Preparation method of fishy smell removing agent for freshwater fish

Abstract

The invention discloses a preparation method of a fishy smell removing agent for freshwater fishes, and belongs to the technical field of fishy smell removing agents for freshwater fishes. Specific spices are selected, mixed and prepared, then internal fishy smell removing components are extracted through frying, then gelatin is adopted for embedding to prepare the fishy smell removing agent in an emulsion form, the fishy smell removing components can be effectively protected, the stability is improved, and the fishy smell removing effect is good. The problem that the fishy smell removing effect is reduced due to poor stability of the fishy smell removing components such as linalool and myrcene is solved; and the fishy smell removing substance is extracted and prepared into the emulsion through the method disclosed by the invention, so that the emulsion can play a high-efficiency fishy smell removing effect in the non-spicy boiled fish, and has a good application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of freshwater fish deodorizing agents, in particular to a preparation method of the freshwater fish deodorizing agent. Background Art

[0002] Bulk freshwater fish have a strong fishy smell due to factors such as the growth environment and the activity of endogenous proteases. Removing the fishy smell is one of the main bottlenecks restricting the development of the bulk freshwater fish processing industry. In Sichuan and Chongqing, freshwater fish fillets are often used to make spicy boiled fish, which can effectively remove or mask the fishy smell of fish fillets. However, the effect of removing and masking the fishy smell of non-spicy boiled fish is relatively poor. Therefore, the development of ingredients with good deodorizing effect for non-spicy boiled fish is of great significance to the promotion of freshwater fish processing industry.

[0003] Linalool, myrcene, limonene and anethole in natural spices have good effects on removing fishy smell and have good application prospects in the preparation of non-spicy boiled fish deodorizers. However, linalool, myrcene, limonene and anethole are fat-soluble components with poor water solubility and volatility, which greatly limits their application in freshwater fish food processing. Constructing water-in-oil emulsions is a good solution to improve their stability. Gelatin is a protein biopolymer obtained by partial hydrolysis of natural collagen. It has the advantages of low price, wide sources, low toxicity, excellent biocompatibility and biodegradability. It is widely used in the food field and is an ideal emulsifier raw material for preparing water-in-oil emulsions. However, the emulsion prepared by directly using gelatin to encapsulate fat-soluble components under the conventional method has poor stability, and the internal fat-soluble components are easily oxidized and deteriorated during storage. In addition, the gelatin-encapsulated emulsion prepared by the conventional method has poor thermal stability, and freshwater fish processing requires cooking. Therefore, the emulsion prepared by gelatin-encapsulating fat-soluble deodorizing components prepared by the conventional method will have poor stability, which will greatly reduce its effect.

[0004] Therefore, there is an urgent need to find a preparation method for a freshwater fish deodorant to solve the problem that the water-in-oil emulsion prepared by gelatin under the conventional method has poor stability, the internal oil phase deodorizing component is separated out and flocculated, thereby reducing its effect. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a method for preparing a freshwater fish deodorizing agent to solve the problem that the oil-in-water emulsion prepared by gelatin under the conventional method has poor storage stability and thermal stability, and the internal oil phase deodorizing components are easy to precipitate and flocculate, thereby reducing its deodorizing effect.

[0006] The present invention solves the above technical problems by the following technical means:

[0007] A preparation method of a freshwater fish deodorizing agent, the preparation method is as follows:

[0008] (1) heating edible oil and adding mixed spices, stirring and frying continuously, removing spice residues, and then cooling in an ice water bath to room temperature to obtain a deodorizing agent oil phase;

[0009] (2) adding gelatin to 100 times the mass of water and stirring to disperse, then adding ammonium glycyrrhizinate, stirring and reacting at room temperature for 1 to 2 hours to obtain a gelatin mixed solution, and adjusting the pH of the gelatin mixed solution to 4 to 5; dissolving methyl anthranilate in ethanol and adding it to the gelatin mixed solution, stirring and reacting at room temperature for 1 hour, then heating to 60° C. and stirring and reacting for 30 minutes, cooling to room temperature after the reaction is completed, and adjusting the pH to 5 to obtain a deodorizing agent aqueous phase;

[0010] (3) The deodorant aqueous phase is added to the deodorant oil phase for high-speed homogenization and dispersion, and then the glutamine aminotransferase solution is heated to 45°C and added, and placed in a 45°C hot water water bath for heating to react for 1 hour. After the reaction is completed, the deodorant is placed in a boiling water water bath for 10 minutes to inactivate the enzyme to obtain the deodorant.

[0011] Furthermore, in the step (1), the mixed spice is obtained by mixing red pepper, green pepper and star anise in a mass ratio of 1:1:1.

[0012] Furthermore, the edible oil in step (1) is rapeseed oil.

[0013] The invention prepares spices by mixing red pepper, green pepper and star anise, extracts internal deodorizing components such as linalool and myrcene through frying, and then prepares a deodorizing agent in the form of an emulsion by embedding with gelatin. The deodorizing components can be protected to better exert the deodorizing effect, and the spice can be better applied to the deodorizing treatment of non-spicy boiled fish.

[0014] However, the stability of the emulsion formed by directly using gelatin as an emulsifier to homogeneously encapsulate the deodorizing ingredients is poor. Therefore, before encapsulating the deodorizing oil phase components, ammonium glycyrrhizate and methyl o-aminobenzoate are used to treat gelatin in sequence to prepare the deodorizing agent aqueous phase, so as to improve the stability of the prepared deodorizing agent emulsion.

[0015] Specifically, the ammonium glycyrrhizinate of the present invention is combined with the gelatin molecular chain, and the gelatin molecular chain stability is enhanced by changing the charge properties and molecular structure of gelatin, and the degree of interweaving and entanglement between gelatin molecular chains is increased, thereby inhibiting the thermal motion of gelatin molecular chains at high temperatures and improving thermal stability; further, methyl anthranilate is hydrolyzed in an acidic environment and chemically bonded to the gelatin molecular chain to form a hydrophobic group, thereby reducing the water absorption of gelatin, inhibiting the swelling of gelatin to cause the internal oil phase components to separate out, and at the same time increasing the interaction force between gelatin molecules and oil droplet molecules, thereby inhibiting the migration of internal oil phase molecules, making it more stable and being wrapped inside the gelatin network structure. The present invention sequentially treats gelatin with ammonium glycyrrhizinate and methyl anthranilate to adjust the interaction forces between gelatin and gelatin and between gelatin and internal oil phase components, thereby improving the stability of the prepared deodorant emulsion, and further glutamate aminotransferase is added as a cross-linking agent to form a denser three-dimensional network structure of gelatin, and better protect the internal oil phase components.

[0016] Furthermore, in step (1), the mass ratio of edible oil to mixed spice is 4:1.

[0017] Furthermore, in the step (1), the edible oil is heated to 130° C. and mixed spices are added, and the mixed spices are fried for 15 minutes.

[0018] Furthermore, in the step (2), the mass ratio of gelatin to ammonium glycyrrhizinate is 1:(0.1-0.2).

[0019] Furthermore, in the step (2), the mass ratio of the gelatin mixture to methyl anthranilate is 100:(0.1-0.2).

[0020] Furthermore, in step (3), the concentration of the glutamine transaminase solution is 0.2 wt %.

[0021] Furthermore, in the step (3), the mass ratio of the deodorizing agent aqueous phase, the deodorizing agent oil phase, and the glutamine aminotransferase solution is (25-40): (60-75): (1-2).

[0022] Furthermore, in the step (3), the high-speed homogenization and dispersion speed is 15000 rpm and the homogenization and dispersion time is 90 s.

[0023] Beneficial effects:

[0024] 1. The present invention extracts the deodorizing components in spices by frying and then embeds them in gelatin to prepare an emulsion form, which can effectively protect the deodorizing components and thus ensure that they can better exert the deodorizing effect. At the same time, the deodorizing agent in this form can be better applied to non-spicy boiled fish.

[0025] 2. In the process of preparing the deodorizing agent, the present invention adds ammonium glycyrrhizinate and methyl anthranilate to treat gelatin, thereby adjusting the interaction between the internal oil phase component and gelatin and between gelatin, and then further cross-linking is performed using glutamine aminotransferase to prepare an emulsion of gelatin-embedded deodorizing components with good storage stability and thermal stability, which has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 : The deodorizing agent finished product prepared by Example 1 of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be described in detail below with reference to specific embodiments and accompanying drawings:

[0028] Example 1: Preparation of deodorizing agent

[0029] (1) Mixing red pepper, green pepper and star anise in a mass ratio of 1:1:1 to obtain a mixed spice; heating rapeseed oil to 130° C., then adding the mixed spice in a mass ratio of rapeseed oil: mixed spice = 4:1, frying for 15 minutes with constant stirring, removing the spice residue, and then placing in an ice water bath to cool to room temperature to obtain a deodorizing agent oil phase;

[0030] (2) Add 1 g of gelatin to 100 g of water and stir to disperse, then add 0.15 g of ammonium glycyrrhizinate, stir and react at room temperature for 1.5 h to obtain a gelatin mixed solution, and adjust the pH of the gelatin mixed solution to 4.5; dissolve 0.15 g of methyl anthranilate in 1.5 g of ethanol and add it to 100 g of the gelatin mixed solution, stir and react at room temperature for 1 h, then heat to 60° C. and stir and react for 30 min. After the reaction is completed, cool to room temperature, adjust the pH to 5 to obtain a deodorizing agent aqueous phase;

[0031] (3) Add 25 g of the deodorizing agent aqueous phase to 75 g of the deodorizing agent oil phase, and homogenize and disperse them together at a speed of 15,000 rpm for 90 seconds. Then, add 1.5 g of a 0.2 wt% glutamine transaminase solution heated to 45°C, place it in a 45°C hot water water bath for heating to react for 1 hour, and after the reaction is completed, place it in a boiling water water bath for 10 minutes to inactivate the enzyme to obtain the deodorizing agent.

[0032] Example 2: Preparation of deodorizing agent II

[0033] (1) Mixing red pepper, green pepper and star anise in a mass ratio of 1:1:1 to obtain a mixed spice; heating rapeseed oil to 130° C., then adding the mixed spice in a mass ratio of rapeseed oil: mixed spice = 4:1, frying for 15 minutes with constant stirring, removing the spice residue, and then placing in an ice water bath to cool to room temperature to obtain a deodorizing agent oil phase;

[0034] (2) Add 1 g of gelatin to 100 g of water and stir to disperse, then add 0.1 g of ammonium glycyrrhizinate, stir and react at room temperature for 1 hour to obtain a gelatin mixed solution, and adjust the pH of the gelatin mixed solution to 4; dissolve 0.1 g of methyl anthranilate in 1 g of ethanol and add it to 100 g of the gelatin mixed solution, stir and react at room temperature for 1 hour, then heat to 60° C. and stir and react for 30 minutes. After the reaction is completed, cool to room temperature, and adjust the pH to 5 to obtain a deodorizing agent aqueous phase;

[0035] (3) Add 25 g of the deodorizing agent aqueous phase to 60 g of the deodorizing agent oil phase, and homogenize and disperse them together at a speed of 15,000 rpm for 90 seconds. Then, add 1 g of a 0.2 wt% glutamine transaminase solution heated to 45°C, place it in a 45°C hot water water bath for heating to react for 1 hour, and after the reaction is completed, place it in a boiling water water bath for 10 minutes to inactivate the enzyme to obtain the deodorizing agent.

[0036] Example 3: Preparation of deodorizing agent

[0037] (1) Mixing red pepper, green pepper and star anise in a mass ratio of 1:1:1 to obtain a mixed spice; heating rapeseed oil to 130° C., then adding the mixed spice in a mass ratio of rapeseed oil: mixed spice = 4:1, frying for 15 minutes with constant stirring, removing the spice residue, and then placing in an ice water bath to cool to room temperature to obtain a deodorizing agent oil phase;

[0038] (2) 1 g of gelatin was added to 100 g of water and stirred to disperse, and then 0.2 g of ammonium glycyrrhizinate was added, and the mixture was stirred at room temperature for 2 h to obtain a gelatin mixture, and the pH of the gelatin mixture was adjusted to 5; 0.2 g of methyl anthranilate was dissolved in 2 g of ethanol and added to 100 g of the gelatin mixture, and the mixture was stirred at room temperature for 1 h, and then the mixture was heated to 60° C. and stirred for 30 min. After the reaction was completed, the mixture was cooled to room temperature, and the pH was adjusted to 5 to obtain a deodorizing agent aqueous phase;

[0039] (3) Add 40 g of the deodorizing agent aqueous phase to 75 g of the deodorizing agent oil phase, and homogenize and disperse them together at a speed of 15,000 rpm for 90 seconds. Then, add 2 g of a 0.2 wt% glutamine transaminase solution heated to 45°C, place it in a 45°C hot water water bath for heating to react for 1 hour, and after the reaction is completed, place it in a boiling water water bath for 10 minutes to inactivate the enzyme to obtain the deodorizing agent.

[0040] Comparative Example 1: Preparation of deodorizing agent

[0041] In contrast to Example 1, the only difference is that ammonium glycyrrhizate is not added in step (2) when preparing the deodorizing agent in Comparative Example 1, as shown below:

[0042] (1) Same as Example 1;

[0043] (2) Add 1 g of gelatin to 100 g of water and stir to disperse to obtain a gelatin dispersion, and adjust the pH of the gelatin dispersion to 4.5; dissolve 0.15 g of methyl anthranilate in 1.5 g of ethanol and add it to 100 g of the gelatin dispersion, stir and react at room temperature for 1 hour, then heat to 60° C. and stir to react for 30 minutes. After the reaction is completed, cool to room temperature and adjust the pH to 5 to obtain a deodorizing agent aqueous phase;

[0044] (3) Same as Example 1.

[0045] Comparative Example 2: Preparation of deodorizing agent

[0046] In contrast to Example 1, the only difference is that methyl anthranilate is not added in step (2) when preparing the deodorizing agent in Comparative Example 2, as shown below:

[0047] (1) Same as Example 1;

[0048] (2) Add 1 g of gelatin to 100 g of water and stir to disperse, then add 0.15 g of ammonium glycyrrhizinate, stir and react at room temperature for 1.5 h to obtain a gelatin mixed solution, and adjust the pH to 5 to obtain a deodorizing agent aqueous phase;

[0049] (3) Same as Example 1.

[0050] Comparative Example 3: Preparation of deodorizing agent

[0051] In contrast to Example 1, the only difference is that in the preparation of the deodorizing agent in Comparative Example 3, no glutamine aminotransferase solution is added in step (3), as shown below:

[0052] (1)-(2) are the same as in Example 1;

[0053] (3) Add 25 g of the deodorizing agent aqueous phase to 75 g of the deodorizing agent oil phase, and homogenize and disperse them together at a speed of 15,000 rpm for 90 seconds to obtain the deodorizing agent.

[0054] Comparative Example 4: Preparation of deodorizing agent

[0055] In contrast to Example 1, the only difference is that the deodorizing agent in Comparative Example 4 lacks step (2) in the preparation, gelatin is directly dispersed in water to obtain a deodorizing agent aqueous phase, and no glutamine aminotransferase is added, as shown below:

[0056] (1) Same as Example 1;

[0057] (2) Add 1 g of gelatin into water and stir to disperse, adjust the pH to 5 to obtain a deodorant aqueous phase; add 25 g of the deodorant aqueous phase into 75 g of the deodorant oil phase, and homogenize and disperse them together at a speed of 15,000 rpm for 90 seconds to obtain a deodorant.

[0058] Comparative Example 5: Preparation of deodorizing agent

[0059] In contrast to Example 1, the only difference is that the deodorizing agent in Comparative Example 5 lacks step (2) and step (3), that is, the deodorizing agent is obtained by directly frying the spices, as shown below:

[0060] Red peppercorns, green peppercorns and star anise are mixed in a mass ratio of 1:1:1 to obtain a mixed spice; rapeseed oil is heated to 130°C, and then the mixed spice is added in a mass ratio of rapeseed oil: mixed spice = 4:1, and after frying for 15 minutes with constant stirring, the spice residue is removed and placed in an ice water bath to cool to room temperature to obtain a deodorizing agent.

[0061] Experiment 1: Deodorant stability test

[0062] The storage stability and thermal stability of the deodorizing agents prepared in Example 1 and Comparative Examples 1 to 5 were tested, and the specific experimental methods are as follows:

[0063] Thermal stability:

[0064] Take 10g of deodorant and put it in a centrifuge tube, place it in a 100℃ water bath and heat it for 5min, 10min, 15min and 20min, then cool it to room temperature and measure the emulsion index of the deodorant emulsion;

[0065] Storage stability:

[0066] The initial average droplet size of the deodorizing agent was measured, and then the average droplet size after being placed at 25°C for 10 days and 20 days was measured.

[0067] The data of the creaming index and average droplet size of the deodorizing agent emulsions prepared in Example 1 and Comparative Examples 1 to 4 according to the above method are shown in Table 1.

[0068] Table 1

[0069]

[0070] According to the data analysis in Table 1:

[0071] The deodorant emulsion prepared by the present invention has good thermal stability and storage stability, and can maintain a relatively stable state after being heated at 100°C for 20 minutes, with a low creaming index; and after being placed at a normal temperature of 25°C for 20 days, the internal oil phase component droplets can also maintain a relatively good stable state, with a low degree of flocculation, indicating that the deodorant emulsion prepared according to the method of the present invention effectively improves its thermal stability and storage stability, and has good application prospects.

[0072] In Comparative Example 1, ammonium glycyrrhizinate gelatin was not added during the preparation of the deodorizing agent, and the gelatin molecular chain stability was poor. It was easy to flow and migrate under high-temperature heat treatment, resulting in the precipitation of internal oil droplets and an increase in the creaming index; in Comparative Example 2, methyl anthranilate was not added during the preparation of the deodorizing agent; the deodorizing agent was easy to absorb water and swell during storage, and the interaction between gelatin and oil droplets was poor, so the oil droplets were easy to precipitate and flocculate, and with the increase of storage time, the droplets aggregated and increased in size significantly; in Comparative Example 3, glutamine aminotransferase was not added during the preparation of the deodorizing agent, and the gelatins were bonded by hydrogen bonds with poor stability, and the thermal stability and storage stability were significantly reduced.

[0073] Experiment 2: Deodorant deodorizing effect test

[0074] The deodorizing effects of the deodorizing agents prepared in Example 1 and Comparative Examples 1 to 5 were tested, and the specific experimental methods are as follows:

[0075] 12 g of deodorizing agent was weighed and added to 200 mL of pure water. The water was heated to boiling at a power of 1800 W on an induction cooker. Then 40 g of fresh grass carp fillets were added. The water was heated for 75 s and the fillets were taken out. The contents of n-hexanal, nonanal and 1-octen-3-ol in the grass carp fillets before and after boiling were determined. The reduction rates of n-hexanal, nonanal and 1-octen-3-ol before and after boiling of the grass carp were calculated. The data are shown in Table 2.

[0076] Table 2

[0077]

[0078]

[0079] According to the data analysis in Table 2:

[0080] The deodorizing agent prepared by the invention has good storage stability and thermal stability, and can efficiently remove fishy substances in freshwater fish. After using the deodorizing agent prepared by the invention, the content reduction rate of n-hexanal, a fishy substance in freshwater fish, is 94.33%; the content reduction rate of nonanal is 92.34%; the content reduction rate of 1-octen-3-ol is 92.85%; and the content reduction rates of heptaldehyde and octanal both reach 100%, indicating that the deodorizing agent prepared by the invention has a good effect of removing fishy substances in freshwater fish. In addition, the deodorizing component in spices is fried and extracted, and then embedded in gelatin to prepare an emulsion, which can better play a good deodorizing effect on non-spicy fish and has good application prospects.

[0081] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should be included in the scope of the claims of the present invention. The techniques, shapes, and structural parts not described in detail in the present invention are all known technologies.

Claims

1. A method for preparing a freshwater fish deodorizing agent, characterized in that: The preparation method is as follows: (1) heating edible oil and adding mixed spices, stirring and frying continuously, removing spice residues, and then cooling in an ice water bath to room temperature to obtain a deodorizing agent oil phase; (2) adding gelatin to 100 times the mass of water and stirring to disperse, then adding ammonium glycyrrhizinate, stirring and reacting at room temperature for 1 to 2 hours to obtain a gelatin mixed solution, and adjusting the pH of the gelatin mixed solution to 4 to 5; dissolving methyl anthranilate in ethanol and adding it to the gelatin mixed solution, stirring and reacting at room temperature for 1 hour, then heating to 60° C. and stirring and reacting for 30 minutes, cooling to room temperature after the reaction is completed, and adjusting the pH to 5 to obtain a deodorizing agent aqueous phase; (3) The deodorizing agent aqueous phase is added to the deodorizing agent oil phase for high-speed homogenization and dispersion, and then the glutamine aminotransferase solution is heated to 45°C and added, and the solution is placed in a 45°C hot water water bath for heating to react for 1 hour. After the reaction is completed, the solution is placed in a boiling water water bath for heating to inactivate the enzyme for 10 minutes to obtain the deodorizing agent.

2. The method for preparing a freshwater fish deodorizing agent according to claim 1, wherein: The mixed spice in step (1) is obtained by mixing red pepper, green pepper and star anise in a mass ratio of 1:1:

1.

3. The method for preparing a freshwater fish deodorizing agent according to claim 2, wherein: The edible oil in step (1) is rapeseed oil.

4. The method for preparing a freshwater fish deodorizing agent according to claim 3, wherein: In the step (1), the mass ratio of edible oil to mixed spice is 4:

1.

5. The method for preparing a freshwater fish deodorizing agent according to claim 4, wherein: In the step (1), the edible oil is heated to 130° C. and mixed spices are added thereto. The mixed spices are fried for 15 minutes.

6. The method for preparing a freshwater fish deodorizing agent according to claim 5, characterized in that: In the step (2), the mass ratio of gelatin to ammonium glycyrrhizinate is 1:(0.1-0.2).

7. The method for preparing a freshwater fish deodorizing agent according to claim 6, wherein: In the step (2), the mass ratio of the gelatin mixture to methyl anthranilate is 100:(0.1-0.2).

8. The method for preparing a freshwater fish deodorizing agent according to claim 7, characterized in that: The concentration of the glutamine transaminase solution in step (3) is 0.2 wt %.

9. The method for preparing a freshwater fish deodorizing agent according to claim 8, characterized in that: In the step (3), the mass ratio of the deodorizing agent aqueous phase, the deodorizing agent oil phase, and the glutamine aminotransferase solution is (25-40): (60-75): (1-2).

10. The method for preparing a freshwater fish deodorizing agent according to claim 9, characterized in that: In the step (3), the high-speed homogenization and dispersion speed is 15000 rpm and the homogenization and dispersion time is 90 s.

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