Method for deodorizing donkey-hide gelatin powder

Abstract

The invention discloses a method for deodorizing donkey-hide gelatin powder, and relates to the technical field of donkey-hide gelatin powder.The method comprises the steps that S1, donkey hide is obtained, hair and meat on the donkey hide are removed, and the donkey hide is washed with ultrapure water; s2, adding the donkey hide into a sodium carbonate solution, and heating and boiling; s3, carrying out subcritical water gelatin extraction on the donkey skin, ultrapure water and rock candy, and carrying out a glycosylation reaction; s4, mixing the donkey hide with yellow rice wine and soybean oil, boiling and fusing to obtain donkey-hide gelatin; s5, drying the donkey-hide gelatin, and carrying out a secondary glycosylation reaction; s6, performing superheated steam treatment on the donkey-hide gelatin; and S7, refining the donkey-hide gelatin to obtain the donkey-hide gelatin powder. The preparation method has the beneficial effects that the rock candy and the ultrapure water are added for subcritical water gelatin extraction, a glycosylation reaction is carried out to generate a certain flavor to cover the fishy smell, secondary glycosylation is carried out while drying is carried out through microwave treatment, then the fishy smell is dissipated through superheated steam treatment, and the problem that the fishy smell of the donkey-hide gelatin powder is heavy is solved.

Description

Technical Field

[0001] The invention relates to a processing technology of donkey-hide gelatin powder, in particular to a method for removing the fishy smell of donkey-hide gelatin powder. Background Art

[0002] Donkey hide gelatin is a product made from donkey skin through a certain process. Its main ingredients include collagen, protein, amino acids, polysaccharides and various trace elements. It has the functions of nourishing yin and blood, moistening dryness and stopping bleeding, beautifying and nourishing the skin, invigorating qi and promoting sleep, etc. It is also found that it has certain potential in anti-oxidation, anti-inflammation, and promoting wound healing. However, donkey hide gelatin has a special fishy smell, which is difficult for consumers to accept, which to a certain extent affects its application in industry.

[0003] The prior art discloses that the deodorization of donkey-hide gelatin includes the following steps: soaking the donkey skin in clean water to remove the hair, then blanching the skin, and rinsing the donkey skin with clean water until the pH value is 7.0. Soaking the blanched donkey skin in pure water containing fruit enzymes and salt for a period of time, and then rinsing it with clean water; extracting the washed donkey skin, stirring it every 2 to 3 hours during the extraction process; adding an appropriate amount of rice wine and white sugar before producing the gelatin to further remove the fishy smell, and adding an appropriate amount of soybean oil to obtain donkey-hide gelatin slurry. After cooling the donkey-hide gelatin slurry, a gelatin lump is obtained, and the gelatin lump is cut into pieces, dried, and packaged to obtain high-quality donkey-hide gelatin without fishy smell. The prior art also discloses a production process for removing the fishy smell of donkey-hide gelatin, including: S1: raw material preparation; selecting, cleaning, soaking, hair removal, meat removal, skin cutting, skin washing, and skin blanching according to quality standards, thereby completing the preparation of raw materials; S2: extracting gelatin juice; placing the donkey skin blanched in S1 in an extraction device, adding water and heating to extract twice, filtering the gelatin juice, placing it in a sandwich evaporator, and removing the residue after the extraction is completed; S3: clarifying and filtering; the gelatin juice proposed in S2 is subjected to a process of removing its internal impurities by a clarifying and filtering method; S4: concentration and preparation; after the gelatin juice treated in S3 is initially concentrated, it is transferred to a sandwich pot for continued concentration, and after reaching a certain concentration, foaming and impurity removal are performed; soybean oil, crystal sugar, and yellow wine are added, and the gelatin is boiled until it is thick and paste-like; S5: gelling; the thick paste-like gelatin liquid in S4 is condensed in a gel box, cut into pieces, and dried to obtain the finished donkey-hide gelatin. Although the above method can remove the fishy smell to a certain extent, the fishy smell removal effect is general. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art, and to provide a method for removing the fishy smell of donkey-hide gelatin powder. The method comprises the following steps: using donkey hide as a raw material, adding rock sugar and ultrapure water to perform subcritical water extraction, and causing the rock sugar to decompose to form reducing sugar, preparing a donkey-hide gelatin-reducing sugar system, and causing a glycosylation reaction to produce a certain flavor to cover up the fishy smell. The method is dried by microwave treatment, and secondary glycosylation is performed at the same time. The method is further treated with superheated steam to dissipate the fishy smell, thereby solving the problem of heavy fishy smell of donkey-hide gelatin powder, thereby greatly improving the application experience and market recognition of donkey-hide gelatin powder in the fields of food and medicine, and expanding the application of donkey-hide gelatin powder in industry.

[0005] The technical solution of the present invention is as follows: A method for removing the fishy smell of donkey-hide gelatin powder comprises the following steps: S1. Obtain donkey skin, remove hair and meat from the donkey skin, and wash it with ultrapure water; S2, adding the donkey skin treated in step S1 into a sodium carbonate solution, heating and boiling, and removing the grease and epidermal keratin; S3, subjecting the donkey skin treated in step S2 to subcritical water extraction with ultrapure water and crystal sugar, and causing glycosylation reaction; S4, mixing the donkey skin treated in step S3 with rice wine and soybean oil, boiling and blending, and obtaining donkey-hide gelatin; S5, drying the donkey-hide gelatin in step S4 to cause a secondary glycosylation reaction; S6, subjecting the donkey-hide gelatin in step S5 to superheated steam treatment; S7, refining the donkey-hide gelatin in step S5 to obtain donkey-hide gelatin powder.

[0006] Preferably, in step S1, the hair and meat on the donkey skin are removed, the water is drained, and the donkey skin is cut into small pieces of 2 cm×2 cm.

[0007] Preferably, in step S2, the weight percentage concentration of the sodium carbonate solution is 2-5%.

[0008] Preferably, in step S2, the solid-liquid ratio of the donkey skin to the sodium carbonate solution is 1 g: 3-5 mL.

[0009] Preferably, in step S2, the heating and boiling time is 5 to 15 minutes, and the process is performed 2 to 4 times.

[0010] Preferably, in step S3, the material-liquid ratio of the donkey skin to ultrapure water is 1 g:15-30 mL, and the mass ratio of donkey-hide gelatin to crystal sugar is 1-20:1.

[0011] Preferably, in step S3, the subcritical water temperature is 110-130° C., and the subcritical water treatment time is 30-120 min. Preferably, in step S4, the material-liquid ratio of donkey-hide gelatin to rice wine is 5-10 g:1 mL, and the ratio of donkey-hide gelatin to soybean oil is 10-20 g:1 mL.

[0012] Preferably, in step S5, the drying is microwave drying, the microwave power is 800-1200 W, the microwave time is 10-30 min, and the thickness of the donkey-hide gelatin is 2-8 mm.

[0013] Preferably, in step S6, the superheated steam temperature is 110-150° C., and the processing time is 1-3 min.

[0014] The present invention uses subcritical, microwave treatment and superheated steam deodorization methods to remove the fishy smell of donkey-hide gelatin. The specific principles are as follows: First, add the donkey skin to the sodium carbonate solution to remove the oil and epithelial keratin; then, subcritical water extraction is carried out with ultrapure water and crystal sugar. Subcritical water has a high ion product, a low relative dielectric constant, viscosity and surface tension, which is conducive to the extraction of substances. It has the advantages of high extraction rate, short time consumption, no organic solvent residue, and environmental friendliness. It is a green and efficient treatment method. Using subcritical water to extract collagen from donkey skin will effectively improve the utilization rate of donkey skin; and promote the decomposition of crystal sugar to form reducing sugar, prepare donkey-hide gelatin-reducing sugar system, and produce a certain flavor to cover its fishy smell by glycosylation reaction. Then microwave drying occurs, and secondary glycosylation reaction occurs; microwave treatment is a method of heating, drying and other treatments of substances using microwave technology. Since microwaves can directly penetrate the surface of the substance and generate heat inside, the substance can be heated both inside and outside at the same time, which can achieve rapid and uniform heating and achieve drying effect. At the same time, microwave treatment can cause donkey-hide gelatin to react with sugar to produce a stronger flavor to cover the fishy smell. Finally, superheated steam treatment is used to further remove the fishy smell. The superheated steam deodorization technology is to heat saturated steam to above its saturation temperature, so that the steam is in a supersaturated state. When the high-temperature steam contacts the surface of the food, some volatile substances on the surface of the food will evaporate quickly, which may include compounds that cause the fishy smell. At the same time, substances that produce fishy smell may undergo chemical changes at high temperatures, thereby reducing or eliminating the odor. At present, in the food field, superheated steam is mostly used for drying and sterilization. There are no related reports on the use of microwave treatment combined with superheated steam to remove the fishy smell of donkey-hide gelatin powder.

[0015] The present invention has at least one of the following beneficial effects: The present invention adopts the above-mentioned method for removing the fishy smell of donkey-hide gelatin powder, takes donkey hide as raw material, adds rock sugar and ultrapure water to perform subcritical water extraction of gelatin, and promotes the decomposition of rock sugar to form reducing sugar, prepares donkey-hide gelatin-reducing sugar system, causes glycosylation reaction to produce a certain flavor to cover its fishy smell, and then performs drying through microwave treatment, performs secondary glycosylation at the same time, and further performs superheated steam treatment to dissipate the fishy smell, thereby solving the problem of heavy fishy smell of donkey-hide gelatin powder, thereby greatly improving the application experience and market recognition of donkey-hide gelatin powder in the fields of food and medicine, and expanding the application of donkey-hide gelatin powder in industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a graph showing the electronic nose measurement results of the donkey-hide gelatin powder prepared in Examples 1 to 5 and Comparative Examples 1 to 5. DETAILED DESCRIPTION

[0017] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] The present invention is further described in detail below with specific examples, but the present invention is not limited to the following specific examples.

[0019] Example 1 A method for removing the fishy smell of donkey-hide gelatin powder, the method comprising the following steps: (1) Pretreatment of donkey skin: Use donkey skin as the main raw material, remove the hair and grease on the donkey skin, wash it with ultrapure water, drain the water, and cut it into small pieces of 2 cm × 2 cm.

[0020] (2) Degreasing treatment: Weigh 20 g of donkey hide, add 2% sodium carbonate solution with a solid-liquid ratio of 1 g:3 mL, heat and boil for 10 min, repeat the process three times to remove oil and epithelial keratin.

[0021] (3) Subcritical water extraction and preparation of donkey-hide gelatin-reducing sugar system: donkey skin and ultrapure water were added in a ratio of donkey skin: ultrapure water = 1g:20mL, and rock sugar was added in a mass ratio of donkey-hide gelatin: rock sugar = 10:1, and subcritical water extraction was performed to promote the decomposition of rock sugar to form reducing sugar, prepare donkey-hide gelatin-reducing sugar system, and cause glycosylation reaction. The subcritical water temperature was 125℃, and the subcritical water treatment time was 60min.

[0022] (4) Add rice wine and soybean oil and mix: Add rice wine at a ratio of 10 g donkey hide gelatin: rice wine to 1 mL, and add soybean oil at a ratio of 20 g donkey hide gelatin: soybean oil to 1 mL, and further boil and blend.

[0023] (5) Microwave drying: The donkey-hide gelatin prepared in step (4) is subjected to microwave drying to cause secondary glycosylation. The microwave power is 1000 W, the microwave time is 15 min, and the thickness of the material is 4 mm.

[0024] (6) Superheated steam treatment: The donkey-hide gelatin in step (5) is subjected to superheated steam treatment to further remove the fishy smell. The superheated steam temperature is 110°C and the treatment time is 2 minutes.

[0025] (7) Crushing: The deodorized donkey-hide gelatin powder is refined to form a high-quality donkey-hide gelatin powder product.

[0026] Example 2 A method for removing the fishy smell of donkey-hide gelatin powder, the method comprising the following steps: (1) Pretreatment of donkey skin: Use donkey skin as the main raw material, remove the hair and grease on the donkey skin, wash it with ultrapure water, drain the water, and cut it into small pieces of 2 cm × 2 cm.

[0027] (2) Degreasing treatment: Weigh 20 g of donkey hide, add 2% sodium carbonate solution with a solid-liquid ratio of 1 g:3 mL, heat and boil for 10 min, repeat the process three times to remove oil and epithelial keratin.

[0028] (3) Subcritical water extraction and preparation of donkey-hide gelatin-reducing sugar system: donkey skin and ultrapure water were added in a ratio of donkey skin: ultrapure water = 1g:20 mL, and rock sugar was added in a mass ratio of donkey-hide gelatin: rock sugar = 1:1, and subcritical water extraction was performed to promote the decomposition of rock sugar to form reducing sugar, prepare donkey-hide gelatin-reducing sugar system, and cause glycosylation reaction. The subcritical water temperature was 125℃, and the subcritical water treatment time was 60min.

[0029] (4) Add rice wine and soybean oil and mix: Add rice wine at a ratio of 10 g donkey hide gelatin: rice wine to 1 mL, and add soybean oil at a ratio of 20 g donkey hide gelatin: soybean oil to 1 mL, and further boil and blend.

[0030] (5) Microwave drying: The donkey-hide gelatin prepared in step (4) is subjected to microwave drying to cause secondary glycosylation. The microwave power is 1000 W, the microwave time is 15 min, and the thickness of the material is 4 mm.

[0031] (6) Superheated steam treatment: The donkey-hide gelatin in step (5) is subjected to superheated steam treatment to further remove the fishy smell. The superheated steam temperature is 110°C and the treatment time is 2 minutes.

[0032] (7) Crushing: The deodorized donkey-hide gelatin powder is refined to form a high-quality donkey-hide gelatin powder product.

[0033] Example 3 A method for removing the fishy smell of donkey-hide gelatin powder, the method comprising the following steps: (1) Pretreatment of donkey skin: Use donkey skin as the main raw material, remove the hair and grease on the donkey skin, wash it with ultrapure water, drain the water, and cut it into small pieces of 2 cm × 2 cm.

[0034] (2) Degreasing treatment: Weigh 20 g of donkey hide, add 2% sodium carbonate solution with a solid-liquid ratio of 1 g:3 mL, heat and boil for 10 min, repeat the process three times to remove oil and epithelial keratin.

[0035] (3) Subcritical water extraction and preparation of donkey-hide gelatin-reducing sugar system: donkey skin and ultrapure water were added in a ratio of donkey skin: ultrapure water = 1g:20mL, and rock sugar was added in a mass ratio of donkey-hide gelatin: rock sugar = 20:1, and subcritical water extraction was performed to promote the decomposition of rock sugar to form reducing sugar, prepare donkey-hide gelatin-reducing sugar system, and cause glycosylation reaction. The subcritical water temperature was 125℃, and the subcritical water treatment time was 60min.

[0036] (4) Add rice wine and soybean oil and mix: Add rice wine at a ratio of 10g:1mL for donkey hide gelatin and 20g:1mL for soybean oil, and further boil until blended.

[0037] (5) Microwave drying: The donkey-hide gelatin prepared in step (4) is subjected to microwave drying to cause secondary glycosylation. The microwave power is 1000 W, the microwave time is 15 min, and the thickness of the material is 4 mm.

[0038] (6) Superheated steam treatment: The donkey-hide gelatin in step (5) is subjected to superheated steam treatment to further remove the fishy smell. The superheated steam temperature is 110°C and the treatment time is 2 minutes.

[0039] (7) Crushing: The deodorized donkey-hide gelatin powder is refined to form a high-quality donkey-hide gelatin powder product.

[0040] Example 4 A method for removing the fishy smell of donkey-hide gelatin powder, the method comprising the following steps: (1) Pretreatment of donkey skin: Use donkey skin as the main raw material, remove the hair and grease on the donkey skin, wash it with ultrapure water, drain the water, and cut it into small pieces of 2 cm × 2 cm.

[0041] (2) Degreasing treatment: Weigh 20 g of donkey hide, add 2% sodium carbonate solution with a solid-liquid ratio of 1 g:3 mL, heat and boil for 10 min, repeat the process three times to remove oil and epithelial keratin.

[0042] (3) Subcritical water extraction and preparation of donkey-hide gelatin-reducing sugar system: donkey skin and ultrapure water were added in a ratio of donkey skin: ultrapure water = 1g:20mL, and rock sugar was added in a mass ratio of donkey-hide gelatin: rock sugar = 10:1, and subcritical water extraction was performed to promote the decomposition of rock sugar to form reducing sugar, prepare donkey-hide gelatin-reducing sugar system, and cause glycosylation reaction. The subcritical water temperature was 125℃, and the subcritical water treatment time was 60min.

[0043] (4) Add rice wine and soybean oil and mix: Add rice wine at a ratio of 10g:1mL for donkey hide gelatin and 20g:1mL for soybean oil, and further boil until blended.

[0044] (5) Microwave drying: The donkey-hide gelatin prepared in step (4) is subjected to microwave drying, and secondary glycosylation occurs at the same time. The microwave power is 800 W, the microwave time is 10 min, and the thickness of the material is 4 mm.

[0045] (6) Superheated steam treatment: The donkey-hide gelatin in step (5) is subjected to superheated steam treatment to further remove the fishy smell. The superheated steam temperature is 110°C and the treatment time is 2 minutes.

[0046] (7) Crushing: The deodorized donkey-hide gelatin powder is refined to form a high-quality donkey-hide gelatin powder product.

[0047] Example 5 A method for removing the fishy smell of donkey-hide gelatin powder, the method comprising the following steps: (1) Pretreatment of donkey skin: Use donkey skin as the main raw material, remove the hair and grease on the donkey skin, wash it with ultrapure water, drain the water, and cut it into small pieces of 2 cm × 2 cm.

[0048] (2) Degreasing treatment: Weigh 20 g of donkey hide, add 2% sodium carbonate solution with a solid-liquid ratio of 1 g:3 mL, heat and boil for 10 min, repeat the process three times to remove oil and epithelial keratin.

[0049] (3) Subcritical water extraction and preparation of donkey-hide gelatin-reducing sugar system: donkey skin and ultrapure water were added in a ratio of donkey skin: ultrapure water = 1g:20mL, and rock sugar was added in a mass ratio of donkey-hide gelatin: rock sugar = 10:1, and subcritical water extraction was performed to promote the decomposition of rock sugar to form reducing sugar, prepare donkey-hide gelatin-reducing sugar system, and cause glycosylation reaction. The subcritical water temperature was 125℃, and the subcritical water treatment time was 60min.

[0050] (4) Add rice wine and soybean oil and mix: Add rice wine in the ratio of 10g donkey-hide gelatin to rice wine, and add soybean oil in the ratio of 20g donkey-hide gelatin to soybean oil, and further boil and blend. (5) Microwave drying: The donkey-hide gelatin prepared in step (4) is subjected to microwave drying to cause secondary glycosylation. The microwave power is 1000 W, the microwave time is 15 min, and the thickness of the material is 4 mm.

[0051] (6) Superheated steam treatment: The donkey-hide gelatin in step (5) is subjected to superheated steam treatment to further remove the fishy smell. The superheated steam temperature is 150°C and the treatment time is 2 minutes.

[0052] (7) Crushing: The deodorized donkey-hide gelatin powder is refined to form a high-quality donkey-hide gelatin powder product.

[0053] Comparative Example 1 (no preparation of donkey-hide gelatin-reducing sugar system and no superheated steam treatment) The following steps are involved: (1) Pretreatment of donkey skin: Use donkey skin as the main raw material, remove the hair and grease on the donkey skin, wash it with ultrapure water, drain the water, and cut it into small pieces of 2 cm × 2 cm.

[0054] (2) Degreasing treatment: Weigh 20 g of donkey hide, add 2% sodium carbonate solution with a solid-liquid ratio of 1 g:3 mL, heat and boil for 10 min, repeat the process three times to remove oil and epithelial keratin.

[0055] (3) Subcritical water extraction: Donkey skin and ultrapure water were added in a ratio of 1 g donkey skin: ultrapure water = 20 mL, and subcritical water extraction was performed. The subcritical water temperature was 125 °C, and the subcritical water treatment time was 60 min.

[0056] (4) Add rice wine and soybean oil and mix: Add rice wine in the ratio of 10g donkey-hide gelatin to rice wine, and add soybean oil in the ratio of 20g donkey-hide gelatin to soybean oil, and further boil and blend. (5) Microwave drying: The donkey-hide gelatin in step (4) was dried by microwave with a microwave power of 1000 W, a microwave time of 15 min, and a layer thickness of 4 mm.

[0057] (6) Crushing: Grind the dried donkey-hide gelatin into fine powder to form high-quality donkey-hide gelatin powder products.

[0058] Comparative Example 2 (without superheated steam treatment) The following steps are involved: (1) Pretreatment of donkey skin: Use donkey skin as the main raw material, remove the hair and grease on the donkey skin, wash it with ultrapure water, drain the water, and cut it into small pieces of 2 cm × 2 cm.

[0059] (2) Degreasing treatment: Weigh 20 g of donkey hide, add 2% sodium carbonate solution with a solid-liquid ratio of 1 g:3 mL, heat and boil for 10 min, repeat the process three times to remove oil and epithelial keratin.

[0060] (3) Subcritical water extraction and preparation of donkey-hide gelatin-reducing sugar system: donkey skin and ultrapure water were added in a ratio of donkey skin: ultrapure water = 1g:20mL, and rock sugar was added in a mass ratio of donkey-hide gelatin: rock sugar = 10:1, and subcritical water extraction was performed to promote the decomposition of rock sugar to form reducing sugar, prepare donkey-hide gelatin-reducing sugar system, and cause glycosylation reaction. The subcritical water temperature was 125℃, and the subcritical water treatment time was 60min.

[0061] (4) Add rice wine and soybean oil and mix: Add rice wine in the ratio of 10g donkey-hide gelatin to rice wine, and add soybean oil in the ratio of 20g donkey-hide gelatin to soybean oil, and further boil and blend. (5) Microwave drying: The donkey-hide gelatin prepared in step (4) is subjected to microwave drying to cause secondary glycosylation. The microwave power is 1000 W, the microwave time is 15 min, and the thickness of the material is 4 mm.

[0062] (6) Crushing: Grind the dried donkey-hide gelatin into fine powder to form high-quality donkey-hide gelatin powder products.

[0063] Comparative Example 3 (No donkey-hide gelatin-reducing sugar system was prepared) The following steps are involved: (1) Pretreatment of donkey skin: Use donkey skin as the main raw material, remove the hair and grease on the donkey skin, wash it with ultrapure water, drain the water, and cut it into small pieces of 2 cm × 2 cm.

[0064] (2) Degreasing treatment: Weigh 20 g of donkey hide, add 2% sodium carbonate solution with a solid-liquid ratio of 1 g:3 mL, heat and boil for 10 min, repeat the process three times to remove oil and epithelial keratin.

[0065] (3) Subcritical water extraction: Donkey skin and ultrapure water were added in a ratio of 1 g donkey skin: ultrapure water = 20 mL, and subcritical water extraction was performed. The subcritical water temperature was 125 °C, and the subcritical water treatment time was 60 min.

[0066] (4) Add rice wine and soybean oil and mix: Add rice wine in the ratio of 10g donkey-hide gelatin to rice wine, and add soybean oil in the ratio of 20g donkey-hide gelatin to soybean oil, and further boil and blend. (5) Microwave drying: The donkey-hide gelatin in step (4) was dried by microwave with a microwave power of 1000 W, a microwave time of 15 min, and a layer thickness of 4 mm.

[0067] (6) Superheated steam treatment: The donkey-hide gelatin in step (5) is subjected to superheated steam treatment to further remove the fishy smell. The superheated steam temperature is 110°C and the treatment time is 2 minutes.

[0068] (7) Crushing: The deodorized donkey-hide gelatin powder is refined to form a high-quality donkey-hide gelatin powder product.

[0069] Comparative Example 4 (no subcritical water extraction and no preparation of donkey-hide gelatin-reducing sugar system) The following steps are involved: (1) Pretreatment of donkey skin: Use donkey skin as the main raw material, remove the hair and grease on the donkey skin, wash it with ultrapure water, drain the water, and cut it into small pieces of 2 cm × 2 cm.

[0070] (2) Degreasing treatment: Weigh 20 g of donkey hide, add 2% sodium carbonate solution with a solid-liquid ratio of 1 g:3 mL, heat and boil for 10 min, repeat the process three times to remove oil and epithelial keratin.

[0071] (3) Extraction of glue: Add donkey skin and ultrapure water in the ratio of donkey skin: ultrapure water = 1g:20mL, and heat to extract glue. The extraction temperature is 80℃ and the extraction time is 3h.

[0072] (4) Add rice wine and soybean oil and mix: Add rice wine at a ratio of 10 g donkey hide gelatin: rice wine to 1 mL, and add soybean oil at a ratio of 20 g donkey hide gelatin: soybean oil to 1 mL, and further boil and blend.

[0073] (5) Microwave drying: The donkey-hide gelatin prepared in step (4) is subjected to microwave drying to cause secondary glycosylation. The microwave power is 1000 W, the microwave time is 15 min, and the thickness of the material is 4 mm.

[0074] (6) Superheated steam treatment: The donkey-hide gelatin in step (5) is subjected to superheated steam treatment to further remove the fishy smell. The superheated steam temperature is 110°C and the treatment time is 2 minutes.

[0075] (7) Crushing: The deodorized donkey-hide gelatin powder is refined to form a high-quality donkey-hide gelatin powder product.

[0076] Comparative Example 5 (without microwave drying) (1) Pretreatment of donkey skin: Use donkey skin as the main raw material, remove the hair and grease on the donkey skin, wash it with ultrapure water, drain the water, and cut it into small pieces of 2 cm × 2 cm.

[0077] (2) Degreasing treatment: Weigh 20 g of donkey hide, add 2% sodium carbonate solution with a solid-liquid ratio of 1 g:3 mL, heat and boil for 10 min, repeat the process three times to remove oil and epithelial keratin.

[0078] (3) Subcritical water extraction and preparation of donkey-hide gelatin-reducing sugar system: donkey skin and ultrapure water were added in a ratio of donkey skin: ultrapure water = 1g:20mL, and rock sugar was added in a mass ratio of donkey-hide gelatin: rock sugar = 10:1, and subcritical water extraction was performed to promote the decomposition of rock sugar to form reducing sugar, prepare donkey-hide gelatin-reducing sugar system, and cause glycosylation reaction. The subcritical water temperature was 125℃, and the subcritical water treatment time was 60min.

[0079] (4) Add rice wine and soybean oil and mix: Add rice wine at a ratio of 10 g donkey hide gelatin: rice wine to 1 mL, and add soybean oil at a ratio of 20 g donkey hide gelatin: soybean oil to 1 mL, and further boil and blend.

[0080] (5) Superheated steam treatment: The donkey-hide gelatin in step (4) is subjected to superheated steam treatment to further remove the fishy smell. The superheated steam temperature is 110°C and the treatment time is 2 minutes.

[0081] (6) Crushing: The deodorized donkey-hide gelatin powder is refined to form a high-quality donkey-hide gelatin powder product.

[0082] Example 6 The donkey-hide gelatin powder prepared in Examples 1 to 5 and Comparative Examples 1 to 5 was subjected to electronic nose detection. The electronic nose detection method for donkey-hide gelatin powder is as follows: 1 g of donkey-hide gelatin powder prepared in each example and comparative example was weighed, quickly put into a 20 ml headspace bottle, sealed, and heated in a 50 ° C water bath for 30 min. The electronic nose device was used for the measurement, wherein the electronic nose set the probe cleaning time to 120 s, the reset time to 5 s, the pre-sampling time to 5 s, the carrier gas flow rate to 300 mL / min, and the sample measurement time to 100 s.

[0083] The electronic nose has 10 different metal oxide sensors. W1C is sensitive to aromatic components; W5S is sensitive to nitrogen oxides; W3C is sensitive to ammonia and aromatic components; W6S is selective for hydrides; W5C is sensitive to short-chain alkanes and aromatic components; W1S is sensitive to methyls; W1W is sensitive to inorganic sulfides; W2S is sensitive to alcohols, aldehydes and ketones; W2W is sensitive to aromatic components and organic sulfides; W3S is sensitive to long-chain alkanes.

[0084] Depend on Figure 1It can be seen that the response values ​​of the six sensors W3S, W1C, W5S, W3C, W6S, and W5C are all relatively low, indicating that less aromatic compounds, ammonia compounds, and hydrocarbon compounds are produced during the sample treatment process, and the response value of the W1C sensor in Example 2 is significantly lower than that of other embodiments and comparative examples, indicating that aromatic substances are significantly reduced during the treatment process. For the response values ​​of the four sensors W1S, W1W, W2S, and W2W, each embodiment and comparative example has a significant change, indicating that the gelatin powder prepared by distinguishing these embodiments and comparative examples mainly contributes to these four sensors. The response values ​​of the four sensors of the gelatin powder in Example 1 are all relatively low, indicating that the smell of the gelatin powder is significantly dissipated during this treatment process, including its fishy smell. However, the response values ​​of the four sensors in Example 3 and Example 4 are not much different from those in Comparative Example 1, indicating that the fishy removal effect of these two embodiments is not obvious. The response values ​​of the three sensors W1S, W1W, and W2W in Example 5 are also significantly lower than those in Comparative Example 1, but higher than those in Example 1, indicating that the treatment process in Example 5 has a slight deodorizing effect, but the deodorizing effect is lower than that in Example 1. The response values ​​of W1S and W2S in Comparative Example 2 are significantly lower than those in Comparative Example 1, indicating that the glycosylation reaction in Comparative Example 2 has a certain deodorizing effect. The response values ​​of the four sensors W1S, W1W, W2S, and W2W in Comparative Example 3 are slightly lower than those in Comparative Example 1, indicating that the deodorizing effect is average. The response values ​​of the W1W and W2W sensors in Comparative Examples 4 and 5 are significantly higher than those in Example 1, indicating that their deodorizing effects are not good.

[0085] Example 7 The donkey-hide gelatin powder prepared in Examples 1 to 5 and Comparative Examples 1 to 5 was subjected to sensory evaluation. Ten professional sensory assessors (5 males and 5 females) aged between 20 and 30 were selected to conduct sensory evaluation on the donkey-hide gelatin powder prepared in Examples 1 to 5 and Comparative Examples 1 to 5. The indicators included color, smell, and texture. Each indicator was scored according to 1 to 10 points. The lower the score, the darker the color of the prepared donkey-hide gelatin powder, the heavier the fishy smell, and the rough and not fine texture. The results are shown in Table 1.

[0086] Table 1 As can be seen from Table 1, the donkey-hide gelatin powder prepared in Example 1 has the highest sensory score, indicating that this treatment can effectively remove the fishy smell without changing its color and texture characteristics to a certain extent.

[0087] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for removing the fishy smell of donkey-hide gelatin powder, characterized in that: The following steps are involved: S1. Obtain donkey skin, remove hair and meat from the donkey skin, and wash it with ultrapure water; S2, adding the donkey skin treated in step S1 into a sodium carbonate solution, heating and boiling, and removing the grease and epidermal keratin; S3, subjecting the donkey skin treated in step S2 to subcritical water extraction with ultrapure water and crystal sugar, and causing glycosylation reaction; S4, mixing the donkey skin treated in step S3 with rice wine and soybean oil, boiling and blending, and obtaining donkey-hide gelatin; S5, drying the donkey-hide gelatin in step S4 to cause a secondary glycosylation reaction; S6, subjecting the donkey-hide gelatin in step S5 to superheated steam treatment; S7, refining the donkey-hide gelatin in step S5 to obtain donkey-hide gelatin powder.

2. The method for removing the fishy smell of donkey-hide gelatin powder according to claim 1, characterized in that: In step S1, the hair and meat on the donkey skin are removed, the water is drained, and the skin is cut into small pieces of 2 cm×2 cm.

3. The method for removing the fishy smell of donkey-hide gelatin powder according to claim 1, characterized in that: In step S2, the weight percentage concentration of the sodium carbonate solution is 2-5%.

4. The method for removing the fishy smell of donkey-hide gelatin powder according to claim 1, characterized in that: In step S2, the material-liquid ratio of the donkey skin to the sodium carbonate solution is 1 g: 3-5 mL.

5. The method for removing the fishy smell of donkey-hide gelatin powder according to claim 1, characterized in that: In step S2, the heating and boiling time is 5 to 15 minutes, and the process is performed 2 to 4 times.

6. The method for removing the fishy smell of donkey-hide gelatin powder according to claim 1, characterized in that: In step S3, the material-liquid ratio of the donkey skin to ultrapure water is 1 g:15-30 mL, and the mass ratio of donkey-hide gelatin to crystal sugar is 1-20:

1.

7. The method for removing the fishy smell of donkey-hide gelatin powder according to claim 1, characterized in that: In step S3, the subcritical water temperature is 110-130° C., and the subcritical water treatment time is 30-120 min.

8. The method for removing the fishy smell of donkey-hide gelatin powder according to claim 1, characterized in that: In step S4, the material-liquid ratio of donkey-hide gelatin to rice wine is 5-10 g:1 mL, and the ratio of donkey-hide gelatin to soybean oil is 10-20 g:1 mL.

9. The method for removing the fishy smell of donkey-hide gelatin powder according to claim 1, characterized in that: In step S5, the drying is microwave drying, the microwave power is 800-1200 W, the microwave time is 10-30 min, and the thickness of the donkey-hide gelatin is 2-8 mm.

10. The method for removing the fishy smell of donkey-hide gelatin powder according to claim 1, characterized in that: In step S6, the superheated steam temperature is 110-150° C., and the processing time is 1-3 minutes.

Images