Tuna protein peptide with high goose carnosine content and preparation method thereof

Abstract

The invention provides tuna protein peptide with high goose carnosine content and a preparation method of the tuna protein peptide, and belongs to the technical field of tuna protein peptide preparation. The preparation method provided by the invention comprises the following steps: grinding ultralow-temperature tuna, mixing the ground ultralow-temperature tuna with water, alkaline protease and neutral protease, carrying out enzymolysis at 45-60 DEG C for 2-5 hours, and carrying out residue-liquid separation after enzyme deactivation; mixing the separated liquid with diatomite, and filtering; and concentrating the filtrate, and drying until the water content is less than 7%. The tuna protein peptide prepared by the method disclosed by the invention has the advantages that the content of goose carnosine is up to 25% or above, the product yield is up to 11.4% or above, and the tuna protein peptide is light in color, free of fishy smell and bitter taste, fresh and sweet in taste and excellent in quality. The process is optimized and simplified, and production conversion is facilitated. The alkaline protease is applied to a neutral environment, decomposition of the goose carnosine and racemization or dextrorotation of amino acid in the alkaline environment are avoided, and the content of the goose carnosine in the tuna protein peptide and the utilization rate of the tuna protein peptide in a human body are further increased.

Description

Technical Field

[0001] The invention belongs to the technical field of tuna protein peptide preparation, and particularly relates to a tuna protein peptide with high anserine content and a preparation method thereof. Background Art

[0002] Tuna is a large ocean fish species, distributed in the central and western Pacific, Atlantic, Indian Oceans and other waters. Its gills are degenerate, and it needs to swim tirelessly. One of the reasons is that its muscles contain a lot of anserine. According to SGS testing, the anserine content in its muscles is 57.5g / kg. Currently, due to the limitations of the extraction method, when tuna protein peptides containing anserine are extracted from tuna, the content of anserine in tuna protein peptides is generally between 7% and 12%, and the color, odor and taste are relatively strong. Its application in food is limited. It is generally used in swallowing products such as compressed tablets, and is rarely used in products that are taken with water. Even if it is used, it is only a conceptual addition. Therefore, how to extract tuna protein peptides with a high content of anserine from tuna and improve the sensory quality has always been a technical problem that needs to be solved in this field. Summary of the Invention

[0003] In view of this, the object of the present invention is to provide a method for preparing a tuna protein peptide with a high anserine content, so that the anserine content in the tuna protein peptide is as high as 25% (on a dry basis) or more.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The invention provides a preparation method of a tuna protein peptide with a high anserine content, comprising the following steps: grinding ultra-low temperature tuna, mixing the mixture with water, alkaline protease and neutral protease, performing enzymatic hydrolysis at 45-60° C. for 2-5 hours, and inactivating the enzymes; performing residue-liquid separation on the enzymatic hydrolysis liquid after the enzyme inactivation, and collecting the separated liquid; mixing the separated liquid with diatomaceous earth, filtering and collecting the filtrate; and concentrating the filtrate and drying it to a moisture content of less than 7% to obtain the tuna protein peptide with a high anserine content.

[0006] Preferably, the mass volume ratio of ultra-low temperature tuna to water is 1g:1-3mL, the mass of the alkaline protease is 0.1%-0.3% of the mass of the ultra-low temperature tuna; the mass of the neutral protease is 0.3%-0.5% of the mass of the ultra-low temperature tuna.

[0007] Preferably, the temperature for inactivating the enzyme is 105 to 121° C., and the time for inactivating the enzyme is 12 to 21 seconds.

[0008] Preferably, the slag-liquid separation method includes centrifugation, and the centrifugal speed is ≥3000r / min.

[0009] Preferably, the mass of the diatomaceous earth is 0.5% to 2% of the mass of the ultra-low temperature tuna, and the mesh size of the diatomaceous earth is 100 to 200 meshes.

[0010] Preferably, the filtering method includes filtering with a plate and frame filter press, and the filter cloth used in the plate and frame filter press is an XN630 closed filter cloth.

[0011] Preferably, the concentration method includes vacuum concentration, the temperature of the vacuum concentration is 60° C. to 70° C., and the vacuum degree of the vacuum concentration is below -0.095 MPa.

[0012] Preferably, the concentration is to concentrate to a solid content of 35 Brix to 45 Brix.

[0013] Preferably, the drying method includes centrifugal spray drying, and the air inlet temperature of the centrifugal spray drying is 190°C to 200°C, and the air outlet temperature is 50°C to 65°C.

[0014] The present invention also provides a tuna protein peptide with high anserine content. The tuna protein peptide with high anserine content is prepared by the above preparation method.

[0015] Beneficial effects of the present invention:

[0016] The tuna protein peptide produced by the preparation method of the present invention has an anserine content exceeding 25% (on a dry basis) and a high product yield of over 11.4%. Through process optimization and simplification, the present invention reduces process losses and facilitates production conversion. Furthermore, the tuna protein peptide produced by the preparation method of the present invention has a light color, no fishy or bitter taste, and a fresh and sweet taste of excellent quality. DETAILED DESCRIPTION

[0017] The invention provides a preparation method of a tuna protein peptide with a high anserine content, comprising the following steps: grinding ultra-low temperature tuna, mixing the mixture with water, alkaline protease and neutral protease, performing enzymatic hydrolysis at 45-60° C. for 2-5 hours, and inactivating the enzymes; performing residue-liquid separation on the enzymatic hydrolysis liquid after the enzyme inactivation, and collecting the separated liquid; mixing the separated liquid with diatomaceous earth, filtering and collecting the filtrate; and concentrating the filtrate and drying it to a moisture content of less than 7% to obtain the tuna protein peptide with a high anserine content.

[0018] The present invention does not specifically limit the specific source of ultra-low-temperature tuna. In the present invention, the ultra-low-temperature tuna is preferably ultra-low-temperature tuna mince; the grinding is preferably ground until it is minced and free of grains. In the present invention, the mass-to-volume ratio of ultra-low-temperature tuna to water is preferably 1g:1-3mL, more preferably 1g:2mL, and the water is preferably purified water. The mass of the alkaline protease is preferably 0.1%-0.3% of the mass of the ultra-low-temperature tuna, more preferably 0.2% of the mass of the ultra-low-temperature tuna; the mass of the neutral protease is preferably 0.3%-0.5% of the mass of the ultra-low-temperature tuna, more preferably 0.4% of the mass of the ultra-low-temperature tuna. In the present invention, the enzymatic activity of the alkaline protease is preferably ≥2.4AU-A / g, and the enzymatic activity of the neutral protease is preferably ≥0.8AU-A / g. The present invention utilizes the alkaline protease in a neutral environment to avoid the decomposition of anserine and the racemization or dextrorotation of amino acids in an alkaline environment, thereby increasing the content of anserine in tuna protein peptides and their utilization by the human body.

[0019] In the present invention, the temperature for inactivating the enzyme is preferably 105-121°C, more preferably 110-118°C, and even more preferably 112-115°C; the time for inactivating the enzyme is preferably 12s-21s, more preferably 14s-19s, and even more preferably 16s-18s. In the present invention, the method for separating the slag and liquid preferably includes centrifugation, the speed of the centrifugation is preferably ≥3000r / min, and the centrifugation machine is preferably a horizontal centrifuge. In the present invention, the mass of the diatomaceous earth is preferably 0.5%-2% of the mass of the ultra-low temperature tuna, more preferably 1%-1.5% of the mass of the ultra-low temperature tuna, the mesh size of the diatomaceous earth is preferably 100-200 mesh, more preferably 120-180 mesh, and even more preferably 140-160 mesh. In the present invention, the filtration method preferably includes filtration with a plate and frame filter press, and the filter cloth used for the plate and frame filter press is preferably XN630 closed filter cloth.

[0020] In the present invention, the concentration method preferably includes vacuum concentration, and the temperature of the vacuum concentration is preferably 60°C to 70°C, more preferably 62°C to 68°C, and further preferably 64°C to 66°C. The vacuum degree of the vacuum concentration is preferably -0.095Mpa or less. The concentration is preferably concentrated to a solid content of 35Brix to 45Brix, more preferably concentrated to a solid content of 38Brix to 42Brix, and further preferably concentrated to a solid content of 39Brix to 40Brix. In the present invention, drying is performed after the above-mentioned concentration, so the present invention is a double-effect concentration. The drying method preferably includes centrifugal spray drying, and the inlet air temperature of the centrifugal spray drying is preferably 190°C to 200°C, more preferably 194°C to 198°C, and further preferably 196°C to 197°C. The outlet air temperature of the centrifugal spray drying is preferably 50°C to 65°C, more preferably 54°C to 62°C, and further preferably 56°C to 60°C.

[0021] The preparation method of the present invention can address the poor quality of direct enzymatic hydrolysis in the existing invention patent CN116439360A. In CN116439360A, to ensure a smooth texture, anserine is prepared using water extraction and extraction with a 0.1-1% sodium bicarbonate solution. The two extracts are then combined for enzymatic hydrolysis. The poor quality of this patent's direct enzymatic hydrolysis method is due to the fact that tuna meat contains some water-soluble peptides. In this patent, the tuna meat is minced into 0.1-0.5 cm chunks using a meat grinder. The enzyme preferentially acts on the water-soluble peptides and the surface of the chunks, resulting in excessive enzymatic hydrolysis of the water-soluble peptides and the surface of the chunks, exposing more hydrophobic amino acids and causing a bitter taste and poor quality. Compared to this existing technology, the present invention controls the degree of enzymatic hydrolysis by controlling the degree of tuna grinding, the amount of alkaline protease added, the amount of neutral protease added, and the ratio of their amounts, thereby avoiding excessive enzymatic hydrolysis. The patent uses 0.1-1% sodium bicarbonate or sodium carbonate for extraction. Although alkaline conditions make protein more easily hydrolyzed, this can cause amino acids to racemize or become dextrorotatory, leaving the amino acids that humans can utilize as L-amino acids. Therefore, while the extract can be extracted, its utilization by the human body is low. Furthermore, the anserine content in the patent is only approximately 8%, while the present invention contains much higher levels of anserine than the patent.

[0022] The preparation method of the present invention can solve the technical problems in the existing invention patent CN115558692A, that is, direct enzymatic hydrolysis brings undesirable flavors such as bitterness to the product, and the addition of flavor enzymes to improve the flavor causes the loss of anserine enzymatic hydrolysis. In the invention patent CN115558692A, in order to ensure the taste and anserine content, water extraction is first used twice, and then the fish meat is enzymatically hydrolyzed and flavor enzymes are used to improve the flavor, and then the filtrate is combined for decolorization, concentration and drying. The generation of fishy smell is related to the degradation of trimethylamine oxide in the fish body. The longer the fish is out of the freezing temperature, the stronger the fishy smell. The process of the present invention is greatly simplified. The time for tuna to be out of the freezing temperature in the preparation method of the present invention is shorter than that of the existing technology, and there is no need for two water extractions, flavor enzyme hydrolysis, and ZX616 # Diatomaceous earth filtration, SX821 # Process steps such as diatomaceous earth filtration and activated carbon fiber membrane filtration significantly shorten the extraction process time, efficiently completing enzymatic hydrolysis and extracting, and avoiding the generation of fishy odors. The main reason for the dark color is the tuna blood. The present invention uses 105°C to 121°C to inactivate the enzyme for 12 seconds, turning the fish blood into blood foam, which is then centrifuged out during the subsequent centrifugation process, thereby increasing the thermal stability of the product.

[0023] In addition, after water extraction according to the methods of the above two existing invention patents, it is difficult to separate the tuna and the extract during the production conversion process. The laboratory can use a centrifuge to separate the supernatant. In actual production, a horizontal centrifuge is used. After the fish meat is separated, it is put back into the tank under naked conditions. Specifically, in the actual production of the existing technology, water extraction is first adopted, and then solid-liquid separation is achieved by centrifugation. The solid residue separated by centrifugation is re-tanked and then enzymatically hydrolyzed, resulting in increased production costs and increased risk of microbial contamination of the product. The present invention adopts a one-time extraction and enzymatic hydrolysis. The liquid separated by the horizontal centrifuge is directly transported to the next process through a pipeline. After enzymatic hydrolysis, there is less solid residue and it is directly discharged through the centrifuge discharge port. There is no need to collect and re-tank for extraction, which reduces production costs and the risk of microbial contamination.

[0024] In summary, the present invention solves the bitterness caused by excessive enzymatic hydrolysis and the fishy smell caused by a long extraction process from the source. Direct enzymatic hydrolysis is performed without decolorization and deodorization of active peptides. The prepared tuna protein peptide has a light color, basically no fishy smell, a fresh and sweet taste, and an anserine content of more than 25%. In addition, although the alkaline protease is used under neutral conditions and its partial enzyme activity is reduced, it is used in combination with the neutral protease to solve the problems of color, fishy smell and taste, and at the same time avoids the racemization or conversion of amino acids to dextrorotatory under alkaline conditions, which affects the absorption and utilization by the human body.

[0025] The present invention also provides a tuna protein peptide with high anserine content. The tuna protein peptide with high anserine content is prepared by the above preparation method.

[0026] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0027] In the following examples, unless otherwise specified, all methods are conventional.

[0028] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0029] In the following examples, alkaline protease was purchased from novozymes (imported from Novozymes, Denmark, with an enzyme activity of ≥2.4 AU-A / g), and neutral protease was purchased from novozymes (imported from Novozymes, Denmark, with an enzyme activity of ≥0.8 AU-A / g).

[0030] Example 1

[0031] A method for preparing tuna protein peptide with high anserine content comprises the following steps:

[0032] The ultra-low temperature tuna was ground into a meat-like shape without any granularity. The ultra-low temperature tuna and purified water were mixed and stirred evenly according to the ratio of ultra-low temperature tuna to purified water = 1 g: 2 mL. The temperature was raised to 55°C. 0.1% alkaline protease and 0.5% neutral protease of the ultra-low temperature tuna were added and enzymolysis was performed for 3 hours. The enzyme was inactivated by high temperature instantaneous inactivation at 105°C for 12 seconds. The inactivated enzymatic hydrolyzate was passed through a horizontal centrifuge at a flow rate of 1 T / h and a rotation speed of 3000 r / min for slag-liquid separation. The separated liquid was collected. 1% by weight of the ultra-low temperature tuna is added to the separated liquid, wherein the diatomaceous earth has a mesh size of 100, and the separated liquid is filtered through a plate and frame filter press with an XN630 closed filter cloth, and the filtrate is collected; the filtrate is subjected to a double-effect concentration, wherein the first-effect concentration temperature is 65° C. and the vacuum degree is -0.095 MPa. When the filtrate is concentrated to a solid content of 40 Brix, it is dried by centrifugal spray drying in a spray tower with an air inlet temperature of 195° C. and an air outlet temperature of 55° C. The moisture content is determined to be 5.08%, thereby obtaining a tuna protein peptide with a high anserine content.

[0033] Beijing SGS was commissioned to determine the anserine content in tuna protein peptides. From every 400 g of tuna meat, approximately 45.7 g of tuna protein peptides with an anserine content of 25% (on a dry basis) could be produced. Therefore, the product yield was (45.7 / 400)×100≈11.4%.

[0034] In addition, it was determined that the tuna protein peptide obtained in this example was a white powder, which dissolved in water quickly, produced a clear and bright solution, had no fishy smell, and tasted sweet and fresh without bitterness.

[0035] Example 2

[0036] A method for preparing tuna protein peptide with an anserine content of 25% or more (on a dry basis) comprises the following steps:

[0037] The ultra-low temperature tuna was ground into a meat-like shape without any granularity, and the ultra-low temperature tuna and purified water were mixed and stirred uniformly according to the ratio of ultra-low temperature tuna to purified water = 1 g: 1 mL. The temperature was raised to 50° C., and 0.2% alkaline protease and 0.4% neutral protease of the ultra-low temperature tuna by weight were added. The mixture was enzymatically hydrolyzed for 3 h. The enzyme was inactivated by high temperature instantaneous inactivation at 110° C. for 21 s. The inactivated enzymatic hydrolyzate was passed through a horizontal centrifuge at a flow rate of 1 T / h and a rotation speed of 3000 r / min for slag-liquid separation. The separated liquid was collected. The invention relates to a method for preparing a tuna protein peptide comprising 1% by weight of ultra-low temperature tuna and 200 mesh diatomaceous earth. The diatomaceous earth is filtered through a plate and frame filter press using an XN630 closed filter cloth, and the filtrate is collected. The filtrate is subjected to a double-effect concentration, wherein the first-effect concentration temperature is 65° C. and the vacuum degree is controlled below -0.095 MPa. When the filtrate is concentrated to a solid content of 40 Brix, the filtrate is dried using a centrifugal spray tower with an air inlet temperature of 195° C. and an air outlet temperature of 60° C. The moisture content is determined to be 4.07%, thereby obtaining a tuna protein peptide having an anserine content of 25% or more (on a dry basis).

[0038] The tuna protein peptide obtained in this example was determined to be a white powder that dissolves quickly in water. The solution is clear and bright, has no fishy smell, and tastes sweet and fresh without bitterness.

[0039] Example 3

[0040] A method for preparing tuna protein peptide with high anserine content comprises the following steps:

[0041] The ultra-low temperature tuna was ground into a meat-like shape without any granularity, and the ultra-low temperature tuna and purified water were mixed and stirred evenly according to the ratio of ultra-low temperature tuna to purified water = 1 g: 2 mL. The temperature was raised to 60°C, and 0.3% alkaline protease and 0.3% neutral protease of the ultra-low temperature tuna were added. The enzyme was hydrolyzed for 3 hours. The high temperature instantaneous enzyme inactivation method was used, and the enzyme was inactivated at 115°C for 18 seconds. The enzyme hydrolyzed solution after enzyme inactivation was passed through a horizontal centrifuge at a flow rate of 1 T / h and a speed of 3000 r / min for slag-liquid separation. The separation was collected. liquid; adding 1% by weight of ultra-low temperature tuna diatomaceous earth with a mesh size of 180 to the separated liquid, filtering through a plate and frame filter press with a closed filter cloth model XN630, and collecting the filtrate; concentrating the filtrate with a double-effect concentration, wherein the temperature of the first effect is 60° C. and the vacuum degree is controlled below -0.095 MPa, and when the solid content is 45 Brix, the filtrate is concentrated using a centrifugal spray drying tower with an air inlet temperature of 200° C. and an air outlet temperature of 65° C. The moisture content is determined to be 3.04%, thereby obtaining a tuna protein peptide with a high anserine content.

[0042] The tuna protein peptide obtained in this example was determined to be a white powder that dissolves slowly in water. The solution was clear and bright, had no fishy smell, and tasted sweet and fresh without bitterness.

[0043] Comparative Example 1

[0044] The difference from Example 1 is that 0.5% of alkaline protease by weight of ultra-low temperature tuna and 0.3% of neutral protease by weight of ultra-low temperature tuna are added, and the rest are the same as Example 1.

[0045] The results showed that the tuna protein peptide obtained in this comparative example was a white powder, which dissolved in water quickly, the solution was clear and transparent, had no fishy smell, had no fresh and sweet taste, had a slightly bitter taste, and could be felt astringent on the tongue.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing tuna protein peptide with high anserine content, characterized in that: The method comprises the following steps: grinding ultra-low temperature tuna, mixing with water, alkaline protease and neutral protease, performing enzymatic hydrolysis at 45-60°C for 2-5 hours to inactivate the enzymes; separating the hydrolyzed liquid after inactivation of the enzymes into residue and liquid, and collecting the separated liquid; The separated liquid is mixed with diatomaceous earth, and the filtrate is collected by filtration; the filtrate is concentrated and dried to a moisture content of less than 7% to obtain a tuna protein peptide with a high anserine content.

2. The preparation method according to claim 1, characterized in that The mass volume ratio of ultra-low temperature tuna to water is 1g:1-3mL, the mass of the alkaline protease is 0.1%-0.3% of the mass of the ultra-low temperature tuna, and the mass of the neutral protease is 0.3%-0.5% of the mass of the ultra-low temperature tuna.

3. The preparation method according to claim 1, characterized in that The temperature for inactivating the enzyme is 105 to 121° C., and the time for inactivating the enzyme is 12 to 21 seconds.

4. The preparation method according to claim 1, characterized in that The slag-liquid separation method includes centrifugation, and the centrifugal rotation speed is ≥3000r / min.

5. The preparation method according to claim 1, characterized in that The mass of the diatomaceous earth is 0.5% to 2% of the mass of the ultra-low temperature tuna, and the mesh number of the diatomaceous earth is 100 to 200 meshes.

6. The preparation method according to claim 1, characterized in that The filtering method includes filtering with a plate and frame filter press, and the filter cloth used in the plate and frame filter press is an XN630 closed filter cloth.

7. The preparation method according to claim 1, characterized in that The concentration method includes vacuum concentration, the temperature of the vacuum concentration is 60° C. to 70° C., and the vacuum degree of the vacuum concentration is below -0.095 MPa.

8. The preparation method according to claim 1, characterized in that The concentration is to concentrate until the solid content is 35 Brix to 45 Brix.

9. The preparation method according to claim 1, characterized in that The drying method includes centrifugal spray drying, wherein the air inlet temperature of the centrifugal spray drying is 190° C. to 200° C., and the air outlet temperature is 50° C. to 65° C.

10. A tuna protein peptide with high anserine content, characterized in that: The tuna protein peptide with high anserine content is prepared by the preparation method according to any one of claims 1 to 9.