Pet glue and preparation method thereof

Abstract

The invention relates to pet glue and a preparation method thereof. The pet glue comprises the following components: collagenous fiber carboxylate, collagen and / or collagen polypeptide. Collagen fiber carboxylate introduced into the pet glue reduces the hardness of the chew, and carboxyl on collagen / polypeptide can be complexed with ions such as calcium and zinc on collagen fibers, so that the loss of collagen / polypeptide along with water is reduced, and the nutritional value of the pet glue is improved.

Description

Technical Field

[0001] The invention relates to the field of raw leather processing, in particular to pet glue and a preparation method thereof. Background Art

[0002] The main component of animal skin is collagen fibrillary protein. In addition to good mechanical properties, animal skin is also edible, so it can be used as pet chews and is widely used in the production of pet chewing products. The animal skin used to produce pet chews is generally the second or third layer of leather left after leather production. Since the second or third layer of leather does not have the natural grain of the first layer of leather, the added value of leather production is relatively low, so it is widely used in the production of pet chew products. In recent years, due to the decline in the price of raw leather, the first layer of leather with poor quality is also beginning to be used in the production of pet chew products.

[0003] Animal skins are first soaked in water, dehaired, and limed before being split into layers to obtain multi-layered gray skins. The split gray skins with better quality can be used for leather production after screening; the rest can be used to produce pet chew products. Due to the dehairing and expansion stages, the main component of the split gray skins used to produce pet chews is collagen fiber, and the pet chews obtained after production processing and drying have a relatively pure collagen fiber structure. After the animal skins are made into pet chews, they can be cut, softened, knotted or molded to obtain pet products of various shapes, which can be used for pets to play, bite and chew, and finally can be eaten by pets as food.

[0004] There are two disadvantages of using animal skins to make pet glue. First, animal skin resources are limited and the production cost is relatively high. Second, this kind of pet chew glue maintains the structure of animal skins, which is relatively strong and not easy to be chewed and digested by animals. Especially for some young dogs, eating it can easily cause diarrhea and intestinal obstruction, threatening the health of pets. In response to this problem, there are also some technologies that use the scraps of animal skins, which are pre-treated and then pulped and defibrated to obtain collagen fiber pulp, which is then molded to obtain pet glue. This type of technology can make full use of relatively small leather pieces and improve the utilization rate, but the product still maintains the collagen fiber structure. Pets have a relatively weak ability to digest and absorb the compact structure of collagen, which reduces the nutritional value of pet glue products.

[0005] Although the pet chews made by collagen fiber slurry have improved in terms of easy chewing and digestion compared with the original leather, there are still problems. Because collagen fibers contain a large number of active groups such as collagen carboxyl, collagen amino and collagen hydroxyl, when the collagen fibers contain water, these active groups can combine with water. Due to the isolation of water, the active groups keep a certain distance from each other, which can keep the wet leather soft. When the collagen fibers are dried, these active groups are close to each other and combine due to the loss of water isolation, causing the collagen fibers to become very tight and hard. Pet chews made from original leather or pulped collagen fibers still have this problem and are not easy to be chewed and digested by pets, especially young dogs.

[0006] In order to address the problem that collagen fibers in pet chews are difficult to digest and absorb due to their relatively large molecular weight and the formation of a network-interwoven structure, some technologies and products have added collagen molecules with relatively small molecular weight to enhance their nutritional properties. However, due to the strong water solubility of small molecule collagen, most of the collagen will be removed along with the water during the product's water filtration process, resulting in a relatively low collagen content in the resulting pet chews, which fails to achieve the purpose of increasing nutritional properties. Summary of the invention

[0007] Based on this, it is necessary to provide a pet glue and a preparation method thereof in view of the above technical problems.

[0008] The present invention reacts collagen fiber slurry with calcium and zinc ions, and utilizes the collagen carboxyl groups on the collagen fibers to react with the calcium and zinc ions to generate collagen fiber carboxylates calcium and collagen fiber carboxylates zinc, thereby reducing the binding force between the fibers after the collagen fiber slurry is dried. In addition, the carboxyl groups on the collagen protein / polypeptide added later can complex with the calcium and zinc ions on the collagen fiber, thereby preventing the collagen protein / polypeptide from being lost in the subsequent water filtration process.

[0009] In a first aspect of the present invention, a pet glue is provided, which comprises the following components: collagen fiber carboxylate, collagen and / or collagen polypeptide.

[0010] In one embodiment of the first aspect of the present invention, the pet glue comprises the following components by weight: 25-95 parts of collagen fiber carboxylate, and 3-50 parts of collagen and / or collagen polypeptide.

[0011] In one embodiment of the first aspect of the present invention, the collagen fiber carboxylate comprises at least one of collagen fiber calcium carboxylate and collagen fiber zinc carboxylate.

[0012] In one embodiment of the first aspect of the present invention, the pet glue further comprises, by weight: 1-5 parts of a cross-linking agent; the cross-linking agent can react with active functional groups on collagen fiber carboxylates and / or collagen proteins and / or collagen polypeptides.

[0013] In one embodiment of the first aspect of the present invention, the pet glue further comprises, by weight: additives: 1-20 parts.

[0014] In one embodiment of the first aspect of the present invention, the cross-linking agent includes at least one of glutaraldehyde, tannin plant extract, and aluminum salt.

[0015] In one embodiment of the first aspect of the present invention, the additives include: meat and / or raw materials with appetite-inducing nutritional functions; the meat includes at least one of chicken, duck, goose, pork, beef, mutton, fish, and animal offal; the raw materials with appetite-inducing nutritional functions include at least one of chicken essence, monosodium glutamate, vinegar, edible flavors, edible spices, vitamins, and minerals.

[0016] In the second aspect of the present invention, a method for preparing pet glue is provided, comprising: mixing a slurry of collagen fiber calcium carboxylate and / or collagen fiber zinc carboxylate with collagen and / or collagen polypeptide to react and combine the carboxyl groups on the collagen and / or collagen polypeptide with the calcium and / or zinc ions on the collagen fiber calcium carboxylate and / or collagen fiber zinc carboxylate; adding a cross-linking agent to combine the collagen and / or collagen polypeptide with the collagen fiber calcium carboxylate and / or collagen fiber zinc carboxylate; adding additives and mixing evenly, filtering the slurry obtained after mixing, molding, and drying to obtain a pet glue product.

[0017] In one embodiment of the second aspect of the present invention, the preparation steps of collagen fiber carboxylate calcium and / or collagen fiber carboxylate zinc include: 1) soaking and washing the raw skin, removing the oil, using an enzyme dehairing method to remove the hair and epidermis, and then pre-treating with an enzyme and washing; 2) pelletizing, refining, and bleaching the raw skin obtained by step 1) to obtain collagen fiber slurry; 3) adding calcium ions and / or zinc ions to the collagen fiber slurry, and the calcium ions and / or zinc ions react with the carboxylic acid groups on the collagen fibers to generate collagen fiber carboxylate calcium and / or collagen fiber carboxylate zinc. The addition of calcium ions and zinc ions can be achieved by adding water-soluble inorganic salts such as calcium chloride, calcium nitrate, and zinc chloride. The calcium and zinc ions generated after the inorganic salts are ionized in water can be combined with the carboxyl groups on the collagen fibers to generate collagen fiber carboxylate calcium and / or zinc. Organic calcium and organic zinc such as calcium gluconate, calcium lactate, amino acid calcium, etc. will not be ionized in water. Calcium and zinc ions will not react and combine with collagen carboxylic acid, and cannot play the role of the present invention. The collagen fiber carboxylate calcium and / or zinc obtained by the reaction is organic calcium and / or zinc, wherein the calcium ion content is 0.5-5% by dry basis weight, and the calcium ion content is 0.5-5% by dry basis weight. The raw material skin is selected from animal skin or its scraps. If depilated gray skin or pet glue cutting waste is used as raw material, the above step 1) can be omitted.

[0018] In one embodiment of the second aspect of the present invention, collagen and / or collagen polypeptides are prepared by first heating and degrading collagen fibers and then adding proteolytic enzymes to hydrolyze them. The collagen fiber slurry can be heated to above 75°C and kept warm for 1-3 hours, then cooled to 35-55°C, treated with proteolytic enzymes for 1-3 hours, heated and sterilized, filtered, concentrated and dried to obtain collagen and / or collagen polypeptides. The use of biological enzymes to dehair animal skins avoids the problem of environmental pollution caused by the use of alkali sulfide and lime treatment in the production process of traditional leather factories, and can avoid the contamination of collagen fibers by impurities in alkali sulfide and lime. In the present invention, the collagen fibers are first thermally degraded and then hydrolyzed by biological enzymes. The obtained collagen / polypeptide does not use any chemical degradation method, can maintain the biological properties and nutritional components of the collagen / polypeptide, and can prevent the collagen / polypeptide from being contaminated by chemical substances.

[0019] In a third aspect of the present invention, a pet product is provided, which is made from any one of the above-mentioned pet glues.

[0020] In the present invention, calcium ions and zinc ions can be replaced by other mineral ions such as selenium, iron, manganese, etc., and the pet glue of the present invention can be obtained by the same method.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. Calcium and zinc ions are combined with the carboxyl groups on the collagen fibers to block the carboxyl groups on the collagen fibers, reducing the bonding force between the fibers after the collagen fiber slurry is dried, making the prepared pet chews softer and meeting the needs of young dogs.

[0023] 2. Add small molecule collagen / peptide. The carboxyl group on the collagen / peptide can complex with the calcium and zinc ions on the collagen fibers. The collagen / peptide can be combined with the collagen fibers to prevent the collagen / peptide from being removed in the subsequent water filtration process.

[0024] 3. The collagen carboxylate calcium and collagen carboxylate zinc introduced into pet chews have good calcium and zinc supplementing effects, which can improve the growth and development of pets' bones and teeth and enhance the pets' immunity.

[0025] 4. The collagen fibers obtained from the raw hides are further treated with enzymes to hydrolyze them to obtain collagen or collagen polypeptides. Collagen / polypeptides have comprehensive nutritional components, high protein digestibility, and are easily absorbed. In addition, collagen has strong disease resistance and can significantly improve the gloss of animal hair.

[0026] 5. Raw hides and collagen fibers obtained by physical treatment have stable collagen macromolecular structures, which are difficult for pets to digest and absorb after consumption, and can only be used for grinding teeth and cleaning teeth. The present invention hydrolyzes collagen fibers into easily absorbable collagen proteins / peptides and then compounds them with collagen fibers, which can not only play the role of grinding teeth, but also improve the nutritional value of pet glue products.

[0027] 6. The collagen / peptide used can not only increase the nutritional properties of pet glue, but also play the role of bonding collagen fibers and other additives, thereby improving the strength and plasticity of the product. DETAILED DESCRIPTION

[0028] The embodiments of the present invention will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. If the specific conditions are not specified in the examples, they are carried out according to the conditions recommended by the normal conditions or the manufacturers. If the manufacturers are not specified in the reagents or instruments used, they are all conventional products that can be obtained commercially. The percentages involved in the examples are weight percentages, except for those specifically noted.

[0029] Example 1: Preparation of collagen fiber slurry using hairy animal skins

[0030] Take 100 kg of hairy animal skins or their trimming byproducts and use them as the basis for the following materials.

[0031] 1) Soaking and degreasing: 300% water, 0.5-1% enzyme preparation, 1-3% detergent, wash for 10-24 hours, drain, remove the flesh, and wash once with clean water.

[0032] 2) Enzyme depilation: 200% water, 35-45℃, 0.5% penetrant, 1-3% enzyme preparation, act for 60 minutes; then rotate intermittently until most of the hair falls off, and shave with a machine after exiting the drum.

[0033] 3) Washing: 300% water, wash twice, 15 minutes each time, and drain dry.

[0034] 4) Mincing: Cut the skin into small pieces smaller than 3×3cm, and then mince using a meat grinder.

[0035] 5) Defibrination and beating: Add 5 times the amount of water into a pulping machine, and beat at a speed of more than 1000 rpm for 1-3 minutes to obtain collagen fiber slurry.

[0036] Example 2: Preparation of collagen fiber slurry using lime skin

[0037] Take 100 kg of lime skin or its trimming by-products and use it as the basis for the following materials.

[0038] 1) Washing: 300% water, wash 3 times, 15 minutes each time, and drain.

[0039] 2) Deashing and softening: 150% water, 35°C, 0.5-1.5% formic acid, treat for 60 minutes, add 0.2% softening enzyme, treat for 60 minutes, and control to dry.

[0040] 3) Washing: 300% water, wash twice, 15 minutes each time, and drain dry.

[0041] 4) Mincing: Cut the skin into small pieces smaller than 3×3cm, and then mince using a meat grinder.

[0042] 5) Defibrination and beating: Add 5 times the amount of water into a pulping machine, and beat at a speed of more than 1000 rpm for 1-3 minutes to obtain collagen fiber slurry.

[0043] Example 3: Preparation of collagen / collagen polypeptide using collagen fiber slurry

[0044] The collagen fiber slurry of Example 1 was taken as the raw material and used as the basis for the following dosage.

[0045] 1) Pyrolysis: Heat the collagen fiber slurry to above 75°C and keep it warm for 1-3 hours

[0046] 2) Enzymatic hydrolysis: Cool the pyrolysis solution to 35-55°C, add proteolytic enzymes for 1-3 hours, then heat and sterilize, filter, concentrate, and spray dry to obtain collagen / peptide.

[0047] Example 4: Preparation of pet glue

[0048] 1) Add 2% calcium chloride and 1% zinc sulfate based on the dry weight of the collagen fibers to the collagen fiber slurry of Example 1, stir evenly and react for 2-5 hours to obtain collagen fiber calcium carboxylate / zinc slurry.

[0049] 2) Mix 75 parts of collagen fiber calcium carboxylate / zinc slurry (on a dry basis) and 25 parts of collagen / polypeptide (on a dry basis) evenly, react for 2-5 hours, then add 2 parts of glutaraldehyde crosslinker solution and 10 parts of chicken paste, mix for 30 minutes to make it evenly dispersed.

[0050] 3) The mixed slurry was heated to 35°C and kept warm for 60 minutes.

[0051] 4) Laying the net and filtering water: Spread the collagen fiber slurry on the net to filter water (the thickness of the regenerated leather can be controlled by controlling the amount of slurry spread per unit area), vacuum filter, and squeeze water to form.

[0052] 5) Drying and molding: Drying the molded collagen pet glue to obtain the pet glue product.

[0053] Example 5: Preparation of pet products using pet glue

[0054] The pet glue prepared according to the method of Examples 1-4 was cut into a rectangle of 20×10 cm, then soaked in clean water until soft, taken out and rolled up, knotted at both ends of the roll, and dried to obtain a knotted bone pet product similar to a bone shape.

[0055] Comparative Example 1

[0056] 1) Mix 75 parts of the collagen fiber slurry (on a dry basis) of Example 1, 25 parts of collagen / polypeptide (on a dry basis), 2 parts of glutaraldehyde crosslinking agent solution, and 10 parts of chicken paste for 30 minutes to evenly disperse them.

[0057] 2) Heat the mixed slurry to 35 degrees and keep it warm for 60 minutes.

[0058] 3) Spreading the net and filtering water: Spread the collagen fiber slurry on the net to filter water (the thickness of the regenerated leather can be controlled by controlling the amount of slurry spread per unit area), vacuum filter, and squeeze water to form.

[0059] 4) Drying and molding: Drying the molded collagen pet glue to obtain the pet glue product.

[0060] The pet glue obtained by Example 4 and Comparative Example 1 were compared, and the results are shown in Table 1.

[0061] Table 1

[0062] Compare Projects Example 4 Comparative Example 1 Calcium content 1.2％ Not detected Zinc content 0.5％ Not detected Collagen / peptide content 20.4％ 12.2％ hardness Relatively soft Hard

[0063] As can be seen from Table 1, the pet glue of the present invention can greatly improve the binding ability of small molecule collagen / polypeptide after introducing collagen fiber calcium carboxylate and collagen fiber zinc carboxylate. In the comparative example without introducing collagen fiber calcium carboxylate and collagen fiber zinc carboxylate, although the amount of collagen / polypeptide is the same, nearly half of the collagen / polypeptide is lost with water because it is not combined in the chewing glue. The introduction of collagen fiber calcium carboxylate and collagen fiber zinc carboxylate can also reduce the hardness of the chewing glue, making it suitable for consumption by young dogs, and the introduced calcium and zinc become organic calcium and organic zinc, which can play the role of calcium and zinc supplementation, improve the growth and development of pet bones and teeth, and improve the immunity of pets.

[0064] So far, the embodiments of the present invention have been described in detail. In order to avoid obscuring the concept of the present invention, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions disclosed herein.

[0065] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A pet glue, characterized in that: The pet glue comprises the following components: collagen fiber carboxylate, collagen and / or collagen polypeptide.

2. The pet glue according to claim 1, characterized in that: The pet glue comprises the following components by weight: Collagen fiber carboxylate: 25-95 parts, Collagen and / or collagen polypeptide: 3-50 parts.

3. The pet glue according to claim 1 or 2, characterized in that: The collagen fiber carboxylate includes at least one of collagen fiber calcium carboxylate and collagen fiber zinc carboxylate.

4. The pet glue according to claim 1 or 2, characterized in that: By weight, the pet glue also includes: Cross-linking agent: 1-5 parts; The cross-linking agent can react with the active functional groups on the collagen fiber carboxylates and / or the collagen proteins and / or the collagen polypeptides.

5. The pet glue according to claim 1 or 2, characterized in that: By weight, the pet glue also includes: Additives: 1-20 parts.

6. The pet glue according to claim 3, characterized in that: The cross-linking agent includes at least one of glutaraldehyde, tannin plant extract and aluminum salt.

7. The pet glue according to claim 4, characterized in that: The additives include: meat and / or raw materials with appetizing and nutritional functions; The meat includes at least one of chicken, duck, goose, pork, beef, mutton, fish and animal offal; The raw materials with appetite-inducing and nutritional functions include at least one of chicken essence, monosodium glutamate, vinegar, edible flavors, edible spices, vitamins and minerals.

8. A method for preparing pet glue, characterized in that: The following steps are involved: The slurry of collagen fiber calcium carboxylate and / or collagen fiber zinc carboxylate is mixed with collagen and / or collagen polypeptide to react, so that the carboxyl groups on the collagen and / or collagen polypeptide react with the calcium and / or zinc ions on the collagen fiber calcium carboxylate and / or collagen fiber zinc carboxylate and combine; a cross-linking agent is added to combine the collagen and / or collagen polypeptide with the collagen fiber calcium carboxylate and / or collagen fiber zinc carboxylate; additives are added and mixed evenly, and the slurry obtained after mixing is filtered, formed, and dried to obtain a pet glue product.

9. The method for preparing pet glue according to claim 8, characterized in that: The preparation steps of the collagen fiber calcium carboxylate and / or collagen fiber zinc carboxylate include: 1) After soaking and washing the raw hides and removing the grease, the hair and epidermis are removed by enzyme dehairing, and then the raw hides are pretreated with enzymes and washed; 2) pelletizing and grinding the raw leather obtained in step 1) to obtain collagen fiber slurry; 3) adding calcium ions and / or zinc ions to the collagen fiber slurry, and the calcium ions and / or zinc ions react with the carboxylic acid groups on the collagen fibers to generate collagen fiber calcium carboxylate and / or collagen fiber zinc carboxylate.

10. The method for preparing pet glue according to claim 8, characterized in that: The collagen and / or collagen polypeptide is prepared by first heating and degrading collagen fibers and then adding proteolytic enzymes for hydrolysis.

11. A pet product, made from the pet glue according to any one of claims 1 to 7.