Raw Hide Having a Coating Containing an Inorganic Pyrophosphate

In the examples, the following procedure was used. The coated raw hide strips were prepared by:

(a) blending the dry powders.

(b) adding 1/4 of the water and slurring the composition.

(c) adding remaining 3/4 of water and mixing to form the coating formulation.

(d) heating the coating formulation to 185.degree. F. to 200.degree. F. with intermittent stirring (add animal fat at about 125.degree. F. during the heating).

(e) maintaining the coating formulation at 160.degree. to 190.degree. F.

(f) Immersing raw hide strips by dipping in the heated coating formulation and holding the raw hide strips to the edge to let drain for about 15 seconds.

(g) placing the coated raw hide strips on a screen and drying at 275.degree. F. for 7 minutes in a forced-air laboratory oven.

(h) let the raw hide strips cool and then package them.

Any deviations from such procedure is set out in the specific examples.

The raw hide strips had a calculated average weight of 17 grams each, although actual weight ranged from 8.5 to 335 grams.

The specific ingredients, conditions, etc., are set out in the following tables:

The invention includes a viscous, liquefied coating formulation comprised of a surfactant, an effective polysaccharide gum, a binding agent, a starch carrier, a hydrogenated vegetable oil. A preferred coating formulation contains a surfactant, such as, lecithin or modified lecithin, xanthan gum (or other suitable polysaccharide gum), a starch or modified food starch, hydrogenated vegetable oil and a binding agent, such as, malto-dextrin, and water. Optional ingredients include animal fat, flavorant and colorant. A suitable humectant, preferably propylene glycol, can be used in the coating formulation. The invention coating can, but does not have to, contain at least one inorganic pyrophosphate salt.

The invention coating can be applied to any suitable human or animal food, such as, non-human animals, e.g., cats and dogs. The invention coating is preferably applied to baked dog biscuits and then both are dried.

The liquefied coating formulation best contains at least one suspension agent. The preferred suspension agent is a polysaccharide gum, most preferably xanthan gum. Preferably about 0.05 to 1.25 weight percent of polysaccharide gum (xanthan gum) is used. Xanthan gum is one of the few gums which acts as an acceptable suspension agent in the invention. The xanthan gum is an excellent agent for controlling the bodying effect, as it is stable over a broad temperature range, i.e., it holds the same viscosity over a large temperature range without any separation of the coating ingredients. Other suitable gums and mucilages can be used.

Malto-dextrin produced by hydrolyzing corn starch is preferred; it serves as a carrier (bodying), binding agent and suspension agent and helps the appearance of the coating; and it is a preferred ingredient. Other malto-dextrins can also be used.

An adhesive or binding agent, such as, malto-dextrins, is needed in the coating slurry to help the coating material bind (adhere) to the raw hide when the raw hide is dipped in the coating slurry. Preferably about 5 to about 15 weight percent of the malto-dextrin is included in the coating material.

A carrier, such as, starch or a modified food starch, is included in the coating formulation. Preferably about 0.1 to about 5 weight percent of the food starch or modified food starch is included in the coating material. The food starch or modified food starch also serves to control the viscosity.

Animal fat preferably is included for flavor purposes.

Other suitable flavorants can be used or included, particularly salt. The flavorants can be any dairy product flavorant, such as milk or cheese, meat flavorants, such as, liver or beef, poultry and fish. Flavorants help provide palatability for the invention coating.

Preferably a hydrogenated vegetable oil is included in the coating formulation for sheen and to modify the melting point of the formula fats in the finished product. It also helps to prevent flaking of the coating; also the coating does not have a tacky feeling.

Any suitable colorant can be included in the coating formulation. The preferred is caramel color which also provides some flavor to the product.

The coating also incorporates sufficient water to achieve the liquefied coating composition. Amounts of the other ingredients are those which are effective to achieve their functions in the coating formulation.

A preferred coating formualtion for dog biscuits contain water, animal fat, a surfactant, such as, a modified lecithin, xanthan gum, a modified food starch, flavorant, colorant, hydrogenated vegetable oil and a carrier, such as a malto-dextrin.

Another preferred embodiment for the invention coating for dog biscuits and ranges of the ingredients of the coating is:

The invention coating formulation can contain a humectant, such as, corn syrup, sugar and polyalcohols, such as, propylene glycol (preferred), sorbitol and glycerin.

The invention product does not include any fluorine-containing compound or other fluoride ion source, or quaternary ammonium compounds.

The invention coating can be applied, for example, to any suitable dog food, such as, dog biscuits, which can be made from any suitable dog food dough, such as, suitable dog biscuit dough. Any suitable dough comprising at least one flour, meal, fat and water can be employed for the product. For instance, when the desired product is a canine biscuit, a conventional dough for dog biscuits can be used, optionally containing discrete particles of meat and/or meat by products or farinaceous material. Such doughs typcially contain fat solids. Examples of suitable doughs for the production of hard dog biscuits are disclosed in U.S. Pat. No. 4,454,163, and suitable doughs for the production of soft dog biscuits (containing humectant to control water activity) are disclosed in U.S. Pat. No. 4,454,164. The pertinent portions of U.S. Pat. Nos. 4,454,163 and 4,454,164 are incorporated herein by reference. Particulate proteinaceous particles, such as particles of meat, texturized vegetable protein and/or meat byproducts can be incorporated to add flavor to the biscuits and texturize the surface. Particulate farinaceous materials such as bran particles can also be employed to texturize the interior and/or surface of the biscuits and to provide other useful properties to the product. A dough found to produce biscuits highly palatable to dogs includes suitable proportions of wheat flour, wheat meal, soybean meal, meat and bone meal, animal fat and natural flavors in admixture with water. The meal used in the doughs suitable for production of biscuits useful in the invention can comprise meat and/or bone and/or vegetable matter including farinaceous materials, materials prepared from legumes such as bean and peas, tuberous materials such as potato meal, and the like. The means can be finely or coarsely ground as desired for the texture. Flours made from any suitable farinaceous material can be used.

The doughs generally have a water activity of about 0.90 and above upon completion of mixing of the dough ingredients. A suitable dough contains farinaceous material, an edible oil, an antioxidant, an antimycotic, salt, animal fat, added vitamins and minerals, such as those disclosed in U.S. Pat. No. 4,229,485, column 5, lines 7 to 57, which is incorporated herein by reference. The compositions of the invention also preferably contain at least one animal-derived proteinaceous meal such as meat meal, bone meal and fish meal. A good biscuit dough for producing the biscuits of the invention contains about 50 to 60 percent by weight wheat flour, about 5 to 10 percent by weight soybean meal, about 3 to 10 percent by weight meat meal and bone meal, about 1 to 5 percent wheat meal, about 1 to 5 percent animal fat preserved with BHA, about 20 to 30 percent by weight water, and about 2 to 5 percent by weight of natural flavors, vitamin and mineral preblend, and acidulant.

The dog biscuit doughs can contain a softening agent. Any suitable softening agent can be used. The preferred humectant is propylene glycol. Examples of other suitable humectants are corn syrup, sugar and polyalcohols, such as, sorbitol and glycerin. Any suitable humectant known in the art can be used.

The dough ingredients are generally mixed at a temperature of about 45.degree. to about 140.degree. F. preferably about 60.degree. to about 125.degree. F.

The dog biscuit dough for the outer portion and the inner portion can be mixed using any suitable or conventional equipment. For example, the mixing can be at 20 to 100 rpm. For example a dry blending step can be done typically at room temperature for a period of time of about 3 minutes to about 20 minutes. The dry-blended mixture can then be mixed with the hot water to form a first stage dough. The water which can be admixed with the dry-blended mixture is typically at a temperature of about 65.degree. to about 150.degree. F. The hot water can be added, with mixing, over a period of time of about 3 minutes to about 6 minutes to form the first stage dough. Then, the fat portion of the biscuit dough can be admixed with the first stage dough to form the final stage dough. The fat portion can be added at a temperature at which it is at least fluid, typically at about 100.degree. to about 150.degree. F. The fat portion can be mixed for a period of time which is sufficient to form a dough whose homogeneity is visually apparent. A typically final mixing time is about 3 to about 5 minutes.

Preparation of the dough is achieved at about atmospheric pressure with mixing of the components being conveniently achieved in an upright sigma blade mixer or other bakery-type mixers. The various ingredients can be added over a period of time or in a one-shot manner according to the above order of addition. However, melted fat and water can be added simultaneously and mixed for 6 to 10 minutes.

The dough can be formed into dough pieces using any suitable or conventional manner, such as, by extrusion, molding, stamping or cutting. Any suitable dog biscuit shapes can be used, such as, bone-shaped canine biscuts. Holes can be formed in the dog biscuits to facilitate the escape of moisture during baking, cooking and/or drying.

The dog biscuit dough pieces can be baked using any suitable or conventional equipment and conditions. For example, the dog biscuit dough pieces can be passed into an oven such as a conventional band oven where the biscuits are baked. The conveyor belts of the oven can be coated with an edible lubricant such as a natural or synthetic cooking oil or shortening to facilitate separation from the conveyor belts of the baked products. Temperatures in the range of about 300.degree. to about 600.degree. F. can be used.

The invention coating can be applied to the dog biscuit dough pieces before baking followed by baking at a low baking temperature of, say, about 300.degree. to about 310.degree. F. It prefers to apply the invention coating after the dog biscuit dough pieces have been baked.

The baked dog biscuits can also be subjected to subsequent drying at temperatures of about 200.degree. to 400.degree. F. (e.g., for 25 to 12 mintues), either within the baking oven or separately, to produce the desired moisture content. If dealing with coating dog biscuits which have been baked with the coating on the dog biscuits, the baked, coated dog biscuits should not be dried at a temperature at above about 300.degree. F. Drying is usually done at a temperature of about 75.degree. to 300.degree. F. to achieve the desired moisture content (about 5 to 13 weight percent).

The invention coating is preferably applied to baked dog biscuits. The coating is preferably applied to the baked dog biscuits in the form of a liquefied coating formulation by any suitable means, such as dipping, spraying, etc. The coating can encompass all or part of the baked dog biscuits.

The coating formulation usually is viscous enough so that the coating formulation generally only coats the surface regions of the baked dog biscuits. The presence of coating in the surface regions of the baked dog biscuits helps to anchor the resultant coating and to prevent the coating from easily being separated from the baked dog biscuits during handling and shipping.

The coating slurry can be applid to the baked dog biscuits by an suitable means, such as, spraying, dipping, etc. The coating slurry is applied generally at a temperature of 45.degree. to 200.degree. F., preferably at about 60.degree. to about 190.degree. F., and most preferably at about 180.degree. F., (the baked dog biscuits best having been cooled, or allowed to cool, to less than 200.degree. F.). The coating slurry has a low microbial profile at such higher temperatures.

After treating the baked dog biscuits with the invention coating slurry, the coated baked dog biscuits are dried. While the coated, baked dog biscuits are preferably air dried, it is also advantageous to dry the coated animal food using applied heat, e.g., in a hot air oven at a temperature of say 75.degree. to 300.degree. F. (typically 250.degree. F. for 20 minutes). The coated dog biscuits are dried to obtain coated dog biscuits having a water activity of 0.70 or less. On a weight basis, the moisture content of the final coated biscuit product is less than or equal to about 15 percent by weight and preferably about 10 to 12 percent by weight of the final biscuit at 70 percent relative humidity. The coated dog biscuits are shelf stable.

The animal food within the scope of this invention needs to have a sufficient integrity to not fall apart during processing and handling, especially, so that the coating can be applied, dried/baked, etc., without losing its integrity or cracking. The anial food is best in the form of pieces or the like, such as, kibbles, biscuits, snacks, etc., The animal food pieces can be made by any suitable forming means, such as, extruding, molding, stamping, etc. The invention composition is used to reduce and control tartar accumulation on canine teeth.

The animal food can be the dog food disclosed in commonly-owned, copending U.S. patent application Ser. No. 242,292, filed on Sept. 9, 1988, now U.S. Pat. No. 4,904,494, entitled "Chewy Dog Snacks", the pertinent parts of which are incorporated herein by reference. A chewy, semi-plastic, non-extruded, non-porous, microbiologically-stable dog food which includes: 12 to about 30 weight percent, based upon the total weight of the dog food, of gelatin; at least one acidulant; at least one cereal starch-containing textural agent; at least one release agent; at least one taste agent; at least one sugar; salt; and added water. The dog food is in a molded form. The dog food has a pH of about 3 to 5, and has a moisture content of about 10 to 25 weight percent, based on the weight of the dog food. The process for preparing the dog food includes (a) mixing the dry components and liquid components with low speed agitation and continuing the mixing until a dough is obtained; (b) forming the dough by molding or rotary molding into molded snack or biscuit; (c) conditioning the molded dough at 185.degree. to 200.degree. F. for about 7 to 8 minutes; and (d) packaging the molded dog snack or biscuit in a protective package.