CN114317657A

CN114317657A - Fishbone peptide and preparation method and application thereof

Info

Publication number: CN114317657A
Application number: CN202111666549.0A
Authority: CN
Inventors: 陈旭华; 柳平
Original assignee: Beijing Xiangnong Food Technology Co ltd
Current assignee: Beijing Xiangnong Food Technology Co ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2022-04-12

Abstract

The invention provides fishbone peptide and a preparation method and application thereof, belonging to the technical field of fishbone peptide extraction. The extraction method mainly comprises the following steps: s1, unfreezing and crushing the raw material; s2, heating; s3 inoculating Bacillus subtilis; fermenting and hydrolyzing the culture solution S4; s5 inactivating the culture solution; s6, separating and filtering the fishbone residues and the fishbone soup; s7 vacuum concentration; s8 vacuum freeze drying; finally obtaining the fish bone peptide. The method for extracting the fishbone peptide by using the bacillus subtilis has the advantages of low consumption, high yield, thorough fermentation and enzymolysis, low production cost and high production efficiency, and can realize continuous and industrial production.

Description

Fishbone peptide and preparation method and application thereof

Technical Field

The invention relates to the technical field of fish bone peptide extraction, and particularly relates to fish bone peptide and a preparation method and application thereof.

Background

The fish is rich in nutrition and is an important food source for human beings. However, the fish can generate 20 to 25 percent of fishbone and fish head in the whole weight of the fish in the processing and production process. The fishbone and the fish head are directly discarded in the production, which causes serious waste and environmental pollution; or the product is simply processed into feed or fertilizer for use, and the added value of the product is low. The main components of the fishbone are protein, fat, water and ash (mainly comprising Ca, Fe, Zn, Mg, P and the like), wherein the content of collagen is very high, and the fishbone peptide is a high-quality resource for developing fishbone peptide.

The current extraction method of the fishbone peptide generally utilizes hot-pressing extraction or enzymolysis extraction. The collagen peptide is extracted by hot pressing, the process is mature, the equipment is simple, but the reaction condition is severe, the hydrolysis degree of the protein in the product is different, the extraction temperature is high, the reaction is severe, the energy consumption is large, and the extraction efficiency is low; the fish bone collagen peptide is extracted by enzymolysis, papain, flavourzyme and alkaline protease are usually selected and adjusted to a proper pH value for extraction, the extraction conditions are mild, but the optimum extraction conditions of various enzymes are different, so that the extraction efficiency is low, the extracted collagen peptide is often excessively hydrolyzed, the bitterness is serious, and the further application is influenced. Therefore, a method for extracting the fishbone peptide with low energy consumption and high yield is urgently needed.

Disclosure of Invention

In order to solve the defects in the prior art, the invention provides a method for preparing fish bone peptide by utilizing microbial fermentation extraction, and the method has mild extraction process conditions and high extraction yield. In order to achieve the purpose, the invention adopts the following technical scheme: a method for extracting fishbone peptide comprises taking fishbone as raw material, inoculating Bacillus subtilis, and performing fermentation enzymolysis; the inoculation amount of the bacillus subtilis is 1 wt% -5 wt%, and the conditions of fermentation and enzymolysis are as follows: the fermentation time is more than 18h, and the fermentation temperature is 30-40 ℃. Preferably, the inoculation amount of the bacillus subtilis is 2-3 wt%.

The extraction method of the present invention further comprises a step of heating treatment, the heating treatment comprising: preparing fishbone into fishbone paste, adding the fishbone paste into a fermentation extraction tank, adding water and maltose respectively, adjusting the pH value to 6.5-7.5, stirring, heating to 95-105 ℃, and preserving heat. Maltose is added into the fermentation tank to provide a carbon source for subsequent fermentation, and the production cost can be effectively reduced. Preferably, the addition amount of maltose is 0.1 times of the weight of the fish bone paste. The pH value is adjusted to 6.5-7.5, the proper fermentation pH value is provided for the selected bacillus subtilis, and in the pH range, the fermentation speed is high, and the activity of the produced protease is high. Preferably, the temperature is raised to 100 ℃ and the temperature is maintained for 1 hour.

Preferably, the fermentation extraction tank is an enzymolysis fermentation extraction tank with a stirring paddle and a heating and cooling water cooling system.

Preferably, the mass ratio of the fishbone paste to the water is 100: (50-400); more preferably, the mass ratio of the fishbone paste to the water is 100: (150-200).

The extraction method also comprises the step of cooling to 30-40 ℃ and preserving heat for 18-30 hours after the heating treatment. Preferably, the temperature is reduced to 37-38 ℃, and the temperature is kept for 18-24 hours.

The extraction method also comprises the steps of inactivating the product obtained by fermentation and enzymolysis, separating, filtering, concentrating and vacuum drying, wherein the filtrate with the molecular weight of 1000-.

Preferably, a vibrating screen, a horizontal spiral centrifuge and a ceramic membrane filter are adopted for separation and filtration.

Preferably, after inactivation, separating the fishbone residues from the fishbone soup, collecting the fishbone soup, performing centrifugal separation, removing impurities and bone oil, and keeping a clear liquid in a middle layer; and filtering the clear liquid in the middle layer, and only retaining the part of 1000-3000 daltons to obtain refined filtrate.

Preferably, the refined filtrate is subjected to vacuum double-effect concentration, the temperature is controlled to be 50-75 ℃, the pressure is controlled to be-0.050-0.100 MPa, and when the solid content is concentrated to be 30-50%, the concentration is stopped, so that concentrated solution is obtained. More preferably, the temperature is controlled at 60 ℃.

Preferably, the obtained concentrated solution is homogenized, and then the concentrated solution is dehydrated by vacuum freeze drying, and finally the powdery fishbone peptide is prepared.

As a preferred embodiment of the present invention, the method for extracting fish bone peptide comprises the following steps:

s1 grinding the unfrozen fish bones into fish bone paste for later use;

s2, adding the fishbone paste prepared in S1 into a fermentation extraction tank, then respectively adding water and maltose which is 0.1 time of the weight of the fishbone paste, adjusting the pH value to 6.5-7.5 by using citric acid and sodium citrate, starting stirring, heating to 95-105 ℃, and preserving heat to obtain a mixture; the fermentation extraction tank is an enzymolysis fermentation extraction tank with a stirring paddle and a heating and cooling water cooling system;

the mass ratio of the fishbone paste to the water is 100: (150-;

s3, cooling the mixture prepared in S2 to 37-38 ℃, preserving heat for 18-24 hours, and inoculating 2 wt% of bacillus subtilis to obtain fermentation liquor;

s4, after the fermentation liquor in S3 is hydrolyzed, heating to 95-105 ℃, and stopping heating;

s5, separating the fishbone residues and the fishbone soup of the feed liquid obtained in the step S4, collecting the fishbone soup, carrying out centrifugal separation, removing impurities and bone oil, and keeping a clear liquid in a middle layer; filtering the clear liquid in the middle layer, and only retaining the part of 1000-3000 daltons to obtain refined filtrate;

s6, carrying out vacuum double-effect concentration on the refined filtrate obtained in the step S5, controlling the temperature at 60 ℃ and the pressure at-0.050 to-0.100 MPa, and stopping concentration when the solid content is concentrated to 30-50% to obtain a concentrated solution;

s7 homogenizing the concentrated solution obtained in S6, dehydrating the concentrated solution by vacuum freeze drying, and finally preparing the powdery fishbone peptide.

The invention also provides the fishbone peptide prepared by any method, wherein the content of the delicious amino acid and the content of the sweet amino acid in the fishbone peptide are respectively 5.59 wt% and 19.24 wt%.

The invention also provides application of the fishbone peptide in preparing food, food additives or medicines.

Compared with the prior art, the invention has the following beneficial effects:

1. low energy consumption and overall cost

The energy and power consumption of the fermentation extraction method only accounts for 40-50% of that of the traditional method, heat can be generated due to the metabolism of microorganisms in the fermentation process, the heat energy loss of the fermentation extraction tank is almost zero when the fermentation extraction tank has the heat preservation function, and only stirring power needs to be provided.

In the traditional method for extracting the fish bone peptide by enzymolysis, various proteases are firstly used, and the production of the proteases needs to provide a culture medium for fermentation, separate and purify the proteases and needs to be stored under proper conditions so as not to be inactivated. The technical scheme of the invention omits the steps of separation, purification and preservation, and does not need to provide a special culture medium (the fish bone can become the culture medium required by fermentation after being crushed and extracted by simple hot pressing), thereby integrally reducing the production cost. The fishbone peptide is extracted by taking fishbone and fish head as raw materials, so that the environmental pollution can be reduced, the raw materials can be used as a nitrogen source, and the final hydrolysate is the target peptide.

2. Thorough fermentation and enzymolysis, uniform molecular size and good flavor

The protein is hydrolyzed by the metabolite of the bacillus subtilis, is more similar to natural fermentation, is similar to the traditional starter propagation brewing, has more natural reaction, and extracts fishbone peptide product molecules which are more uniform and are both 1000-3000 dalton micromolecular peptides, thereby being beneficial to subsequent processing and absorption of human bodies. The protease is only used for hydrolyzing the surface layer of the fishbone, and can not hydrolyze the peptide in the deep layer of the fishbone, so that the overall yield is low, the hydrolysis degree of the hydrolyzed part is relatively high, the molecular weight is small, the proportion of the bitter peptide is high, and the product quality is low.

3. High yield

By using the fermentation extraction method, the yield of the product is 8-11 percent, the average yield is 10 percent, the yield is higher than the average yield (4 percent) of the hot-pressure extraction method by more than 2.5 times, and the yield is higher than the yield (6-8 percent) of the enzymolysis extraction method by more than 50 percent. The method is suitable for preparing the fishbone peptide from the fishbone and the fishhead, is a novel fishbone peptide fermentation and extraction method, has low production cost and high production efficiency, and can realize continuous and industrial production.

The invention organically combines the traditional protease preparation technology and the fishbone peptide extraction technology by referring to the traditional fermentation technology, has mild extraction conditions and high yield, integrally improves the extraction efficiency and reduces the production cost.

Drawings

FIG. 1 is a graph of the extraction rate of fermentation extraction;

FIG. 2 shows the extraction rate of fishbone peptide in different extraction processes;

FIG. 3 is a radar chart of amino acid composition of fishbone peptide under different extraction processes.

Detailed Description

The following details are given by way of example of the preparation of tuna bone peptide:

the invention provides a method for preparing fishbone peptide by microbial fermentation extraction, which comprises the following steps:

s1 raw material thawing and crushing

Opening the box of the frozen bone raw material of the tuna, uniformly stacking the whole bag in a plastic basket, then stacking the bag in a thawing pool, introducing thawing water, thawing for 1-2 h until the bone raw material is completely thawed, and then cleaning the bone raw material for later use; crushing the unfrozen tuna bones into particles of 10-30 mm by using a bone crusher, and then putting the crushed tuna bones into a bone paste mill to mill the tuna bones. When the bone cement mill works, water accounting for 30-35% of the weight of the fish bone raw material is required to be added so as to enable bone fracture to be smooth.

S2 heating

Putting the fishbone paste into a fermentation extraction tank, then adding water, wherein the mass ratio of the fishbone paste to the water after pretreatment is 100: (50-400), the specific ratio is 100: (150-200). Then adding maltose 0.1 times of the weight of fishbone, and adjusting pH to 6.5-7.5 with citric acid and sodium citrate. Then starting stirring, maintaining the stirring speed at 20-24 r/min, then starting a jacket to heat uniformly to 95-105 ℃, and preserving heat for 2 hours. The heat preservation can kill most microbes and create conditions for inoculation. The fermentation tank is used for extraction, stirring is always started in the fermentation and extraction processes due to the fact that the fermentation tank is provided with the stirring paddle, fishbone mud cannot settle to the bottom of the tank, extraction efficiency is improved, and the fermentation and extraction temperature can be controlled due to the fact that the fermentation tank is provided with the heating and cooling water cooling system.

Heating to make part of fishbone undergo preliminary hydrolysis so as to provide nitrogen source for growth of bacillus subtilis, and no nitrogen source is required to be added separately.

S3 inoculation

The bacillus subtilis can be used for fermentation and extraction of fishbone after acclimation. After the fermentation tank is kept warm for 1 hour, the heating is stopped, the temperature of the feed liquid is reduced to 30-40 ℃ by using cooling water, and the temperature is kept for 18-30 hours. Then inoculating the activated bacillus subtilis in the inoculation tank, wherein the inoculation amount of the bacillus subtilis is controlled to be 1-5%, and the preferred inoculation amount is 2%. Preferably, the temperature of the fermentation tank is controlled to be 36-37 ℃, and the temperature is kept for 18-24 hours.

In order to test the optimal process parameters of the fermentation extraction process, the content of crude protein and the content of peptide in the product are detected every 1 hour, so that the extraction rate of the fishbone peptide is calculated, and finally, the extraction rate curve of the fishbone peptide is obtained. The protein content is determined according to the Kjeldahl method of the national standard GB/T5009.5-2016, and the fishbone peptide content is determined by a biuret method colorimetric method.

As shown in FIG. 1, Bacillus subtilis starts to grow at a suitable temperature and produces protease, amylase and lipase, which can sufficiently hydrolyze bone protein of tuna and hydrolyze the fat terminal linked to the end of the bone protein to facilitate fat separation. In the early stage of the fermentation extraction (within 7 hours), the extraction rate rises relatively slowly, because the amount of bacillus subtilis does not grow in a large amount at this time, and the hydrolysis mainly comes from the thermal hydrolysis of the product; from 7 hours to 17 hours, the extraction rate rises linearly, the bacillus subtilis is propagated in a large amount, and a plurality of proteases are generated to hydrolyze the fishbone quickly; however, when the extraction time is more than 18 hours, the extraction curve hardly rises, which indicates that the protein in the fishbone is almost completely hydrolyzed, and the hydrolysis rate cannot be improved with the time. Therefore, 18 hours of fermentation extraction was selected as the final extraction time.

S4 inactivation

After the fermentation and hydrolysis of S3 are finished, the temperature is raised to 95-105 ℃, and the culture solution is inactivated.

S5 separation of fishbone residue and fishbone soup

And after the inactivation in the S4 is finished, pumping the fermentation liquor into a vibrating screen of 150 meshes, and separating the bone residues from the bone soup. And pumping the bone soup into a standing separation tank after the bone soup is collected. And collecting the turbid emulsion layer soup through a container by observing an observation window at the lower part of the standing tank when at least 50kg of turbid emulsion layer soup is collected. And directly feeding the lower layer soup of the standing separation tank into a horizontal spiral centrifuge for centrifugal separation through vacuum, wherein the centrifuge is controlled at 15000 r/min. By centrifugal separation, the excess impurities and a small amount of bone oil are separated out again. The centrifuged filtrate was ready for further ceramic membrane filtration. And (3) separating the bone soup at the lower layer of the standing separation tank, and separately collecting the residual oil at the upper layer to obtain the crude fish oil.

And (3) passing the feed liquid after centrifugal separation through a ceramic membrane filter, separating materials with the molecules lower than 1000 daltons and higher than 3000 daltons, and only retaining the part with the molecules of 1000-3000 daltons. In the fermentation and extraction process, the enzymolysis degree of the protein is mastered by adjusting the fermentation time. The soluble peptides in the fermentation broth were essentially 1000-. Filtering with ceramic membrane to remove small molecular peptides, amino acids and saccharides below 1000 daltons, and removing peptides above 3000 daltons, and only retaining refined fishbone peptide which is most easily absorbed by human body, i.e. refined filtrate.

S6 vacuum concentration

Pumping the obtained refined filtrate into a double-effect concentrator for concentration, controlling the temperature to be 50-75 ℃, particularly 60 ℃, controlling the pressure to be-0.050-0.100 MPa, and stopping concentration when the solid content is concentrated to be 30-50 percent, particularly 40 percent, so as to obtain concentrated solution. By using vacuum double-effect concentration, the concentration temperature can be reduced, the energy consumption can be saved by more than 50%, and the concentration time can be saved.

S7 vacuum freeze drying

Homogenizing the concentrated solution by a homogenizer, then conveying to a vacuum freeze dryer, dehydrating the fishbone peptide by vacuum freeze drying, and finally preparing the powdery fishbone peptide.

The present invention will be further illustrated with reference to the following specific examples, but the present invention is not limited to the following examples. The method is a conventional method unless otherwise specified. The starting materials are commercially available from the public unless otherwise specified.

Example 1

S1 grinding the unfrozen fish bones into fish bone paste for later use;

s2, adding the fishbone paste prepared in S1 into a fermentation extraction tank, then respectively adding water and maltose which is 0.1 time of the weight of the fishbone paste, adjusting the pH value to 6.5 by using citric acid and sodium citrate, starting stirring, heating to 95 ℃, and preserving heat to obtain a mixture;

the mass ratio of the fishbone paste to the water is 100: 150;

s3, cooling the mixture prepared in S2 to 36 ℃, and preserving heat for 20 hours to obtain fermentation liquor after inoculating 2 wt% of bacillus subtilis;

s4, after the fermentation liquor in S3 is hydrolyzed, heating to 105 ℃, and preserving heat for 1 hour;

s6, carrying out vacuum double-effect concentration on the refined filtrate obtained in the step S5, controlling the temperature at 50 ℃ and the pressure at-0.075 MPa, and stopping concentration when the solid content is concentrated to 30% to obtain a concentrated solution;

Example 2

The difference from the example 1 is that the pH value in S2 is 7.5, the temperature is 105 ℃, and the mass ratio is 100: 240; cooling to 30 ℃ in S3, and preserving the temperature for 30 hours, wherein the inoculation amount of the bacillus subtilis is 1 wt%; controlling the temperature in S6 at 60 ℃, concentrating the solid content to 50%, and stopping concentrating;

example 3

The difference from the example 1 is that the pH value in S2 is 7, the temperature is 100 ℃, and the mass ratio is 100: 400; cooling to 40 ℃ in S3, and preserving the temperature for 24 hours, wherein the inoculation amount of the bacillus subtilis is 5 wt%; concentrating the solid content in S6 to 30%, and stopping concentrating;

example 4

The difference from the example 1 is that the Bacillus subtilis with the mass ratio of 100:200 in S2 and the inoculation amount of 3 wt% in S3 is kept for 18 hours, the temperature in S4 is raised to 100 ℃, the temperature in S6 is controlled to 75 ℃, the pressure is controlled to-0.100 MPa, the solid content is concentrated to 40%, and the concentration is stopped;

example 5

The difference from the example 1 is that the mass ratio of S2 is 100:50, the temperature is kept for 18 hours in S3, the temperature is raised to 95 ℃ in S4, the temperature is controlled to 63 ℃ in S6, and the pressure is controlled to-0.050 MPa;

comparative example 1 extraction of tuna bone peptide by Hot pressing

Tuna bone peptide was prepared as follows:

1. thawing, trimming and cleaning raw material

Opening the box of the frozen tuna bone raw material, uniformly stacking the whole bag in a thawing pool, introducing thawing water and blowing air to accelerate thawing, and thawing for 0.5-1 h. And after the thawing is finished, removing redundant impurities for later use.

2. Crushing of raw materials

The bone crusher and the bone paste mill are firstly sterilized by sterile water, the bone crusher and the bone paste mill are started after the sterilization is finished, and then the crushed fish bones are put into the bone paste mill to prepare the tuna bone paste. When the bone cement mill works, water accounting for 30-35% of the weight of the fish bone raw material is required to be added so as to enable bone fracture to be smooth. The tuna bones are processed into the fishbone paste to facilitate the extraction of the fishbone peptide.

3. Hot pressing extraction

Loading the fishbone paste into an enzymolysis tank, then adding water which is 1.3-1.5 times the weight of the fishbone paste (containing water), then starting stirring, keeping the stirring speed at 20-24 r/min, then starting a jacket to heat uniformly to 120 +/-2 ℃, starting timing, and carrying out hot-pressing extraction for 3 hours. Use the enzymolysis tank to carry out hot pressing and extract, mainly because the enzymolysis tank has the stirring rake, opens the stirring all the time at the leaching in-process, and the fish bone mud can not subside to the tank bottoms portion, can strengthen the efficiency that hot pressing was extracted.

4. Filtering and separating

And after the hot-pressing extraction is finished, pumping the extract into a vibrating screen to separate the bone residues from the bone soup. And pumping the bone soup into a standing separation tank after the bone soup is collected. Pumping the bone soup in the lower layer of the standing separation tank into a vacuum concentration tank, and separately collecting the residual oil in the upper layer to obtain the crude fish oil.

5. Concentrating

The soup in the concentrating and feeding tank is pumped into a double-effect concentrator for concentration, and the steam pressure of an interlayer is controlled within 0.10MPa during concentration, so that the stability of concentration is ensured; the temperature is controlled to be 50-75 ℃, the pressure is controlled to be-0.050-0.095 MPa, the temperature index is mainly controlled in the concentration process, and the pressure is used as an auxiliary index. When the stop concentration of the concentrated solution reaches the specified requirement (when the total solid content reaches 40%), the next procedure can be carried out, and the measurement must be carried out once again.

6. Homogenizing

Firstly, the cooling water of the colloid mill is started, and whether the pipeline is smooth or not and the lubricating oil condition of the colloid mill are checked. Then the colloid mill is started, and materials can be added for homogenization after the colloid mill is cleaned and disinfected. The gap of the colloid mill is opened to the maximum, the gap is adjusted to be small after homogenization once, and when the material is less, the backflow pipe can be used for repeatedly homogenizing, so that the homogenizing effect is better. After the colloid mill is homogenized, the mixture can be directly pumped into a filling machine.

Comparative example 2 extraction of tuna bone peptide by enzymatic hydrolysis

Tuna bone peptide was prepared as follows:

1. thawing, trimming and cleaning raw material

2. Crushing of raw materials

The bone crusher and the bone paste mill are firstly sterilized by sterile water, the bone crusher and the bone paste mill are started after the sterilization is finished, and then the crushed bone is put into the bone paste mill to prepare the tuna bone paste. When the bone cement mill works, water accounting for 30-35% of the weight of the fish bone raw material is required to be added so as to enable bone fracture to be smooth. The tuna bones are processed into the fishbone paste to facilitate the extraction of the fishbone peptide.

3. Extraction by enzymolysis

Loading the crushed fishbone into an enzymolysis tank, adding water with the weight 2.0-2.5 times of the weight of the fishbone, starting stirring at the stirring speed of 20-24 r/min, then starting a jacket, heating to 50 +/-2 ℃, adding 0.3 per mill of compound protease (including papain, alkaline protease and flavourzyme) of the weight of the fishbone, stirring for 3-5min, and carrying out enzymolysis for 30 min. The enzymolysis tank is used for enzymolysis and extraction, and mainly because the enzymolysis tank is provided with the stirring paddle, the stirring is always started in the enzymolysis and extraction processes, and fishbone cannot settle to the bottom of the tank, so that the extraction efficiency is enhanced.

4. Filtering and separating

And after the enzymolysis extraction is finished, pumping the extract into a vibrating screen to separate the bone residues from the bone soup. And pumping the bone soup into a standing separation tank after the bone soup is collected. Pumping the bone soup in the lower layer of the standing separation tank into a vacuum concentration tank, and separately collecting the residual oil in the upper layer to obtain the crude fish oil.

5. Concentrating

6. Homogenizing

The extraction rate of the fishbone peptide is calculated by detecting the crude protein content and the peptide content of the product respectively in examples 1-5 and comparative examples 1-2. The protein content is determined according to the Kjeldahl method of the national standard GB/T5009.5-2016, and the peptide content is determined by the biuret method, so that the peptide yield is detected.

The fish bone peptide is extracted by fermentation extraction, traditional enzymolysis extraction and hot pressing extraction, each extraction is carried out at least 4 times according to the optimal process, and the average extraction rate of the peptide is calculated, which is shown in table 1 and figure 2. As can be seen from Table 1, the average extraction rate of the product by fermentation extraction method is 10.23%; the average extraction rate by hot pressing method is 4.06%, and the average extraction rate by enzymolysis is 7.83%. It can be seen that the average extraction rate of the fermentation extraction method is higher than that of the hot-pressure extraction method by more than 2.5 times, and the average extraction rate is higher than that of the enzymolysis extraction method by about 50%, which is shown in table 1.

TABLE 1 comparison of the extraction rates of fishbone peptide in different extraction processes

Extraction method

Extraction ratio

1

Extraction ratio 2

Extraction ratio 3

Extraction ratio 4

Average extraction rate

Fermentation extraction

10.67％

10.03％

10.02％

10.20％

10.23％

Hot pressing extraction

3.88％

4.13％

4.25％

3.98％

4.06％

Enzymolysis extraction

7.41％

7.63％

7.98％

8.3％

7.83％

The amino acid composition of the extracted peptides was measured by examining examples 1 to 5 and comparative examples 1 to 2, respectively, and radar maps (see FIG. 3) were prepared for comparison, and the average values were obtained, and the amino acid contents were determined according to the method for measuring amino acids in foods of GB/T5009.124, as shown in Table 2.

TABLE 2 amino acid composition of fishbone peptide in different extraction processes

As can be seen from tables 1, 2 and 3, the fishbone peptide obtained by fermentation extraction has a higher content and a better flavor. Namely, the contents and the proportion of amino acids with delicate flavors (glutamic acid and aspartic acid) and amino acids with sweet flavors (glycine, proline, alanine, serine, threonine and the like) are superior to those of hot-pressing extraction and enzymolysis extraction, while the contents of the amino acids with bitter flavors (valine and isoleucine) in products prepared by enzymolysis extraction are higher. This conclusion is consistent with the conclusions of the sensory evaluation, see tables 3, 4. Meanwhile, the extraction rate and flavor of the fermentation extraction are superior to those of the enzymolysis extraction and hot-pressing extraction processes.

TABLE 3 sensory evaluation of fishbone peptide in different extraction processes

TABLE 4 organoleptic evaluation of fishbone peptides

Claims

1. A method for extracting fishbone peptide is characterized in that fishbone is used as a raw material, and bacillus subtilis is inoculated for fermentation and enzymolysis; the inoculation amount of the bacillus subtilis is 1 wt% -5 wt%, and the conditions of fermentation and enzymolysis are as follows: the fermentation time is more than 18h, and the fermentation temperature is 30-40 ℃.

2. The extraction process according to claim 1, wherein the amount of Bacillus subtilis is from 2% to 3% by weight.

3. The extraction method according to claim 1, further comprising a step of heating treatment comprising:

preparing fishbone into fishbone paste, adding the fishbone paste into a fermentation extraction tank, adding water and maltose respectively, adjusting the pH value to 6.5-7.5, stirring, heating to 95-105 ℃, and preserving heat.

4. The extraction method according to claim 3, further comprising the step of cooling to 30-40 ℃ and maintaining the temperature for 18-30 hours after the heating treatment.

5. The extraction method as claimed in any one of claims 1 to 4, further comprising the steps of inactivating the product obtained by fermentation and enzymolysis, separating, filtering, concentrating, and vacuum drying, wherein the filtration retains the filtrate with molecular weight of 1000-.

6. The extraction method according to claim 5, wherein the separation and filtration are carried out by using a vibrating screen, a horizontal spiral centrifuge or a ceramic membrane filter.

7. The extraction method according to claim 3, wherein the fermentation extraction tank is an enzymolysis fermentation extraction tank with a stirring paddle and a heating and cooling water cooling system.

8. A fishbone peptide produced by the method of any one of claims 1 to 7.

9. The fishbone peptide of claim 8, wherein the fishbone peptide has an umami amino acid content of 5.59 wt% and a sweet amino acid content of 19.24 wt%.

10. Use of the fishbone peptide of claim 8 in the preparation of a food, nutraceutical or pharmaceutical product.