Dry animal digestive components

Abstract

The dried animal digest composition may include dried animal digest particles having an animal fat content of about 16% by weight or less and a moisture content of about 3% by weight or less. In this embodiment, the dried animal digest particles have a volumetric particle size distribution with a D10 of about 20 μm to about 50 μm, a D50 of about 60 μm to about 150 μm, and a D90 of about 160 μm to about 275 μm. Furthermore, the dried animal digest composition is substantially free of a silicon dioxide flow aid.

Description

Detailed Description of the Invention

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 425,414, filed November 15, 2022, the entire disclosure of which is incorporated herein by reference.

[0002] [Background technology]

[0002] Animal digests are often used as flavorings in animal feeds, such as domestic pet foods for companion animals, e.g., canines or dogs, felines or cats, hamsters, etc. Liquid animal digests (LAD) can be produced by chemically and / or enzymatically hydrolyzing animal tissues, e.g., chicken, pork, beef, lamb, to reduce the proteins and peptides and / or fatty chains of the raw animal tissue. In preparation, the animal tissue may also be exposed to heat, physical shear, acids, alkaline compounds, and / or enzymes to aid in the breakdown of proteins and / or fats that may be present in the raw animal tissue. In some instances, the liquid animal digest can be dried to form dried animal digest (DAD) particles using any of a number of drying techniques. Regardless of whether liquid or dried animal digests are used, the goal is typically to enhance the palatability and / or nutrition of the pet food by incorporating the animal digest into the pet food. [Brief explanation of the drawings]

[0003]

[0003] [Figure 1] 1 illustrates an exemplary belt spray dryer that can be used to prepare dried animal digesta particles according to the present disclosure. [Figure 2] FIG. 1 is a graph illustrating exemplary particle size distribution values ​​for multiple samples of dried animal digesta particles, according to the present disclosure. [Figure 3] FIG. 10 is a graphical diagram illustrating further exemplary particle size distribution values ​​for multiple samples of dried animal digesta particles, particularly with respect to the presence of small particles, according to the present disclosure. [Figure 4] 1 includes scanning electron microscope images showing exemplary particle size distribution values ​​and particle morphologies according to the present disclosure. [Figure 5] 1 includes scanning electron microscope images showing exemplary particle size distribution values ​​and particle morphologies according to the present disclosure.

[0004] [Mode for Carrying Out the Invention]

[0007] The dried animal digest compositions of the present disclosure can be prepared by drying liquid animal digests containing hydrolyzed animal tissue mixed with other compounds, such as antioxidants, flavor compounds, nutritional additives, preservatives, etc. The process of making liquid animal digests can involve multiple steps, including a digestion process in which the animal tissue is hydrolyzed, followed by a thermal reaction process in which the Maillard reaction can occur. In these methods, raw animal tissues, such as meat and / or fat from chicken, pork, beef, lamb, etc., are hydrolyzed to produce shorter-chain proteins and / or peptides than those naturally prevalent in the raw animal tissue. The breakdown of the raw proteins and components of the raw animal tissue into shorter-chain hydrolyzed proteins and peptides and / or shorter-chain fats can occur by exposing the raw animal tissue to, for example, heat, physical shear, acid, and / or enzymes. Prior to the breakdown of proteins and / or fats, the raw animal tissue can contain highly concentrated proteins. In some instances, enzymatic hydrolysis and heat can be used together as an effective method of hydrolyzing proteins and / or fats to produce a hydrolysate that provides an acceptable digestible product for use in providing good nutrition and / or palatability to animals.

[0005]

[0008] Liquid animal digest can be used to prepare the dried animal digesta composition of the present disclosure, for example, using a gentle two-stage drying process. In some examples, the two-stage drying process can be carried out using a belt spray dryer. An exemplary belt spray dryer that can be used is known in the industry as the FILTERMAT® belt spray dryer from GEA (Denmark), although other belt spray dryers can also be used. The use of the gentle drying process provided by a belt spray dryer can have several advantages, such as more precise control of the drying temperature and drying resistance times in each stage, and the ability to independently control, for example, the air temperature in different zones, thereby manipulating particle properties, making it effective for drying products that may be more heat-sensitive. Belt spray dryers also work well with sticky products that may be hygroscopic and / or have a high content of short-chain carbohydrates.

[0006]

[0009] However, when using belt spray dryers, retention of very small particles, which may be sticky, can cause flow problems, even when significantly dried, for example, at a moisture content of about 0.5% to about 3% by weight. For example, belt spray dryers typically include an air pressure outlet through which the dried product is pneumatically pumped and collected in a container (possibly after grinding). The air pressure outlet can clog as a result of the lack of flowability of the dried product, e.g., dried animal digesta particles. One promising solution to alleviate clogging is the inclusion of chemical flow aids or nanomaterials, such as silicon dioxide (SiO). However, environmental trends have led to the removal of these types of nanomaterials from many commercial products. Furthermore, even when silicon dioxide is present at concentrations that may provide some clogging improvement, it remains difficult to reduce clogging sufficiently to be useful, especially for large batches in which the dried particles exhibit stickiness. Thus, the advantages of using a gentle belt spray dryer (particularly the absence of silicon dioxide as a flow aid) present engineering challenges associated with preparing dry animal digesta particles from liquid animal digesta.

[0007]

[0010] According to embodiments of the present disclosure, a dry animal digest composition includes dried animal digest (DAD) particles having an animal fat content of about 16% by weight or less and a moisture content of about 3% by weight or less. The dried animal digest particles may have a volume diameter particle size distribution with a D10 of about 20 μm to about 50 μm, a D50 of about 60 μm to about 150 μm, and a D90 of about 160 μm to about 275 μm. Furthermore, the dry animal digest composition may be substantially free of silicon dioxide flow aids. In some examples, the percentage of dry animal digest particles less than 30 μm based on volume diameter may be 3% to 20% and / or the percentage of dry animal digest particles less than 45 μm based on volume diameter may be 5% to 25%. The volume mean diameter of the dried animal digest particles may be, for example, about 60 μm to about 160 μm. More specifically, the D10 can be about 25 μm to about 40 μm, the D50 can be about 75 μm to about 125 μm, and / or the D90 can be about 185 μm to about 250 μm. The dry animal digesta composition, in some examples, can be completely free of silicon dioxide flow aids and can also be free of chemical flow aids selected from the group consisting of clays, flours, fly ash, quicklime, starches (natural or modified), zeolites, silicates, stearates, phosphates, polysaccharides, salts of fatty acids, and carbonates, e.g., calcium carbonate, diatomaceous earth, bamboo shoots, corn cobs, pea fiber, pea hulls, citrus fiber, cellulose powder, and / or microcrystalline cellulose. These additives can be in the form of particulates, solutions, dispersions, extracts, and the like.

[0008]

[0011] The dried animal digest particles may contain, for example, about 40% to about 80% by weight of protein and about 10% to about 16% by weight of fat. To keep the animal fat content in the dried animal digest particles low, in some examples, about 80% to 100% by weight of the animal tissue used to prepare the dried animal digest particles may be derived from liver tissue, and in other examples, the animal tissue used to prepare the dried animal digest particles may be pre-processed to remove animal fat. The dried animal digest compositions of the present disclosure may be entirely (100% by weight) dried animal digest particles, or in some examples, 25% to 99.99% by weight of the dried animal digest composition may consist of dried animal digest particles, and 0.01% to 75% by weight of the animal digest composition may consist of one or more additives selected from the group consisting of, for example, phosphate compounds, pyrophosphate compounds (e.g., tetrasodium pyrophosphate (TSPP)), choline compounds, amino acids, vitamins, probiotics, egg yolk, and yeast. These may be added after the drying process in some examples. However, in some examples, the dried animal digest particles may be prepared to include yeast.

[0009]

[0012] In another example, a pet food composition may include a kibble and a dried animal digest composition applied to the kibble. The dried animal digest composition may include dried animal digest particles, and the pet food composition as a whole may include about 0.5% to about 5% by weight of the dried animal digest particles. The dried animal digest particles may have an animal fat content of about 16% or less by weight and a moisture content of about 3% or less by weight, based on the total weight of the dried animal digest particles. Further, the dried animal digest particles may have a volume size distribution in which D10 is about 20 μm to about 50 μm, D50 is about 60 μm to about 150 μm, and D90 is about 160 μm to about 275 μm. The dried animal digest composition may be substantially free of silicon dioxide flow aids. In some examples, the pet food composition may include about 1% to about 12% by weight of additional animal fat coated on the kibble, based on the total weight of the pet food composition. In other examples, the dried animal digest particles can be applied to the kibble at about 0.8% to about 3.5% by weight, based on the total weight of the pet food composition. In some examples, the dried animal digest composition applied to the kibble is 100% by weight of dried animal digest particles. In other examples, the dried animal digest applied to the kibble is 25% to 99.99% by weight of dried animal digest particles and 0.01% to 75% by weight of one or more additives selected from the group consisting of tetrasodium pyrophosphate (TSPP), choline compounds, amino acids, vitamins, probiotics, egg yolk, and yeast.

[0010]

[0013] In another example, a method for preparing a pet-consumable composition, e.g., a dried animal digesta composition or a pet food composition, can include hydrolyzing proteins and fats from raw animal tissue to form a mixture of short-chain proteins and / or peptides and fatty acids (and, in some instances, amino acids). The method can also include introducing heat and a reactive compound to the mixture to initiate a thermal reaction and form a liquid animal digesta, and drying the liquid animal digesta using a belt spray dryer to form dried animal digesta particles having a volume mean diameter of about 60 μm to about 160 μm, an animal fat content of about 16% by weight or less, and a moisture content of about 3% by weight or less. The pet-consumable composition can be substantially free of silicon dioxide flow aids. In some examples, the dried animal digesta particles can have a volume diameter particle size distribution with a D10 of about 20 μm to about 50 μm, a D50 of about 60 μm to about 150 μm, and a D90 of about 160 μm to about 275 μm. In other examples, the method further comprises applying about 0.5% to about 5% by weight (based on the total weight of the pet food composition) of dry animal digest particles to the kibble to form the pet food composition.

[0011]

[0014] It should be noted that when discussing examples described herein relating to methods of preparing dried animal digesta compositions, pet food compositions, and / or pet-edible compositions, such discussions can be considered applicable to one another, regardless of whether they are explicitly discussed in the context of the example. Thus, for example, when discussing "dried animal digesta particles" in the context of dried animal digesta compositions, such disclosure is also relevant to and directly supported in the context of methods of preparing pet food compositions and pet-edible compositions, and vice versa.

[0012]

[0015] Furthermore, terms used herein have their ordinary meaning in the relevant art unless otherwise specified. In some cases, there are more specifically defined terms throughout the specification, and some more general terms are included at the end of the specification. These more specifically defined terms have the meanings set forth herein.

[0013] Dried animal digest composition

[0016] The dried animal digesta composition of the present disclosure can be prepared from dried animal digesta (DAD) particles, which can be prepared from liquid animal digesta (LAD). Essentially, liquid animal digesta can be introduced into the dryer as a feed source. The resulting dry product is referred to herein as dried animal digesta particles. A belt spray dryer can be used to produce the dried animal digesta particles of the present disclosure. An exemplary belt spray dryer found suitable for use is the FILTERMAT® spray dryer. Alternatively, the dried animal digesta composition can be prepared solely from dried animal digesta particles (100% by weight), or the dried animal digesta particles can be combined or homogenously mixed with other dry additives or ingredients, which may be added after the drying process. Thus, in some cases, the dry animal digest composition may comprise 100% by weight of dried animal digest particles, while in other examples, the dry animal digest composition may comprise less than 100% by weight of dried animal digest particles in combination with other additives, such as tetrasodium pyrophosphate (TSPP), choline compounds, amino acids, vitamins, probiotics, egg yolk, and / or yeast, etc. The compounds in some examples may be in the form of a salt, chelate, phospholipid, hydroxide, or oxide, etc., such as, for example, a choline halide, a choline phospholipid, a choline hydroxide, an amino acid complex, an amino acid chelate, a protein complex, etc.

[0014]

[0017] To illustrate the inclusion of additive(s), a dry animal digesta composition can comprise 25% to 99.99% by weight of dry animal digesta particles and 0.01% to 75% by weight of one or more additives. In other examples, the dry animal digesta composition can comprise 35% to 99.99%, 50% to 99.99%, 75% to 99.99%, or 90% to 99.99% by weight of dry animal digesta particles, with other additive(s) combined with such particles being present as the remainder of the dry weight content, excluding, for example, moisture content. As one specific example, the dry animal digesta composition can comprise 40% by weight of dried animal digesta (collected from a belt spray dryer) mixed with 40% by weight of yeast and 20% by weight of tetrasodium pyrophosphate as additives.

[0015]

[0018] In examples of the present disclosure, the dry animal digesta composition may comprise dry animal digesta particles having an animal fat content of about 16% by weight or less and a moisture content of about 3% by weight or less, and may be substantially free or completely free of silicon dioxide flow aids. In some examples, the dry animal digesta particles may also be free of chemical flow aids selected from the group consisting of clay, flour, fly ash, quicklime, starch (natural or modified), zeolite, silicates, stearates, phosphates, polysaccharides, salts of fatty acids, and carbonates, such as calcium carbonate, diatomaceous earth, bamboo shoots, corn cobs, pea fiber, pea hulls, citrus fiber, cellulose powder, or microcrystalline cellulose, starch (natural and modified), and the like. The animal fat content may be, for example, from about 10% by weight to about 15.9% by weight, or from about 12% by weight to about 15.5% by weight. The moisture content can be, for example, about 0.5% to about 2.9% by weight, about 1% to about 2.7% by weight, about 1.2% to about 2.6% by weight, about 1.5% to about 2.4% by weight, or about 1.8% to about 2.0% by weight. In some examples, the dried animal digest particles can have a protein content of about 40% to about 80% by weight, or about 50% to about 70% by weight.

[0016]

[0019] With respect to particle size distribution, in some examples, the dried animal digest particles may have a volume diameter particle size where D10 is about 20 μm to about 50 μm, or about 25 μm to about 40 μm. The D50 volume diameter particle size may be about 60 μm to about 150 μm, or about 75 μm to about 125 μm. The D90 volume diameter particle size may be about 160 μm to about 275 μm, or about 185 μm to about 250 μm. In some examples, the percentage of dried animal digest particles less than 30 μm based on volume diameter may be about 3% to about 20%, or about 5% to about 15%. In other examples, the percentage of dried animal digest particles less than 45 μm based on volume diameter may be about 5% to about 25%, or about 10% to about 22%. In some examples, the volume mean diameter of the dried animal digest particles can be from about 60 μm to about 160 μm, or from about 80 μm to about 130 μm.

[0017]

[0020] "Volume diameter" refers to a hypothetical spherical particle having the same volume as a physically existing particle. The volume diameter of a powder in the range under consideration can be estimated using laser diffraction (light scattering), dynamic image analysis, or static image analysis, which can be verified, for example, using a scanning electron microscope (SEM).

[0018]

[0021] Volume diameter particle sizes may be reported in terms of D10, D50, D90, or volume mean diameter values. For example, a "D50" particle size is the particle size value at which about 50% of the particles (by number) are smaller and about 50% of the particles are larger, based on the spherical equivalent diameter of the particle volume. A "D10" particle size is the particle size value at which about 10% of the particles (by number) are smaller and about 90% of the particles are larger. A "D90" particle size is the particle size value at which about 90% of the particles (by number) are smaller and about 10% of the particles are larger. The volume mean diameter is similar to the D50 value, but this value does not represent the median of a particle population, but rather represents the average diameter based on an equivalent spherical particle volume.

[0019]

[0022] A good source animal tissue for producing dried animal digest particles having an animal fat content of about 16% or less by weight can be liver from any of a number of animals, such as chicken, pig, cow, etc. Thus, in some examples, the dried animal digest particles can be prepared from 80% to 100% liver tissue by weight. In other examples, the animal tissue used to prepare the dried animal digest particles can be pre-treated to remove animal fat using a process such as centrifugation.

[0020]

[0023] According to industry standards, there are generally two types of animal digesta compositions: natural and non-natural. Natural animal digesta may contain some additives used in processing, but does not contain other additives. An animal digesta is considered non-natural if it is not natural. For example, an animal digesta is considered "natural" if it contains raw materials / additives, such as naturally occurring amino acids, amino peptides, amino proteins, reducing sugars, and / or other natural additives, but does not contain certain artificial additives and / or preservatives. In further detail, AAFCO defines natural as a feed or feed ingredient derived exclusively from plant, animal, or mined sources, either in a raw state or subjected to physical, thermal, rendering, purification, extraction, hydrolysis, enzymatic degradation, or fermentation, but not produced or subjected to chemical synthetic methods, and does not contain any chemically synthesized additives or processing aids, except in amounts that may occur in good manufacturing practices. For example, additives such as tocopherol, rosemary extract, and ascorbic acid can be included as antioxidants according to the definition of natural ingredients as defined by AAFCO. Additives such as BHA, PG, BHT, and OG are examples of non-natural ingredients as defined by AAFCO. Notably, this example relates to the U.S. definition, while relevant European regulations are more restrictive. For example, xylose is considered a natural product occurring in nature in the U.S., but is not considered natural in Europe because the extraction process exceeds what is considered natural. Therefore, as defined herein, the distinction between natural and non-natural is based on the U.S. definition as of the earliest priority date of this application.

[0021]

[0024] According to embodiments of the present disclosure, dry animal digest compositions can be prepared from either natural or non-natural liquid animal digests, resulting in compositions containing either natural or non-natural dry animal digest particles.

[0022]

[0025] Furthermore, in some examples, dry animal digest compositions can be prepared to include dry animal digest particles containing one or more antioxidants. For example, the liquid animal digest used to prepare the dry animal digest particles can include antioxidant(s) added at any stage of the preparation process. For example, antioxidant(s) may be added before digestion or during digestion to break down proteins and / or fats. Antioxidant(s) may also be added after digestion, e.g., before, during, or after the reaction process. In particular, antioxidants can be used to prevent oxidation often associated with the presence of fat. Including about 0.01% to about 0.2% by weight of antioxidant(s) can protect the resulting liquid animal digest, and ultimately the resulting dry animal digest composition, from oxidation. Examples of antioxidants that can be selected for use include natural or synthetic antioxidants, such as butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate, octyl gallate, tocopherol, rosemary extract, ascorbic acid, citric acid, or combinations thereof.

[0023] Pet food composition

[0026] According to other examples herein, pet food compositions can be prepared. For example, dried animal digest particles can be prepared and applied to any of a number of pet food bases / pellets, generally referred to herein as "kibble." The term "applied" refers to combining the dried animal digest particles with the kibble by coating on the kibble, incorporating within the kibble, homogeneously mixing with the kibble, or a combination thereof. The dried animal digest used to prepare the pet food composition can include hydrolyzed animal tissue, antioxidant(s), and / or other additives that can be prepared as a liquid animal digest and then dried as described herein to maintain an animal fat content of about 16% by weight or less and a moisture content of less than 3% by weight. For example, about 0.5% by weight to about 5% by weight, or about 0.8% by weight to about 3.5% by weight, of the dried animal digest particles can be applied to the kibble, based on the total weight of the pet food composition.

[0024]

[0027] The dried animal digest particles used to apply to the kibble may have a volume size distribution with a D10 of about 20 μm to about 50 μm, a D50 of about 60 μm to about 150 μm, and a D90 of about 160 μm to about 275 μm. Additionally, the dry animal digest composition may be substantially free of silicon dioxide flow aids, or in some instances, may be completely free of silicon dioxide flow aids.

[0025]

[0028] Further details regarding the prepared dry animal digest composition containing the above-described dried animal digest particles are applicable to pet food compositions and are incorporated herein. However, the weight percentages of various ingredients within the dry animal digest composition can be converted to the weight percentages of these various ingredients applied to the kibble when forming the pet food composition based on the solids content. In other words, unless expressly indicated otherwise, when referring to the content of any particular ingredient in the pet food composition described herein, the weight percentage refers to the content of the pet food composition based on the total weight of the prepared pet food composition. For example, the dried animal digest particles applied to the kibble may include the use of the aforementioned dry animal digest composition, which may contain an animal fat content of up to about 16 wt.% (based on the total weight of the dry animal digest composition); however, after application to the kibble at an application weight of about 1 wt.% to about 3 wt.% (based on the total weight of the pet food composition), the animal fat content provided by the dry animal digest composition, in this example, remains in the pet food composition at a maximum of about 0.16 wt.% to about 0.48 wt.%. When the moisture content of the dried animal digesta composition is less than 3% by weight, the moisture content inherent in the kibble is also believed to be present, and therefore this value is primarily based on the moisture content of the kibble, and is believed to be minimally affected by the application of the dried animal digesta particles of the dried animal digesta composition. With this in mind, the moisture content of the pet food composition as a whole, when packaged for distribution and / or other use, can typically range from about 2% to about 12% by weight, about 3% to about 10% by weight, or about 4% to about 10% by weight. In some instances, immediate packaging can be implemented if the goal is to retain some moisture. While moisture contents outside these ranges may exist, these moisture content ranges provide a good balance between the energy savings associated with removing excess moisture and the product waste associated with maintaining a higher moisture content, for example, without the use of additional preservatives.

[0026]

[0029] More specifically, the dry animal digest composition that can be applied to kibble can contain not only dry animal digest particles but also other additives, such as antioxidant(s), which can be added to protect the hydrolyzed animal fat from undesired oxidation during the preparation of the dry animal digest composition and / or during storage before use. As mentioned above, if a liquid animal digest is prepared before drying, the antioxidant(s) can be added before the digestion process (when or after grinding the animal tissue for addition to the reactor) or during the digestion process, but they can also be added at a later point in the overall process of preparing the dry animal digest composition. Because oxidation can begin soon after grinding the animal tissue and can be accelerated by heating, it may be more typical to add the antioxidant(s) at about this point. It should also be noted that stabilizing or formulation ingredients can also be added during digestion or at any stage during the preparation of the dry animal digest. However, according to the examples of the present disclosure, a silicon dioxide flow aid is typically not included. The drying process described herein can result in the formation of dried animal digesta particles that are sufficiently fluid and non-sticky to avoid clogging of the air pressure outlet after the drying process, for example, using a belt spray dryer apparatus. Other additives that can be included, such as the addition of pyrophosphate and / or yeast, can help improve palatability, and these additives can be incorporated into the dried animal digesta particles for drying and / or throughout the dried animal digesta composition after drying. The pyrophosphate and / or yeast can be present in the pet food composition (total, based on the total weight of the pet food composition) at the concentrations described above.

[0027]

[0030] In some examples, other palatable and / or nutritional additives can be applied to or incorporated into the kibble as well, such as the separate application of animal fat, e.g., rendered animal fat, or vegetable oil. When additional animal fat is added to the dried animal digesta composition, the additional animal fat added to provide a total animal fat content of more than 16% by weight of the dried animal digesta particles is typically not added before drying the dried animal digesta particles because it can cause clogging of the air pressure pipes. In other examples, the additional animal fat can be applied to the kibble separately from the application of the dried animal digesta composition. The animal fat that can be used can be partially unhydrolyzed or completely unhydrolyzed. Examples of animal fats or rendered animal fats that can be used include beef tallow, rendered pork fat, chicken fat, fish oil, etc. The animal fat can be applied in a weight range of about 1 wt % to about 12 wt %, about 2 wt % to about 12 wt %, about 3 wt % to about 10 wt %, or about 4 wt % to about 10 wt %, based on the total weight of the pet food composition. The application of additional animal fat to the kibble can, in some cases, provide enhanced palatability. After the dry animal digest composition is prepared, the dry animal digest composition can, in some cases, be applied to the kibble using any of a number of techniques, such as batch and / or continuous mixing, co-pelleting, etc.

[0028] Method for preparing a pet ingestible composition According to another example of the present disclosure, a method for preparing a pet-consumable composition is disclosed. The term "pet-consumable composition" encompasses both dry animal digest compositions and pet food compositions prepared using the dry animal digest compositions described herein. The method may include hydrolyzing proteins and fats from raw animal tissue to form a mixture of shorter-chain proteins and / or peptides and fatty acids, and in some cases, amino acids may also be produced. The method may further include introducing heat and a reactive compound to the mixture to initiate a thermal reaction and form a liquid animal digest. As an example, amino acids may be produced depending on the enzyme used. With respect to animal fats, fatty acids may be produced from triglycerides (triacylglycerols, TAGs, or triacylglycerides). This may be particularly true when liver is used as the raw animal tissue, for example, triglycerides are produced in the liver. However, fatty acids may, in some examples, be hydrolyzed from phospholipids.

[0029]

[0031] More specifically, the method can include drying the liquid animal digest along a belt spray dryer, such as a FILTERMAT® spray dryer, to form dried animal digest particles having a volume mean diameter (VMD) of about 60 μm to about 160 μm, an animal fat content of about 16% by weight or less, a moisture content of about 3% by weight or less, and being substantially free of silicon dioxide flow aids. Further details regarding volume particle size, volume mean diameter, percentage of particles less than 30 μm and 45 μm, etc. that can be used in the method have been provided previously. In some examples, the method can further include applying about 0.5% by weight to about 5% by weight, or about 0.8% by weight to about 3.5% by weight, of the dried animal digest particles to the kibble, based on the total weight of the pet food composition. More particularly, with respect to pet food compositions, the method may include applying from about 1% to about 12%, from about 2% to about 10%, or from about 3% to about 8% by weight of a fat coating to the pet food composition, based on the dry content of the pet food composition.

[0030]

[0032] As mentioned above, dry animal digesta particles (DAD) are prepared from liquid animal digesta (LAD). Liquid animal digesta can be prepared by sequentially performing two processes: a digestion process followed by a thermal reaction process. For digestion, animal tissues from various raw materials, such as beef, chicken, pork, lamb, venison, sheep, fish, crustaceans, insects, shellfish, etc., including muscle, organs (such as viscera and liver), epithelial tissue, connective tissue, and fat, can be ground and blended together.

[0031]

[0033] Regarding the selection of raw animal tissues with low initial animal fat content, more specific examples of suitable examples include various liver tissues, such as chicken liver, pork liver, and beef liver. For example, chicken liver and / or pork liver may have an initial percentage of animal fat content of about 2.5% to about 6% by weight, or about 3% to about 5% by weight, with the animal fat content of pork liver typically being slightly lower than that of chicken liver. The drying process can increase the total relative weight percent of animal fat content as volatile substances, such as water, evaporate from the liquid animal digest. However, according to the present disclosure, particularly when the raw animal tissues selected for inclusion contain a large amount of, for example, liver tissue, the animal fat content of dried animal digest particles prepared from such animal tissues can be maintained at about 16% by weight or less. For example, a blend of 50% chicken liver and 50% pork liver can be used to prepare dry animal digest particles having an animal fat content of about 12% to less than about 16% by weight, or about 13.5% to about 15.5% by weight, and a moisture content of about 3% or less by weight. More specifically, there are other raw animal tissues or blends of raw animal tissues available for use that may have a somewhat higher initial animal fat content but still have a relatively low initial animal fat content, such as heart tissue, a blend of liver and heart tissue, or a blend of liver, heart, and lung tissue (sometimes referred to as "offal" or "chicken pluck" in the case of raw animal tissues derived from chicken). When used in appropriate amounts, various blends of raw animal tissues (other than those made solely from liver) can be used to prepare dry animal digest particles having a fat content of about 16% or less by weight. For example, for an animal tissue, e.g., meat, ingredient of the formulation, a blend of 80% by weight liver with up to 20% by weight other tissues may result in a final dry animal digest particle that also has about 16% by weight or less animal fat.More specifically, pork liver having an initial animal fat content of about 3% by weight can be combined with an offal and chicken heart blend having an initial animal fat content of about 6% by weight in a 4:1 weight ratio to obtain dried animal digesta particles having an animal fat content of 15.1% by weight. In some examples, when animal tissue with a higher fat content is used initially in greater amounts, the animal tissue may be pre-processed to remove a portion of the animal fat content so that the animal fat content of the dried animal digesta particles remains at or below about 16% by weight. For example, the animal tissue may be pre-processed using centrifugation or other methodologies to remove a portion of the animal fat prior to drying in a belt spray dryer in accordance with the present disclosure.

[0032]

[0034] For purposes of this disclosure, the term "raw animal tissue" refers to any animal tissue, including meat, fat, bone, organs, tendons, etc., that can be recovered and used to make the liquid animal digesta of the present disclosure. For example, the Association of American Feed Control Officials (AAFCO) defines animal digesta as including materials resulting from the chemical and / or enzymatic hydrolysis of clean, undecayed animal tissue, and the animal tissue used shall be free of hair, horns, teeth, hooves, and feathers, except in trace amounts such as may inevitably occur in good factory practice, as appropriate. Thus, in many instances, ground or powdered raw animal tissue can be used to make liquid animal digesta that meets the AAFCO definition, and such animal tissue can include meat from a variety of sources, such as muscle, organs (such as offal, liver, etc.), epithelial tissue, connective tissue, fat, etc., from beef, chicken, pork, lamb, venison, sheep, fish, crustaceans, insects, or shellfish. In more specific detail, raw animal tissue may include any meat or other tissue that is edible but would not enter the human food supply chain. For example, raw animal tissue may include a "meat mix," which may be a ground mixture of animal tissues, such as pork, liver, spleen, trachea, lungs, etc. In that regard, according to the present disclosure, the selection of raw animal tissue should be such that the dried animal digesta particles formed therefrom have an animal fat content of about 16% or less by weight and a moisture content of less than about 3% by weight.

[0033]

[0035] After raw animal tissue is selected, ground, and blended, steam can be used to obtain a pumpable mixture that can be easily transferred to a reactor to begin the digestion process. The pumpable mixture of animal tissue used to form the liquid animal digesta can include or be mixed with ingredients for the digestion process other than the main portion of the raw animal tissue, such as industrial enzymes (e.g., 0.01% to 1% by weight to hydrolyze the animal tissue), and optionally pH adjusters (e.g., 0.1% to 1.5% by weight to achieve a target pH), antioxidants (e.g., 0.01% to 0.2% by weight), and / or yeast. Thus, digestion can be performed on the raw animal tissue using industrial enzymes, which can include proteases, lipases, or both, and the animal tissue can be hydrolyzed during this digestion. Exemplary proteases can include chymosin, pepsin, trypsin, papain, bromelain, subtilisin, and the like. Some raw animal tissues, such as animal organs, can be used that naturally contain proteases and / or lipases. These enzymes can be employed for use during digestion, or some or all of these enzymes can be inactivated by heat or other methods to facilitate the addition of industrial enzymes. pH and temperature can be adjusted appropriately depending on the particular application. For example, pH can be adjusted as desired using sodium hydroxide, potassium hydroxide, phosphoric acid, etc. For example, in some instances, the pH can be increased by adding, for example, sodium hydroxide or potassium hydroxide, to enhance the functionality of the enzymes used during digestion. In other instances, the pH can be decreased by adding, for example, phosphoric acid, to enhance enzyme activity or for some other purpose. Temperature can be adjusted to suit the enzymes used, for example, by adding steam adjusted (raised or lowered) to a temperature selected to be high enough to perform digestion but low enough to maintain enzyme activity.

[0034]

[0036] When yeast is added to the pumpable mixture or raw animal tissue during the preparation of the liquid animal digesta (or at any time thereafter), yeast can be included in any amount such that the dry animal digesta produced from such liquid animal digesta contains at least 50% animal tissue by weight and less than 16% animal fat by weight. Thus, even when a relatively large amount of yeast is included, raw animal tissue may be present at 50% or more by weight of the pumpable mixture, and typically, 60% or 70% or more by weight of the pumpable mixture comprises raw animal tissue. In some examples, raw animal tissue can be present at 80% or more by weight, 90% or more by weight, 95% or more by weight, or 98% or more by weight in the pumpable mixture in the preparation of the liquid animal digesta, even when other ingredients are added later in the process of preparing the liquid animal digesta. More specifically, when yeast is added in the preparation of the liquid animal digest feedstock (for the preparation of dried animal digest particles), raw animal tissue can be combined with yeast in a tissue-to-yeast weight ratio of about 2:1 to about 199:1, about 3:1 to about 99:1, about 4:1 to about 99:1, or about 6:1 to about 50:1. In some examples, yeast can be added during the preparation of the liquid animal digest, as described above. That is, adding some yeast when preparing the liquid animal digest can provide another method of reducing the total animal fat content present in the dried animal digest particles formed during the belt spray drying process described herein. In particular, yeast or other additives can be present in combination with the dried animal digest particles (which may or may not already contain some yeast) when preparing the dried animal digest compositions described herein.

[0035]

[0037] In some examples of preparing liquid animal digesta, raw animal tissue can be comminuted and then processed to obtain an intermediate product comprising hydrolyzed animal tissue. The term "hydrolyzed" with respect to animal tissue, e.g., proteins and / or fats, refers to raw animal tissue that has been broken down into shorter chain length proteins, peptides, and / or fatty acids based on the average chain length compared to the proteins and / or fats of the raw animal tissue source. Hydrolyzed animal tissue can be broken down via any of a number of processes, including, for example, processes utilizing heat, shear, acid, and / or enzymes.

[0036]

[0038] Thus, hydrolyzed animal tissue is formed in a process called "digestion," in which raw animal tissue is broken down and certain ingredients are added, leaving behind hydrolyzed animal tissue. Note that "digestion" or "digestive process" does not refer to the digestion that occurs in the GI tract of an animal, but rather is a technical term that refers to the breakdown of proteins and / or fats in the preparation of animal digesta. By way of example, processing raw animal tissue by digestion can include the use of enzymes, such as proteases to break down proteins in the raw animal tissue and, in some cases, lipases to break down fats in the animal tissue. Enzymes are typically considered processing aids because they are used and inactivated during digestion. Other chemicals or ingredients can additionally or alternatively be included to break down fats and / or proteins. More specifically regarding enzymes that can be added, such as proteases and / or lipases, these enzymes are sometimes referred to as "technical enzymes" and are not the same as natural enzymes that may be naturally present in the raw animal tissue. For example, with particular reference to proteases, there are several types of industrial enzymes or enzyme packages that can be used in protein digestion, including endoproteases, which break down peptide bonds between non-terminal amino acids within a protein or peptide, and / or exopeptidases, which cleave amino acids at the termini of a protein or peptide. Examples of endoproteases include chymosin, pepsin, trypsin, papain, bromelain, subtilisin, and the like. Some raw animal tissues, such as animal organs, can be used, which naturally contain proteases and / or lipases. These enzymes can be employed for use during digestion, or some or all of these enzymes can be inactivated by heat or other processes to favor the addition of industrial enzymes.

[0037]

[0039] When heat is used during the digestion process, heating can be accomplished by any of a number of methods, such as steam injection or jacket heating. In some examples, steam injection can be particularly useful because it uses a relatively small amount of water, e.g., about 5% to about 25% by weight or about 7.5% to about 20% by weight, based on the total weight of the ingredients used to prepare the liquid animal digest, and can also provide rapid heating to promote the breakdown of raw animal tissue into hydrolyzed animal tissue. Heat can also be used to inhibit or stop the enzymatic activity of some enzymes. For example, some raw animal tissues contain protease and lipase enzymes, but temperatures above about 55-60°C can inactivate many of these enzymes. As temperatures increase, other enzymes can also become inactive. Therefore, in some examples, industrial enzymes that survive temperatures above about 55°C or above about 65°C can be added so that the added industrial enzymes act primarily to hydrolyze the raw animal tissue. In some systems, the processing temperature may be, for example, about 55°C to about 80°C, about 62°C to about 80°C, about 65°C to about 77°C, about 65°C to about 74°C, about 65°C to about 72°C, or about 68°C to about 74°C. These ranges are provided for illustrative purposes only based on many of the industrial enzymes that can be used to perform the digestion, and temperatures outside these ranges may also be used. Accordingly, a heating temperature profile can be selected that allows some or all of the enzyme activity to occur during the digestion.

[0038]

[0040] After digestion, the intermediate digestive composition undergoes a "reaction process" or "reaction," sometimes referred to as the "Maillard reaction." The reaction process may, in some cases, be a thermal reaction process. The reaction process is associated with the stage at which additional flavors of the digesta are generated. More specifically, the Maillard reaction is an organic chemical reaction in which reducing compounds, e.g., sugars, react with amino acids to form a complex mixture of volatile and non-volatile compounds. This reaction can be classified as a non-enzymatic browning reaction and can occur at a variety of temperatures, from room temperature to temperatures significantly higher than room temperature. However, in many reaction processes, the process is a "thermal reaction" process that occurs at elevated temperatures, e.g., from about 80°C to about 130°C, from about 80°C to about 115°C, or typically from about 90°C to about 105°C, which may be higher than the temperatures used during the digestion process. Depending on the flavor compounds added, the temperature, pH, and / or the time profile used, the reaction process can produce multiple flavor compounds that can be decomposed from other flavor compounds. In some examples, amino compounds, such as amino acids, amino peptides, and / or amino proteins, can be combined with reducing sugars, such as monosaccharides (such as xylose, ribose, fructose, or glucose), disaccharides (such as lactose), and a reaction can be initiated under heat. Furthermore, throughout the reaction process, the compounds used to initiate the reaction (or other added compounds) can be selected for use to satisfy a flavor profile depending on the type of animal the dried animal digest composition will be used to feed. Thus, any of a number of specific compounds can be used in the reaction process to provide a variety of flavor profiles, such as any of the naturally occurring amino acids, amino proteins, and / or peptides, xylose, ribose, fructose, glucose, lactose, etc., that can be added to modify the flavor and / or enhance the nutritional value of the dried animal digest composition being prepared.

[0039]

[0041] A reaction process can then be initiated to bring the mixture to the appropriate temperature for the thermal reaction to occur. The liquid animal digestate prepared from this process may then be filtered to remove any undigested material, and the liquid animal digestate may be prepared as a feedstock material for introduction into a belt spray dryer. In some instances, the liquid animal digestate may be transferred directly to a surge tank without the need for cooling, concentration, or pH adjustment. A surge tank may be used to introduce the liquid animal digestate into a belt spray dryer, for example, as illustrated in FIG. 1 below.

[0040]

[0042] In some examples of the present disclosure, it has been found that the preparation of dried animal digest particles can be carried out without the inclusion of certain chemical flow aids, such as silicon dioxide. Many industries avoid nanoparticles in their products for environmental reasons, but removing chemical flow control aids from the drying process can be a challenge. For example, when feeding conventional liquid animal digest into a belt spray dryer, the surfaces of the particles formed can become sticky and clump together, clogging the machine and ultimately interrupting the manufacturing process. Some small particles can also cause machine clogging if not controlled. Furthermore, even when some silicon dioxide is used as a flow aid for dried animal digest particles, some clogging can still occur.

[0041]

[0043] Therefore, it has been recognized that by formulating liquid animal digest so that the dried animal digesta particles prepared from such digesta have a low animal fat content, for example, an animal fat content of about 16% by weight or less, and drying such particles to a moisture content of less than about 3% by weight, it becomes possible to use a belt spray dryer. Belt spray dryers offer several advantages in producing dried animal digesta particles, including good control of particle size distribution and a gentler drying process compared to other spray drying methodologies. By controlling the animal fat content, moisture content, and particle size distribution as defined herein, the dried animal digesta particles formed for distribution through pneumatic pipes are sufficiently non-sticky, flowable, and dispensable to avoid clogging, even in the absence of added silicon dioxide flow aids.

[0042]

[0044] To provide further detail, and referring now to Figure 1, an exemplary belt spray dryer 100 is shown in which liquid animal digestate feedstock 102 is introduced from a surge tank 104 through multiple nozzles 110 into a drying chamber 120 where atomization pressure produces atomized feedstock 112. Drying chamber parameters can be controlled by the supply of heated air via an air flow supply assembly, which in this particular example includes air intake 142A, air intake valve 144A, air filter 146A, and in-line heater 148A. The liquid animal digestate atomized feedstock thus falls through the drying chamber and is partially dried to form sticky particles 114 that are received by a dryer conveyor 130. As the sticky particles pass along the dryer conveyor, some of the smaller particles 118 may fall through the porous dryer conveyor and pass through a small particle collector assembly 132, where they may be transported to a bag filter assembly 134 for reprocessing. The bag filter assembly may include a valve, an exhaust assembly 136, and / or other components for removing fines 138 from the exhaust assembly 136. The sticky particles on the dryer conveyor are transported through multiple drying zones, as shown at 140A, 140B, and 140C. Heat and airflow are supplied to the various drying zones, which may be specific to that particular drying zone, using a separate airflow supply assembly. This second airflow assembly may similarly include an air intake 142B, an air intake valve 144B, an air filter 146B, and an in-line heater 148A. Thus, one of the lines (h) may be heated. However, one of the lines (c) may not have an in-line heater as shown in this particular example, as cold air may be supplied as well. As shown in this example, a heat distribution manifold 150 can be used to create drying profiles, e.g., heat and airflow, in the various drying zones designated 140A-C.As an example, drying zone 140A may be configured to receive more heat than drying zone 140B, which may be configured to receive more heat than drying zone 140C; this configuration is the configuration shown in this figure, although the drying profile may also differ from that shown.

[0043]

[0045] After passing through the various drying zones 140A-C, the partially dried animal digesta particles are fed from the dryer outlet 160 to a pneumatic pipe 162, which in this particular example comprises a pneumatic conveying section 162A and a pneumatic outlet 162B. The dried animal digesta particles 116 fed to the pneumatic conveying section may or may not have a moisture content of about 3% or less by weight at this point, but the fed dried animal digesta particles should have a moisture content of about 3% or less by weight (and an animal fat content of about 16% or less by weight), based on the total weight of the dried animal digesta particles, by the time the dried animal digesta particles are fed through the pneumatic outlet to a collection bin 180 or storage bin.

[0044]

[0046] If too many small particles are present when the dried animal digesta particles reach the pneumatic outlet for delivery to the collection vessel, the pneumatic pipe, e.g., the pneumatic conveying section and / or the pneumatic outlet, may become clogged, potentially shutting down production. For example, too many small particles less than about 10-15 μm (based on volume diameter particle size) may cause clogging problems. In some instances, if the proportion of dried animal digesta particles less than about 15 μm exceeds about 5-10% by particle number, the tendency for clogging may increase significantly. Furthermore, the tendency for clogging may also be reduced if small dried animal digesta particles less than 30 μm in size are maintained below about 10-15% by particle number, and / or if small particles less than 45 μm in size are maintained below about 20-25% by particle number. With this in mind, in some examples, the dried animal digesta particles may or may not be further sized by passing them through a grinder 164 to break down larger particles into smaller, more uniform sizes, as well as sieving out a portion of the very fine particles or fines 168, which may then exit the bottom of the grinder through a particle sizer 166. In some examples, a grinder may or may not be present. These very small particles or fines, which may otherwise contribute to clogging, may be removed at this stage of processing. Thus, in some examples, the very small particles may be removed just before being dispensed by the dryer conveyor 130 and / or the grinder pneumatic outlet, as described above. In some examples, the majority of the smaller particles may be removed along the belt.

[0045]

[0047] Liquid animal digestate can be dried in a belt spray dryer under a variety of conditions. For example, a FILTERMAT® spray dryer may, in some instances, be set with a primary burner at about 200°C to 240°C, a secondary burner at 80°C to 140°C, a chamber outlet at 65°C to 80°C, and an atomization pressure of 50 bar to 125 bar. In some cases, three or more drying zones may be provided, each with different temperatures and airflows (e.g., reduced temperatures and / or airflows), to gently dry specific (and initially sticky) dried animal digesta particles moving along the belt to obtain dried animal digesta particles with moisture and animal fat contents that help reduce the degree of clogging of air pressure pipes that may occur when the dried animal digesta particles are dispensed into a collection container.

[0046]

[0048] It should be noted that these belt spray dryer settings are exemplary only, and several modifications and / or settings were evaluated to attempt to reduce the number of small particles to avoid clogging. However, it was recognized that the reduction in small particles achieved by simply adjusting some of the FILTERMAT® spray dryer settings was very modest, and that at this setting, the reduction in very small particles was typically not sufficient to avoid clogging. For example, reducing the atomization pressure applied to the nozzle 110, e.g., by 15 bar (-15 bar), resulted in a very slight improvement in mitigating the presence of small particles and may reduce the number of small particles, but this reduction was very modest. Similarly, by increasing the vacuum pressure in the drying chamber 120 from -1.5 mm to -7.0 mm, a limited reduction in particle size generation could also be achieved (HO column), but again the reduction in small particle size was modest. Other changes in parameters resulted in an increase in the number of small particles, leading to clogging of the dryer outlet and / or air pressure outlet.

[0047]

[0049] Because it was found that changing the process parameters of the belt spray dryer 100 did not have a significant impact on clogging by reducing the number of small particles in the prepared dried animal digesta particles, changing the formulation used to prepare the dried animal digesta particles provided a more effective solution to prevent clogging. Furthermore, the addition of silicon dioxide as a chemical flow aid was undesirable, further compounding the formulation challenge. Accordingly, the dried animal digesta composition of the present disclosure was formulated to include dried animal digesta particles having an animal fat content of about 16% by weight or less and a moisture content of about 3% by weight or less. A liquid animal digesta feedstock formulation that yielded these characteristics significantly enhanced the ability of pneumatic pipes to flow reliably and continuously without significant risk of clogging.

[0048]

[0050] For example, dried animal digest particles can be prepared from animal sources that, when prepared and dried as described herein, can yield a protein content of about 40% to about 80% by weight, or about 50% to about 70% by weight. The animal fat content of the dried animal digest particles can be about 16% or less by weight, about 10% to less than about 16% by weight, or about 12% to about 15.5% by weight. As noted above, the moisture content can be about 3% or less by weight, or in some examples, the moisture content can be about 0.5% to about 2.9% by weight, about 1% to about 2.7% by weight, or about 1.2% to about 2.6% by weight. In some examples, the dried animal digest particles can have a protein content of about 40% to about 80% by weight, or about 50% to about 70% by weight.

[0049]

[0051] With respect to particle size distribution, in some examples, the dried animal digest particles may have a volume diameter particle size where D10 is about 20 μm to about 50 μm, or about 25 μm to about 40 μm. The D50 volume diameter particle size may be about 60 μm to about 150 μm, or about 75 μm to about 125 μm. The D90 volume diameter particle size may be about 160 μm to about 275 μm, or about 185 μm to about 250 μm. In some examples, the percentage of dried animal digest particles less than 30 μm based on volume diameter may be about 3% to about 20%, or about 5% to about 15%. In other examples, the percentage of dried animal digest particles less than 45 μm based on volume diameter may be about 5% to about 25%, or about 10% to about 22%. In some examples, the volume mean diameter of the dried animal digest particles can be from about 60 μm to about 160 μm, or from about 80 μm to about 130 μm.

[0050]

[0052] As described above, the prepared dried animal digesta particles can be in the form of a dry animal digesta composition, or the particles can be blended or combined with other ingredients to form a dry animal digesta composition. Thus, the dry animal digesta composition can be 100% by weight of dried animal digesta particles collected from the belt spray dryer, or it can comprise less than 100% by weight of dried animal digesta particles collected from the belt spray dryer and then combined or blended with additives. These additives can be present at about 0.01% to about 75% by weight, 0.01% to about 65% by weight, about 0.01% to about 50% by weight, about 0.01% to about 25% by weight, or about 0.01% to about 10% by weight, with the dried animal digesta particles comprising the remainder of the dry content, e.g., excluding moisture content, by weight. Weight percentages of additives outside these ranges can be used as well, depending on nutritional, palatability, and / or stability profile objectives.

[0051]

[0053] In some examples, flavor additives, nutritional additives, stabilizing additives, antioxidants, or other types of additives can be blended with the dried animal digest particles as part of the dry animal digest composition. These additives used to formulate the dry animal digest composition are added to either these or other ingredients used in preparing the liquid animal digest that is introduced into the belt spray dryer to form the dry animal digest particles. With this in mind, exemplary additives that can be combined or blended with the dried animal digest particles to form the dry animal digest composition include tetrasodium pyrophosphate (TSPP), yeast, amino acids, vitamins such as B1 (thiamine), probiotics, egg yolk, yeast, and the like. For example, dried animal digest particles can be blended with tetrasodium pyrophosphate in a weight ratio of about 50:1 to about 300:1 to form a dry animal digest composition containing at least these two compounds. In other examples, dried animal digesta particles can be blended with probiotics in a DAD to probiotic weight ratio of about 3:1 to about 30:1, about 5:1 to about 20:1, or about 7.5:1 to about 15:1 to form a dry animal digesta composition containing at least these two compounds. Other exemplary formulations can be prepared from any of these or other combinations of dried animal digesta particles and additives to form unique and useful dry animal digesta compositions in accordance with the present disclosure.

[0052]

[0054] When the prepared pet-edible composition is a pet food composition, the dry animal digesta composition can be incorporated with kibble, which can be in the form of large particles or small pieces of dry or semi-dry bulk pet feed material suitable for use as a pet food. The kibble can be suitable for bird feed, livestock feed (horse, cow, goat, sheep, donkey, pig, etc.), cat food, dog food, rodent feed, rabbit feed, etc. The kibble can be uncoated or pre-coated with about 1% to about 12%, about 2% to about 10%, or about 3% to about 8% by weight of a fat coating, based on the total weight of the pet food composition. The fat coating can provide, for example, enhanced palatability to the target animal and can be provided by, for example, animal fat and / or vegetable oil. Examples of animal fats can include poultry fat, lard (pork fat), or tallow (beef tallow). The fat coating can be applied to the kibble by spraying or dusting it onto the kibble pieces.

[0053]

[0055] In some instances, the dry animal digest composition can be homogeneously blended with kibble to form the pet food composition. In other instances, the dry animal digest can be dusted onto the dry animal digest. As noted above, the dry animal digest composition can be 100% by weight dry animal digest particles alone, or can be blended or combined with other additives.

[0054] definition

[0056] The term "pet" refers to livestock or other animals kept by humans as companion animals, such as birds; horses; felines; canines; rodents, such as hamsters, guinea pigs, mice, gerbils, etc.; lagomorphs, such as rabbits; ferrets; cows; goats; sheep; donkeys; pigs, etc.

[0055]

[0057] The term "about" means ±10%, in another embodiment ±5%, and in a more specific embodiment ±2%. For example, in one embodiment where about is ±10% of a numerical value, the phrase "about 5% to about 10%" can include ranges of 6% to 8% or 7% to 10%, including any subranges thereof. Furthermore, ranges including "about" herein explicitly include the exact value recited. For example, the phrase "about 16% by weight or less" explicitly supports the direct teaching of "16% by weight or less" as a subrange.

[0056]

[0058] As used herein, the terms "comprising" or "including" or other open-ended language may be replaced with "consisting essentially of" and "consisting of," as if such transitional phrases were expressly included in such examples.

[0057]

[0059] The term "substantially" when referring to the absence of a component indicates that the material is not present in any concentration greater than a trace amount, for example, the amount that may be present inherently as an impurity, or an amount so low that it does not function when normally used.For example, a composition containing a small amount of silicon dioxide flow aid that does not provide a measurable improvement in flow can still be considered to be "substantially free of silicon dioxide flow aid", especially when present in a trace amount.In some examples, a composition can be "substantially free" of a compound when it is present in, for example, less than about 0.05% by weight, or even less than about 0.01% by weight.

[0058]

[0060] All percentages expressed herein are by weight of the composition, unless otherwise stated, which is referenced on a dry matter basis. For example, the weight percentage of an ingredient in a dry animal digest composition is based on the total weight of the dry animal digest composition. The weight percentage of an ingredient in a pet food composition is based on the total weight of the pet food composition.

[0059]

[0061] As used herein, ranges are shorthand for avoiding the need to enumerate and describe each and every value within the range. Any suitable value within the range, whether appropriate as an upper limit, lower limit, or terminus of a range, can be selected; thus, when numerical values ​​and subranges are explicitly recited, they should be interpreted flexibly as including the numerical value explicitly recited as limiting the range, as well as including each individual numerical value or subrange encompassed within the range. By way of example, a numerical range of "about 1% to about 5% by weight" should be interpreted as including the explicitly recited values ​​from about 1% to about 5% by weight, as well as each individual value and subrange within the recited range. Thus, this numerical range includes individual values, e.g., 2, 3.5, and 4, as well as subranges, e.g., 1 to 3, 2 to 4, and 3 to 5. The same principle applies to ranges reciting a single numerical value. Moreover, such interpretation should apply regardless of the breadth of a range or characteristic being described.

[0060]

[0062] As used herein, singular forms of words include plurals and vice versa unless the context clearly dictates otherwise. Thus, references to "one," "an," and "the" ("a," "an," and "the") generally include the plurals of the respective terms. For example, reference to a "dried animal digesta composition," a "pet food composition," a "method," etc. includes a plurality of such dried animal digesta, pet food composition, method, etc.

[0061]

[0063] The term "example(s)", particularly when followed by a listing of terms, is merely exemplary and illustrative and should not be considered exclusive or comprehensive.

[0062]

[0064] The methods and compositions and other developments disclosed herein are not limited to the particular methodology, procedures, and reagents described herein, as these may vary as will be recognized by those of skill in the art. Further, the terminology used herein is for the purpose of describing particular examples only and is not intended to, and does not, limit the scope of the disclosure or claims.

[0063]

[0065] Unless otherwise defined, all technical and scientific terms, terminology, and acronyms used herein have the meaning commonly understood by one of ordinary skill in the art of one or more areas of the invention or in the area or areas where the term is used. Although compositions, methods, products, or other means or materials similar or equivalent to those described herein can be used in the practice of the invention, particular compositions, methods, products, or other means or materials are described herein.

[0064]

[0066] As used herein, multiple elements, components, and / or materials may be presented in common lists for convenience. However, these lists should be construed as though each individual element of the list were individually identified as a separate and unique element. Accordingly, each individual element of such a list should not be construed as being effectively equivalent to any other element of the same list solely based on their presentation in a common grouping, absent a statement to the contrary.

[0065] [Example]

[0067] Features of the present invention can be further illustrated by the following examples, which are provided for illustrative purposes only and are not intended to limit the scope of the invention unless otherwise specified.

[0066] Example 1 Preparation of Liquid Animal Digestives (LAD)

[0068] Several liquid animal digests were prepared by sequentially performing two processes: 1) a digestion process followed by 2) a thermal reaction process. For each prepared liquid animal digest (LAD1 and LAD2), the digestion process was performed by grinding and blending frozen animal tissue (or meat). More specifically, LAD1 was prepared from blended organ tissues containing 25% by weight of pork liver, 25% by weight of chicken liver, 25% by weight of chicken heart and liver, and 25% by weight of chicken offal (combined heart, liver, and lung). More specifically, LAD2 was prepared from blended organ tissues containing 50% by weight of pork liver and 50% by weight of chicken liver. In each case, steam was added to obtain a pumpable mixture, which was then transferred to a reactor for digestion. By way of reference, pork liver may have an initial animal fat content of about 3% to about 3.5% by weight, chicken liver may have an initial animal fat content of about 3.5% to about 4.5% by weight, and chicken offal may have an initial animal fat content of about 5.5% to about 7% by weight, although animal fat contents outside these ranges may be found as well.

[0067]

[0069] The digestion was carried out using industrial enzymes, relying mainly on proteases, e.g., subtilisin (Alcalase) protease from Novozyme (Denmark), at a pH of about 7.3 to about 7.7 (adjusted with sodium hydroxide) and a temperature of about 54°C to about 67°C (supplied by added steam), which are suitable for the function of the enzymes.

[0068]

[0070] After digestion, sugars and precursors suitable for carrying out the Maillard reaction were added, and then a thermal reaction process was initiated to bring the mixture to a temperature ranging from about 90°C to about 100°C (at atmospheric pressure) for about 30-45 minutes. The liquid animal digest prepared from this process was then filtered to remove any undigested material and then transferred to a surge tank maintained at above about 80°C, or even above 90°C in some instances. No cooling or pH adjustment was performed on the liquid animal digest before feeding it to the dryer. In this particular example, there was no concentration step before drying.

[0069] Example 2 Preparation of Dried Animal Digesta Particles Using a Belt Spray Dryer (DAD1 and DAD2)

[0071] Liquid animal digesta (DAD1 and 2) prepared according to Example 1 were dried using a FILTERMAT® spray dryer from GEA (Denmark) to produce dried animal digesta particles (DAD1 and 2, respectively). DAD1 was dried using the following settings and conditions: primary burner 222-225°C, secondary burner 85-95°C, chamber (outlet) temperature 70-71°C, and atomization pressure 65-105 bar (typically 85-100 bar). DAD2 was dried using the following settings and conditions: primary burner 218-220°C, secondary burner 122-126°C, chamber (outlet) temperature 71-72°C, and atomization pressure 80-85 bar. DAD1 and DAD2 produced dried particles with moisture content, animal protein content, animal fat content, and particle size distribution as described in Example 4.

[0070] Example 3 Dried Animal Digesta Particles Prepared from a Fluidized Spray Dryer (Comparative DAD)

[0072] For comparative purposes, a commercially available dried animal digest (D'TECH8P 9130 available from SPF (part of Symrise Pet Food)) was obtained and is referred to herein as Comparative DAD. The Comparative DAD was prepared from 100% by weight pork liver. However, unlike the drying process of Example 2, the liquid animal digest used to prepare the Comparative DAD was dried using a fluidized spray dryer (instead of a belt spray dryer). The moisture content, animal protein content, animal fat content, and particle size distribution of the Comparative DAD are provided in Example 4.

[0071] Example 4 Particle size distribution value

[0073] The following Tables 1 to 3 show the water content, animal protein content, and animal fat content of DAD1, DAD2, and comparative DAD, respectively.

[0072] [Table 1]

[0073] [Table 2]

[0074] [Table 3]

[0075]

[0074] As can be seen from this data, DAD2 was the only sample prepared using a belt spray dryer that did not cause noticeable clogging of the air pressure outlet during production.

[0076] Particle size distribution data for DAD1, DAD2, and the Comparative DAD are provided in Figures 2 and 3. In particular, DAD1 was analyzed by two separate laboratories utilizing two different processes to verify relative consistency in particle size distribution using a belt spray dryer. As can be seen in Figures 2 and 3, the particle size distribution of the Comparative DAD included much larger D10, D50, and D90 particles than those prepared using a belt spray dryer.

[0077]

[0076] In particular, DAD2 was within the range of about 16% by weight or less animal fat content and also within the particle size distribution range provided in accordance with the present disclosure.

[0078] Example 5 Comparison of DAD particle morphology Particle morphology can also affect the flowability of dried animal digesta particles. Particle morphology can be significantly different when dried in a belt spray dryer than when dried in a fluidized spray dryer. Furthermore, the addition of silicon dioxide when using a belt spray dryer can affect the smoothness of the dried animal digesta particles formed from such a spray dryer.

[0079] To compare the particle morphology of the belt spray dryer with that of the fluidized spray dryer, DAD2 particles and comparative DAD particles were observed using a scanning electron microscope (SEM). Exemplary images are shown in FIG. 4. Images collected at two different magnifications for each sample are shown. Images A1 and A2 show DAD2 samples prepared in accordance with the present disclosure. Notably, the particles are, on average, approximately spherical and not agglomerated. On the other hand, images B1 and B2, which are images of comparative DAD samples prepared using a fluidized spray dryer, show much more irregularly shaped particles, which may more readily lead to particle agglomeration. As seen in images A1 and A2, less than about 2.5% of the particles appear to be agglomerated. While irregular particle shape is not as significant a negative factor in terms of flowability as particle size distribution and animal fat content, particle morphology, in combination with these factors, may also contribute to reduced flowability.

[0080]

[0079] Figure 5 shows dried animal digesta particles prepared with and without a silicon dioxide flow aid. Thus, this figure demonstrates that, while the addition of silicon dioxide as a flow aid is typically known to aid particle flow, the presence of silicon dioxide can also contribute to improved flow properties in the present invention. For example, in dried animal digesta with a higher fat content, and therefore in the presence of SiO2, free fat on the surface can cause the SiO2 particles to slide past each other, somewhat promoting improved flow. However, reducing the fat, with the aim of eliminating the undesirable silicon dioxide as a flow aid, can also result in acceptable flow. More specifically, as shown in these examples, lowering the animal fat content was a suitable solution for improving flow without the need for silicon dioxide, which was surprising. Images C1 and C2 show samples containing silicon dioxide, while images D1 and D2 show samples without silicon dioxide. The surface of the sample without silicon dioxide in this example is quite smooth.

[0081] Example 6 Preparation of a Pet Food Composition Comprising Kibble and DAD2 Pet food compositions were prepared comprising approximately 90-94% by weight of kibble coated with approximately 5-7.5% by weight of a fat coating and further dusted with 0.6-2% by weight of DAD2 and approximately 0.4-0.5% by weight of tetrasodium pyrophosphate (TSPP). In this example, the fat coating can be provided by an animal fat, such as poultry fat, lard, or beef tallow. A blend of DAD2 and TSPP was prepared and dusted onto the animal fat-coated kibble. The weight percentages in this example are based on the total weight of the pet food composition. In this example, the dry animal digest composition formulated for dusting onto the surface of the animal fat coated kibble included both DAD and TSPP, however, it should be noted that the dry animal digest composition could have been provided solely by the DAD collected from the belt spray dryer or alternatively / in addition could have been combined with ingredients such as nutritional and / or palatability enhancing additives, e.g., amino acids, vitamins such as B1 (thiamine), probiotics, egg yolk, yeast, etc.

[0082]

[0081] Specific embodiments according to the present disclosure are disclosed herein. Although specific terms are employed, they are used generically and for descriptive purposes only and are not intended to be limiting. The scope of the invention is defined in the appended claims. Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims

1. 1. A dried animal digest composition comprising dried animal digest particles having an animal fat content of about 16% by weight or less and a moisture content of about 3% by weight or less, wherein the dried animal digest particles have a volume size distribution in which D10 is about 20 μm to about 50 μm, D50 is about 60 μm to about 150 μm, and D90 is about 160 μm to about 275 μm, and the dried animal digest composition is substantially free of a silicon dioxide flow aid.

2. 2. The dried animal digest composition of claim 1, wherein the percentage of dry animal digest particles less than 30 μm based on volume diameter is between 3% and 20%.

3. 2. The dried animal digest composition of claim 1, wherein the percentage of dry animal digest particles less than 45 μm based on volume diameter is between 5% and 25%.

4. 10. The dried animal digest composition of claim 1, wherein the volume mean diameter of the dried animal digest particles is from about 60 μm to about 160 μm.

5. 10. The dried animal digesta composition of claim 1, wherein the D10 is from about 25 μm to about 40 μm, the D50 is from about 75 μm to about 125 μm, and the D90 is from about 185 μm to about 250 μm, or a combination thereof.

6. 10. The dried animal digesta composition of claim 1, wherein the dried animal digesta composition is completely free of the silicon dioxide flow aid and is also free of chemical flow aids selected from the group consisting of clay, flour, fly ash, quicklime, starch, zeolite, silicates, stearates, phosphates, polysaccharides, salts of fatty acids, diatomaceous earth, bamboo shoots, corn cobs, pea fiber, pea hulls, citrus fiber, cellulose powder, microcrystalline cellulose, or combinations thereof.

7. 10. The dried animal digest composition of claim 1, wherein the dried animal digest particles are about 40% to about 80% by weight protein and about 10% to about 16% by weight animal fat.

8. 10. The dried animal digest composition of claim 1, wherein about 80% to 100% by weight of the animal tissue used to prepare the dried animal digest particles is derived from liver tissue.

9. 10. The dried animal digesta composition of claim 1, wherein the animal tissue used to prepare the dried animal digesta particles has been pre-processed to remove animal fat.

10. 10. The dried animal digest composition of claim 1, wherein 100% by weight of said dried animal digest composition consists of said dried animal digest particles.

11. 10. The dried animal digest composition of claim 1, wherein from about 25% to about 99.99% by weight of the dried animal digest composition consists of the dried animal digest particles, and from about 0.01% to about 75% by weight of the animal digest composition comprises one or more additives selected from the group consisting of phosphate compounds, pyrophosphate compounds, tetrasodium pyrophosphate (TSPP), choline compounds, amino acids, vitamins, probiotics, egg yolk, and yeast.

12. 10. The dried animal digest composition of claim 1, wherein the dried animal digest particles comprise yeast.

13. 1. A pet food composition comprising: Kibble and a dried animal digest composition applied to the kibble, wherein the dried animal digest composition comprises dried animal digest particles, the pet food composition comprising from about 0.5% to about 5% by weight of the dried animal digest particles, based on the total weight of the pet food composition, the dried animal digest particles having an animal fat content of about 16% or less by weight and a moisture content of about 3% or less by weight, based on the total weight of the dried animal digest particles, the dried animal digest particles having a volume size particle size distribution with a D10 of about 20 μm to about 50 μm, a D50 of about 60 μm to about 150 μm, and a D90 of about 160 μm to about 275 μm, and the dry animal digest composition is substantially free of a silicon dioxide flow aid.

14. 14. The pet food composition of claim 13, wherein the pet food composition comprises from about 1% to about 12% by weight of additional animal fat coated onto the kibble, based on the total weight of the pet food composition.

15. 14. The pet food composition of claim 13, wherein the dried animal digest particles are applied to the kibble at about 0.8% to about 3.5% by weight, based on the total weight of the pet food composition.

16. 14. The pet food composition of claim 13, wherein 100% by weight of said dry animal digest composition consists of said dry animal digest particles.

17. 14. The pet food composition of claim 13, wherein from about 25% to about 99.99% by weight of the dry animal digest composition is derived from the dry animal digest particles, and from about 0.01% to about 75% by weight of the animal digest composition comprises one or more additives selected from the group consisting of phosphate compounds, pyrophosphate compounds, tetrasodium pyrophosphate (TSPP), choline compounds, amino acids, vitamins, probiotics, egg yolk, and yeast.

18. 1. A method for preparing a pet ingestible composition, said method comprising: hydrolyzing proteins and fats from raw animal tissue to form a mixture of peptides and fatty acids; introducing heat and a reactive compound to the peptide and fatty acid mixture to initiate a thermal reaction and form a liquid animal digest; drying the liquid animal digest using a belt spray dryer to form dried animal digest particles having a volume mean diameter of about 60 μm to about 160 μm, an animal fat content of about 16% by weight or less, a moisture content of about 3% by weight or less, and being substantially free of silicon dioxide flow aids; A method comprising:

19. 20. The method of claim 18, wherein the dried animal digesta particles have a volumetric size distribution with a D10 of about 20 μm to about 50 μm, a D50 of about 60 μm to about 150 μm, and a D90 of about 160 μm to about 275 μm.

20. 18. The method of claim 17, further comprising applying about 0.5% to about 5% by weight of the dried animal digest particles to a kibble to form a pet food composition, wherein the weight percentage is based on the total weight of the pet food composition.

Images