Aerated polymeric composition
The present invention relates to an aerated polymeric composition. The composition includes a protein polymer and an agent or method for causing porosity in the finished aerated polymeric composition, such as a leavening agent. Additionally, the present invention relates to methods for forming the aerated polymeric composition, in particular, methods for forming aerated pet treats or chews.
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This application claims priority from Provisional Application Ser. No. 60/647,499 filed on Jan. 27, 2005, which is hereby incorporated by reference in its entirety.
FIELD OF INVENTIONThe present invention is directed to an aerated polymeric composition, with the composition formed from a protein polymer and an agent or method for causing porosity in the finished aerated polymeric composition, such as a leavening agent. Additionally, the present invention relates to methods for forming the aerated polymeric composition, in particular, methods for forming aerated pet treats or chews.
BACKGROUND OF INVENTIONPlant protein polymers have been known for use in a variety of compositions. In particular, it has been known to use wheat gluten and related plant protein compositions to form a variety of chews and treats, as identified in U.S. Pat. No. 5,665,152 and applied to pet treats. These known chew and treat products tend to be of a dense nature. It is desired to have a method related to a protein polymer product formation, which produces an aerated product that is ductile and compressible. Such an aerated product is desired because it can be used in any of a variety of applications.
SUMMARY OF INVENTIONThe present invention relates to an aerated, protein based polymeric composition, which exhibits unique textural and functional properties. The resultant aerated polymeric composition is well suited for use as a unique pet chew for geriatric pets and those pets less prone to chew, a unique confectionery product, or biodegradable packing material. As would be guessed, additional uses for the resultant material are also contemplated. As such, the aerated polymeric composition can be used as packing foam, with the benefit of being biodegradable.
The method for producing the aerated composition starts with a protein polymer material. Any of a variety of protein sourced polymers may be used to form the polymer material; however, it is most preferred to use a plant derived protein polymer. More particularly, it is desired to use an amount of wheat gluten, or a similar plant polymer. In particular, the polymer disclosed in U.S. Pat. No. 5,665,152, is well suited for use. The polymer material will be formed from a protein polymer and additives.
A variety of additives or constituents may be mixed with the plant protein polymer to form the dry blend. Such additives include processing aids, flavors, starch, and colors. The addition and amount of such constituents are dependent upon the desired final product.
An amount of leavening agent is added to the dry blend. The leavening agent is added to cause the formation of a polymer having an aerated construction and a lower density. Generally, a variety of leavening agents or methods can be used to aerate the polymeric material, including physical addition of chemical leavening agents, compressed gasses, or microbiologic fermentation. The leavening agent may be selected from the group consisting of sodium bicarbonate, baking powder, sodium acid pyrophosphate, monocalcium phosphate, sodium aluminum phosphate, and combinations thereof. The chemical leavening agent will be added in an amount ranging between 0.05% and 5.0% by weight of the polymeric composition. The amount added will depend upon the desired finished product, in particular, the amount of product aeration.
Water is added to the dry blend as part of a liquid slurry that is added to the dry blend before or after the addition of the leavening agent. This forms a polymeric composition. The slurry is added so that an amount of water is available to react with the chemical leavening agent to thereby cause the formation of CO2 and, resulting in the aerated construction. Additionally, it is preferred to add glycerin or propylene glycol, or similar processing aids, in with the slurry. Sodium metabisulfite is also preferred for inclusion in the slurry as it affects the softness of the structure. The sodium metabisulfite will cleave sulfite bonds and relax the protein. Magnesium stearate may also be used as a processing aid to enhance flow and reduce stickiness.
Thus, the slurry, leavening agent, and dry blend are all mixed together and heated at a temperature sufficient that the polymeric composition will flow, but is not denatured, and that the reaction between the leavening agent and the water may occur. As a result, the polymeric composition entraps the CO2 causing an aeration of the polymeric composition and forms an aerated polymeric composition.
Dependent upon the desired characteristics of the end product, the amount of bicarbonate, or leavening agent, and water added will be varied. If a more aerated construction is desired, the amount of bicarbonate will be increased. Water is important as an additive, because this helps to plasticize the protein and allow elasticizing of the protein.
It is preferred to extrude or injection mold the polymeric composition to form the desired end product. However, other methods may be used to form a finished product of a desired shape and size. Following the shaping of the aerated polymeric composition, the aerated polymeric composition is dusted or coated with a substance to reduce sticking. Coatings could include starch dusting, spraying with oil, or coating with cellulose or other compounds.
Once the shape of the extruded or injection molded product has been formed, it is preferred to thermally set the aerated polymeric composition to form a product. Thermal setting is desired because it causes the protein to denature, and thereby causes the individual protein strands to cross-link and associate with one another. This will cause the resultant product to have a unique structure and texture that is ductile, pliable, and somewhat elastic.
After thermal or heat setting the product, it is preferred, but not required, to polish the product. This can be achieved using a variety of compositions and techniques, including adding petrolatum to the product.
The resultant invention is advantageous for a variety of reasons. The aerated polymeric composition is desired because it has a pliable construction that is made from “natural” materials. The product is additionally advantageous because it is made of protein so that it will generally be considered healthier than other compositions used to form similar products. Additionally, the product is readily biodegradable, and exhibits unique textural and functional attributes, which makes it desired for use in any of a variety of industries.
DETAILED DESCRIPTIONThe present invention relates to an aerated polymeric composition, methods for forming the composition, and compositions for use in forming the aerated polymeric composition. In particular, the method relates to using a leavening agent or method to aerate a protein polymer, preferably a plant protein polymer. The method further includes denaturing an extruded or injection molded polymeric product. The present invention further relates to methods of using plant protein polymers to form the aerated polymeric composition. The resulting aerated polymeric composition is preferably used as a pet chew. The present invention, in particular, relates to a pliable and flexible dog chew, whereby the chew has an aerated construction, forming a porous structure. Preferably, the chew is formed from plant protein polymers, such as wheat gluten, which produce edible and digestible chews having unique characteristics. Additionally, the present invention relates to methods of making the chew and methods for using plant protein polymer with a leavening agent. Alternatively the aerated polymeric composition may include materials that discourage infestation and consumption by animals. This composition may be used as a packing material.
The pet chew generally has a smooth outer surface, substantially free of indentations or protrusions. This chew, in the alternative can be wrinkled to some degree on the outside. In fact, in certain constructions, it is desired to have some degree of wrinkling. The inner portion of the article is formed of air cells or caverns, resulting from aeration. The size of those caverns may vary, depending on the desired texture and use. This inner portion provides the article with a spongy texture, making it compressible, flexible and accordingly, pliable for the jaws (teeth and gums) of a typical dog. The resultant product has memory, so that when compressed, it returns to its original shape once force is removed. As such, the resulting product, when applied to pets, provides chewing satisfaction for a pet, but can be consumed and swallowed in a comparatively shorter period of time, depending on the formulation and the size and distribution of the air cells.
The resultant pet chew has a body that includes a substantially sealed, non-porous, outer skin. The inner portion of the pet chew is integral with the skin. The inner portion has a porous construction and is substantially surrounded by the skin. The inner portion includes a plurality of cavities or air pockets to provide the body with elastic deformability and flexibility. The pet chew may also include a grain protein, or a plant protein polymer, in an amount ranging between about 20% and about 70%, and a reducing agent, whereby disulfide bonds have been cleaved within the pet chew in a range between about 2.0% and about 75%. The pet chew preferably has a body with a length ranging between 1 inch and 10 inches, and a diameter ranging between 0.125 inches and 4 inches.
Additionally, the chew has a pliability equal to being bent in half, without breaking. The shape of the chew will include a round stick, which has cavities ranging between 0.0005 inches and 0.040 inches in diameter. Conversely, the chew can be a hollow tube; however, the cavity size remains the same. Thus, the pet chew product can be of a variety of shapes, lengths, and diameters. The shape and size selected will depend upon the animal intended to consume the product. The age and size of the animal will also influence the finished product. Animals which are intended to consume the product include, but are not limited to, dogs, cats, birds, and small animals, such as hamsters, gerbils, chinchillas, ferrets, rats, and mice. Forming methods have been demonstrated through extrusion and injection molding, but other methods may also be used.
The method for forming the aerated polymeric composition, especially the pet chew, is dependent on the desired shape and the resultant aerated properties. The method is initiated by selecting a polymer for use in forming the product. The selected polymer and resulting polymeric composition should be such that gas trapping and rheological properties are provided to produce the unique textures and functionalities of the resultant pet chew product. Additionally, the flow properties of the selected polymer should allow for processing through extrusion or injection molding equipment.
A polymeric composition is used to form an aerated polymeric composition. The polymeric composition includes an amount of a dry blend, a slurry mixture, and a leavening agent. Once the polymeric composition is heated, it is known as an aerated polymeric composition. When the aerated polymeric composition is cured, or heat set, it forms a pet chew. The polymeric composition includes any of a variety of polymers and polymeric compositions, can optionally serve as a carrier of other materials, and can be flavored.
The dry blend includes an amount of a polymer equal to from about 5% to about 85% by weight of the dry blend. Any polymer, which can be aerated, consumed, and shaped into a desired structure, may be used. Preferably, the polymer is a plant protein, or grain protein; however, other proteins with the same characteristics may be used. More preferably, the dry blend includes an amount of plant protein equal to between about 20% and about 70% by weight of the dry blend. Preferably, the plant protein is a gluten composition. The definition of gluten is a tenacious elastic protein substance, and includes, but is not limited to proteins such as gliadin, glutenin, globulin, and albumin. The gluten, when denatured, can form disulfide cross-links and hydrogen bonding between the proteins or their constituent amino acids. Wheat gluten is the most preferred gluten composition for use; however, soy protein, corn gluten, and mixtures thereof may also be used.
The selected plant protein is combined with other constituents to form the dry blend. Other constituents included in the dry blend include starch, flavors, colors, and reducing agents. Preferably, starch is added in an amount ranging between about 5% and about 50% by weight of the dry blend. A variety of starch types can be used, such as corn, wheat, potato, and tapioca starches, and mixtures thereof. The starches can be native or modified by gelatinization or chemical treatment. The resultant starches can be oxidized, acetylated, carboxymethyl, hydroxyethyl, hydrox-propyl, high amylose, and alkyl-modified starches. The starches are added to further modify the texture of the finished product.
Reducing agents are added as a processing aid. The reducing agents improve flavor characteristics and reduce damage to the protein caused by heat and shear. Reducing agents available for use include those selected from the group consisting of the alkali metal and ammonium sulfites, bisulfites, metabisulfites, and nitrites, and mercaptoethanol, cystein, cysteamine, ascorbic acid, and mixtures thereof. The reducing agents are included in the formulation at a level of at least 0.01% by weight of the dry blend. Alternatively, the reducing agents are included in the formulation at a level of between about 0.01% and about 3% by weight of the dry blend. Preferably, the reducing agents are included in the formulation at a level of between about 0.01% and about 0.5% by weight of the dry blend. The reducing agent cleaves the disulfide bonds in the formulation in a range between 2.0% and about 75%.
Flavors, for example, beef, chicken, or other flavors, attractive to the senses of dogs, can be added to the formulation. Any of a variety of flavors can be used to impart taste characteristics to the finished product. Flavors, typically meat (chicken, beef, pork, etc.), fruit and the like, can be added to the mixture in the extruder. For example, beef flavoring may be added by placing beef broth, beef stock, or concentrated flavors into the extruder. Also, compositions such as liquid smoke, for example, Charsol C-10 can be added as flavoring. The flavors are added according to taste.
Colors may also be part of the extrusion mixture and added thereto at any time during the extrusion. These colors can include for example, Carmel coloring, Red (for example Red #40), Yellow (for example, Yellow #5 Lake), and the like. The colors may be added to the extrusion mixture. The amount added is dependent upon the finished color desired.
The method for forming a polymeric composition includes mixing a slurry mixture with the dry blend. The slurry can include water, humectants, and processing aids. The formulation includes an amount of water necessary to promote polymer formation. An amount of water, up to about 30% by weight, more preferably up to about 25% by weight and, most preferably, from about 10% to about 20% by weight of the slurry may be included. The slurry has an amount of water ranging between about 5% and about 25% by weight of the polymer composition. The water, as detailed above, acts as a plasticizer, hydrates the protein to make it functional, and reacts with the sodium bicarbonate to form the gas for aeration of the polymer.
A humectant is normally used at a level equal to from about 5% to about 80% by weight in the slurry and, more preferably, from about 10% to about 50% by weight of the slurry. The preferred class of humectants include those selected from the group consisting of glycerol, diglycerol, propylene glycol, triethylene glycol, urea, sorbitol, mannitol, maltitol, hydrogenated corn syrup, polyvinyl alcohol, polyethylene glycol, C12-C22 fatty acids, and metal salts of such fatty acids, and mixtures thereof. The most preferred plasticizer is glycerol or glycerin. The formulations of this invention also include processing aids, cellulose, flavors, and colors.
An amount of a leavening agent is mixed with the dry blend and slurry mixture to form a polymeric composition. The leavening agent can be added to the dry blend prior to the addition of the slurry, or can be added after the addition of the slurry. It is, however, preferred to aerate the polymeric composition during extrusion. This will contribute to the desired texture of the chew. Aeration, that forms the caverns, or a plurality of gas bubbles, in the article or chew, typically occurs as a result of adding a leavening agent, such as bicarbonate, to the extrusion mixture.
Leavening agents, such as sodium bicarbonate, react with water in the extrusion mixture, forming a gas that aerates the extruded aerated polymeric composition. A leavening agent is a compound that produces a gas in the presence of heat. Chemical leavening agents from the following chemical families can be used: carbonates, bicarbonates, phosphates, or other chemical additives used separately, or in combination, which produce a gas when reacted under heat and/or in the presence of water. For example, the leaving agent may be selected from the group consisting of sodium bicarbonate, baking powder, sodium acid pyrophosphate, monocalcium phosphate, sodium aluminum phosphate, and combinations thereof. Also, injection of a compressed gas into the polymeric composition within the extruder or injection molding screw can produce the same effect. Gaseous CO2, compressed air, nitrogen, helium, and combinations thereof can be added to the extrusion mixture for this aeration step. It is preferred to use chemical leavening agents to form the aerated structure. It is more preferred to use sodium bicarbonate or baking powder. As such, any of a variety of compositions and methods can be practiced to promote aeration. The chemical leavening agent is added in a variety of amounts. Preferably, the chemical leavening agent is added in an amount ranging between about 0.05% and about 5.0% by weight of the polymeric composition. More preferably, the chemical leavening agent is added in an amount ranging between about 0.5% and about 2.5% by weight of the polymer mix.
As such, aeration occurs before or after forming the homogeneous, flowable aerated polymeric composition, but before forming into the finished shape and subsequent product.
The polymer composition is heated under moderate temperatures and mild sheer force to create a substantially homogeneous mixture and flowable formulation. The flowable formulation is mildly heated and formed into desired shapes using extrusion or injection molding.
It is preferred that the polymeric composition formulation not be subjected to excessive heat during the process prior to shaping, as this will denature more than about 10% by weight of the protein contained in the formulation. Therefore, it is desired to process and form the flowable polymeric composition formulation without damaging the protein constituent by heat or sheer forces until after formation of the desired shape. The flowable formulation can be made by using a variety of macro-molecules in combination with plasticizers, which can be shaped, extruded, or injection-molded.
The polymeric composition is heated to form an aerated polymeric composition, which can be extruded or injection molded into a polymeric composition pet chew. The extruding temperature preferably ranges between about 25° C. and about 75° C.
It is important to maintain the temperature of the mixture within the extrusion barrel at a temperature below about 70° C. It is also important that the temperature of the mixture, as it exits the die of the extruder, does not exceed about 80° C. and, preferably, the temperature should be below about 65° C.
As such, the polymeric composition is processed into a flowable homogeneous mixture through extrusion technologies using single or twin screw extruders. The flowable polymeric composition can be formed into pellets off of the extruder system for subsequent use in injection molding or the flowable polymeric composition can be formed into the finished shape directly off of the extrusion system. If the flowable polymeric composition is to be used in injection molding, the pellets would be processed through injection molding equipment so that the temperature of the flowable polymeric composition does not exceed about 80° C. through the screw and into the mold. Also, these formulations can be mixed and processed directly as virgin material in conventional injection molding equipment.
The handling of the flowable polymeric composition is noticeably difficult due to its sticky nature. It is essential that the flowable polymeric composition is coated immediately after extrusion to eliminate sticking and to maintain individual pieces. A wide range of coating can be used, such as starches, oils, emulsifiers, release agents, fibers, etc. It is preferred to use starch to dust and coat the surface of the flowable polymeric composition soon after it exits the extruder die. It is more preferred to use cornstarch.
After extrusion, the aerated polymeric composition is heat set by curing at a temperature ranging between about 80° C. and about 145° C. The temperatures are such that the protein polymer is denatured. The aerated polymeric composition pet chew is denatured by heating the chew at a temperature ranging between about 80° C. and about 145° C. to form a heat set pet chew.
Once the flowable aerated polymeric composition is denatured, it is a fixed polymeric composition. Through either process, the chemical leavening is reacted through single acting or double acting gas release. Depending on the desired effect, aeration can be produced within the extruder and, if desired, a second gassing can be achieved within the injection molding screw or upon heating during the denaturing process.
After the product is heat set, it can be polished to remove the coating initially applied, up-stream in the process, to prevent individual products from readily sticking together. This step can be achieved by applying corn or wheat starch to the surface or by applying heat. It is most preferred to apply cornstarch. Lubricants, such as mineral oil, petroleum jellies, for example, petrolatum, waxes, and blends thereof may also be applied in post processing steps to prevent the finished products from sticking together. Most preferably, the product is polished with cornstarch, followed by petrolatum.
Following the heat denaturing of the extruded polymeric material, it is desired to remove the appearance of the starch dusting to make the appearance more acceptable to consumers. The starch is polished from the surface of the fixed polymeric material using petrolatum and typical confectionary polishing techniques. The polishing agent is heated above its melting point and applied to the surface of the fixed polymeric composition. Usage rate of petrolatum is preferred to be less than about 2% by weight, and a more preferred level is less than about 1% by weight. Other types of materials can be used to cover or remove the starch from the surface of the fixed polymeric composition, such as vegetable oils, natural waxes, parafins, glycerin, and water sprays.
Alternatively, the aerated polymeric composition may be used as a packing material. The composition includes a dry blend comprising a compound selected from the group consisting of a plant protein polymer, processing aids, materials that discourage infestation, and materials that discourage consumptions by humans as well as by pets. For example, the composition may include an amount of Cedar oil of from about 0.5% to about 1% by weight of the composition and an amount of a bittering agent of from about 1% to about 3% by weight of the composition.
The invention will now be described by way of Examples.
EXAMPLES Example 1 A method for producing co-extruded pet chews was practiced. In particular, tests were conducted to determine if dog chews could be co-extruded using a protein polymeric material. Products with and without a leavening agent were made. As such, the present invention relates to methods for co-extruding protein polymers, that are aerated and formed into pet treats or chews. The extruders used in this Example were an X-85 single screw extruder and a TX-57 twin screw extruder, both are manufactured by the Wenger Manufacturing Co. Any shape can be used to demonstrate this invention; however, in the present Example, a bone shape was used, with a round center for the secondary extrusion. The X-85 was used to form the outside extrusion flow, and the TX-57 was used to form the inside extrusion flow. The polymeric material used for both the inside and outside extrusion flows was a flowable formulated protein polymer. The base polymer formula consisted of the following constituents:
This mixture was used to form a dry mix equal to 100 lbs. Next, a slurry was formed, with the slurry consisting of 18.5 lbs. of glycerin, 2 lbs. of water, and 0.1 lbs. of sodium metabisulfate. The slurry was intended to plasticize the material.
Slurry, in the amount of 26 parts by weight, was added to 100 parts of the dry mix in the extrusion process. The extruder conditions were such that the feed rates yielded 225 lbs/hr. The extruder barrel temperature did not exceed 60° C. The die temperatures were maintained below 66° C., and the extruder screws were running at 120 rpm. Following extrusion, the formed polymeric mixture was heated in a convection oven at a temperature ranging between 88° C. and 110° C. to denature the protein.
The polymer was extruded using the mentioned devices to determine whether a suitable product could be formed using this method. The test runs were as follows, with the inside polymer described, followed by the outside polymer. Any varying conditions or constituents are also described.
Test Run No. 1: Protein Polymer/Protein Polymer, standard set-up was used.
Test Run No. 2: Protein Polymer/Protein Polymer, increased gap between front die and internal die.
Test Run No. 3: Protein Polymer/Baking Powder, mixed with Protein Polymer.
It was observed that an unstable process occurred throughout the three extrusions; however, samples were collected to test the concept.
A second set of tests was conducted. The extrusion was changed to cause a reversal of flows at the die to achieve better skin and allow the center to extrude at a higher moisture to reduce surges. The second set of runs were as follows:
Test Run No. 4: Protein Polymer/Protein Polymer.
Test Run No. 5: Protein Polymer/Protein Polymer with bicarbonate—200 lb. batch, 1½% baking powder, center formulation.
Test Run No. 6: Protein Polymer/Protein Polymer with Rice—20% addition both outside and inside.
Test Run No. 7: Protein Polymer/Starch Polymer.
From the above tests or runs, it was observed that co-extrusion of a protein polymeric material was possible with no unique capital beyond equipment to converge flows. It was also demonstrated from these tests that a polymeric material could be aerated to achieve a unique texture and product.
Example 2 The trials of Example 1 were further continued. In this Example, 9 test runs were conducted. The present Example relates to the continued development of formulations for a unique pet chew, as well as texture and shape configuration development. The Example is directed to aerating the protein polymer and on the merging of two different polymeric materials, a starch polymer and a protein polymer. Resultantly, a unique product with dual textures was produced. The protein polymeric material was ductile, while the starch polymer was more crystalline. New configurations were evaluated, as well as co-extrusion configurations. The below information discloses recipe information, preconditioning information, and extrusion information. The extrusion information for the runs was as follows:
The drying conditions for each run was as follows:
From above, wb stands for wet basis.
Comments: RECIPE MIXED TWO TIMES; dry blend for X-85
Comments: Slurry for X-85: Add 11.2% of this to Recipe #1
Comments: Dry blend for TX-57: Add 26% of customer's slurry to this. Mixed 1⅓ times.
Comments: Pounds listed do not indicate pounds used
Comments: Mixed 1 time
Comments: Made another 200 lb. batch
Starch polymer pellets used herein were comprised of cellulose addition, chlorophyll, and chlorophyll coarse rice flour (30-40 mesh), and colored with chlorophyll. Rolled sheets of starch polymer (plain) 300 pcs at 150 lbs. were also used.
The runs below pertained to non-aerated polymers. The analysis of the runs is as follows:
Run No. 1: This run related to the initial die set-up. Formula No. 5 for starch and beef flavored No. 1 protein polymer were co-extruded. The formula was non-aerated. It was observed that a fairly good extrusion was produced. The starch flow was restricted due to die opening versus volume of extruder capacity. The TX-57 extruded was used to form the protein shell. Note that Run Nos. 1 and 3 were best, but had higher slurry.
Run No. 2: The die was modified so that the front die had an open nipple so that it protruded beyond the outside plane of the protein. Formula No. 5 for starch and Beef No. 1 Protein Polymer were used. The formula was non-aerated. Same as Run No. 1, but modified final insert to be more open to allow increased filling. Correcting the slurry ratio made the product not weld together as well. The feed holes in the back die show in the final product.
Run No. 3: The die was modified so that the front die had an open nipple so that it protruded beyond the outside plane of the protein. A higher slurry level was used to achieve better appearance. The formula was non-aerated. Very good appearance, slightly sticky, welds seemed to improve, observed to be the best run. Increased slurry rate to higher level—improved shape—smooth, uniform.
Run No. 4: The die was modified so that the front die had an open nipple so that it protruded beyond the outside plane of the protein. An aerated protein was formed. Formula No. 2 Beef, with 1.5% bicarbonate, plus Formula No. 5 starch was used. Dry recipe with 1.5% sodium bicarbonate.
Good expansion and texture for a protein polymer were observed.
Run No. 5: This run relates to aerated protein polymer having—0.75% bicarbonate. Beef broth was added and increased to 3%; Color Red #40 Lake 0.25%. The starch polymer used was the same as all previous runs; no changes were made to the starch polymer. Expansion under control and good solid extrusion and shape resulted. The product was heated in a convection oven at 110° C. for 14.7 minutes. Some increased expansion occurred in the Dryer.
Run No. 6: This run relates to an aerated protein polymer having 0.5% bicarbonate/3% beef broth/color 0.25%. The starch polymer was the same as previous runs. Very good shape and expansion, almost as much as 0.75, visually. Cure: 110° C.—14.7 minutes (5.4 minutes, top, and 9.3 minutes, bottom). Best expanded product. The starch polymer extruded best when cooked. Lowered bicarbonate to 0.5% was stable, as long as the inlet was cleaned every few minutes.
Run No. 7: This run relates to a protein polymer containing no leavening agent. Protein Polymer—Back to Beef No. 1 with 0.5% beef broth and no bicarbonate. The starch polymer was the same as previous runs. Intent of the run was to duplicate Run No. 3—but fill pin had been straightened. Cure: 110° C.—14.8 minutes. No bicarbonate.
Run No. 8: This run relates to a protein polymer containing no leavening agent. Co-Extruded Tube. Protein Polymer—Formula Beef No. 1, no bicarbonate, with 0.5% beef broth. The starch polymer was the same as previous runs. No bicarbonate, round rod.
Run No. 9: This run relates to an aerated protein polymer with a modified die. Co-Extruded Tube. Protein Polymer—Formula Beef No. 7, with 0.5 bicarbonate. Starch Polymer—same as previous runs. Round rod with 0.5% bicarbonate.
It was observed that co-extruded pet chews containing two uniquely different polymers can be produced. Further, it was observed that a protein polymer can be aerated to produce a variant texture and densities. Co-extruded chews of aerated protein and starch in a targeted shape could be produced.
Example 3The present Example discloses a process for producing protein polymer chew sticks, which are intended as pet chews for older dogs, which have difficulty chewing harder materials, and for those dogs which typically do not chew. A Wenger TX57 twin screw extruder was selected as the device for extrusion.
The pet treats were formed by extruding the protein polymeric formula into a rope that was cut into various lengths. As seen below, a number of processes and formulations were tried to determine the preferred method and formula for producing a desired resultant product. The extrudate was then heated to denature the protein.
The formulas used were as follows:
Comments: Recipe mixed 3 times
Comments: Recipe mixed 3 times
The information on the process parameters are as listed below. In the reference number section, the specific number of the above recipes for each Run is listed.
The material extruded and processed was of a soft aerated protein polymeric material intended for use as a chew. The shapes were round sticks and hollow tube chews. A five head set-up on a TX 57 magnum extruder was used. The ratio of length to diameter in the extruder was 25.5/1 L/D ratio. The round stick was about 1″ in diameter (die hole to be 0.5″-0.75″ diameter). The hollow tube was about 1″-1.25″ in diameter. The tube was cut to 5″-6″ in length. The tube wall thickness was approximately 0.125″.
Sample Run No. 1 included hexamatophosphate. It was observed that when the amounts of slurry was reduced, there was some ripping of the surface of the extrudate. The slurry was reduced to 17.3 kg/hr slurry from 57 kg/hr dry. When slurry was less than 17 kg/hr, there appeared a ripping effect of the die on the surface of the extrudate. Expansion off of the die was controlled.
Sample Run No. 1 had an oven temperature of 110° C., 110° C., 90° C. There was significant expansion and subsequent shrinking, leading to shriveled surface.
The second half of Sample 1 had an oven temperature of 95° C., 95° C., and 70° C. There was less expansion and improved surface, but still some light shriveling. It had pretty good texture and firmness.
Sample Run No. 2. A round stick having a 5/16″ hole was formed.
Formula No. 1B was used, which had 0.75% bicarbonate (hexametaphosphate used). The oven temperature was 95° C., 95° C., 80° C.—expansion similar to the 0.5% bicarbonate. A much softer chew was produced that was noticeably easier to rip. It was observed that the texture was too soft.
In Sample No. 3, a round stick, having a ⅜″ hole was produced using Formula No. 4. Formula No. 1 C —0.25% bicarbonate (sodium hexametphosphate used). The oven temperature was 88° C., 88° C., 80° C. A product with a good appearance after thermal heat set resulted. There was minimal surface shriveling.
Sample No. 4, Run No. 104: Round Stick, ⅜″ hole. Formula No. 1C—0.25% bicarbonate (sodium hexametphosphate used). The oven temperature was 88° C., 88° C., 80° C. A good appearance after thermal heat set resulted. Again, there was minimal surface shriveling.
Sample No. 5, Run No. 106: Round Stick, ⅜″ hole. Formula No. 1-0.5% bicarbonate (sodium hexametaphosphate). The oven temperature was 88° C., 88° C., 80° C. Good appearance out of dryer, but wrinkled later.
Sample No. 6, Run No. 107: Round Stick, ⅜″ hole. Formula No. 1-0.5% bicarbonate (sodium hexametaphosphate). The oven temperature was 88° C., 88° C., 80° C. Increased slurry rates 10% to reduce surface wrinkling. Thought to be a result of increased surface area, due to larger hole.
Sample No. 7, Run No. 108: Round Stick, ⅜″ hole. Formula No. 1-0.5% bicarbonate (sodium hexametaphosphate). The oven temperature was 88° C., 88° C., 80° C. Cut short—Increased slurry rates 10% to reduce surface wrinkling. Thought to be a result of increased surface area, due to larger hole.
It was determined that a mono-extruded aerated protein polymeric material could be produced. Additionally, the selected die affected the texture and performance of the material flow. As such, a chew with a smooth surface and soft, pliable, aerated construction, was produced. It was observed that all of the formulations exhibited a significant stick character and had an affinity to stick.
Example 4 In the present Example, a Beef Geriatric Dental Chew (Protein Based) was produced. In the Example, a new formulation was tested. In particular, it was desired to reproduce Run No. 6 from Example 3 to evaluate coatings to reduce sticking and allow processing through the heating steps to denature the protein without sticking. Application of coatings before and/or after heat setting were evaluated. As such, the conditions of the present Example were identical to those of Example 3. The formulation was as follows:
Pet chews similar to those in Example 3 were again produced, but under varying conditions. The procedure for Run No. 3, from Example 3, was again used.
The beef flavored chews were aerated with 0.25% bicarbonate.
Variables applied to the finished product were:
The runs were as follows:
The product showed excellent appearance.
Materials from Run No. 1 (cornstarch coated protein polymer sticks post heat treatment and cooled) were taken and placed in continuous tumbler for polishing. Petrolatum (snow white) was melted and drizzled onto pile of sticks. The pile consisted of about ½ of the total number of sticks. All were loaded into the tumbler, one handful at a time, alternating between drizzled and non-drizzled sticks. It was determined that too much petrolatum was applied, and towels were added to wipe off some excess. Residence time in the tumbler was variable, depending on angle of tumbler.
The product was run through a couple of times until all surfaces were polished. Approximate time=7 minutes, but can be shortened if the petrolatum was more uniformly applied, and tumbler was placed level the whole time. It took more time due to the non-coated products getting completely polished.
The results are as follows:
Run No. 1: Cornstarch was dusted onto the extruded protein polymeric mixture immediately following extrusion and prior to cutting the extruded product. There was no sticking through the down stream processing and Dryer. The product was allowed to sit hot for 30 minutes in the tub, with no sticking.
It was determined that the starch dusting was very apparent following exit from the dryer. The extruded product needed to be polished to improve the starchy coated appearance.
Run No. 2: Solka-Flok was used instead of cornstarch Did not cover well, and sticking occurred.
Run No. 3: Silica dioxide was used instead of cornstarch
Not as good of apparent coverage as cornstarch; however, exhibited virtually the same non-sticking qualities. Appearance was slightly less powder coverage.
Note: Run Nos. 1-3 were conducted under the same conditions.
Run No. 4: Mineral oil was applied to the ropes, prior to cutting. Atomized mineral oil was used via a ventury nozzle. The coated and cut pieces were tumbled in a Rotary Continuous Tumbler with slight angle to maximize residence time. This product exhibited fairly good non-sticking characteristics; however, after setting in bags, there is slight sticking of product. Clumps of sticks are easily broken apart; however, the short cut pieces of the clumps were more difficult to separate.
It was concluded that the composition that produced the best performance for eliminating stickiness was the use of cornstarch; however, the dusty appearance is not acceptable until it is polished with petrolatum. The second best performance was mineral oil coating prior to cutting. This, however, exhibited minor clumping issues later. Not tried, but should work very well, is spraying petrolatum prior to cutting. The silica dioxide worked farily well, however, not as well as starch, and needed to be polished after heat setting.
Example 5 A method for producing an aerated polymeric composition to be used as packing material. The packing material is biodegradable. The extruder used in this Example was a twin screw extruder. The base polymer formula consisted of the following constituents:
This mixture was used to form a dry mix equal to 100 lbs. Next, a slurry was formed, with the slurry consisting of 18.5 lbs. of glycerin, 2 lbs. of water, and 0.1 lbs. of sodium metabisulfate. The slurry was intended to plasticize the material.
Slurry, in the amount of 26 parts by weight, was added to 100 parts of the dry mix in the extrusion process. The extruder conditions were such that the feed rates yielded 225 lbs/hr. The extruder barrel temperature did not exceed 60° C. The die temperatures were maintained below 66° C., and the extruder screws were running at 120 rpm. Following extrusion, the formed polymeric mixture was heated in a convection oven at a temperature ranging between 88° C. and 110° C. to denature the protein. The process yielded an aerated polymeric composition to be used as packing material.
Thus, there has been shown and described an aerated polymeric composition which fulfills all the objects and advantages sought therefore. It is apparent to those skilled in the art, however, that many changes, variations, modifications, and other uses and applications to the aerated polymeric composition are possible, and also such changes, variations, modifications, and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is limited only by the claims which follow.
Claims
1. An aerated pet chew, the pet chew comprising:
- (a) a body, the body including a substantially sealed, non-porous outer skin; and,
- (b) an inner portion integral with the skin, with the inner portion having a porous construction and, at least, substantially surrounded by the skin, the inner portion including a plurality of cavities or air pockets to provide the body with elastic deformability and flexibility;
- (c) a plant protein polymer in an amount ranging between about 20% and about 70%; and,
- (d) a reducing agent, whereby the disulfide bonds have been cleaved within the pet chew in a range between about 2.0% and about 75%.
2. The pet chew of claim 1, wherein the chew has a pliability equal to being bent in half, without breaking.
3. The pet chew of claim 1, wherein the chew has cavities ranging in size between 0.0005 inches and 0.040 inches.
4. A method for forming an aerated pet chew, the method comprising:
- (a) forming a dry blend composition containing a protein polymer that is biodegradable, digestible, flowable, and can be formed into a selected shape;
- (b) adding a slurry mixture to the dry blend;
- (c) adding an amount of a leavening agent to the dry blend, whereby the dry blend, slurry mixture, and leavening agent combine to form a polymeric composition;
- (d) heating the polymeric composition to achieve a homogeneous and flowable composition and activate the leavening agent to form an aerated polymeric composition;
- (e) forming the aerated polymeric composition pet chew; and,
- (f) curing the pet chew with heat to form a thermal set pet chew.
5. The method of claim 4, wherein the method further includes coating the pet chew after the forming step and prior to the curing step to eliminate sticking.
6. The method of claim 4, wherein the temperatures for heating the polymeric composition range between about 25° C. and about 75° C.
7. The method of claim 4, wherein the leavening agent is a compound that produces a gas in the presence of heat.
8. The method of claim 7, wherein the compound is selected from the group consisting of sodium bicarbonate, baking powder, sodium acid pyrophosphate, monocalcium phosphate, sodium aluminum phosphate, and combinations thereof.
9. The method of claim 4, wherein the leavening agent is a compressed gas.
10. The method of claim 9, wherein the compressed gas is selected from the group consisting of CO2, nitrogen, compressed air, helium, and combinations thereof.
11. The method of claim 4, wherein the protein polymer is a plant protein.
12. The method of claim 11, wherein the plant protein is wheat gluten.
13. The method of claim 4, wherein the curing step comprises denaturing the aerated polymeric composition pet chew by heating the pet chew at a temperature ranging between about 80° C. and about 145° C. to form a thermal set pet chew.
14. The method of claim 4, wherein the dry blend comprises plant protein equal to between about 20% and about 70% by weight of the dry blend, starch equal to between about 5% and about 50% by weight of the dry blend, and a reducing agent for cleaving disulfide bonds equal to between about 0.01% and about 0.5% by weight of the dry blend.
15. The method of claim 4, wherein the dry blend further comprises processing aids, cellulose, flavors, starch, and colors.
16. The method of claim 4, wherein the slurry mixture comprises a humectant and water.
17. The method of claim 16, wherein the humectant is selected from the group consisting of propylene glycol, glycerin, sucrose, glucose, fructose, dextrose, maltose, maltitol, sorbitol, salt, monosaccharide, disaccharide, metal salt, sodium chloride, and combinations thereof.
18. The method of claim 4, wherein the leavening agent is added in an amount ranging between about 0.05% and about 5.0% by weight of the polymeric composition.
19. The method of claim 4, wherein the method for shaping is an extrusion process that utilizes an extruder selected from the group consisting of a twin screw extruder and a single screw extruder.
20. The method of claim 16, wherein the slurry mixture comprises an amount of water ranging between about 5% and about 25% by weight of the slurry mixture.
21. The method of claim 4, which comprises a method of shaping selected from the group consisting of extrusion, injection molding, and compression molding.
22. The method of claim 16, wherein the slurry mixture comprises a humectant in an amount equal to between about 5% and about 85% by weight of the slurry mixture.
23. The method of claim 5, wherein the coating step includes adding an agent selected from the group consisting of fine milled grain flour, cornstarch, petrolatum, wheat starch, mineral oil, petroleum jellies, and combinations thereof.
24. A composition for forming an aerated polymeric composition, the composition comprising:
- (a) a dry blend;
- (b) a slurry mixture;
- (c) a leavening agent; and,
- (d) a reducing agent.
25. The composition of claim 24, wherein the dry blend comprises a compound selected from the group consisting of a plant protein polymer, processing aids, cellulose, flavors, and colors.
26. The composition of claim 24, wherein the slurry comprises a humectant and water.
27. The composition of claim 26, wherein the humectant is selected from the group consisting of propylene glycol, glycerin, sucrose, glucose, fructose, dextrose, maltose, maltitol, sorbitol, salt, monosaccharide, disaccharide, metal salt, sodium chloride, and combinations thereof.
28. The composition of claim 24, wherein the leavening agent is added in an amount ranging between about 0.05% and about 5.0% by weight of the composition.
29. The composition of claim 26, wherein the amount of water in the composition ranges between about 5.0% and about 25.0% by weight of the composition.
30. The composition of claim 24, wherein the dry blend comprises a plant protein polymer in an amount equal to between about 20% and about 70% by weight, a starch equal to between about 5% and about 50% by weight, and a reducing agent equal to between about 0.01% and about 0.5% by weight of the dry blend.
31. The composition of claim 24, further comprising a coating, wherein the coating is selected from the group consisting of fine milled grain flour, cornstarch, petrolatum, wheat starch, mineral oil, petroleum jellies, and combinations thereof.
32. The composition of claim 24, wherein the leavening agent is a compound that produces a gas in the presence of heat.
33. The composition of claim 32, wherein the compound is selected from the group consisting of sodium bicarbonate, baking powder, sodium acid pyrophosphate, monocalcium phosphate, sodium aluminum phosphate, and combinations thereof.
34. The composition of claim 24, wherein the leavening agent is a compressed gas.
35. The composition of claim 34, wherein the compressed gas is selected from the group consisting of CO2, nitrogen, compressed air, helium, and combinations thereof.
36. The composition of claim 24, wherein the dry blend comprises a compound selected from the group consisting of a plant protein polymer, processing aids, a compound that discourages infestation, and a compound that discourages consumption by animals.
37. A method for forming an aerated pet chew, the method comprising:
- (a) mixing a dry blend, with a slurry mixture, an amount of a leavening agent and a reducing agent to form a polymeric composition;
- (b) heating the polymeric composition to cause aeration in the composition and formation of an aerated polymeric composition; and,
- (c) curing the aerated pet chew with heat.
38. The method of claim 37, wherein the method further includes coating the pet chew after the formation of the aerated polymeric composition and prior to the curing step to eliminate sticking.
39. The method of claim 37, wherein the leavening agent is a compound that produces a gas in the presence of heat.
40. The method of claim 39, wherein the compound is selected from the group consisting of sodium bicarbonate, baking powder, sodium acid pyrophosphate, monocalcium phosphate, sodium aluminum phosphate, and combinations thereof.
41. The method of claim 37, wherein the leavening agent is a compressed gas.
42. The method of claim 41, wherein the compressed gas is selected from the group consisting of CO2, nitrogen, compressed air, helium, and combinations thereof.
43. The method of claim 37, wherein the dry blend further comprises a plant protein polymer.
44. The method of claim 37, wherein the curing step comprises denaturing the polymeric composition pet chew by heating the chew at a temperature ranging between about 80° C. and about 145° C. to form a thermal set pet chew.
45. The method of claim 37, wherein the dry blend comprises a plant protein polymer in an amount equal to between about 20% and about 70% by weight, a starch in amount equal to between about 5% and about 50% by weight, and a reducing agent equal to between about 0.01% and about 0.5% by weight of the dry blend.
46. The method of claim 37, wherein the leavening agent is added in an amount ranging between about 0.05% and about 5.0% by weight of the polymeric composition.
47. A method of forming an aerated product, whereby a formulation comprises from about 20% to about 70% by weight of plant protein polymer, from about 5% to about 50% by weight starch, from about 10% to about 50% by weight humectant and at least about 0.01% by weight of a reducing agent operable for cleaving disulfide bonds present in said plant protein polymer; heating the formulation to a maximum temperature of up to about 25° C. in order to render the formulation substantially homogeneous and flowable while avoiding any substantial heat denaturation of said plant protein polymer, the method comprising:
- adding an amount of a leavening agent to the formulation, wherein the leavening agent is added in an amount equal to between about 0.05% and about 5.0% by weight of the formulation.
48. A method for forming an aerated pet chew, the method comprising:
- (a) adding an amount of a leavening agent to a polymeric composition containing a reducing agent and slurry mixture to form a polymeric composition;
- (b) forming an aerated polymeric composition; and,
- (c) thermally setting the aerated polymeric composition by heating the composition at a temperature ranging between about 80° C. and about 145° C. to form a thermal set pet chew.
49. The method of claim 48, wherein the formed aerated polymeric composition is coated following the shaping step to eliminate sticking.
50. The method of claim 48, wherein the thermal set aerated pet chew is polished to remove or cover up the coating used to eliminate sticking.
51. A composition for forming a pet chew, the composition comprising:
- (a) a plant protein polymer composition;
- (b) a slurry mixture having an amount of water ranging between about 5% and about 25% by weight of the composition;
- (c) a leavening agent added in an amount ranging between about 0.05% and about 5.0% by weight of the composition; and,
- (d) a reducing agent, whereby the disulfide bonds have been cleaved within the composition in a range between about 2.0% and about 75%.
52. A method of using a plant protein polymer to form an aerated polymeric composition, the method comprising:
- (a) selecting a dry blend that is biodegradable, digestible, and that can be formed into a selected shape;
- (b) adding a slurry mixture to the dry blend;
- (c) adding an amount of a leavening agent to the dry blend and slurry mixture to form a polymeric composition;
- (d) adding an amount of reducing agent;
- (e) heating and extruding the polymeric composition to form a shaped aerated polymeric composition; and,
- (f) thermally setting the formed polymeric composition.
Type: Application
Filed: Jan 27, 2006
Publication Date: Jul 27, 2006
Applicant:
Inventors: Mark Levin (Papillion, NE), Li Nie (Parkville, MO)
Application Number: 11/341,314
International Classification: B65D 85/78 (20060101);
