Preparation method of high-quality fish gelatin

Abstract

The invention discloses a preparation method of high-quality fish gelatin, and belongs to the technical field of food processing. According to the method, the raw materials are decalcified through ion exchange, and ultrasonic treatment is assisted, so that the high-quality fish gelatin is prepared; and performing glycosylation modification treatment on the fish gelatin to finally obtain the high-quality fish gelatin. According to the method, efficient ion exchange decalcification is adopted in the decalcification process, the problem of low decalcification efficiency of an acid method can be solved, the influence of low pH on bioactive components in fish gelatin in the decalcification process of the acid method is also avoided, meanwhile, compared with EDTA decalcification, resin for decalcification in ion exchange can be recycled and repeatedly used, and the production cost can be reduced; ultrasonic or microwave treatment is assisted during ion exchange decalcification, so that the decalcification efficiency can be improved through high-frequency vibration generated by ultrasonic or microwave, the decalcification time is further shortened, and the production cost is reduced; and the fish gelatin is modified by adopting a glycosylation mode, so that the quality of the fish gelatin is further improved.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, and specifically relates to a method for preparing high-quality fish gelatin. Background Art

[0002] Gelatin is widely favored by consumers due to its excellent thickening, emulsifying, and gelling properties, as well as its high nutritional value. The main sources of gelatin are the skin and bones of pigs and cattle. However, with the outbreak of mad cow disease and the rise of kosher food markets, and the fact that most people with gelatin allergies react to bovine and porcine gelatin but generally do not react to fish gelatin, using fish gelatin as a substitute for traditional gelatin has become a viable trend. Currently, the utilization rate of fish products during processing is low, often generating a lot of waste, nearly half of which consists of fish bones, scales, and skin. This is not only a waste of resources but also pollutes the environment. Using fish waste as a raw material to prepare gelatin can not only serve as a way to supplement protein but also improve resource utilization and reduce environmental pressure.

[0003] Fish bones are rich in collagen fibers and hydroxyapatite, among other substances. Hydroxyapatite often deposits on the surface of collagen fibers as insoluble calcium, giving the bone tissue a hard texture that hinders subsequent processing and affects the yield, purity, and gel strength of gelatin products. Therefore, decalcification and softening treatment is necessary for fish bones. Removing calcium also facilitates the purification of collagen components. Common decalcification methods include acid decalcification and EDTA decalcification. While decalcification using acids such as hydrochloric acid is efficient and low-cost, the conditions are relatively strict. Furthermore, the low pH (around 2) not only affects the biological activity of proteins in fish skin but also causes some protein loss during decalcification. EDTA decalcification, on the other hand, is more effective due to its milder decalcification solution (around 7 pH), causing less damage to proteins and preserving their biological activity to the greatest extent. However, the processing cycle is longer, and EDTA is more expensive, resulting in higher production costs.

[0004] As a physical method, ion exchange, in addition to removing Ca from the environment... 2+It possesses strong adsorption and efficient separation capabilities, requiring no special chemical reagents or specialized equipment. During the process, the system maintains a neutral pH, preserving the chemical structure and biological activity of proteins. Furthermore, the resin is easily recoverable after decalcification, retaining good stability and allowing for repeated use, thus saving costs. Similarly, as physical methods, ultrasonic and microwave-assisted processing technologies are widely used in food production due to their ability to improve the functional properties of food. Simultaneous decalcification with ultrasound or microwaves accelerates the removal of calcium from collagen fibers through high-frequency vibrations, thereby improving decalcification efficiency and further reducing production costs.

[0005] Although fish gelatin has a wide range of applications, it has inherent drawbacks. The most prominent one is that the raw materials used to extract fish gelatin contain low levels of imino acids (proline and hydroxyproline), which makes some physical properties of fish gelatin, such as gelling properties, inferior to those of bovine or porcine gelatin. Therefore, fish gelatin needs to be modified to obtain high-quality products. Summary of the Invention

[0006] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the present invention provides a method for preparing high-quality fish gelatin, which adopts ion exchange decalcification to avoid affecting the protein structure and activity in fish bones, thereby improving decalcification efficiency and reducing production costs.

[0007] Technical solution: To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for preparing high-quality fish gelatin includes the following steps:

[0009] (1) Raw material pretreatment: The raw materials are washed with water to remove impurities and then crushed into pieces;

[0010] (2) Decalcification: The crushed raw material is mixed with water to make a liquid, then ion exchange resin is added, and decalcification is carried out by physical means.

[0011] (3) Filtration: The liquid is filtered step by step using screens with different pore sizes to recover the resin and obtain the decalcified raw material;

[0012] (4) Cleaning: Clean the decalcified raw materials to remove residual resin and other impurities;

[0013] (5) Gum extraction: The decalcified raw material is made into a liquid by adding water, then enzyme is added for enzymatic hydrolysis, and ultrasonic treatment is also performed. Then, the material is heated to extract the gum.

[0014] (6) Washing: Wash the residue after extraction with water to remove residual components;

[0015] (7) Filtration: The extracted gelatin solution is filtered to remove impurities;

[0016] (8) Purification: The filtered gelatin solution is subjected to ion exchange treatment to remove metal ions and acid radical ions;

[0017] (9) Concentration: The purified gelatin liquid is subjected to membrane filtration and evaporation to increase the gelatin concentration;

[0018] (10) Glycosylation modification: Add oligogalactomannan to the concentrated gelatin liquid for glycosylation modification;

[0019] (11) Sterilization: The modified gelatin liquid is sterilized;

[0020] (12) Drying: After the sterilized gelatin solution cools and solidifies into gelatin strips, it is placed in a dryer for drying.

[0021] (13) Crushing: The dried gelatin solid is crushed and refined to obtain the finished gelatin product.

[0022] In the steps described above, the raw material in step (1) is fish bone, and the size of the crushed fragments is about 1cm.

[0023] The liquid prepared in step (2) has a material-to-liquid ratio of 1:50 (g:ml); the ion exchange resin is a Na-type cation exchange resin, with an addition amount of 2-12g / 100g raw material, a decalcification temperature of 15-40℃, and a decalcification time of 0.5-2h; the physical method is either ultrasound or microwave, wherein the power of ultrasound treatment is 45W-225W and the time is 15-60min; the power of microwave treatment is 160-480W and the time is 15-60min.

[0024] In step (3), the sieves with different aperture sizes used to retain raw materials are 10 mesh, and the sieves used to retain resin are 20 mesh.

[0025] In step (5), the ratio of water to raw material in the liquid is 10:1-20:1 (L / g); the protease is a neutral protease, the amount added is 1.5% (w / w) of the raw material, the enzymatic hydrolysis temperature is 40℃, the enzymatic hydrolysis time is 4h; the ultrasonic power is 180W, the ultrasonic time is 10min; the gel extraction temperature is 65℃, and the gel extraction time is 4h.

[0026] The filtration described in step (7) is performed using a cotton cake filter.

[0027] The ion exchange in step (8) uses type 732 cation exchange resin and type 717 anion exchange resin;

[0028] The membrane filtration concentration process described in step (9) is ultrafiltration concentration, concentrated to a gelatin concentration of 5-10% (w / v); the evaporation process is multi-effect evaporation, concentrated to a gelatin concentration of 25-50% (w / v);

[0029] The glycosylation modification in step (10) is carried out using oligogalactomannan at a concentration of 2% (w / v) relative to the gelatin liquid. The crosslinking agent is transglutaminase at a concentration of 0.5% (w / v) relative to the gelatin liquid. The reaction time is 1 h and the reaction temperature is 40 °C.

[0030] The sterilization method described in step (11) is high-temperature instantaneous sterilization, with a temperature of 135-140℃ and a time of 2-8s;

[0031] The drying temperature in step (12) is 25-60℃, and the drying mode is gradient drying with temperature gradients of 25-34℃, 28-36℃, 33-41℃, 38-46℃, 43-51℃, 48-56℃, 50-58℃, and 52-60℃.

[0032] The pulverization mesh size mentioned in step (13) is 10-20 mesh.

[0033] Beneficial effects: This invention provides a method for preparing high-quality fish gelatin, with the following beneficial effects:

[0034] 1) The present invention uses ion exchange during decalcification, which can avoid the impact of the low pH during decalcification on the protein structure and biological activity in fish bones;

[0035] 2) The present invention uses ion exchange during decalcification, which has a good decalcification effect, and the resin is easy to recycle, has good stability, and can be reused multiple times, which helps to reduce production costs.

[0036] 3) This invention uses ion exchange during decalcification, supplemented by ultrasonic or microwave treatment. High-frequency vibration is used to promote the removal of calcium from collagen fibers, thereby shortening the decalcification time, improving decalcification efficiency, and helping to reduce production costs.

[0037] 4) This invention modifies fish gelatin through glycosylation, which further improves the quality of fish gelatin. After testing, it was found that compared with the existing fish gelatin preparation methods, the fish gelatin prepared by the method of this invention has improved gel strength, Blaine viscosity and transmittance. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the process for preparing high-quality fish gelatin in an embodiment of the present invention.

[0039] Figure 2This is a schematic diagram of the process flow for preparing fish gelatin using acid or EDTA decalcification and enzymatic methods, as shown in the comparative example. DETAILED DESCRIPTION

[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0041] Test method:

[0042] 1. Determination of calcium ion content

[0043] The calcium ion content was determined in accordance with the People's Republic of China National Standard GB5009.268-2016 "National Food Safety Standard - Determination of Multiple Elements in Food" using inductively coupled plasma mass spectrometry (ICP-MS).

[0044] 2. Determination of gelatin gel strength

[0045] The gel strength of gelatin was determined in accordance with the People's Republic of China Light Industry Standard QB / T 4087-2010 "Edible Gelatin".

[0046] 3. Determination of the Blaine viscosity of gelatin

[0047] The Blaine viscosity of gelatin was determined in accordance with the People's Republic of China Light Industry Standard QB / T 4087-2010 "Edible Gelatin".

[0048] 4. Determination of gelatin transmittance

[0049] The determination of gelatin transmittance was carried out in accordance with the People's Republic of China Light Industry Standard QB / T 4087-2010 "Edible Gelatin".

[0050] Example 1

[0051] A method for preparing high-quality fish gelatin, the specific steps of which are as follows:

[0052] (1) Raw material pretreatment: The raw materials are washed with water to remove impurities, and then crushed into pieces of about 1cm;

[0053] (2) Decalcification: The crushed raw material is mixed with water to make a liquid with a material-liquid ratio of 1:50 (g:ml). Then, ion exchange resin is added for decalcification. The addition amounts are 2, 4, 6, 8, and 10 g / 100g raw material, the decalcification temperature is 25℃, and the decalcification time is 1h.

[0054] (3) Filtration: The liquid is filtered step by step using 10-mesh and 20-mesh sieves to recover the resin and obtain the decalcified raw material;

[0055] (4) Cleaning: Clean the decalcified raw materials to remove residual resin and other impurities;

[0056] (5) Gum extraction: The decalcified raw material is made into a liquid by adding water, then enzyme is added for enzymatic hydrolysis, and ultrasonic treatment is also performed. Then, the material is heated to extract the gum.

[0057] (6) Washing: Wash the residue after extraction with water to remove residual components;

[0058] (7) Filtration: The extracted gelatin solution is filtered using a cotton cake filter to remove impurities;

[0059] (8) Purification: The filtered gelatin solution is subjected to ion exchange treatment with anion and cation exchange resins to remove metal ions and acid radical ions;

[0060] (9) Concentration: The purified gelatin liquid is concentrated by ultrafiltration and multi-effect evaporation to increase the gelatin concentration;

[0061] (10) Sterilization: Sterilize the concentrated gelatin liquid at 135℃-140℃ for 2s-8s;

[0062] (11) Drying: After the sterilized gelatin solution cools and solidifies into gelatin strips, it is placed in a dryer for gradient drying at a temperature of 25℃-60℃.

[0063] (12) Pulverization: The dried gelatin solid is pulverized to a fineness of 10-20 mesh to obtain the high-quality fish gelatin.

[0064] Table 1 shows the amount of ion exchange resin added and the corresponding calcium ion content and decalcification rate of the decalcified raw material. As can be seen from Table 1, with the increase of resin addition, the calcium ion content in the raw material gradually decreases, and the decalcification rate gradually increases. However, when the resin addition is 8%-12%, there is no significant difference in the calcium ion content and decalcification rate of the raw material.

[0065] Table 1. Calcium ion content and decalcification rate of raw materials after decalcification.

[0066]

[0067] Note: Different lowercase letters in the same column indicate significant differences between data (P < 0.05).

[0068] Example 2

[0069] A method for preparing high-quality fish gelatin, the specific steps of which are as follows:

[0070] (1) Raw material pretreatment: The raw materials are washed with water to remove impurities, and then crushed into pieces of about 1cm;

[0071] (2) Decalcification: The crushed raw material is mixed with water to make a liquid with a material-to-liquid ratio of 1:50 (g:ml). Then, ion exchange resin is added for decalcification. The amount added is 8g / 100g of raw material. The decalcification temperature is 15-40℃ and the decalcification time is 1h.

[0072] (3) Filtration: The liquid is filtered step by step using 10-mesh and 20-mesh sieves to recover the resin and obtain the decalcified raw material;

[0073] (4) Cleaning: Clean the decalcified raw materials to remove residual resin and other impurities;

[0074] (5) Gum extraction: The decalcified raw material is made into a liquid by adding water, then enzyme is added for enzymatic hydrolysis, and ultrasonic treatment is also performed. Then, the material is heated to extract the gum.

[0075] (6) Washing: Wash the residue after extraction with water to remove residual components;

[0076] (7) Filtration: The extracted gelatin solution is filtered using a cotton cake filter to remove impurities;

[0077] (8) Purification: The filtered gelatin solution is subjected to ion exchange treatment with anion and cation exchange resins to remove metal ions and acid radical ions;

[0078] (9) Concentration: The purified gelatin liquid is concentrated by ultrafiltration and multi-effect evaporation to increase the gelatin concentration;

[0079] (10) Sterilization: Sterilize the concentrated gelatin liquid at 135℃-140℃ for 2s-8s;

[0080] (11) Drying: After the sterilized gelatin solution cools and solidifies into gelatin strips, it is placed in a dryer for gradient drying at a temperature of 25℃-60℃.

[0081] (12) Pulverization: The dried gelatin solid is pulverized to a fineness of 10-20 mesh to obtain the high-quality fish gelatin.

[0082] Table 2 shows the decalcification temperature and the corresponding calcium ion content and decalcification rate of the raw materials. As can be seen from Table 2, with the increase of decalcification temperature, the calcium ion content in the raw materials first decreases and then increases, while the decalcification rate first increases and then decreases. However, when the decalcification temperature is 25-30℃, there is no significant difference in the calcium ion content and decalcification rate of the raw materials.

[0083] Table 2. Calcium ion content and decalcification rate of raw materials at different decalcification temperatures.

[0084]

[0085] Note: Different lowercase letters in the same column indicate significant differences between data (P < 0.05).

[0086] Example 3

[0087] A method for preparing high-quality fish gelatin, the specific steps of which are as follows:

[0088] (1) Raw material pretreatment: The raw materials are washed with water to remove impurities, and then crushed into pieces of about 1cm;

[0089] (2) Decalcification: The crushed raw material is mixed with water to make a liquid with a material-to-liquid ratio of 1:50 (g:ml). Then, ion exchange resin is added for decalcification. The amount added is 8g / 100g of raw material. The decalcification temperature is 25℃ and the decalcification time is 0.5-2h.

[0090] (3) Filtration: The liquid is filtered step by step using 10-mesh and 20-mesh sieves to recover the resin and obtain the decalcified raw material;

[0091] (4) Cleaning: Clean the decalcified raw materials to remove residual resin and other impurities;

[0092] (5) Gum extraction: The decalcified raw material is made into a liquid by adding water, then enzyme is added for enzymatic hydrolysis, and ultrasonic treatment is also performed. Then, the material is heated to extract the gum.

[0093] (6) Washing: Wash the residue after extraction with water to remove residual components;

[0094] (7) Filtration: The extracted gelatin solution is filtered using a cotton cake filter to remove impurities;

[0095] (8) Purification: The filtered gelatin solution is subjected to ion exchange treatment with anion and cation exchange resins to remove metal ions and acid radical ions;

[0096] (9) Concentration: The purified gelatin liquid is concentrated by ultrafiltration and multi-effect evaporation to increase the gelatin concentration;

[0097] (10) Sterilization: Sterilize the concentrated gelatin liquid at 135℃-140℃ for 2s-8s;

[0098] (11) Drying: After the sterilized gelatin solution cools and solidifies into gelatin strips, it is placed in a dryer for gradient drying at a temperature of 25℃-60℃.

[0099] (12) Pulverization: The dried gelatin solid is pulverized to a fineness of 10-20 mesh to obtain the high-quality fish gelatin.

[0100] Table 3 shows the decalcification time and the corresponding calcium ion content and decalcification rate of the raw materials. As can be seen from Table 3, with the increase of decalcification time, the calcium ion content in the raw materials gradually decreases and the decalcification rate gradually increases. However, when the decalcification time is 1-2 hours, there is no significant difference in the calcium ion content and decalcification rate of the raw materials.

[0101] Table 3. Calcium ion content and decalcification rate of raw materials at different decalcification times.

[0102]

[0103] Note: Different lowercase letters in the same column indicate significant differences between data (P < 0.05).

[0104] Comparative Example 1

[0105] A method for preparing fish gelatin, the specific steps of which are as follows:

[0106] (1) Raw material pretreatment: The raw materials are washed with water to remove impurities, and then crushed into pieces of about 1cm;

[0107] (2) Decalcification: Hydrochloric acid is added to the raw material for decalcification treatment. The material-to-liquid ratio is 1:50 (g:ml), the hydrochloric acid concentration is 0.6mol / L, the decalcification temperature is 25℃, and the decalcification time is 1h.

[0108] (3) Cleaning: Clean the decalcified raw materials;

[0109] (4) Extraction of gum: The decalcified raw material is made into a liquid by adding water, then the protease is added for enzymatic hydrolysis, and ultrasonic treatment is also performed. Then the gum is extracted by heating.

[0110] (5) Washing: Wash the residue after extraction with water to remove residual components;

[0111] (6) Filtration: The extracted gelatin solution is filtered using a cotton cake filter to remove impurities;

[0112] (7) Purification: The filtered gelatin solution is subjected to ion exchange treatment with anion and cation exchange resins to remove metal ions and acid radical ions;

[0113] (8) Concentration: The purified gelatin liquid is concentrated by ultrafiltration and multi-effect evaporation to increase the gelatin concentration;

[0114] (9) Sterilization: Sterilize the concentrated gelatin liquid at 135℃-140℃ for 2s-8s;

[0115] (10) Drying: After the sterilized gelatin solution cools and solidifies into gelatin strips, it is placed in a dryer for gradient drying at a temperature of 25℃-60℃.

[0116] (11) Pulverization: The dried gelatin solid is pulverized to a fineness of 10-20 mesh to obtain the fish gelatin.

[0117] Comparative Example 2

[0118] A method for preparing fish gelatin, the specific steps of which are as follows:

[0119] (1) Raw material pretreatment: The raw materials are washed with water to remove impurities and then crushed into pieces;

[0120] (2) Decalcification: EDTA is added to the raw material for decalcification treatment. The material-to-liquid ratio is 1:50 (g:ml), the EDTA concentration is 0.15mol / L, the decalcification temperature is 25℃, and the decalcification time is 1h.

[0121] (3) Washing: Wash the decalcified raw materials with water;

[0122] (4) Extraction of gum: The decalcified raw material is made into a liquid by adding water, then the protease is added for enzymatic hydrolysis, and ultrasonic treatment is also performed. Then the gum is extracted by heating.

[0123] (5) Washing: Wash the residue after extraction with water to remove residual components;

[0124] (6) Filtration: The extracted gelatin solution is filtered using a cotton cake filter to remove impurities;

[0125] (7) Purification: The filtered gelatin solution is subjected to ion exchange treatment with anion and cation exchange resins to remove metal ions and acid radical ions;

[0126] (8) Concentration: The purified gelatin liquid is concentrated by ultrafiltration and multi-effect evaporation to increase the gelatin concentration;

[0127] (9) Sterilization: Sterilize the concentrated gelatin liquid at 135℃-140℃ for 2s-8s;

[0128] (10) Drying: After the sterilized gelatin solution cools and solidifies into gelatin strips, it is placed in a dryer for gradient drying at a temperature of 25℃-60℃.

[0129] (11) Pulverization: The dried gelatin solid is pulverized to a fineness of 10-20 mesh to obtain the fish gelatin.

[0130] Table 4 shows the calcium ion content and decalcification rate of different decalcification methods and their corresponding raw materials. As can be seen from Table 4, acid decalcification has a higher calcium ion content and a lower decalcification rate, while ion exchange decalcification and EDTA decalcification have lower calcium ion content and higher decalcification rates, with no significant difference between the two methods. Hydrochloric acid mainly achieves decalcification by dissolving inorganic calcium salts in collagen fibers, but the lower pH can cause some damage to the protein structure, thus affecting the decalcification efficiency. In contrast, EDTA and ion exchange decalcification operate in a milder environment, causing less damage to the protein structure and thus facilitating decalcification.

[0131] Table 4. Calcium ion content and decalcification rate of raw materials after different decalcification methods.

[0132]

[0133] Note: Different lowercase letters in the same column indicate significant differences between data (P < 0.05).

[0134] Example 4

[0135] A method for preparing high-quality fish gelatin, the specific steps of which are as follows:

[0136] (1) Raw material pretreatment: The raw materials are washed with water to remove impurities, and then crushed into pieces of about 1cm;

[0137] (2) Decalcification: The crushed raw material is mixed with water to make a liquid with a material-liquid ratio of 1:50 (g:ml). Then, ion exchange resin is added for decalcification. The amount added is 8g / 100g of raw material. The decalcification temperature is 25℃ and the decalcification time is 1h. At the same time, ultrasonic treatment is performed with an ultrasonic power of 45W-225W and an ultrasonic time of 1h.

[0138] (3) Filtration: The liquid is filtered step by step using 10-mesh and 20-mesh sieves to recover the resin and obtain the decalcified raw material;

[0139] (4) Cleaning: Clean the decalcified raw materials to remove residual resin and other impurities;

[0140] (5) Gum extraction: The decalcified raw material is made into a liquid by adding water, then enzyme is added for enzymatic hydrolysis, and ultrasonic treatment is also performed. Then, the material is heated to extract the gum.

[0141] (6) Washing: Wash the residue after extraction with water to remove residual components;

[0142] (7) Filtration: The extracted gelatin solution is filtered using a cotton cake filter to remove impurities;

[0143] (8) Purification: The filtered gelatin solution is subjected to ion exchange treatment with anion and cation exchange resins to remove metal ions and acid radical ions;

[0144] (9) Concentration: The purified gelatin liquid is concentrated by ultrafiltration and multi-effect evaporation to increase the gelatin concentration;

[0145] (10) Sterilization: Sterilize the concentrated gelatin liquid at 135℃-140℃ for 2s-8s;

[0146] (11) Drying: After the sterilized gelatin solution cools and solidifies into gelatin strips, it is placed in a dryer for gradient drying at a temperature of 25℃-60℃.

[0147] (12) Pulverization: The dried gelatin solid is pulverized to a fineness of 10-20 mesh to obtain the high-quality fish gelatin.

[0148] Table 5 shows the ultrasonic power and the corresponding calcium ion content and decalcification rate of the decalcified raw materials. As can be seen from Table 5, with the increase of ultrasonic power, the calcium ion content in the raw materials gradually decreases and the decalcification rate gradually increases. However, when the ultrasonic power is 180-225W, there is no significant difference in the calcium ion content and decalcification rate of the raw materials.

[0149] Table 5. Calcium ion content and decalcification rate of raw materials after decalcification.

[0150]

[0151] Note: Different lowercase letters in the same column indicate significant differences between data (P < 0.05).

[0152] Example 5

[0153] A method for preparing high-quality fish gelatin, the specific steps of which are as follows:

[0154] (1) Raw material pretreatment: The raw materials are washed with water to remove impurities, and then crushed into pieces of about 1cm;

[0155] (2) Decalcification: The crushed raw material is added to water to make a liquid with a material-liquid ratio of 1:50 (g:ml). Then, ion exchange resin is added for decalcification. The amount added is 8g / 100g of raw material. The decalcification temperature is 25℃ and the decalcification time is 1h. At the same time, ultrasonic treatment is performed with an ultrasonic power of 180W and an ultrasonic time of 15-60min.

[0156] (3) Filtration: The liquid is filtered step by step using 10-mesh and 20-mesh sieves to recover the resin and obtain the decalcified raw material;

[0157] (4) Cleaning: Clean the decalcified raw materials to remove residual resin and other impurities;

[0158] (5) Gum extraction: The decalcified raw material is made into a liquid by adding water, then enzyme is added for enzymatic hydrolysis, and ultrasonic treatment is also performed. Then, the material is heated to extract the gum.

[0159] (6) Washing: Wash the residue after extraction with water to remove residual components;

[0160] (7) Filtration: The extracted gelatin solution is filtered using a cotton cake filter to remove impurities;

[0161] (8) Purification: The filtered gelatin solution is subjected to ion exchange treatment with anion and cation exchange resins to remove metal ions and acid radical ions;

[0162] (9) Concentration: The purified gelatin liquid is concentrated by ultrafiltration and multi-effect evaporation to increase the gelatin concentration;

[0163] (10) Sterilization: Sterilize the concentrated gelatin liquid at 135℃-140℃ for 2s-8s;

[0164] (11) Drying: After the sterilized gelatin solution cools and solidifies into gelatin strips, it is placed in a dryer for gradient drying at a temperature of 25℃-60℃.

[0165] (12) Pulverization: The dried gelatin solid is pulverized to a fineness of 10-20 mesh to obtain the high-quality fish gelatin.

[0166] Table 6 shows the ultrasonic time and the corresponding calcium ion content and decalcification rate of the decalcified raw materials. As can be seen from Table 6, with the increase of ultrasonic time, the calcium ion content in the raw materials gradually decreases and the decalcification rate gradually increases. However, when the ultrasonic power is 45-60 min, there is no significant difference in the calcium ion content and decalcification rate of the raw materials.

[0167] Table 6. Calcium ion content and decalcification rate of raw materials after decalcification.

[0168]

[0169] Note: Different lowercase letters in the same column indicate significant differences between data (P < 0.05).

[0170] Example 6

[0171] A method for preparing high-quality fish gelatin, the specific steps of which are as follows:

[0172] (1) Raw material pretreatment: The raw materials are washed with water to remove impurities, and then crushed into pieces of about 1cm;

[0173] (2) Decalcification: The crushed raw material is added to water to make a liquid with a material-liquid ratio of 1:50 (g:ml). Then, ion exchange resin is added for decalcification. The amount added is 8g / 100g of raw material. The decalcification temperature is 25℃ and the decalcification time is 1h. At the same time, microwave treatment is used. The microwave power is 160-480W and the microwave time is 1h.

[0174] (3) Filtration: The liquid is filtered step by step using 10-mesh and 20-mesh sieves to recover the resin and obtain the decalcified raw material;

[0175] (4) Cleaning: Clean the decalcified raw materials to remove residual resin and other impurities;

[0176] (5) Gum extraction: The decalcified raw material is made into a liquid by adding water, then enzyme is added for enzymatic hydrolysis, and ultrasonic treatment is also performed. Then, the material is heated to extract the gum.

[0177] (6) Washing: Wash the residue after extraction with water to remove residual components;

[0178] (7) Filtration: The extracted gelatin solution is filtered using a cotton cake filter to remove impurities;

[0179] (8) Purification: The filtered gelatin solution is subjected to ion exchange treatment with anion and cation exchange resins to remove metal ions and acid radical ions;

[0180] (9) Concentration: The purified gelatin liquid is concentrated by ultrafiltration and multi-effect evaporation to increase the gelatin concentration;

[0181] (10) Sterilization: Sterilize the concentrated gelatin liquid at 135℃-140℃ for 2s-8s;

[0182] (11) Drying: After the sterilized gelatin solution cools and solidifies into gelatin strips, it is placed in a dryer for gradient drying at a temperature of 25℃-60℃.

[0183] (12) Pulverization: The dried gelatin solid is pulverized to a fineness of 10-20 mesh to obtain the high-quality fish gelatin.

[0184] Table 7 shows the microwave power and the corresponding calcium ion content and decalcification rate of the decalcified raw materials. As can be seen from Table 7, with the increase of microwave power, the calcium ion content in the raw materials gradually decreases, while the decalcification rate gradually increases. However, when the microwave power is 320-360W, there is no significant difference in the calcium ion content and decalcification rate of the raw materials.

[0185] Table 7 Calcium ion content and decalcification rate of raw materials after decalcification.

[0186]

[0187]

[0188] Note: Different lowercase letters in the same column indicate significant differences between data (P < 0.05).

[0189] Example 7

[0190] A method for preparing high-quality fish gelatin, the specific steps of which are as follows:

[0191] (1) Raw material pretreatment: The raw materials are washed with water to remove impurities, and then crushed into pieces of about 1cm;

[0192] (2) Decalcification: The crushed raw material is added to water to make a liquid with a material-liquid ratio of 1:50 (g:ml). Then, ion exchange resin is added for decalcification. The amount added is 8g / 100g of raw material. The decalcification temperature is 25℃ and the decalcification time is 1h. At the same time, microwave treatment is used. The microwave power is 320W and the microwave time is 15-60min.

[0193] (3) Filtration: The liquid is filtered step by step using 10-mesh and 20-mesh sieves to recover the resin and obtain the decalcified raw material;

[0194] (4) Cleaning: Clean the decalcified raw materials to remove residual resin and other impurities;

[0195] (5) Gum extraction: The decalcified raw material is made into a liquid by adding water, then enzyme is added for enzymatic hydrolysis, and ultrasonic treatment is also performed. Then, the material is heated to extract the gum.

[0196] (6) Washing: Wash the residue after extraction with water to remove residual components;

[0197] (7) Filtration: The extracted gelatin solution is filtered using a cotton cake filter to remove impurities;

[0198] (8) Purification: The filtered gelatin solution is subjected to ion exchange treatment with anion and cation exchange resins to remove metal ions and acid radical ions;

[0199] (9) Concentration: The purified gelatin liquid is concentrated by ultrafiltration and multi-effect evaporation to increase the gelatin concentration;

[0200] (10) Sterilization: Sterilize the concentrated gelatin liquid at 135℃-140℃ for 2s-8s;

[0201] (11) Drying: After the sterilized gelatin solution cools and solidifies into gelatin strips, it is placed in a dryer for gradient drying at a temperature of 25℃-60℃.

[0202] (12) Pulverization: The dried gelatin solid is pulverized to a fineness of 10-20 mesh to obtain the high-quality fish gelatin.

[0203] Table 8 shows the microwave time and the corresponding calcium ion content and decalcification rate of the decalcified raw materials. As can be seen from Table 8, with the increase of microwave time, the calcium ion content in the raw materials gradually decreases and the decalcification rate gradually increases. However, when the decalcification time is 30-60 min, there is no significant difference in the calcium ion content and decalcification rate of the raw materials.

[0204] Table 8. Calcium ion content and decalcification rate of raw materials after decalcification.

[0205]

[0206]

[0207] Note: Different lowercase letters in the same column indicate significant differences between data (P < 0.05).

[0208] Example 8

[0209] A method for preparing high-quality fish gelatin, the specific steps of which are as follows:

[0210] (1) Raw material pretreatment: The raw materials are washed with water to remove impurities, and then crushed into pieces of about 1cm;

[0211] (2) Decalcification: The crushed raw material is added to water to make a liquid with a material-liquid ratio of 1:50 (g:ml). Then, ion exchange resin is added for decalcification. The amount added is 8g / 100g of raw material. The decalcification temperature is 25℃ and the decalcification time is 1h. At the same time, microwave treatment is used. The microwave power is 320W and the microwave time is 15-60min.

[0212] (3) Filtration: The liquid is filtered step by step using 10-mesh and 20-mesh sieves to recover the resin and obtain the decalcified raw material;

[0213] (4) Cleaning: Clean the decalcified raw materials to remove residual resin and other impurities;

[0214] (5) Gum extraction: The decalcified raw material is made into a liquid by adding water, then enzyme is added for enzymatic hydrolysis, and ultrasonic treatment is also performed. Then, the material is heated to extract the gum.

[0215] (6) Washing: Wash the residue after extraction with water to remove residual components;

[0216] (7) Filtration: The extracted gelatin solution is filtered using a cotton cake filter to remove impurities;

[0217] (8) Purification: The filtered gelatin solution is subjected to ion exchange treatment with anion and cation exchange resins to remove metal ions and acid radical ions;

[0218] (9) Concentration: The purified gelatin liquid is concentrated by ultrafiltration and multi-effect evaporation to increase the gelatin concentration;

[0219] (10) Glycosylation: Add 2% oligogalactomannan and 0.5% transglutaminase to the concentrated gelatin solution and stir continuously at 40°C for 1 hour;

[0220] (11) Sterilization: Sterilize the modified gelatin liquid at 135℃-140℃ for 2s-8s;

[0221] (12) Drying: After the sterilized gelatin solution cools and solidifies into gelatin strips, it is placed in a dryer for gradient drying at a temperature of 25℃-60℃.

[0222] (13) Pulverization: The dried gelatin solid is pulverized to a fineness of 10-20 mesh to obtain the high-quality fish gelatin.

[0223] Comparative Example 3

[0224] A method for preparing fish gelatin, the specific steps of which are as follows:

[0225] (1) Raw material pretreatment: The raw materials are washed with water to remove impurities, and then crushed into pieces of about 1cm;

[0226] (2) Decalcification: The crushed raw material is mixed with water to make a liquid, and then hydrochloric acid is added for decalcification. The material-liquid ratio is 1:50 (g:ml), the hydrochloric acid concentration is 0.6mol / L, the decalcification time is 1h, and ultrasonic treatment is also performed at the same time. The ultrasonic power is 180W and the ultrasonic time is 1h.

[0227] (3) Cleaning: Clean the decalcified raw materials;

[0228] (4) Extraction of gum: The decalcified raw material is made into a liquid by adding water, then the protease is added for enzymatic hydrolysis, and ultrasonic treatment is also performed. Then the gum is extracted by heating.

[0229] (5) Washing: Wash the residue after extraction with water to remove residual components;

[0230] (6) Filtration: The extracted gelatin solution is filtered using a cotton cake filter to remove impurities;

[0231] (7) Purification: The filtered gelatin solution is subjected to ion exchange treatment with anion and cation exchange resins to remove metal ions and acid radical ions;

[0232] (8) Concentration: The purified gelatin liquid is concentrated by ultrafiltration and multi-effect evaporation to increase the gelatin concentration;

[0233] (9) Sterilization: Sterilize the concentrated gelatin liquid at 135℃-140℃ for 2s-8s;

[0234] (10) Drying: After the sterilized gelatin solution cools and solidifies into gelatin strips, it is placed in a dryer for gradient drying at a temperature of 25℃-60℃.

[0235] (11) Pulverization: The dried gelatin solid is pulverized to a fineness of 10-20 mesh to obtain the fish gelatin.

[0236] Comparative Example 4

[0237] A method for preparing fish gelatin, the specific steps of which are as follows:

[0238] (1) Raw material pretreatment: The raw materials are washed with water to remove impurities, and then crushed into pieces of about 1cm;

[0239] (2) Decalcification: The crushed raw material is mixed with water to make a liquid, and then EDTA is added for decalcification. The material-liquid ratio is 1:50 (g:ml), the EDTA concentration is 0.15mol / L, the decalcification time is 1h, and microwave treatment is used at the same time. The microwave frequency is 320W and the microwave time is 45min.

[0240] (3) Cleaning: Clean the decalcified raw materials;

[0241] (4) Extraction of gum: The decalcified raw material is made into a liquid by adding water, then the protease is added for enzymatic hydrolysis, and ultrasonic treatment is also performed. Then the gum is extracted by heating.

[0242] (5) Washing: Wash the residue after extraction with water to remove residual components;

[0243] (6) Filtration: The extracted gelatin solution is filtered using a cotton cake filter to remove impurities;

[0244] (7) Purification: The filtered gelatin solution is subjected to ion exchange treatment with anion and cation exchange resins to remove metal ions and acid radical ions;

[0245] (8) Concentration: The purified gelatin liquid is concentrated by ultrafiltration and multi-effect evaporation to increase the gelatin concentration;

[0246] (9) Sterilization: Sterilize the concentrated gelatin liquid at 135℃-140℃ for 2s-8s;

[0247] (10) Drying: After the sterilized gelatin solution cools and solidifies into gelatin strips, it is placed in a dryer for gradient drying at a temperature of 25℃-60℃.

[0248] (11) Pulverization: The dried gelatin solid is pulverized to a fineness of 10-20 mesh to obtain the fish gelatin.

[0249] Table 9 Physicochemical properties of gelatin samples

[0250]

[0251] Note: Different lowercase letters in the same column indicate significant differences between data (P < 0.05).

[0252] The physicochemical properties of some gelatin samples from Examples 1, 5, 7, and 8, and Comparative Examples 3 and 4 are shown in Table 9. As can be seen from Table 9, the decalcification rate of the raw materials significantly increased after ultrasonic or microwave treatment. This is because the high-frequency vibration generated in water by ultrasonic or microwave treatment accelerates the separation of calcium from collagen fibers, thereby promoting the adsorption of free calcium by the resin. Simultaneously, the gel strength and Blaine viscosity of the corresponding products also increased accordingly. This is because after decalcification, the collagen components are purified, and the softened tissue is beneficial for subsequent processing, promoting the extraction of collagen from the raw materials and improving the quality of the final product. Compared with acid decalcification, ion exchange decalcification has better decalcification efficiency; therefore, the product quality prepared by ion exchange decalcification is superior to that prepared by acid decalcification. Compared with EDTA decalcification, ion exchange has a similar decalcification efficiency; therefore, the products prepared by the two processes have similar quality. In Example 8, the quality of fish gelatin was further improved after glycosylation modification. The optimal resin addition is 8g / 100g of raw material, the decalcification temperature is 25℃, the decalcification time is 1h, the ultrasonic power is 180W, and the ultrasonic time is 45min. High-quality fish gelatin is prepared by using oligogalactomannan for glycosylation reaction. The fish gelatin obtained has better quality.

[0253] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing high-quality fish gelatin, characterized in that: The following steps are involved: (1) Raw material pretreatment: The raw materials are washed with water to remove impurities and then crushed into pieces; (2) decalcification: the crushed raw material is added with water to prepare a liquid with a material-liquid ratio of 1:50 (g:ml), and then a cation exchange resin is added at a ratio of 2-12 g / 100 g of ion exchange resin / liquid, and decalcification is performed at 15-40°C; (3) Filtration: Filter the liquid step by step using screens of different apertures to recover the resin and obtain the decalcified raw material; (4) Cleaning: Clean the decalcified raw materials to remove impurities such as residual resin; (5) Extraction of glue: adding water to the decalcified raw material to make a liquid, then adding protease for enzymatic hydrolysis, and simultaneously assisting with ultrasonic treatment, and then extracting glue; (6) Washing: Wash the residue after rubber extraction with water to remove residual components; (7) Filtration: Filtering the extracted gelatin solution to remove impurities; (8) Purification: The filtered gelatin solution is subjected to ion exchange treatment to remove metal ions and acid ions; (9) Concentration: The purified gelatin liquid is concentrated to increase the gelatin concentration; (10) Glycosylation modification: adding oligogalactomannan to the concentrated gelatin liquid for glycosylation modification; (11) Sterilization: sterilize the modified gelatin liquid; (12) Drying: After the sterilized gelatin solution is cooled and solidified into gelatin strips, it is placed in a dryer for drying; (13) Crushing: The dried gelatin solid is crushed and refined to obtain the finished gelatin product.

2. The method for preparing high-quality fish gelatin according to claim 1, characterized in that: In step (2), decalcification is assisted by ultrasonic or microwave treatment.

3. The method for preparing high-quality fish gelatin according to claim 2, characterized in that: The power of ultrasonic treatment is 45W-225W, and the time is 15-60min; the power of microwave treatment is 160-480W, and the time is 15-60min.

4. The method for preparing high-quality fish gelatin according to claim 1, characterized in that: In step (3), the sieve with different apertures used to intercept the raw material is 10 mesh, and the sieve used to intercept the resin is 20 mesh.

5. The method for preparing high-quality fish gelatin according to claim 1, characterized in that: In step (5), the ratio of water to raw material in the liquid is 10:1-20:1 (L / g); the protease is neutral protease, the addition amount is 1.5% of the raw material amount, the enzymatic hydrolysis temperature is 40°C, the enzymatic hydrolysis time is 4h; the ultrasonic power is 180W, the ultrasonic time is 10min; the rubber extraction temperature is 65°C, and the rubber extraction time is 4h.

6. The method for preparing high-quality fish gelatin according to claim 1, characterized in that: The ion exchange in step (8) uses 732 type cation exchange resin and 717 type anion exchange resin.

7. The method for preparing high-quality fish gelatin according to claim 1, characterized in that: The concentration process in step (9) is as follows: membrane filtration concentration to a gelatin concentration of 5-10%, and evaporation concentration to a gelatin concentration of 25-50%.

8. The method for preparing high-quality fish gelatin according to claim 1, characterized in that: In step (10), the concentration of the oligogalactomannan relative to the gelatin liquid is 2% (w / v), the concentration of the cross-linking agent transglutaminase relative to the gelatin liquid is 0.5% (w / v), and the reaction temperature is 40°C.

9. The method for preparing high-quality fish gelatin according to claim 1, characterized in that: The sterilization method in step (11) is high temperature instantaneous sterilization, the temperature is 135-140°C, and the time is 2-8s.

10. The method for preparing high-quality fish gelatin according to claim 1, characterized in that: The drying temperature in step (12) is 25-60°C, and gradient drying is performed with a temperature gradient of 25-34°C, 28-36°C, 33-41°C, 38-46°C, 43-51°C, 48-56°C, 50-58°C, and 52-60°C.

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