Aquatic product phagostimulant based on yeast synergistic enzymolysis soybean meal and enzymolysis fish cream and preparation method of aquatic product phagostimulant

Abstract

The invention discloses an aquatic product phagostimulant based on yeast synergistic enzymolysis soybean meal and enzymolysis fish cream and a preparation method of the aquatic product phagostimulant. The preparation method comprises the following steps: mixing whole soybean meal with high-density yeast liquid, adding a compound enzyme preparation for constant-temperature enzymolysis, and drying after solid-liquid separation to obtain semi-finished soybean meal; adding compound protease into the anchovy fish paste for enzymolysis to obtain enzymolysis fish paste rich in small peptides; and uniformly mixing the two components according to a ratio, and drying at low temperature to obtain the aquatic product phagostimulant. The yeast synergistic enzymolysis and directional proteolysis process is adopted, so that the flavor synergistic effect and the nutritional quality of the product are remarkably improved, and the final product is high in crude protein content, excellent in digestibility, rich in active substances such as flavor nucleotides, small peptides and free amino acids, excellent in food calling effect on aquatic animals and high in quality. The traditional phagostimulant can be replaced, and the feeding enthusiasm is improved.

Description

Technical Field

[0001] This invention relates to the field of aquatic feed attractant technology, and in particular to an aquatic feed attractant based on yeast synergistic enzymatic hydrolysis of soybean meal and enzymatic hydrolysis of fish paste, and its preparation method. Background Technology

[0002] Fishmeal, as a core protein source in aquatic feed, is facing severe challenges due to increasingly scarce resources and persistently high prices. Therefore, developing efficient fishmeal alternatives has become a key issue for the industry. Soybean meal, as a common plant protein source, is a potential fishmeal substitute. Currently, microbial fermentation or enzymatic hydrolysis of soybean meal to enhance its nutritional value is a commonly used technique in this field. However, existing processing technologies generally have the following limitations: First, the degradation of nutrient factors is often insufficient, resulting in the product's protein digestibility and absorption rate not reaching optimal levels; second, the processed soybean meal product is significantly lacking in palatability, lacking the delicious flavor favored by aquatic animals, making it difficult to maintain feed appeal when replacing large quantities of fishmeal; finally, its flavor compounds are relatively simple and cannot compare with the complex flavor of fishmeal. The root of these problems lies in the fact that existing technical solutions mostly focus on processing single raw materials, failing to effectively integrate the advantages of plant and animal protein resources to achieve synergistic effects in nutrition and flavor. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing an aquatic attractant based on yeast synergistic enzymatic hydrolysis of soybean meal and enzymatic hydrolysis of fish paste, and its preparation method.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect is to provide a method for preparing an aquatic attractant based on yeast-co-enzymatic hydrolysis of soybean meal and enzymatic hydrolysis of fish paste, comprising the following steps: Step 1, yeast-assisted enzymatic hydrolysis of soybean meal: Whole, uncrushed soybean meal raw material is mixed with high-density yeast liquid at a mass ratio of 1:(3-4), and a compound enzyme preparation is added at the same time. The compound enzyme preparation includes protease, cellulase and pectinase. The enzymatic hydrolysis reaction is carried out at 34-36℃ for 12-36 hours. After the reaction, solid-liquid separation is carried out, the solid enzymatic hydrolysate is collected and dried until the moisture content is ≤6% to obtain semi-finished soybean meal. Step 2, Enzymatic hydrolysis of fish paste: Grind the whole anchovy into a paste to obtain fish paste, add a complex protease to the fish paste, and enzymatically hydrolyze at 50℃-55℃ for 2-4 hours to obtain enzymatically hydrolyzed fish paste. The mass content of small peptides in the enzymatically hydrolyzed fish paste accounts for ≥70% of the crude protein mass. Step 3, Mixing and post-processing: Mix the semi-finished soybean meal and the enzymatically hydrolyzed fish paste at a mass ratio of 1:(2-2.5) evenly, and then dry them until the moisture content is 6%-7% to obtain the aquatic attractant.

[0005] Furthermore, the semi-finished soybean meal obtained in step one has a crude protein content of ≥60% and a small peptide content accounting for ≥15% of the crude protein content.

[0006] Furthermore, in the compound enzyme preparation described in step one, the percentage of each enzyme component in the total system mass and the enzyme activity are as follows: protease 3%~5%, enzyme activity 100,000 U / g; cellulase 1%~2%, enzyme activity 6,000 U / g; pectinase 0.5%~1%, enzyme activity 10,000 U / g.

[0007] Furthermore, in step one, the viable yeast count of the high-density yeast solution is 1×10⁹ CFU / mL to 9×10⁹ CFU / mL.

[0008] Furthermore, in the complex protease described in step two, the percentage of each enzyme component in the total mass of the fish paste and their enzyme activities are as follows: alkaline protease 1%~2%, enzyme activity 100,000 U / g; aminopeptidase 0.5%~1%, enzyme activity 100,000 U / g.

[0009] Furthermore, in both steps one and three, the drying process is carried out at 50℃-60℃.

[0010] The second aspect is to provide an aquatic feeding attractant, which is prepared by the above-mentioned preparation method, and the physicochemical indicators of the aquatic feeding attractant are: crude protein ≥61%, fat ≥5%, and moisture content 6%-7%.

[0011] The present invention adopts the above technical solution and has the following technical effects compared with the prior art: The core of this invention lies in the synergistic combination of "high-density yeast-fermented soybean meal" and "enzymatically hydrolyzed fish paste," achieving complementary and synergistic flavors. Yeast-fermented soybean meal generates abundant flavor-enhancing substances such as nucleotides and alcohols, while enzymatically hydrolyzed fish paste is rich in umami components such as small peptides and free amino acids. When mixed in a specific ratio, they produce a strong synergistic flavor effect. Feeding behavior tests directly confirm that this product can not only completely replace traditional high-efficiency attractants (such as squid paste), but also synergize with them, greatly enhancing shrimp feeding activity.

[0012] This invention employs a liquid-state deep enzymatic hydrolysis process using a "yeast-co-enzyme complex" for soybean meal. In the presence of yeast, the complex enzymes (protease, cellulase, and pectinase) more effectively disrupt plant cell walls and degrade soybean protein and anti-nutritional factors. Simultaneously, fish paste undergoes targeted enzymatic hydrolysis, breaking down large protein molecules into smaller peptides. Test data shows that the final product achieves a protein digestibility of 95%-97%, with a significant reduction in the content of anti-nutritional factors such as trypsin inhibitors, ensuring efficient utilization of nutrients.

[0013] This invention comprehensively enhances the nutritional value of the product through process design. Soybean meal, after enzymatic hydrolysis, is pressure-filtered and dried, enriching it with protein and yeast metabolites, resulting in a crude protein content of over 60% in the semi-finished product. This is then combined with enzymatically hydrolyzed fish paste, which is high in protein and small peptides, resulting in a finished product with a crude protein content exceeding 62%, a fat content of approximately 5.4%-5.6%, and rich in active small peptides and yeast cells. Its amino acid profile is more balanced, and its nutritional value is comparable to or even superior to ordinary fishmeal.

[0014] Throughout the entire process, this invention consistently employs low-temperature drying technology. This gentle treatment condition can prevent the denaturation or loss of heat-sensitive flavor substances and nutrients such as flavor nucleotides, small peptides, and free amino acids to the greatest extent possible, thereby fully preserving the product's natural palatability and nutritional functions. This is also one of the key guarantees for its excellent palatability. Detailed Implementation

[0015] The present invention will be further described below with reference to specific embodiments, but these are not intended to limit the invention. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other.

[0016] Example 1 This embodiment provides an aquatic attractant based on yeast-co-enzymatic hydrolysis of soybean meal and enzymatic hydrolysis of fish paste, and its preparation method, specifically including: (1) Enzymatic hydrolysis of soybean meal: Take 100 kg of whole soybean meal and 300 kg of high-density brewer's yeast solution (live count 2.3 × 10⁻⁶). 9 The CFU / mL protein and compound enzyme preparation were mixed in a reaction vessel, with protease added at 5% of the total system mass (enzyme activity 100,000 U / g), cellulase at 2% (enzyme activity 6,000 U / g), and pectinase at 1% (enzyme activity 10,000 U / g). Enzymatic hydrolysis was carried out at 35℃ with stirring for 18 hours. After pressure filtration, the mixture was dried at 55℃ to a moisture content of 6%, yielding 70 kg of semi-finished soybean meal. Analysis showed that the crude protein content was 60.5% (according to GB / T 6432-2018), and the small peptide content accounted for 16.5% of the crude protein content (according to GB / T 22492-2008).

[0017] (2) Enzymatic hydrolysis of fish paste: 140 kg of anchovy fish paste was taken and enzymatically hydrolyzed with a complex protease. The amount of alkaline protease added was 1.5% of the total mass of fish paste (enzyme activity 100,000 U / g), and the amount of aminopeptidase added was 1% (enzyme activity 100,000 U / g). Enzymatic hydrolysis was carried out at 53℃ for 3 hours to obtain enzymatically hydrolyzed fish paste. The content of small peptides in the enzymatically hydrolyzed fish paste was measured to be 78% of the crude protein mass (according to GB / T 22492-2008).

[0018] (3) Mixing and drying: Mix 70kg of the above semi-finished soybean meal with 140kg of the above enzymatically hydrolyzed fish paste evenly, and dry at 55℃ until the moisture content is 6.5% to obtain approximately 114kg of finished product.

[0019] The main nutritional components and antigen-related indicators of the above-prepared product were tested, and the results are as follows: 1) Main nutritional components: crude protein 62.8% (GB / T 6432-2018), fat 5.4% (GB / T 6433-2006), moisture 6.5% (GB / T 6435-2014).

[0020] 2) Antigen-related indicators: Protein digestibility (GB / T 17811-2008): 95% Trypsin inhibitor (ELISA kit, Longke New Domain): content 0.31 mg / g.

[0021] Soy globulin (ELISA, kit provided by Longke New Domain): content 0.51 mg / g.

[0022] Total nucleotide content (GB / T 20886.2-2021): 5300ppm.

[0023] Example 2 This embodiment provides an aquatic attractant based on yeast-co-enzymatic hydrolysis of soybean meal and enzymatic hydrolysis of fish paste, and its preparation method, specifically including: (1) Enzymatic hydrolysis of soybean meal: Take 100 kg of whole soybean meal (same batch as in Example 1) and mix it with 300 kg of high-density brewer's yeast solution (live count 3.4 × 10⁻⁶). 9The CFU / mL enzyme and compound enzyme preparation were mixed in a reaction vessel, with protease added at 3.2% of the total system mass (enzyme activity 100,000 U / g), cellulase at 1% (enzyme activity 6,000 U / g), and pectinase at 1% (enzyme activity 10,000 U / g). Enzymatic hydrolysis was carried out at 35℃ with stirring for 24 hours. After pressure filtration, the mixture was dried at 55℃ to a moisture content of 6%, yielding approximately 72 kg of semi-finished soybean meal. Analysis showed that the crude protein content was 60.3% (according to GB / T 6432-2018), and the small peptide content accounted for 15.8% of the crude protein content (according to GB / T 22492-2008).

[0024] (2) Enzymatic hydrolysis of fish paste: 144 kg of anchovy fish paste was taken and enzymatically hydrolyzed with a complex protease. The amount of alkaline protease added was 1.5% of the total mass of fish paste (enzyme activity 100,000 U / g), and the amount of aminopeptidase added was 0.5% (enzyme activity 100,000 U / g). Enzymatic hydrolysis was carried out at 55℃ for 2 hours to obtain enzymatically hydrolyzed fish paste. The content of small peptides in the enzymatically hydrolyzed fish paste was measured to be 73% of the crude protein mass (according to GB / T 22492-2008).

[0025] (3) Mixing and drying: Mix 72kg of the above semi-finished soybean meal with 144kg of the above enzymatically hydrolyzed fish paste evenly, and dry at 55℃ until the moisture content is 6.2% to obtain about 115kg of finished product.

[0026] The main nutritional components and antigen-related indicators of the above-prepared product were tested, and the results are as follows: 1) Main nutritional components: crude protein 62.9%, fat 5.6%, moisture 6.2%.

[0027] 2) Antigen-related indicators: Protein digestibility: 97% Trypsin inhibitor: content is 0.24 mg / g.

[0028] Soy globulin: content is 0.46 mg / g.

[0029] Total nucleotide content: 6200ppm.

[0030] Note: The detection methods involved are all the same as those in Example 1.

[0031] Application examples This application example aims to verify the effectiveness of the aquatic attractant (Examples 1 and 2) prepared according to this invention in actual shrimp feed formulations. The core objective of the experiment is to evaluate the attractant: 1) Substitution value: Can it directly replace expensive imported fish meal or squid paste in feed and maintain or even improve the palatability?

[0032] 2) Synergistic effect: Whether it can produce a synergistic effect when used in combination with traditional food-attracting substances (such as squid paste).

[0033] 3) Performance Boundaries: Whether adding at high proportions will have a negative impact on ingestion, in order to determine its safe application range.

[0034] Therefore, five feed groups were designed to form a complete control system, as shown in Table 1 below: Table 1

[0035] The control group consisted of a basic feed containing no palatability enhancer of this invention. The direct fishmeal replacement group used 5% palatability enhancer to replace 5% of domestic fishmeal, testing its palatability as a direct substitute for protein raw materials. The complete squid paste replacement group used 5% palatability enhancer to completely replace 3% of squid paste (with minor formula adjustments), testing its ability as a core palatability enhancer ingredient.

[0036] In the extreme experiment group, 12% of a high-dose palatability enhancer was added, completely replacing chicken powder and squid paste, to test the high-proportion application potential and safety. In the 50% squid paste replacement group, 5% of the squid paste (1.5%) was replaced with 5% palatability enhancer to test the synergistic effect of the two.

[0037] Select healthy, uniformly sized whiteleg shrimp ( Litopenaeus vannamei Several juvenile shrimp were randomly divided into 5 groups, with 3 replicates per group, and housed in an indoor recirculating aquaculture system. Five isonitrogenous and isolithic experimental diets were prepared according to the formula in the table above. After one week of acclimatization, a formal feeding experiment was conducted. Feed was withheld for 12 hours before the experiment. A maze feeding behavior observation system was used. After adding an equal amount of feed at a fixed feeding point, the total frequency of shrimp entering the maze feeding area within 30 minutes was recorded, with 10-minute intervals. This indicator can sensitively reflect the initial feeding attraction of the feed and the shrimp's feeding enthusiasm.

[0038] The experimental results are shown in Table 2 below: Table 2

[0039] As can be seen, the feeding frequency of the direct fishmeal replacement group and the complete squid paste replacement group was significantly higher than that of the control group. This proves that the attractant of the present invention can not only directly replace part of the fishmeal, but also completely replace squid paste, a traditional high-efficiency attractant, and the attractant effect is better than that of the basal feed. This is mainly due to the attractant substances such as small peptides, nucleotides and yeast metabolites rich in the product.

[0040] The group using 50% squid paste showed the most outstanding feeding frequency, far exceeding the control group and significantly higher than the group using only the attractant and the basic formula using only squid paste. This clearly reveals the synergistic feeding effect between the attractant and squid paste of this invention. When used in combination, they may complement or cascade through complementary signaling pathways of different attractant components, greatly stimulating the feeding behavior of shrimp.

[0041] The feeding frequency in the extreme experiment group was slightly lower than that in the control group, indicating that there may be flavor or component balance issues when all animal protein by-products are completely replaced and added at an ultra-high dose (12%), suggesting that such a high addition amount is not necessary for regular application.

[0042] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the content of the present invention specification should be included within the protection scope of the present invention.

Claims

1. A preparation method of an aquatic phagostimulant based on yeast synergistic enzymatic hydrolysis of soybean meal and enzymatic hydrolysis of fish paste, characterized by, It comprises the following steps: Step one, yeast and enzyme assisted treatment of soybean meal: mix whole soybean meal with high-density yeast solution at a mass ratio of 1:(3-4), and add a compound enzyme preparation including protease, cellulase and pectinase; carry out constant temperature enzymolysis reaction at 34-36℃ for 12-36 hours; after the reaction, carry out solid-liquid separation, collect the solid enzymolysis product and dry it to a moisture content of ≤6% to obtain semi-finished soybean meal; Step two, enzymatic treatment of fish paste: grind whole anchovy to obtain fish paste, add compound protease to the fish paste, and carry out enzymolysis at 50-55℃ for 2-4 hours to obtain enzymolysis fish paste, wherein the mass content of small peptides in the enzymolysis fish paste accounts for ≥70% of the mass percentage of crude protein; Step three, mixing and post-treatment: mix the semi-finished soybean meal with the enzymolysis fish paste at a mass ratio of 1:(2-2.5) and dry them to a moisture content of 6-7% to obtain the aquatic attractant.

2. The production method according to claim 1, characterized by, The semi-finished soybean meal obtained in step one has a crude protein mass content of ≥60% and a small peptide mass content accounting for ≥15% of the mass percentage of crude protein.

3. The preparation method according to claim 1, characterized in that, In the compound enzyme preparation in step one, the mass percentage of each enzyme component in the total system and the enzyme activity are as follows: protease 3%-5%, enzyme activity 100,000 U / g; cellulase 1%-2%, enzyme activity 6,000 U / g; pectinase 0.5%-1%, enzyme activity 10,000 U / g.

4. The method of claim 1, wherein, In step one, the viable yeast cell count of the high-density yeast cell solution is 1 x 10 9 CFU / mL-9 x 10 9 CFU / mL.

5. The preparation method according to claim 1, characterized in that, In the compound protease in step two, the mass percentage of each enzyme component in the total fish paste and the enzyme activity are as follows: alkaline protease 1%-2%, enzyme activity 100,000 U / g; aminopeptidase 0.5%-1%, enzyme activity 100,000 U / g.

6. The method of claim 1, wherein, In step one and step three, the drying is carried out at 50-60℃.

7. An aquaculture phagostimulant, comprising, It is prepared by the preparation method of any one of claims 1-6, and the aquatic attractant has the following physicochemical indexes: crude protein ≥61%, fat ≥5%, and moisture content 6-7%. It is prepared by the preparation method of any one of claims 1-6, and the aquatic attractant has the following physicochemical indexes: crude protein ≥61%, fat ≥5%, and moisture content 6-7%.

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