pet food of improved acceptability. Pet foods, no matter how nutritious, must be palatable for the pets to receive the proper nutrition. This invention provides a pet food of improved palatability by the use of bile palatants selected from the group consisting of bile pigments, bile acids, the soluble salts and lower alkyl esters of the acids and any combination of these. The bile palatant is employed in any effective amount, usually from 0.004 to 0.2 wt. percent, on dry, intermediate-moisture, or canned pet food.

Description

~ESCRIPTION

PET FOOD OF IMPROVED ACCEPTABILITY

Technical Field The present invention relates to pet foods, and 05 particularly to pet foods having additives which make them more acceptable to the intended pets.
There is a continuing problem in making pet foods acceptable to pets. Wh:ile the art is well aware oE the nutritional requirements of pets, foods formulated for them must be made sufficiently accept-able -to asswre that they are consumed so that the pet can take advantage of their nutritional benefits.
Backgrownd Art The use of additives to increase the acceptance of pet foods is well established in the prior art.
For example, U.S. Patent No. 3,857,968 to G.~. Hass et al, discloses incorporating into an animal food an effective amount of a palatability improving composition comprising fat and protein which has been conditioned by emulsifying the fat and trea-ting the mixture with an enzyme mixture comprising lipase and protease. The exact reason for the improvement in palatability obtained according to the disclosure of that patent is not :Eully unclerstood; however, it .

, 8~3 is noted that the starting materials are typical dietary components, and the enzymatic reactions which they undergo may heighten their natural attractiveness.
05 Similarl~, in U.S. Paten-t No. 3,745,023, to Greenberg et al, it is disclosed that a specially treated fat preparation can improve palatability when applied to pet foods. The patentees suggest that a high concentration of ~ree ~atty acids in the fat promotes pal~-tability. Also sug~estive of specific -types of certain combinations of additive materials are ~ni-ted Kingdom Patent Specification 1,293,378, and Netherlands Patent Publication 73-1364~. ~he United ~ingdom patent discloses a synergistic mi~-ture of squalene 3 oleyl alcohol, oleic acid and linoleic acid for improving the acceptability of livestock and pe-t foods. The Netherlands patent p~lblication discloses that spec-ific free fatty acids, caprylic and caproic acid, 2Q improve the aroma of dog foods.
Most of the pet food acceptability enhancers known to the art turn out, a~ter their identifica-tion as such, to be components or derivatives of necessary dietary components for the particular animals involved.
Disclosure of Invention In accordance with the present invention an improved, nutritionally-balanced pet food is pro-vided which comprises fat, protein, carbohydra-tes, vi-tamins and minerals, wherein the improvement comprises: an amount of bile palatant selected from the gro~lp consisting oE bile pigments, bile acids, the nontoxic salts ancl lower alkyl esters o-~ the bile acids, and combinations o any of these, the ~,' ~' ~
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' amount being ef-~ec-tive to increase -the palatabili-ty of the pet food for the intended specie.
The term "pet" as used in this descrip-tion, means small to moderate-sizecl carnivorous animals, 05 normally domesticated and maintained as ho~sehold companions. Particularly, the invention is directed to the improvements of foods especially formulated and nutritiona]ly balanced for dogs and cats. While those skilled in the ar-t are aware of the various nutritional requirements for the particular species as well as the particular stage in the life cycle for a particular animal, the present description will exemplify dog foods intended for normal adult dogs.
The term palatability is broad and encompasses all of the various properties of pet foods, sensecL
by the consuming animal which determine the overall acceptability of the food. Among these properties are -texture, taste and aroma. I-t is believed that the present invention increases palatability as a whole, primarily through improving the taste of the food.
The broad class of the bile pigments, bile acids and the nontoxic salts and lower alkyl esters of -the acids which are included within the scope of the present invention, will be referred to gener-ically as bile palatants. It is to be understood that while these compounds are believed useful as a group for improving the overall acceptability of pet foods, not each and every compound will be effective at all levels for improving the palatabilit~ in all varieties of ~oods for all species of pets. However, given the broad teaching of the invention of the new class of palatants, and the specific e~amples set forth below, the person of ordinary skill in the art ., ' ., , ' ,' ' . - ;

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will be readily able to optimize composi~ions within the broad descrip-tion of the invention for part-icular purposes.
Specifically identified as useful palatants 05 according to the present invention are bile pig-ments, bile acids and their non-toxic salts and lower alkyl esters. Among these are bilirubin, biliver-din, cholic acid, dehydrocholic acid, deoxcholic acid, glycocholic acid, li-thocholic acid, chenodes-oxycholic acid, glychochenodesoxycholic acid, tauro-cholic acid, taurochenodesoxycholic acid, and -tauro-desoxycholic acid. Preferred among the nontoxic salts of these acids are the water soluble salts and par-ticularly the sodium and potassium salts. Among -the es-ters preferred according to the present inven-tion are those lower alkyl esters containing from one to five carbon atoms i.n the alkyl component.
Particularly preferred esters are the methyl and ethyl esters.
Among the more preferred materials for use in dog foods are bilirubin, desoxycholic acid and its sodium salt of-ten referred -to as sodium choleate, glycocholic acid and its sodium salt, lithocholic acid, and the methyl ester of cholic acid. These materials can be selected or prepared from any suitable source. Biles from oxen, cattle, sheep, swine, and the like are suitable. It is -to be understood that the terms bile pigment and bile salts include the extracted, purified and conjuga-ted forms of these materials. Thus, o~ bile for instance is available as a dried extract and contains sal.ts oE the bile acids in normal~y conjugated form. It should be cautioned, however, that the method of recovery or preparation of pure or synthetic com-pounds can alter the effectiveness of the compounds ': :

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in improving pala-tabilit~ of a pet food. ~t has been no-ticed, -for example, that synthetic glyco-cholic acid from at least one commercial source is not effective under -the same conditions of use that 05 naturally derived glycocholic acid is.
The bile palatants identified by the present invention can be employed in any amount which is effective to improve the palatability of the food for the particular specie of pe-t for which it is formulated. No attempt is made here to establish a range of concentrations of universal applicability for all different types of pet foods for serving under all different types of conditions to all different types of pets. It is believed that levels within the range of from about 0.001% up to abou-t 0.5% can be employed with effectiveness, depending on the method o:E application, the type of food and the intended specie of pet. Levels of from abowt O.OOl~% to about 0.2% based on the total weight of the food are preferred, and levels of from about 0.01% to about 0.15% on the same basis are most preferred, for dogs when surface coated onto or blended into the food. This range is considered preferred only for those materials tested in dog foods. Effective levels for at least some of the materials identified by this invention will be outside of this range. For example, a dog food containing 0.1% taurocholic acid showed a loss in palatability to a control product when fed to dogs in one screening study listed in Table 3, but a cat food containing -taurocholic acid was preferred to a control product when fed to cats.
The bile palatants are incorporated into -the desired food products in any sui-table manner. In testing already conducted, it has been found that , . . .

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-they can be coated onto the exterior of a food or intimately mixed with the food ingredients prior to -final formulation. Those skilled in the art will understand that by placing the bile palatant on the 05 surface of the foods it will increase its impact as compared to a product having it incorporated into the interior of the product. Thus, spraying onto the surface of the pet food is the preferred manner of applica-tion ~here this type of processing step is compatible with the overall processing of the pet focd involved.
It may be necessary to dilwte the bile pala-tants with a suitable ma-terial prior to application by spraying. The diluent can be either a liquid or a solid component which is compatible with the food.
Thus, it can be employed as part of a powderous, emulsified, or other coating such as those which are normally applied to the surface of a dry dog or ca-t food.
~here it is desired to employ it by mixing into the interior of the pet food, it is again simply accomplished in a manner compatible with normal processing. And, if experience shows that the particular method of additon causes -the presence of unduly exaggerated concentra-tion due to improper mixing, it may be desirable to dilute the mixture.
The bile palatants identified according to the present invention can be employed on pet foods of all varieties. Because providing nutrition for the intended pet is of overriding concern, it is impor-tant to formulate all pet foods such -that they are nutritionally complete for the intended animal. By nutritionally balancing each individual food in this manner, it is not then necessary for the pet owner .: :
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to balance the quantities of different foods supplied.
Th~ls, the nutritiQnal intake of the pet is assured so long as it intakes a minimum amo~mt of food.
Nutritionally-balancecl foods will contain protein, 05 carbohydrates, fats, vitamins and minerals in the amounts established by feeding tests to be sufficient for the proper growth and maintenance of animals of the intended specie.
The bile palatants identified according to this lQ inven-tion can be employed in dry, intermediate-moisture or canned pet foods. The dry pet foods contain less than 15% moisture, and will typically have a dry, crunch texture due to the maintenance of the moisture belo~ about 8%. The intermediate-moisture foods 15 wi] 1 have moisture above 15% and less than about 50%~ and will typically have a soft -texture with moisutre contents in the range of from 20 to 30%.
The canned ~oocls have moistures above 50% and typi-cally above 70%.
Typical of the dry pet foods are those disclosed in U.S. Patent No. 3,119,691. ~isclosed in this patent is a dry pet food having a gravy-forming coating thereon. It is clesirable to include the palatant in the gravy-forming material such that it will disperse within the gravy in the serving bowl.
Also suitable for incorporation of the bile palatants are the intermediate-moisture pet foods of the type disclosed in U.S. Patent No. 3,202,514 to Burgess et al. In preparing these types of pet foods, the palatan-t can be either mi.xed intimately during the process prior to extrusion or can be coated on the exterior thereof. The palatants identified according to the present invention can also be employed in co-nventional canned pet foofls by adding in an~
suitable manner.

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Best Mode For Carrying Out The Invention The following examples set Eorth the best mode for carrying out the invention. These examples are intended to aid in describing the present invention 05 to those skilled in the art and are not to be taken as limiting in any regard. Unless otherwise in-dicated, all parts and percentages are by weight.
E~ample I
According to -this example, a dry clog food formulated for a normal adwl-t dog is processed to improve its acceptance by normal adult dogs by incorporating into it, as a portion of a at coating, a small but effective amount of a mi~t~lre of conju-ga-ted salts of cholic and desoxycholic acids sold co~ercially as "Bileg Extract, Ox, N.F.XI" by Inolex Corporation of Glenwood, Illinois. This bile produc-t, now identified as a bile pala-tant according to the present invention, is described by the manu--facturer as the dried fraction from o~ bile soluble in 80/~ alcohol, which contains chiefly the sodium salts of cholic and desoxycholic acids, conjugated with taurine and glycine. According to analysis, it contains a minimum of 45% by weight of cholic acid, shows a maximum loss on drying of 5% and contains a maximum of 0.1% by weight of substances which are insoluble in 80% alcohol.
As the base dog food, an uncoa-ted, extruder-kibbled product is employed.
This formulation is prepared and processed in the manner described in the aforementioned ~.S.
Patent No. 3,119,691 except that the coating taught therein is omitted. To prepare a test food coating containing a bi'le palatant according to this inven-, ,; .

tion, 0.01% of ox biLe and ~1% of bleachable fancytallow, both percen-tages based on the total weight of -the food, is blendecl and then sprayed onto the kibbled dog food as it is tumbled in a ro-tating 05 drum. A control prodllct is also prepared in the same manner but without the ox bile.
Two formula-tions prepared in -this manner were fed -to a panel of 30 dogs for two da~s an~ the results shown in Table l were recorded:

Food Preferred No. of By No. of Dogs Days From Panel of 30 15 Example I-Test Food 2 21 Example I-Test Food 1 ~ 3 ~o Preference 1 J
Example I-Tes-t Food 1 ~ 4 Control Sample 1 ~7 20 No Preference 2 2 Control Sample 1 ~ 0 No Preference 1 J
Control Sample 2 0 The above results show a clear cut preference :Eor the produc-t prepared in accordance with the present invention.
EXAMPLE II
Another test dog food sample was prepared and tested in the same manner as set forth in Example I
above wi-th the only change being that the test product made in accordance with this invention contained 0.1% ox bile based upon the weight of the total food. The results oE the testing, with those for one dog which spilled its food eliminated, are as :Eollows:

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Food Preferred No. of By No. of Dogs 05 Days From Panel of 30 Example II-Test Food 2 9 Example II-Test Food 1 ~ 6 No Preference 1 ~
Example II-Test Food 1 ~, 8 10 Control Sample 1 No Preference 2 Control Sample 1 ~ 4 No Preference 1 >
. Control Sample .: : 2 Again here, the da~a show a marked improvement in the acceptability of -the dog food when prepared in accordance with the present invention.
EXAMPLE III
According to this example, bile palatants are employed in an intermediate-moisture dog food form-ula-ted for normal, healthy adult dogs. In preparing the food, the following ingredients were finely chopped and slurried in accordance with -the procedures set forth in the co-pending Canadian Application Serial ~o. 337,791, filed on October 17, 1979.

Ingredient Parts By Weight Beef Tripe and Trimmings 36.5 Soy Grits 32.S
30 Sucrose 17.
Propylene Glycol 5.2 Corn Syrup 3.0 Phosphoric Acid (86%) 0.26 Soy Protein Isolate 1.9 35 Dried Whey 1.0 Ingredient Parts By Weight Iodized Salt 1.25 Monocalcium Phosphate 0.9 Calcium Carbonate 1.0 05 Soybean Hulls 2.2 Sodium Carboxymethylcellulose 0.. 5 Mono- and Di-Glyceride Emwlsifier 0.5 Flavor, Color, Vitamin and Mineral Suppl. .~
Po-tassium ~orbate 0.17 10 Bile Pala-tant (Table 3) Of these, -the meaty materials (the tripe and trimmings), propylene glycol, potassium sorbate, sodium chloride and phosphoric acid are mixed to form a slurry. The meaty materials are first ground frozen through a ~.95 cm hole die on a ~lobart grinder.
The ground meats are then placed in a small ~LBaker-Perkins sigma bladed mixer and the other noted materials are added to form a meaty slurry. The bile palatan-ts listed in Table 3 are added -to sep-2a arate samples of slurry in the amounts shown inTable 3. The mixing was varied within the range of from one to four hours, but this did no-t appear to impact the results.
The dry ingredients are separa-tely blended and then mixed in a ~LDay cooker equipped with sigma arm mixer, wi-th the meaty slurry. The combined ingre-dients are then heated at about 82C for about 15 minutes to provide the necessary heating for pasteur-ization.

~Trademark Upon exiting the cooker, the pasteurized material is cooled by air at about 20~C to a temperat~re of 25C. The coolecl extrudate is then shaped in a Bonnot~ extruder fitted with a die plate having O.~cm - 05 diameter holes. The formed product is then heat sealed in polypropylene film ba~s.
The separate samples prepared in this manner with the specific bile palatants are employed as test portions. Each of the test protions was com-pared to a con-trol portion not containing a bile pala-tant. The total food consumed and the clif-ference between the test and the control samples were noted. Based on feeding tests the results shown in Table 3 were obtained, ~here the conclusion indicates how the -test product compared to the control (preference, no preference, or loss):
Table 3 Palatant Bile PalatantForm in Slurry Conclusion (Wt. %~

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Glycocholic Acid Na Salt O.l Preference Glycocholic Acid Na Salt O.Ol Prefer~nce Sodium Choleate Na Salt 0.1 Preference Bilirubin Pigment O.Ol Preference Lithocholic Acid Acid O.l Preference Cholic Acid Methyl Ester Ester O.l Preference ~esoxycholic Acid Acid O.l Preference Cholic Acid Acid O.l No. Pref.
Dehydrocholic Acid Acid O.l No. Pref.
Chenodesoxy-cholic Acid Acid O.l Loss Biliverdin Pigmen-t O.Ol Loss Taurodesoxy-cholic Acid Acid O.l Loss Taurocholic Acid Acid O.l Loss Glycocholic Acid Acid O.l I.oss ~0 ~Synthe-tic) Trademark ., .

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The above descrlption is for the purpose of teaching those skilled in the ar-t how to practice - the present invention and is not inte-nded to recite all the possible modific~tions and variations thereof 05 which will become apparent to the skilled worker upon reading. It is intended, however, that all such modifications and variations be included within -the scope of the invention which is defined by the following claims.

Claims (8)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a nutritionally-balanced food for dogs and cats comprising fat, protein, carbohydrates, vitamins and minerals, the improvement which comprises: an amount of from about 0.004 to 0.2% based upon the weight of the food of bile palatant selected from the group consisting of ox bile, bile pigments, bilirubin, bile acids, cholic acid, desoxycholic acid, non-toxic salts of bile acids including the sodium and potassium salts, the lower alkyl esters of bile acids, and combinations thereof, effective to increase the palatability of the food.

2. In a nutritionally-balanced cat food comprising fat, protein, carbohydrates, vitamins and minerals, the improve-ment which comprises: an amount of from about 0.004 to 0.2%
based upon the weight of the cat food of bile palatant selected from the group consisting of bile acids, bile pigments, the non-toxic salts and lower alkyl esters of the bile acids, and combin-ations of these, which is effective to increase the palatability of the cat food.

3. In a nutritionally-balanced dog food comprising fat, protein, carbohydrates, vitamins and minerals, the improvement which comprises: an amount of from about 0.004 to 0.2% based upon the weight of the dog food of bile palatant selected from the group consisting of ox bile, cholic acid, desoxylcholic acid, bilirubin, the sodium and potassium salts of the acids, the lower alkyl esters of the acids, and combinations of any of these, which is effective to increase the palatability of the dog food.

4. A nutritionally-balanced food according to claim 1, 2, or 3, having a moisture content of less than 15% by weight.

5. A nutritionally-balanced food according to claim 1, 2, or 3, wherein the moisture content is between about 15 and about 50% by weight.

6. A nutritionally-balanced food according to claim 1, 2, or 3, having a moisture content in excess of 50% by weight.

7. A nutritionally-balanced dog food according to claim 3, wherein the bile palatant comprises glycocholic acid, or a soluble salt or a lower alkyl ester thereof.

8. A nutritionally-balanced dog food according to claim 3, wherein the bile palatant comprises ox bile.