Multi-strain insect protein and microalgae compounded bullfrog feed and preparation method thereof

Abstract

The invention belongs to the crossing field of cultivation and bioengineering, and particularly relates to a multi-strain insect protein and microalgae compounded bullfrog feed and a preparation method thereof, the multi-strain insect protein and microalgae compounded bullfrog feed comprises the following components: 25-45% of fermented insect protein, 15-30% of DHA microalgae powder, 10-20% of an auxiliary protein source, 0.5-2% of compound vitamin selected from fermented soybean meal or enzymolysis cottonseed protein, 0.5-2% of vitamin B, 0.5-2% of vitamin C, 0.5-2% of vitamin C, 0.5-2% of vitamin C, 0.5 1%-3% of composite mineral substances, 2%-5% of an adhesive and the balance of carbohydrate; the total DHA content of the bullfrog feed is larger than or equal to 1.5% by dry weight, the ratio of omega-3 fatty acid to omega-6 fatty acid is maintained to be 1: 1-1: 3, and the bullfrog feed has the advantages that saccharomyces cerevisiae is replaced with candida utilis, so that the capability of decomposing insect chitin is enhanced; chlorella is used for supplementing chlorophyll and algal polysaccharides to form a cell protection synergistic effect with schizochytrium limacinum, and DHA is supplemented at the same time; under the action of alkaline protease secreted by bacillus subtilis, the proportion of a beta-folding structure is reduced from 32% to 18%, and the digestibility is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the interdisciplinary field of breeding and bioengineering, and particularly relates to a bullfrog feed composited with multi-species insect protein and microalgae and a preparation method thereof. Background Art

[0002] The scale of global aquaculture is expanding rapidly. Bullfrog feed, as an important source of protein, has promoted the research and development of high-efficiency bullfrog feed. The core goal of bullfrog feed technology is to reduce dependence on limited resources and reduce environmental burden while ensuring the healthy growth of bullfrog feed. Its development is highly dependent on interdisciplinary innovation and industrial application.

[0003] As we all know, the growth rate and survival rate of bullfrog feed affect the breeding output of farmers, and these factors are closely related to the food of bullfrog feed. As the scale of bullfrog feed breeding gradually expands, high-quality bullfrog feed has also become the focus of people's research. Traditional bullfrog feed is mostly made by coarse mixing, or has a single ingredient and fewer nutrients.

[0004] Based on this, the present invention designs a bullfrog feed composited with multi-species insect protein and microalgae and a preparation method thereof to solve the above problems. Summary of the Invention

[0005] To achieve the above objectives, the present invention provides the following technical solution: a bullfrog feed composited with multi-species insect protein and microalgae, comprising the following components: 25%-45% fermented insect protein, 15%-30% DHA microalgae powder, 10%-20% auxiliary protein source selected from fermented soybean meal or enzymatically hydrolyzed cottonseed protein, 0.5%-2% complex vitamins, 1%-3% complex minerals, 2%-5% binder, and the balance being carbohydrates; the total DHA content of the bullfrog feed is ≥1.5% dry weight, and the ω-3 / ω-6 fatty acid ratio is maintained at 1:1-1:3.

[0006] Preferably, the DHA microalgae powder is selected from Schizochytrium, and has a DHA content of ≥15% by dry weight.

[0007] Preferably, the 25%-45% fermented insect protein is produced by composite fermentation of black soldier fly larvae with Bacillus subtilis, Lactobacillus plantarum and Saccharomyces cerevisiae, and has a crude protein content of ≥60%.

[0008] Preferably, the vitamin complex comprises vitamin C, vitamin E, and B vitamins, and the vitamin C content is not less than 2000 mg / kg.

[0009] Preferably, the adhesive is a mixture of sodium alginate and carboxymethyl cellulose in a ratio of 2:1-1:1.

[0010] Preferably, it further comprises 0.1%-0.5% of a prebiotic composition, wherein the prebiotic is a mixture of fructooligosaccharide and mannooligosaccharide in a ratio of 3:1.

[0011] Preferably, the preparation method of multi-strain fermented insect protein in bullfrog feed is characterized in that the method comprises the following steps: Step 1, raw material pretreatment: the black soldier fly larvae are steam sterilized (105-110°C, 15-20min) and then low-temperature dried (≤60°C) and crushed by a three-stage process (coarse crushing → fine grinding → ultrafine grinding) to a particle size of 80-120 mesh, and the powder moisture is controlled to be ≤8%; Step 2 composite strain expansion: Bacillus subtilis, Lactobacillus plantarum and Candida utilis are inoculated into a special culture medium respectively: Bacillus subtilis: containing 0.3%-0.8 LB medium with % chitin inducer, Lactobacillus plantarum: MRS medium with 2%-5% insect tissue hydrolysate; Candida utilis: YPD medium containing 1%-3% black soldier fly oil, cultured to the logarithmic growth phase (OD600=1.2-1.8), and then mixed in a ratio of 1:(0.6-1.0):(0.4-0.7); Step 3, solid-state staged fermentation: Inoculation stage: spray the composite bacterial solution with an inoculum amount of 6%-9% onto the raw material, and control the initial moisture content at 40%-45%; Aerobic stage: at 30-33℃, ventilation volume 0.3-0.6 Fermentation was performed under VVM conditions for 18-24 hours, with stirring every 6 hours. Anaerobic stage: the moisture content was adjusted to 35%-38%, and the fermentation was sealed for 36-48 hours, during which the pH was maintained at 5.5-6.5. Step 4, post-treatment: the fermentation product was pasteurized (70-75°C, 15s) and immediately cooled to 4°C. The undegraded chitin was separated using air flow classification technology (removal rate ≥ 90%), and then low-temperature spray drying (inlet air temperature ≤ 150°C) and fluidized bed granulation were combined to obtain the final product, multi-strain synergistic fermentation insect protein powder.

[0012] Preferably, the anaerobic fermentation stage in step 3 includes a dynamic pH control process: the first stage (0-12h): controlling the pH to drop naturally to 6.0±0.2 to promote acid production by lactic acid bacteria; the second stage (12-24h): maintaining the pH at 5.8-6.2 by automatically adding 5% sodium bicarbonate solution to induce Bacillus subtilis to secrete alkaline protease; the third stage (24-48h): allowing the pH to drop freely to below 5.5 to activate the chitinase activity of Candida utilis; wherein the temperature in each stage is synchronously adjusted as follows: the first stage: 30-32°C (promoting bacterial proliferation); the second stage: 28-30°C (stabilizing enzyme activity); the third stage: 33-35°C (accelerating substrate degradation).

[0013] In summary, the present application has the following beneficial technical effects: 1. Replacing Saccharomyces cerevisiae with Candida utilis enhances the ability to decompose insect chitin; 2. Chlorella supplements chlorophyll and algae polysaccharides, forming a synergistic cell protection effect with Schizochytrium, while also supplementing DHA; 3. Through the action of alkaline protease secreted by Bacillus subtilis, the proportion of β-folded structure is reduced from 32% to 18%, significantly improving the digestibility. DETAILED DESCRIPTION

[0014] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0015] A bullfrog feed composited with multi-strain insect protein and microalgae and a preparation method thereof comprises the following components: 25%-45% fermented insect protein, 15%-30% DHA microalgae powder, 10%-20% auxiliary protein source selected from fermented soybean meal or enzymatically hydrolyzed cottonseed protein, 0.5%-2% complex vitamins, 1%-3% complex minerals, 2%-5% adhesive, and the balance being carbohydrates; the total DHA content of the bullfrog feed is ≥1.5% dry weight, and the ω-3 / ω-6 fatty acid ratio is maintained at 1:1-1:3.

[0016] Preferably, the DHA microalgae powder is prepared by mixing Schizochytrium and Chlorella in a ratio of 3:1-5:1 and subjected to high-pressure homogenization and wall-breaking treatment, wherein: the DHA content is ≥18% dry weight, the total carotenoids are ≥1.2 mg / g, and the algal polysaccharide content is 8%-15%; Preferably, 25%-45% of the fermented insect protein is obtained by complex fermentation of black soldier fly larvae with Bacillus subtilis, Lactobacillus plantarum and Saccharomyces cerevisiae, with a crude protein content of ≥60%; Preferably, the vitamin complex comprises vitamin C, vitamin E, and B vitamins, and the vitamin C content is not less than 2000 mg / kg; Preferably, the complex minerals specifically include zinc protein chelate, selenium yeast and choline chloride; Preferably, the adhesive is a mixture of sodium alginate and carboxymethyl cellulose in a ratio of 2:1-1:1.

[0017] Preferably, it further comprises 0.1%-0.5% of a prebiotic composition, wherein the prebiotic is a mixture of fructooligosaccharide and mannooligosaccharide in a ratio of 3:1.

[0018] Preferably, the method for preparing multi-strain fermented insect protein in bullfrog feed is characterized in that the method comprises the following steps: Step 1, raw material pretreatment: black soldier fly larvae are steam sterilized (105-110°C, 15-20 min) and then low-temperature dried (≤60°C) and crushed by a three-stage process (coarse crushing → fine grinding → ultrafine crushing) to a particle size of 80-120 mesh, and the powder moisture is controlled to be ≤8%; Step 2: Expansion of composite bacterial strains: Bacillus subtilis, Lactobacillus plantarum, and Candida utilis are inoculated into dedicated culture media: Bacillus subtilis: LB medium containing 0.3%-0.8% chitin inducer; Lactobacillus plantarum: MRS medium supplemented with 2%-5% insect tissue hydrolysate; Candida utilis: YPD medium containing 1%-3% black soldier fly oil, cultured to the logarithmic growth phase (OD600 = 1.2-1.8), and then mixed in a ratio of 1: (0.6-1.0): (0.4-0.7); Step 3, solid-state staged fermentation: inoculation stage: spray the composite bacterial solution onto the raw material at an inoculum rate of 6%-9%, and control the initial moisture content at 40%-45%; aerobic stage: ferment for 18-24 hours at 30-33°C and a ventilation volume of 0.3-0.6 VVM, and stir once every 6 hours; anaerobic stage: adjust the moisture content to 35%-38%, seal and ferment for 36-48 hours, and maintain the pH value at 5.5-6.5 during this period; step 4, post-treatment: the fermentation product is pasteurized (70-75°C, 15s) and immediately cooled to 4°C. The undegraded chitin is separated by air flow classification technology (removal rate ≥90%), and then combined with low-temperature spray drying (inlet air temperature ≤150°C) and fluidized bed granulation to obtain the final product, multi-strain synergistic fermentation insect protein powder.

[0019] Preferably, the anaerobic fermentation stage in step 3 includes a dynamic pH control process: the first stage (0-12h): controlling the pH to drop naturally to 6.0±0.2 to promote acid production by lactic acid bacteria; the second stage (12-24h): maintaining the pH at 5.8-6.2 by automatically adding 5% sodium bicarbonate solution to induce Bacillus subtilis to secrete alkaline protease; the third stage (24-48h): allowing the pH to drop freely to below 5.5 to activate the chitinase activity of Candida utilis; wherein the temperature of each stage is synchronously adjusted as follows: the first stage: 30-32°C (promoting bacterial proliferation); the second stage: 28-30°C (stabilizing enzyme activity); the third stage: 33-35°C (accelerating substrate degradation).

[0020] In summary, the present application has the following beneficial technical effects: 1. Replacing Saccharomyces cerevisiae with Candida utilis enhances the ability to decompose insect chitin; 2. Chlorella supplements chlorophyll and algae polysaccharides, forming a synergistic cell protection effect with Schizochytrium, while also supplementing DHA; 3. Through the action of alkaline protease secreted by Bacillus subtilis, the proportion of β-folded structure is reduced from 32% to 18%, significantly improving the digestibility.

[0021] In the description of the present invention, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" and the like to indicate orientations or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0022] In the present invention, unless otherwise clearly stipulated and limited, the terms "install", "set", "connect", "fix", "screw" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0023] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A bullfrog feed composed of a combination of multi-species insect protein and microalgae, characterized by: The bullfrog feed comprises the following components: 25%-45% fermented insect protein, 15%-30% DHA microalgae powder, 10%-20% auxiliary protein source selected from fermented soybean meal or enzymatically hydrolyzed cottonseed protein, 0.5%-2% complex vitamins, 1%-3% complex minerals, 2%-5% adhesive, and the balance being carbohydrates; the total DHA content of the bullfrog feed is ≥1.5% of dry weight, and the ω-3 / ω-6 fatty acid ratio is maintained at 1:1-1:

3.

2. The bullfrog feed comprising a composite of multi-species insect protein and microalgae according to claim 1, characterized in that: DHA microalgae powder, selected from Schizochytrium sp., with a DHA content of ≥15% by dry weight.

3. The bullfrog feed comprising a composite of multi-species insect protein and microalgae according to claim 1, characterized in that: The 25%-45% fermented insect protein is prepared by composite fermentation of black soldier fly larvae with Bacillus subtilis, Lactobacillus plantarum and Saccharomyces cerevisiae, and the crude protein content is ≥60%.

4. The bullfrog feed comprising a composite of multi-species insect protein and microalgae according to claim 3, characterized in that: The conditions for the multi-strain solid-state fermentation are: total inoculation amount 5%-8%, fermentation temperature 28-35° C., humidity 60-75%, and fermentation time 48-72 hours.

5. The bullfrog feed comprising a composite of multi-species insect protein and microalgae according to claim 1, characterized in that: The vitamin complex comprises vitamin C, vitamin E, and B vitamins, and the vitamin C content is not less than 2000 mg / kg.

6. The bullfrog feed comprising a composite of multi-species insect protein and microalgae according to claim 1, characterized in that: The adhesive is prepared by compounding sodium alginate and carboxymethyl cellulose in a ratio of 2:1 to 1:

1.

7. The bullfrog feed comprising a composite of multi-species insect protein and microalgae according to claim 1, characterized in that: The invention also contains 0.1%-0.5% of a prebiotic composition, wherein the prebiotic is a mixture of fructooligosaccharide and mannooligosaccharide in a ratio of 3:

1.

8. The method for preparing the bullfrog feed according to claim 1, wherein: The method comprises the following steps: Step 1, raw material pretreatment: the black soldier fly larvae are steam sterilized (105-110 ℃, 15-20min) and then low-temperature dried (≤60 ℃) and a three-stage crushing process (coarse crushing → fine grinding → ultrafine crushing) is used to reduce the particle size to 80-120 mesh, and the powder moisture is controlled to be ≤8%; Step 2 composite bacterial culture expansion: Bacillus subtilis, Lactobacillus plantarum and Candida utilis are inoculated into special culture media respectively: Bacillus subtilis: LB culture medium containing 0.3%-0.8% chitin inducer; Lactobacillus plantarum: MRS culture medium supplemented with 2%-5% insect tissue hydrolyzate; Candida utilis: containing 1 The invention relates to a method for preparing a multi-strain synergistically fermented insect protein powder, comprising: culturing the raw material with YPD medium containing 6%-3% black soldier fly oil to the logarithmic growth phase (OD600=1.2-1.8) and then mixing the raw material in a ratio of 1:(0.6-1.0):(0.4-0.7); step 3, solid-state staged fermentation: inoculation stage: spraying the composite bacterial solution onto the raw material at an inoculum size of 6%-9%, controlling the initial moisture content to 40%-45%; aerobic stage: fermenting at 30-33° C. and a ventilation volume of 0.3-0.6 VVM for 18-24 hours, with stirring once every 6 hours; anaerobic stage: adjusting the moisture content to 35%-38%, sealing and fermenting for 36-48 hours, during which the pH value is maintained at 5.5-6.5; and step 4, post-treatment: the fermentation product is pasteurized (70-75° C., 15 seconds) and then immediately cooled to 4° C., using air flow classification technology to separate undegraded chitin, combined with low-temperature spray drying and fluidized bed granulation, to obtain the final product, multi-strain synergistically fermented insect protein powder.

9. The method for preparing multi-strain fermented insect protein in bullfrog feed according to claim 8, characterized in that: The anaerobic fermentation stage of step 3 includes a dynamic pH control process: the first stage (0-12 hours): controlling the pH to naturally drop to 6.0±0.2 to promote acid production by lactic acid bacteria; the second stage (12-24 hours): maintaining the pH at 5.8-6.2 by automatically adding 5% sodium bicarbonate solution to induce Bacillus subtilis to secrete alkaline protease; the third stage (24-48 hours): allowing the pH to freely drop to below 5.5 to activate the chitinase activity of Candida utilis; wherein the temperature of each stage is synchronously adjusted as follows: the first stage: 30-32°C; the second stage: 28-30°C; the third stage: 33-35°C.