CA1077331A - Casein replacement in semi-moist pet foods - Google Patents

Abstract

ABSTRACT
A semi-moist pet food having the appearance and texture of meat includes an unmodified starch, a polyhydric component, and a vegetable protein; and optionally a water binder, an edible acid or a soluble phosphate, in a combina-tion to replace at least part of the casein or casein deriva-tives in a semi-moist pet food.

Description

~ ~ i'73~1l This invention relates to a ~ood and more particu-larly to a mea~-like textured pet food having at least part of the casein or casein derivative binder replaced with a compo-sition comprising an unmodified starch, a polyhydric component, a vegetable protein, and optionally an acid, or a soluble phos-phate and a water binder.
Within the class of foods known as pet foods, there are three basic subdivision: 1) dry pet food containing up to 15 percent moisture, 2) semi-moist pet food usually containing about 15 percent to 50 percent moisture, and 3) moist pet foods containing above 50 percent moisture. The moisture is deter~
mined by considering both the water present in the final pro-~ duct and the water combined with the various components that -~ make up the final product. In general, the dry pet food tends to be the most stable and requires no special handling or pack-aging upon distribution. The semi-moist pet food tends to be less stable than the dry pet food and re~uires a more careful packaging system. However, the semi-moist pet food re~uires no refrigerated storage, and tends to be microbiologically stable due to the presence of various stabilizing agents. The moist pet food requires stringent canning conditions. In fact, the moist pet food is canned and sterilized by retorting in the usual manner. When the can is opened, the pet food not con-sumed must be refrigerated to preserve it. Thus, it may be seen that the dry pet food is the most stable pet food; the semi-moist of medium stability and the moist of lowest stabili-ty after the respective packages are opened. When considering ., '.' ' ' ' ' ~37~733:1 palatability, generally speakiny the moist pet ~ood tends to be the most palatable and the dry pet food tends to be the least palatable. The semi-moist pet food falls somewhere in between the moist and the dry pet food as to palatability.
It follows that both as to palatability and stability the semi-moist pet food ranks in between the dry and the moist pet food. This ranking permits the semi-moist pet food to provide both shelf stability and palatability. In other words, a pet owner using a semi-moist pet food has fewer problems storing a pet food which his pet will eat.
The advantages of a semi-moist pet food thus become obvious. In semi-moist pet foods and other processed foods, casein and casein derivatives such as sodium caseinate provide a highly suitable material. This material is both a good binder, and a good extrudable material. Furthermore, this ma-terial has such a high protein content, that it is used as a standard for determining or measuring protein ~uality of other protein-containing materials. So, in addition to the process-ing advantages of using sodium caseinate, there is also a nutritional advantage due to the protein provided thereby. It thus becomes obvious why this material is so widely used in the food processing art and especially in the pet food art.
However, the pricing of casein and derivatives thereof such as sodium caseinate are very high due to the economic conditions.
This price is so high, that it is economically unfeasible to use the current amounts of casein in pet foods. It follows that it is desirable to develop a replacement for at least . .

~ . .

~t37~33~

some of the casein in ord~r to reduce product cost.
The unique qualities o casein salts such as for example, sodium, calcium, magnesium, ammonium, and potassium caseinate render them difficult to replace. Not only must the replacement provide protein and processability, the appearance and flavor of the product must be substantially maintained. For example, it is customary to extrude semi-moist pet foods. Speci-; fically, semi-moist pet foods containing caseinate derivatives are easily extrudable. It follows that the replacement for this component should also provide easy extrudability for the product in order to avoid substantial changes in machinery and manufacturing equipment. The protein level of the replacement must remain high and the palatability of the product containing the replacement must remain substantially the same.
Furthermore, in the pet food area, meat is an acceptable food, both to pet owners and pets. Pets of the carnivorous type, and pet owners prefer high quality meat over other types of food especially from an appearance standpoint. However, meat is ex-pensive, not completely nutritious, and not customarily used to feed pets. Several replacements or substitutes for meat are on the market and available for use to feed pets. The most success-ful pet foods have the appearance and texture of meat while not actually using the expensive cuts of meat. An example of a marbled meat pet food is found in either U.S. Patent 3,380,382 to Bone or U.S. Pa~ent 3,765,902 to Charter. Each of the cited patents discloses a marbled meat pet food that is highly success-~C~7'733~

ful on the market and has a proven nutritional value or pets.
A key ingredient in the pet foods disclosed in the patents cited is sodium caseinate or similar ingredient. This inyredient per-mits the formation of a marbled meat-type structure that has both the texture and appearance of meat. In this ashion, it is possible to replace the more e~pensive pet food consisting of meat with a product e~ually as acceptable and equally nutri-tious. Casein and its derivatives provide not only an excellent source of protein, but are also excellent binders for the meat-like product as formed in an extrusion/cooking process. Inaddition to the physical properties o~ casein and its deriva-tives (hereafter casein), another advantage has been the cost of the product. With casein, it has not only been possible to duplicate the texture and appearance of meat, it has also been possible to provide the product at a low cost. Thus, casein or its derivatives have provided a product that is both good and inexpensive. This contribution to the pet ood art is sub-stantial.
Thus it may be seen that while availability has made casein and its derivatives an unacc~ptable component of a pet food, it is nevertheless difficult to completely replace a pro-duct component providing so many advantages.
Therefore, it is an object of this invention to pro- "
vide an improved pet food of the semi-moist category.
It is a further object of this invention to provide a palatable, semi-moist pet food.
It is still a urther object o this invention to pro-?

~77331 vide an improved pet food having the caseinate or casein bindertherein at least partially replaced with an e~uivalent bindex~
It is also an object o~ this invention to provide an improved pet food having good processability.
A further objact of this invention is to provide an improved pet food having a high nutritional quality Another object of this i~vention is to provide an improved nutritional pet ~ood.
These and other objects of the invention are accomp-lished by replacing at least part o~ the casein or casein deri-vative binder in a pet ~ood with a starch, vegetable protein and a polyhydric component; and optionally an acid, or soluble phosphate and a water binder.
An acceptable meat type pet food is provided by re-placing a part of sodium caseinate or other casein derivative in the meat type pet ~ood with a composition including starch, a polyhydric component, and vegetable protein, and optionally an acid, water soluble phosphate, or a water binder.
The composition of this invention is suitable ~or use 20 in any type o semi-moist pet ood. This composition is suit- `
able for use in a single color pet ~ood or a multicolor pet food. Color is merely a matter o~ choice, which is ad]usted by adding various edible coloring agents to the pet food. Such coloring agents are well known in the art. Furthermore, amounts of coloring agents are easily determined. In this manner pet ~oods having one or more colors are made and blended.
A highly successul semi-moist pet food is disclosed 7733~

in U.S. Patent 3,380,832 to Bone and U.S. Patent 3,765,902 to Charter, these patents produce a solid, semi-moist, marbled meat-like pet food. The marbled meat-like pet food is a multi-color pet food. The product produced by the method disclosed therein is highly acceptable as a pet food. The method and product disclosed therein are substantially the same as the method and product disclosed in this application. The major improvement of this application over the cited patents and over other semi-moist pet foods is the replacement of the caseinate binder or casein binder in whole or in part, to make a more readily available and lower cost binder which approaches the acceptability of the product using the casein or derivative binder. Many components make up a semi-moist pet food. But it is necessary to discuss only a few in ~iew of the incorpor-ated patents.
A major constituent of the semi-moist pet food is meat or meat by-products. By "meat" is meant the flesh of cattle, swine, sheep, goats, horses, whale, and other mammals, poultry and fish. The term "meat by-products" includes such constituents as are embraced by that term in the Definition of Feed Ingredients published by the Association of American Feed Control Officials, Inc. The animal food of this invention com-prises about 5 percent to about 50 percent by weight meat by-products or meat. Hereafter, the term "meat" includes both meat and meat by-products. Various types of meat can be mixed to form the meat portion of this animal food. Various mixtures .
': . ;

1~7733~L

of meat adjust the flavor o~ the animal food. ~n acceptable range of meat for this animal food includes 10 to 40 percent.
The preferred range of meat for this product is from about 15 percent to about 35 percent by weight of the total product.
The preferred meat by-products vary in color according to the desired product color but include beef tripe, beef intestines, partially defatted beef -tissue, partially defatted pork tissue, and other light color by~products; and also beef liver, pork liver, beef lungs, pork lungs, and other red meat by-products.
Mixtures of meat and meat by-products are also usable. Meat and bone meal is also usable for protein.
The moisture content of this product is about 15 per-cent to about 50 percent by weight, or more preferably 20 per-cent to 40 percent. The moisture is provided in any suitable fashion -- either by components of the product or water in any combination. For example, the meat or meat by-products contain a substantial amount of moisture and provide a portion or all of the moisture suitable when used in the product. Water can also be used to provide the moisture content of the product in whole or in part.
Sugar is also another component of this particular pet food. Typical sugars used are sucrose and corn syrup.
By "sugar" is meant any edible sugar used in the food art.
Substantial examples of suitable sugars for use in the food art are listed in U. S. Patent 3,202,514 to Burgess, et al.
A suitable amount of sugar for use in this product ranges from about 0 percent by weight 7~31 to about 35 percent by weight of the final product~ The pre-ferred range of sugar for use in the composition ranges from 10 percent to 30 percent by weight. The sugars are used singly or in any reasonable combination~
Other various additives are includable in the semi-moist pet food. Various water binders are suitable for use.
Typical water binders include starch flour products. Also cellulosic products are suitable for use. Typical examples of these products include wheat feed flour and carboxymethylcellu-lose. Other examples include corn derived materialO Eowever,almost any pregelatinized flour, cereal meal, or starch aids in the water absorption which provides suitable dough viscosity.
At least one water binder is used in the dough to form the pet food of this invention.
For flavor and nutritional purposes a variety of salts may be added to this pet food. Typical salts suitable for use in this invention include dicalcium phosphate, iodized salt, salt, potassium chloride, and other suitable edible salts. These salts are present in the semi-moist pet food in an amount up to about 7 percent by weight of the pet food.
Various other common additives from 0 to about 25 per-cent may also be added to the semi-moist pet food. Fat is us-ually added in an amount from 0 to about 12 percent by weight of the final product depending on how much fat is naturally contained in the meat or mPat by-products used. The fat may be of either animal or vegetable originO A preferred fat for use in this pet food is an animal fat exemplified by prime steam ~7733~
lard, tallow, and choice white ~rease. Vitamins, mineral~, colorings, and ~lavors are generall~ present in the pet food in the amount of about O to about 6 percent for the purpose of nutrition and overall appearance.
The stabilizer system for the semi-moist pet food of this invention comprises at least one polyhydric alcohol, at least one antimycotic, and optiona:Lly one edible acid. The sugar as above defined also contributes to the stability of the pet food. The antimycotic is generally an edible antimicrobiol acid or acid salt present in the pet food in an amount of less than or equal to 1 percent by weight of the pet food. Typical edible acids and their salts suitable for antimycotic use in-clude benzoic acid, benzoates, parabens, propionic and propion~
ates, acetic acid and acetates, and sorbic acid and sorbates.
An especially preferred antimycotic is potassium sorbate. A
typical polyhydric component suitable for use in this invention is disclosed in U. S. Patent 3,759,714 to Burkwall above-refer-enced. Preferable polyhydric alcohols are propylene glycol and 1,3-butanediol used individually or in combination. Up to about 10 percent by weight of the semi-moist pet food is the polyhydric component.
As above-indicated, the critical ingredients for form-ing a suitable casein or casein derivative (hereafter use of one term includes both terms) replacement in a pet food are a starch, a polyhydric component, and a vegetable protein. Optional com-ponents include a water binder or a texturizing agent such as an acid, phosphate, or mixture thereof to add to the other com-733~ponents to make a suitable replacement.
The starch which is preferable for use in the casein replacement is an unmodified starch. Basically, for the un-modified starch no chemical reaction or other treatment of the unmodified starch is necessary ~o prepare it for use as a re-quired component in this product. Of the unmodified starches suitable for use, examples include but are not limited to corn starch, corn flour, and wheat flour. Corn starch appears to have the best results for sodium caseinate replacements.
Generally speaking, about 4 to about 25 percent by weight starch based on the weight of the pet food is included in the pet food to achieve the proper setting capability. Preferably, about 5 to about 20 percent by weight starch based on the weight of the pet food is included in the pet food to achieve the proper set-ting capability. Preferably, about 5 to about 20 percent by weight starch i9 used in the pet food. Most preferably, about 6 to about 18 percent by weight starch is used in the pet food to allow the proper set up of the semi-moist pet food. This weight range of starch also allows a proper set up of the marbled meat product while at the same time permitting retention of softness and pliability of the product with age.
Modified starches also provide the desired product texture but are in general, less readily available than unmodi-fied starchesO
By modified is meant a chemical or physical treatment of the starch. l~pical chemical treatments include but are not limited thereto acid, base, enzyme or combinations thereof.

~ 10 -. ~ .
;'. .' ' ' . ~ ~

~07~^~33~
Physical treatments include gelatinization thereof and other suitable treatments, Thus modifled starches are operable, but un-modified starches are preferred.
A polyhydric component is also suitable for use to pro-vide the plasticizing capabilities generally associated with caseinate in addition to stabilizing function. Typical polyhy-dric components are the polyhydric alcohols listed in U. S.
Patent 3,759,714 to Burkwall. The polyhydric components are used singly or in mixtures. Of the polyhydric alcohols used, propylene glycol and l,3-butanediol are preferred for this in-vention. Propylene glycol is the most preEerred because of its stabilizing capabilities being combined with more suitable tex-ture, plasticizing capabilities, cost, and availability. In other words, while the propylene glycol contributes both to the microbiological and bacteriological stability of a semi-moist pet food, the prime function of the propylene glycol and other polyhydric components in this particular instance is to provide the plastic mass upon extrusion normally associated with casein or casein derivatives. About 1 to about 15 percent by weight polyhydric alcohol based on the weight of the pet food is used.
More preferably about 3 to about 12 percent by weight of the polyhydric alcohol is used. However, about 4 to about lO per-cent by weight polyhydric alcohol is preferred because it pro-vides the required plastic mass upon extrusion and has a signifi-cant contribution to microbiological stability while minimizing the use of the compound and maximizing the desired values for the pet food.

'733~
I~ re~uired to compensate for the protein lost by eliminating casein or its derivatives from the product in whole or in part, at least one vegetable protein is added to the semi-moist pet ~ood. The vegetable protein may be any suitable pro-tein such as an oil seed protein or grain protein. Typical oil seed proteins include soy bean, rape seed, peanut, and cotton-seed. These particular oil seeds are suitable ~or use in the pet food either as an oil, a meal, a concentrate, an isolate, or a flour. Other vegetable protein sources include corn and wheat.
Various types of corn used include corn germ, corn gluten feed, corn distillers dried grains, and dried corn distillers solubles.
Typical examples of wheat used include wheat germ and wheat germ meal. Especially suitable for use to replace or provide the pro-tein content for the casein or casein derivative replacement is soy protein concentrate. This vegetable protein is especially suitable because of its high nutritional quality, favorable availability as opposed to casein derivatives, and its contribu-tion to a meat-like product texture in combination with the starch and polyhydric component. Other suitable protein sources include whey or yeast. About 0 to about 20 percent by weight vegetable protein based on the weight of the pet food is suitable for use in the casein replacement, however more pre~erred is the 3-15 percent range. Most preferred is about 4 to about 12 per-cent because of the substantial advantages incurred when the casein and casein derivatives are replaced on a protein basis with vegetable proteins.
Textur:Lzing agents suitable for use in this invention .; . ' . . ': ' .

'7~3~
to provide the texture contrlbuted by caseinate include at least one phosphate, at least one edible acid, or mixture there-of. The phosphate is used singly or in combination with the acid or another phosphate. Typical phosphate components include hexametaphosphate, tetrapyrophosphate, pyrophosphate, polyphos-phate, diphosphate, and orthophosphate. ~arious salts of these phosphate components include the sodium salt, the calcium salt, the potassium salt, and the aluminum salt. An especially suit-able salt is dicalcium phosphate. The best distribution of khe phosphate salts is achieved if the phosphate salts are in solu-tion. For this reason, it is preferred that the phosphate salts be water soluble. However, certain phosphate salts are not water soluble but usable in this invention because they are soluble in an acid solution. Accordingly, if the calcium salt is put into solution by use of an acid, it too is suitable for use in this invention.
The product can also be texturized by addin~ a suitable edible acid to the pet food. These edible acids provide the texturizing function as do the phosphates. Typical edible acids include hydrochloric, sulfuric, acetic, adipic, or fumaric.
Generally about 0 to about 3 percent acidic texturizing agent can be added to the pet food. More preferably about 0 to 2 per-cent by weight texturizing agent can be added to the pet food.
Most preferably, the amount of acidic texturizing agent added is about 0 to about 1 percent to provide the stickiness desired without disrupting the meat-like texture provided~ for the most part, by the unmocli~ied starch and vegetable protein. As above ~7733~
stated, acid and phosphate can be used singly or in combination to provide the texturizing. An additional acid which will pro-vide both the phosphate components and the low pH requirement and is suitable for usa in this invention is phosphoric acid.
Another optional component for the casein replacement is a water binder for the dough of the pet food. Any suitable compound which serves as a water binder for water containing pet food dough is suitable. However, pregelatinized flours, vegetable gums, such as cellulose gums or starches,are most suitable as the water binder because of their availability, water binding effectiveness, and contributions to process hand-ling and post axtrusion texture. Typical water binders include at least of the group consisting of pregelatinized tapioca starch, pregelatinized corn meal, and pregelatinized flour such as pregelatinized corn flour, and pregelatinized wheat flour.
The preferred water binder is pregelatinized wheat flour. This flour is the most effective because it maximizes the desired :
characteristics of a water binder and has a positive contribu-tion to finished product texture. The water binder is generally present in the pet food in about 0 to about 20 percent by weight.
More preferably, the amount of water binder is about 2 to about 15 percent by weight. Most preferably the amount of water binder is about 3 to about 10-percent by weight because of its processing and texkure characteristics.
The key reason for the water soluble phosphate or acid and the water binder being optional components of the case-in replacement are that the other components of the casein re-' ' ,: . .
,: . . - .
~ .

3~
placement may have these desired qualities. Whether the other components have the desired contributions of the water binder and the phosphate components is easily determined by a person having ordinary skill in the art and the appropriate amount of the optional aomponents can be added.
The sodium caseinate or casein derivative replacement standardly is applicable to any suitable semi-moist pet food.
Such pet foods are well known in the art. There are a variety of methods used to stabilize the semi-moist pet foodO This contribution for sodium caseinate replacement or caseinate de-rivative replacement is suitable for use with all types of semi-moist pet foods and various limitations are not effective to change the value of this caseinate replacement. However, this replacement has been found especially suitable for use in pet foods such as those described in the Bone and Charter patents above-referenced. Once the ingredients are assembled for making the semi-moist pet food, any suitable process for making semi-moist pet food is usable. A preferable process is an extrusion process. More preferable is an extrusion sheeting process. If a multi-color pet food is desired, the extrusion sheeting pro-cess as set forth in Charter, above-cited.
In the following Examples submitted to illustrate the invention, all parts and percentages are by weightO Where weights do not equal 100 percent, the balance is water.
Example 1 The components listed below are assembled and formed into a suitable meat type pet food as described in the Charter ~C~'7~;'33~
patent but without marbling charactexistics. These components which make up a suitable marbled meat pet food do not include the standard sodium caseinate~ r~hus, a suikable pet food can be made with the complete elimination of a sodium caseinate.

Inqredients Formula /O

Beef Tripe 27.0 Sucrose 23.6 Corn Starch 7.0 Propy}ene Glycol 6.8 Animal Fat (Preserved with BH~,* 6.0 BEIT,* and Citric Acid) Pregelatinized Wheat Feed Flour 3.0 Vitamins, Minerals Salts, Coloring 7O4 PhoSphoric Acid 0.2 Soy Protein Isolate 9.9 *BHA = butylated hydroxy anisole *BHT = butylated hydroxy toluene -Example 2 The procedure of Example l is repeated with the following ingredients to make an acceptable pet food.
Inqredients Formula %

Partially Defatted Beef Tissue 35.0 Sucrose 15.0 Soy Protein Concentrate lOoO
Sodium Caseinate 4.4 Corn Starch 10.0 Propylene Glycol 8O0 Potassium Sorbate 0.1 Animal Fat 2.5 Vitamins, Minerals Salts, Coloring 7O4 Phosphoric Acid 0O3 7'73~1 Example 3 The procedure of Example 1 is repeated with the ingredients listed below, but for the incomplete replacement of the sodium caseinate. This too provides a suitable meat type pet food.
Inqredients Formula %

Beef Tripe 35.1 Sucrose 28.8 Sodium Caseinate 60 3 Peanut Flour 9,4 Corn Starch 7.1 Propylene Glycol 4 0 Animal Fat (Preserved with BHA, 2.5 B~, and Citric Acid) Vitamins, Minerals Salts & Color 4.0 Potassium Sorbate 0.1 Sodium Phospha~e (Monobasic) 0.5 Th~ sodium phosphate is highly effective due to its water solubility.
Example 4 The procedure of Example 1 is repeated, with the ingredients listed below but for the incomplete replacement of the sodium caseinate. This too provides a suitable meat type pet food.
Inqredients Formula %

Beef Intestines 34 0 Sucrose 10.0 Wheat Gluten 9.7 Sodium Caseinate 4.4 Corn Starch 10.0 1,3-Butanediol 7.0 Pregelatinized Whaat Flour 8.0 Vitamins, Minerals Salts & Color 7.6 Corn Syxup 5.0 ~7~73~1 Example 5 The procedure of Example l is repeated with the ingredients below to provide a suitable pet food.
Inqredients Formula Por]c Lungs 5.0 Pork Liver 5.0 Beef Intestines lO.0 Meat & Bone Meal 10.0 Corn Syrup ll.0 Soy Protein Concentrate 12.0 Corn Flour lO.0 Wheat Feed Flour 5.0 Propylene Glycol 8.0 Vitamins, Minerals Salts & Color 7.4 Potassium Sorbate 0.1 Phosphoric Acid 1.0 Example 6 Inqredients Formula Meal & Bone Meal 10.0 Beef Intestines 20.0 Corn Syrup 9.0 Sucrose 6.0 Peanut Protein Isolate 10.0 1,3-Butanediol 6.0 Vitamins, Minerals Salts & Color 3.2 Corn Starch 7.0 Preqelatinized Corn Meal 8.0 Potassium Sorbate 0.1 Hydrochloric Acid 0.5 Dicalcium Phosphate 4.2 ' " ~ ;

Claims (11)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. In a solid, semi-moist meat pet food using casein or a casein salt as a binder, the improvement comprising replac-ing at least part of the casein or casein salt with a composition having the following components:
4-20 percent unmodified starch 1-15 percent polyhydric component 0-20 percent a water binder 0-2 percent a soluble phosphate 0-5 percent edible acid; and 0-20 percent a vegetable protein all percentages being based on the weight of the pet food.

2. The pet food of Claim 1 wherein the water binder is at least one selected from the group consisting of pregela-tinized wheat feed flour, pregelatinized tapioca starch, pre-gelatinized corn meal, and pregelatinized corn flour.

3. The pet food of Claim 2 wherein the phosphate is phosphoric acid, and the unmodified starch is corn starch.

4. The pet food of Claim 3 wherein the vegetable protein is soy protein.

5. The pet food of Claim 1 wherein the composition comprises:
1-20 percent water binder 3-15 percent corn starch 3-10 percent polyhydric component 0-0.5 percent phosphate 0-1 percent acid; and 3-15 percent vegetable protein;
all percentages being based on the weight of the pet food.

6. The pet food of Claim 1 wherein the casein salt is replaced completely with a composition having the following components:
3-10 percent unmodified starch 4-10 percent polyhydric component 4-12 percent vegetable protein 0.1-1 percent acid; and 0.1-1 percent phosphate

7. The pet food of Claim 1 wherein the vegetable protein is at least one selected from the group consisting of cottonseed, rape seed, peanut and sesame.

8. The pet food of Claim 1 wherein the acid is selected from the group consisting of hydrochloric acid, phosphoric acid, citric acid, acetic acid, sulfuric acid, adipic acid, and fu-maric acid.

9. The pet food of Claim 1 wherein the vegetable protein is soy protein concentrate.

10. The pet food of Claim 7 comprising:
about 1 to about 10 percent water binder;
about 3 to about 15 percent corn starch;
about 3 to about 10 percent propylene glycol, up to about 1 percent acid or phosphate; and about 2 to about 15 percent vegetable protein.

11. The pat food of Claim 1 wherein the vegetable protein is soy protein isolate or soy protein concentrate.