Pigskin powder as well as preparation method and application thereof

Abstract

The invention provides pigskin powder as well as a preparation method and application thereof. The method for preparing the pigskin powder comprises the following steps: boiling pigskin; carrying out crushing treatment on the boiled pigskin; carrying out homogenization treatment on the crushed product; carrying out degreasing treatment on the homogenized product; and drying the degreased product to obtain the pigskin powder. The protein content of the pigskin powder prepared by the method disclosed by the invention can reach 80% or above, and the pigskin powder is free of pig hair, low in microbial hidden danger and not easy to oxidize, so that the pigskin powder can be added into food.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to pigskin powder and a preparation method and application thereof. Background Art

[0002] As one of the by-products, skin accounts for about 10% of the pig's body weight. High-quality pig skin is mainly used for the production of leather products, gelatin and other products, while poor-quality scrap pig skin is used for feed processing. Therefore, the pig skin's value is not fully utilized. In addition, the production of leather and gelatin requires a large amount of sewage that is difficult to treat, which puts a lot of pressure on the environment. Collagen peptides are mostly prepared by enzymatic method, which is not only expensive, but also has no functionality after enzymatic hydrolysis. When pig skin is used in the food industry, it needs to be refined to remove pig hair, which not only increases costs, but also easily causes pig hair residue. Before the pig is slaughtered, the pig skin is in direct contact with the external environment, and the microbial problem is serious.

[0003] Therefore, there is an urgent need to develop a new technology to produce pig skin powder that is hair-free and has low microbial risk, and ensure that the product can be safely added to food. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art to at least a certain extent.

[0005] In a first aspect of the present invention, the present invention provides a method for preparing pigskin powder. According to an embodiment of the present invention, the method comprises: boiling pigskin; crushing the boiled pigskin; homogenizing the crushed product; defatting the homogenized product; and drying the defatted product to obtain the pigskin powder.

[0006] The inventor has developed the above-mentioned preparation method through a large number of experiments. The method is simple to operate, low in cost, and no pollutants are generated during the preparation process. In addition, the raw materials of the method of the present invention can be selected from pigskins of different qualities, such as back skin, soft crotch skin, etc. Therefore, skins of poor quality can also be fully utilized to avoid waste. The protein content of the pigskin powder prepared by the method of the present invention can reach more than 80%, there is no pig hair, the microbial hidden danger is low, and it is not easy to be oxidized, so it can be added to food.

[0007] According to an embodiment of the present invention, the method for preparing pigskin powder may further include at least one of the following additional technical features:

[0008] According to an embodiment of the present invention, the boiling process is carried out in water.

[0009] According to an embodiment of the present invention, the weight ratio of the pigskin to water is 1:(3-10).

[0010] According to an embodiment of the present invention, the temperature of the boiling treatment is 70°C-110°C.

[0011] According to an embodiment of the present invention, the boiling time is 1h-3h.

[0012] According to an embodiment of the present invention, the pressure of the homogenization treatment is 15MPa-20MPa.

[0013] According to an embodiment of the present invention, the homogenization process is performed using a homogenizer.

[0014] According to an embodiment of the present invention, the degreasing process includes centrifuging the homogenized product.

[0015] According to an embodiment of the present invention, the rotation speed of the centrifugal treatment is 5000rpm-7000rpm.

[0016] According to an embodiment of the present invention, the temperature of the drying process is 150°C-200°C.

[0017] According to an embodiment of the present invention, the drying process is performed by spray drying.

[0018] In the second aspect of the present invention, the present invention provides a pigskin powder, which is prepared by the method described in the first aspect. Therefore, the protein content of the pigskin powder of the present invention reaches more than 80%, and there are no hidden dangers of pig hair and microorganisms, and it is easy to disperse in food, so it can be added to food to improve the taste of the product.

[0019] In the third aspect of the present invention, the present invention proposes the use of the pigskin powder described in the second aspect in preparing food.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. DETAILED DESCRIPTION

[0021] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0022] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] For simplicity, only some numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and any upper limit can be combined with any other upper limit to form an unspecified range. In addition, each separately disclosed point or single value can itself be combined as a lower limit or upper limit with any other point or single value or with other lower limits or upper limits to form an unspecified range.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" in the description and claims of the present invention and any variations thereof are intended to cover non-exclusive inclusions.

[0025] In this document, the terms “include” or “comprising” are open expressions, that is, including the contents specified in the present invention but not excluding other contents.

[0026] As used herein, the terms "optionally", "optional" or "optionally" generally mean that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0027] Method for preparing pigskin powder

[0028] The present invention provides a method for preparing pigskin powder. According to an embodiment of the present invention, the method comprises: boiling pigskin; crushing the boiled pigskin; homogenizing the crushed product; defatting the homogenized product; and drying the defatted product to obtain the pigskin powder.

[0029] The inventor has developed the above-mentioned preparation method through a large number of experiments. The method is simple to operate, low in cost, and no pollutants are generated during the preparation process. In addition, the raw materials of the method of the present invention can be selected from pigskins of different qualities, such as back skin, soft crotch skin, etc. Therefore, skins of poor quality can also be fully utilized to avoid waste. The protein content of the pigskin powder prepared by the method of the present invention can reach more than 80%, there is no pig hair, the microbial hidden danger is low, and it is not easy to be oxidized, so it can be added to food.

[0030] In some embodiments of the present invention, the pigskin may be, but is not limited to, back skin and soft crotch skin. Thus, through this process, pigskins of various qualities including back skin and soft crotch skin can be used to convert them into pigskin powder, thereby minimizing resource waste.

[0031] In some embodiments of the present invention, the boiling process is carried out in water, thereby, on the one hand, making the pigskin softer for subsequent processing, and on the other hand, killing microorganisms on the surface of the pigskin.

[0032] In some embodiments of the present invention, the weight ratio of the pigskin to water is 1:(3-10). For example, it can be 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, etc., or can be a range of any of the above values. Thus, by making the weight ratio of pigskin to water within the above range, the pigskin can be made soft enough to facilitate subsequent processing.

[0033] In some embodiments of the present invention, the boiling temperature is 70°C-110°C. For example, it can be 70°C, 80°C, 90°C, 100°C, 110°C, etc., or can be a range of any of the above values. Therefore, by making the boiling temperature within the above range, not only can the pigskin become soft, but also the microorganisms on the surface of the pigskin can be killed.

[0034] In some embodiments of the present invention, the boiling time is 1 hour to 3 hours. For example, it can be 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, etc., or it can be a range of any of the above values. Therefore, by making the boiling time within the above range, not only can the pigskin become soft, but also the microorganisms on the surface of the pigskin can be killed.

[0035] In some embodiments of the present invention, the pulverization process is performed using a colloid mill, thereby being able to pulverize the pigskin into very fine particles, which is conducive to the uniformity and efficiency of subsequent processing.

[0036] In some embodiments of the present invention, the homogenization process is performed by a homogenizer, so that the pig hair and pig hair roots can be effectively and thoroughly separated from the crushed product by the homogenization process, ensuring the subsequent separation of pig hair and pig skin protein.

[0037] In some embodiments of the present invention, the pressure of the homogenization treatment is 15MPa-20MPa. For example, it can be 15MPa, 16MPa, 17MPa, 18MPa, 19MPa, 20MPa, etc., or can be a range composed of any of the above values. Therefore, by making the pressure of the homogenization treatment within the above range, it can ensure that the pig hair and the pig hair roots are more thoroughly separated during the homogenization process, which is convenient for the subsequent removal of the pig hair.

[0038] Pigskin has a high fat content. When it is directly processed into pigskin powder, the fat flavor is poor and it is easy to oxidize. During the experiment, the inventor found that if chemical methods are used to remove fat, it will not only cause environmental pollution, but also destroy the protein component, and the separated fat cannot be recycled. Therefore, after a large number of experiments, the inventor used a liquid separation and degreasing method to remove fat from pigskin, which not only avoids environmental pollution, but also can achieve the purpose of continuous production and efficient fat separation, providing support for the processing of raw pigskin into pigskin powder.

[0039] Therefore, in some embodiments of the present invention, the degreasing process includes centrifuging the homogenized product. Thus, the fat in the homogenized product can be separated by centrifugation, so that the fat can be recycled. This physical degreasing method does not produce chemical waste, and the fat content of the finished product is stable and not easily oxidized.

[0040] In some embodiments of the present invention, the centrifugal speed is 5000 rpm-7000 rpm. For example, it can be 5000 rpm, 5500 rpm, 6000 rpm, 6500 rpm, 7000 rpm, etc., or can be a range of any of the above values. Thus, by making the speed within the above range, the fat and pig skin in the homogenized product can be separated more completely.

[0041] In some embodiments of the present invention, the centrifugation time is 5 min-15 min. For example, it can be 5 min, 7 min, 10 min, 12 min, 15 min, etc., or can be a range of any of the above values. Thus, by making the time within the above range, the fat and pig skin in the homogenized product can be separated more completely.

[0042] In some embodiments of the present invention, the drying temperature is 150°C-200°C. For example, it can be 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, etc., or it can be a range of any of the above values. Therefore, by making the drying temperature within the above range, the degreasing product can be converted into a dry powder, which is convenient for storage, transportation and use; at the same time, high temperature helps to kill possible residual microorganisms and solve microbial hazards.

[0043] In some embodiments of the present invention, the drying process is carried out by spray drying, thereby being able to convert the degreasing product into a dry powder while retaining the functionality of the pigskin and killing microorganisms.

[0044] Pigskin powder and its uses

[0045] The present invention provides a pigskin powder. According to an embodiment of the present invention, the pigskin powder is prepared by the above method. Therefore, the protein content of the pigskin powder of the present invention reaches more than 80%, and there is no pig hair, which can reduce the hidden dangers of microorganisms and is easy to disperse in food. Therefore, it can be added to food to improve the taste of the product. Those skilled in the art can understand that the pigskin powder has all the characteristics and advantages of the method for preparing pigskin powder described above, and will not be described in detail here.

[0046] The present invention proposes the use of the above pigskin powder in preparing food. Those skilled in the art can understand that this use has all the characteristics and advantages of the above pigskin powder, which will not be described in detail here.

[0047] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. If no specific techniques or conditions are specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used that do not specify the manufacturer are all conventional products that can be obtained commercially.

[0048] Example 1

[0049] Weigh 10 kg of pig skin, add water at a weight ratio of 1:5, boil at 100° C. for 2 h, and stir every 5 minutes to form the final pig skin soup.

[0050] The boiled pigskin was crushed with a multi-colloid mill to obtain skin particles no larger than 3 mm in size. The skin particles were homogenized with a homogenizer at a pressure of 17 MPa to obtain the fur-separated D 50 =7 micron pigskin particles.

[0051] The homogenized pig skin particles are degreased using a centrifuge at a speed of 7000 rpm for 10 minutes, so that the fat and pig hair can be separated from the pig skin, and the fat is reserved.

[0052] The defatted pigskin was spray dried at a temperature of 170° C. to obtain 3.5 kg of pigskin powder.

[0053] Example 2

[0054] Pigskin powder was prepared according to the method of Example 1, except that the pressure of the homogenizer was 20 MPa, and hairless pigskin particles were obtained.

[0055] Example 3

[0056] Pigskin powder was prepared according to the method of Example 1, except that the pressure of the homogenizer was 15 MPa, and hairless pigskin particles were obtained.

[0057] Example 4

[0058] Pigskin powder was prepared according to the method of Example 1, except that the pressure of the homogenizer was 10 MPa, and hairless pigskin particles were obtained.

[0059] Example 5

[0060] Pigskin powder was prepared according to the method of Example 1, except that the pressure of the homogenizer was 30 MPa, and hairless pigskin particles were obtained.

[0061] Example 6

[0062] Pigskin powder was prepared according to the method of Example 1, except that the rotation speed of the centrifuge was 7000 rpm and the centrifugation was performed for 10 min.

[0063] Example 7

[0064] Pigskin powder was prepared according to the method of Example 1, except that the rotation speed of the centrifuge was 5000 rpm and the centrifugation was performed for 10 min.

[0065] Example 8

[0066] Pigskin powder was prepared according to the method of Example 1, except that the rotation speed of the centrifuge was 4000 rpm and the centrifugation was performed for 10 min.

[0067] Example 9

[0068] Pigskin powder was prepared according to the method of Example 1, except that the rotation speed of the centrifuge was 8000 rpm and the centrifugation was performed for 10 min.

[0069] Comparative Example 1

[0070] Pigskin powder was prepared according to the method of Example 1, except that no degreasing treatment was performed. The specific process was as follows:

[0071] Weigh 10 kg of pig skin, add water in a weight ratio of 1:5, boil at 100°C for 2 h, and drain the water after boiling.

[0072] The boiled pigskin is crushed using a multiple colloid mill to obtain broken skin particles no larger than 3 mm.

[0073] The broken leather particles were homogenized by a homogenizer with a pressure of 17 MPa to obtain pig leather particles separated from the fur.

[0074] The hairless pig skin particles were spray dried at a temperature of 170° C. to obtain 3.5 kg of pig skin powder.

[0075] The differences between Examples 1-10 and Comparative Example 1 are shown in Table 1.

[0076] Table 1

[0077] Homogenizing pressure / MPa Centrifugal speed / rpm Example 1 17 6000 Example 2 20 6000 Example 3 15 6000 Example 4 10 6000 Example 5 30 6000 Example 6 17 7000 Example 7 17 5000 Example 8 17 4000 Example 9 17 8000 Comparative Example 1 17 /

[0078] Performance Testing

[0079] The pigskin powder prepared in Examples 1-9 and Comparative Example 1 was tested for moisture, fat, protein content, and total bacterial count, and the specific process is as follows.

[0080] Moisture content detection: GB5009.3—2016;

[0081] Fat content test: GB5009.5—2016;

[0082] Protein content test: GB5009.6—2016;

[0083] Detection of total colony count: GB4789.2—2022.

[0084] The test results are shown in Table 2. It can be seen from the table that:

[0085] Compared with Comparative Example 1, the protein content of the pigskin powder prepared by the method of the present invention in Examples 1-9 is significantly increased, and the fat content is significantly reduced.

[0086] It can be seen from Examples 1-5 that if the homogenization pressure is too high, the emulsification degree of the pigskin liquid is high, resulting in incomplete subsequent fat separation; if the pressure is low, the pigskin particles are large, and the pigskin and subcutaneous fat are connected together, which easily leads to high fat content or high protein content in the upper layer of the centrifuged pigskin, resulting in protein loss and difficulty in fat recovery;

[0087] It can be seen from Examples 1 and 6-9 that if the rotation speed is too low, the separation effect is poor and the fat content is likely to be high; if the rotation speed is too high, the energy consumption is high.

[0088] Table 2

[0089] Moisture / wt% Fat / wt% Protein / wt% Total colony count / cfu / g Example 1 5.5 3.3 87.8 25 Example 2 5.8 3.6 85.6 30 Example 3 3.7 3.8 89.5 200 Example 4 4.5 5.2 84.3 210 Example 5 6.1 6.4 82.5 140 Example 6 4.2 9.8 82.8 25 Example 7 3.5 4.6 89.9 80 Example 8 4.8 13.6 77.3 100 Example 9 3.4 3.3 89.3 60 Comparative Example 1 3.9 38.7 53.4 195

[0090] The pigskin powder prepared in Examples 1-9 and Comparative Example 1 was placed in a light incubator for 5 days to detect its oxidation degree. Specific detection process: The color difference value and peroxide value of each group were mainly detected. The color difference value was detected using a handheld colorimeter, and the peroxide value was detected according to GB 5009.227. The results showed that the color difference of Comparative Example 1 was 8.62, and the peroxide value was 0.06 (g / 100g). The color difference of Examples 1-9 was 3.12-3.82, and the peroxide value was not detected. It shows that the pigskin powder prepared by the method of the present invention is not easy to be oxidized.

[0091] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0092] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing pigskin powder, characterized in that: include: Boil the pig skin; The boiled pigskin is crushed; homogenizing the crushed product; Degreasing the homogenized product; The defatted product is dried to obtain the pigskin powder.

2. The method according to claim 1, characterized in that The boiling process is carried out in water; Optionally, the weight ratio of the pigskin to water is 1:(3-10); Optionally, the boiling temperature is 70°C-110°C; Optionally, the boiling treatment time is 1h-3h.

3. The method according to claim 1, characterized in that The pressure of the homogenization treatment is 15MPa-20MPa.

4. The method according to claim 3, characterized in that The homogenization process is carried out by using a homogenizer.

5. The method according to claim 1, characterized in that The degreasing process includes subjecting the homogenized product to centrifugation.

6. The method according to claim 5, characterized in that The rotation speed of the centrifugal treatment is 5000rpm-7000rpm.

7. The method according to claim 1, characterized in that The temperature of the drying process is 150°C-200°C.

8. The method according to claim 7, characterized in that The drying process is carried out by spray drying.

9. A pigskin powder, characterized in that: The method is used to prepare the product according to any one of claims 1 to 8.

10. Use of the pigskin powder according to claim 9 in preparing food.