Preparation method of black soldier fly water-soluble protein powder and application thereof

Abstract

The application provides a preparation method of Hermetia illucens water-soluble protein powder and application thereof in egg chicken production, and relates to the technical field of insect protein processing. The method provided by the application is to directly beat and defat the live fresh Hermetia illucens, reduces the drying cost, reasonably matches the components and weight ratio of the composite enzyme preparation and the composite fermentation bacterial liquid, adopts the enzyme hydrolysis-fermentation technology to obtain the Hermetia illucens water-soluble protein powder, significantly improves the content of functional polypeptide after degradation of insect protein and unknown growth factor, reduces the pH of the product, and maximizes the economic value of the Hermetia illucens larvae. The Hermetia illucens water-soluble protein powder provided by the application can significantly improve the production performance and egg quality of egg chickens in egg chicken breeding.

Description

Technical Field

[0001] This invention relates to the field of insect protein processing technology, specifically to a method for preparing water-soluble protein powder from black soldier fly larvae and its application in laying hen production. Background Technology

[0002] Black soldier flies, belonging to the order Diptera and family Bandidae, have become a research hotspot in the field of insect resources in recent years. With the widespread promotion of the resource-based treatment of kitchen waste and livestock manure using black soldier fly larvae, the application technology of black soldier fly larvae as feed has also received significant attention and research.

[0003] Currently, black soldier fly larvae are mainly processed using microwave drying. Numerous studies have reported on the application of microwave-dried black soldier fly larvae powder as a protein substitute in animal husbandry. However, the high cost of microwave drying (2000-3000 yuan / ton) severely limits the application of black soldier fly larvae in livestock production. The current production volume of black soldier fly larvae powder is very small, and its application as a protein source cannot meet market demand. Utilizing modern bioengineering technology to extract new substances from insects and create new products is an efficient, safe, and sustainable way to utilize insect animal resources, and is an important guarantee for promoting environmental protection, healthy animal husbandry development, and food safety. Currently, enzymatic hydrolysis is commonly used to produce peptide powder in actual production. For example, CN107012193A discloses a method for preparing tryptone using black soldier fly larvae, which uses trypsin to enzymatically hydrolyze black soldier fly larvae powder; CN117070274A discloses a method for preparing oil using black soldier fly larvae, which also uses a mixture of neutral protease, lipase, and bromelain to enzymatically hydrolyze black soldier fly larvae slurry. However, the enzymatic hydrolysates obtained above often have a distinct bitter taste and suffer from problems such as incomplete hydrolysis, low protein content, and low nutritional value.

[0004] By utilizing beneficial microorganisms such as beneficial bacteria, black soldier fly larvae raw materials have been processed to produce active peptides with the synergistic effect of multiple enzymes. This not only improves enzymatic hydrolysis efficiency but also effectively reduces the bitterness of products derived from simple enzymatic hydrolysis. Currently, there is no method that combines enzymatic hydrolysis and microbial fermentation to process black soldier fly larvae to obtain protein powder with high protein and high peptide content. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a method for preparing water-soluble protein powder from black soldier fly larvae and its application in egg production. This invention directly pulps and defatts live black soldier fly larvae, reducing drying costs. Then, it employs a pre-enzymatic hydrolysis followed by fermentation technology to degrade the larval protein into various functional peptides and unknown growth factors, maximizing the economic value of the black soldier fly larvae. Furthermore, the efficacy of the water-soluble protein powder in egg production is evaluated, aiming to improve egg production performance and egg quality.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A method for preparing water-soluble protein powder from black soldier fly larvae, the method comprising the following steps:

[0010] (1) Rinse the live black soldier fly larvae with running water to remove impurities from the surface of the larvae;

[0011] (2) The cleaned black soldier fly larvae were steamed in water at 80-90℃ for 30 minutes, then homogenized and dehydrated by centrifuge for 15-20 minutes to obtain black soldier fly larvae solid concentrate.

[0012] (3) Add 3-5L of defatting solvent to the dehydrated black soldier fly solid concentrate and defatt it 3-5 times to remove crude fat from the concentrate.

[0013] (4) Use a centrifuge to remove the defatting solvent and recover the oil to obtain defatted black soldier fly larvae solids and oil;

[0014] (5) The defatted black soldier fly larvae solids were mixed with 4-5L of water per kilogram, and a compound enzyme preparation was added at 3-5% of the weight of the solids. The enzymatic hydrolysis reaction was carried out at a temperature of 40-50℃ for 4-5 hours to obtain the enzymatic hydrolysis product.

[0015] (6) After the enzymatic hydrolysis reaction is completed, add 3-4% glucose and 20-30% compound fermentation liquid according to the liquid volume of the fermentation product, carry out the fermentation reaction, the fermentation temperature is 35-37℃, the fermentation time is 20-24h, and after the fermentation is completed, sterilize at 85-90℃ for 10-15 minutes to obtain the enzymatic hydrolysis fermentation product.

[0016] (7) After centrifuging the above-mentioned enzymatic fermentation products, collect the supernatant and spray dry it to obtain black soldier fly water-soluble protein powder.

[0017] Specifically, in step (3), the degreasing solvent is one of n-hexane, petroleum ether, and ethanol.

[0018] Specifically, in step (5), the complex enzyme preparation is one or more of neutral protease, trypsin, alkaline protease, flavor protease, papain, and acidic protease.

[0019] Specifically, in step (5), the compound enzyme preparation is an alkaline protease and a flavor protease in a mass ratio of 1-3:1-2.

[0020] Specifically, in step (5), the compound enzyme preparation is an alkaline protease and a flavor protease in a mass ratio of 1:1.

[0021] Specifically, in step (5), the amount of the compound enzyme preparation added is 3-5% of the weight of the solids.

[0022] Specifically, in step (6), the compound fermentation liquid is composed of Lactobacillus plantarum seed liquid, Bacillus subtilis seed liquid, and Saccharomyces cerevisiae seed liquid in a volume ratio of 4-8:2-4:1-2.

[0023] Specifically, in step (6), the compound fermentation liquid is composed of Lactobacillus plantarum seed liquid, Bacillus subtilis seed liquid, and Saccharomyces cerevisiae seed liquid in a volume ratio of 4:2:1.

[0024] Specifically, in step (6), the amount of the compound fermentation liquid added is 15-20% of the liquid volume of the fermentation product.

[0025] The black soldier fly water-soluble protein powder prepared using the method of this invention is used to prepare functional feed ingredients for laying hens.

[0026] (III) Beneficial Effects

[0027] This invention provides a method for preparing water-soluble protein powder from black soldier fly larvae and its application in laying hen production, which has the following advantages:

[0028] 1. This invention directly pulps and defatts live black soldier fly larvae, reducing drying costs. It also rationally proportions the components and weight ratios of the compound enzyme preparation and compound fermentation liquid, and uses a pre-enzymatic hydrolysis followed by fermentation technology to obtain water-soluble black soldier fly protein powder. Compared with conventional enzymatic hydrolysis, this method significantly increases the content of functional peptides and unknown growth factors after the degradation of insect protein, and lowers the pH of the product, thereby maximizing the economic value of black soldier fly larvae.

[0029] 2. The present invention provides black soldier fly water-soluble protein powder that can significantly improve the production performance and egg quality of laying hens in egg-laying hen farming. Adding black soldier fly water-soluble protein powder to the diet of laying hens in the later stage can improve eggshell thickness and eggshell strength, thereby reducing the proportion of broken eggs and increasing the laying rate. It can effectively solve the problem of declining eggshell quality and egg quality in the later stage of laying hens in large-scale chicken farms. Attached Figure Description

[0030] Figure 1 Black soldier fly water-soluble protein powder DPPH free radical scavenging activity.

[0031] Figure 2 Effects of different proteases on the degree of hydrolysis of solids and peptide yield in black soldier fly larvae.

[0032] Figure 3 The effects of different types of compound enzyme preparations on the degree of hydrolysis of solids and peptide yield of black soldier fly larvae were investigated.

[0033] Figure 4 The effect of different weight ratios of alkaline protease and flavor protease on the degree of hydrolysis and peptide yield of solids from black soldier fly larvae.

[0034] Figure 5 The effect of different compound fermentation bacterial solutions on pH after treatment with black soldier fly larvae solids.

[0035] Figure 6 The effect of different compound fermentation bacterial solutions on the yield of peptides after treatment with black soldier fly larvae solids.

[0036] Figure 7 The effects of two different preparation methods, Example 2 and Comparative Example 1, on the pH and peptide yield of enzymatic hydrolysis or enzymatic fermentation broth. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Example 1

[0039] 1. Preparation of Lactobacillus plantarum seed culture:

[0040] A small amount of frozen Lactobacillus plantarum strain was inoculated onto sterilized MRS agar medium and incubated at 37°C for 24 hours to activate the strain. Then, the activated strain was inoculated into sterilized MRS broth medium and placed in a constant temperature shaker at 37°C and 160 r / min for 4–6 hours to prepare a seed culture.

[0041] 2. Preparation of Bacillus subtilis seed culture:

[0042] A small amount of frozen Bacillus subtilis culture was inoculated onto sterilized nutrient agar medium and incubated at 30°C for 24 hours to activate the culture. The activated culture was then inoculated into sterilized nutrient broth medium and placed in a constant temperature shaker at 30°C and 160 r / min for 12 hours to prepare the seed culture.

[0043] 3. Preparation of Saccharomyces cerevisiae seed culture:

[0044] A small amount of frozen Saccharomyces cerevisiae was inoculated onto sterilized YPD medium and incubated at 28°C for 48 hours to activate the strain. The activated strain was then inoculated onto sterilized YPD medium (excluding agar) and placed in a constant temperature shaker at 28°C and 160 r / min for 18 hours to prepare the seed culture.

[0045] The specific composition of the culture medium involved is as follows:

[0046] MRS medium: 10.0g peptone, 10.0g beef extract, 4.0g yeast extract, 20.0g glucose, 0.2g magnesium sulfate, 5.0g sodium acetate, 2.0g triammonium citrate, 2.0g dipotassium hydrogen phosphate, 0.04g manganese sulfate, 1.0g Tween 80, 20.0g agar (not included in liquid medium), 1.0L distilled water; pH 5.7±0.2, sterilized at 121℃ for 20min.

[0047] Nutrient agar medium: 3.0g beef extract, 10.0g peptone, 5.0g NaCl, 20.0g agar (not included in liquid medium), 1.0L distilled water, pH 7.0. Sterilize at 121℃ for 20min.

[0048] YPD medium: 10g yeast extract, 20.0g glucose, 20.0g peptone, 20.0g agar (not included in liquid medium), 1.0L distilled water, pH: 6.2±0.2, sterilized at 121℃ for 20min.

[0049] Example 2

[0050] A water-soluble protein powder from black soldier fly larvae is prepared according to the following steps:

[0051] (1) Rinse the live black soldier fly larvae with running water to remove impurities from the surface of the larvae;

[0052] (2) The cleaned black soldier fly larvae were steamed in water at 80-90℃ for 30 minutes, then homogenized and dehydrated by centrifuge for 15-20 minutes to obtain black soldier fly larvae solid concentrate.

[0053] (3) Add hexane to the dehydrated black soldier fly solid concentrate at a ratio of 1:3, heat to 50°C, heat for 2 hours, filter the filtrate, and repeat the above operation on the solid concentrate to remove crude fat from the concentrate by defatting 3-5 times.

[0054] (4) Use a centrifuge to remove the defatting solvent and recover the oil to obtain defatted black soldier fly larvae solids and oil;

[0055] (5) The defatted black soldier fly larvae solids are mixed with water at a ratio of 1:4-5 (Kg / L), and a compound enzyme preparation is added at 3% of the weight of the solids. The enzymatic hydrolysis reaction is carried out at a temperature of 50℃ and a time of 4-5h. The enzymatic hydrolysis product is obtained. The compound enzyme preparation is an alkaline protease and a flavor protease in a mass ratio of 1:1.

[0056] (6) After the enzymatic hydrolysis reaction is completed, add 3-4% glucose and 20% compound fermentation liquid according to the liquid volume of the fermentation product, and carry out the fermentation reaction. The fermentation temperature is 35-37℃ and the fermentation time is 20-24h. After the fermentation is completed, sterilize at 85℃ for 10 minutes to obtain the enzymatic hydrolysis fermentation product. The compound fermentation liquid is composed of Lactobacillus plantarum seed liquid, Bacillus subtilis seed liquid and Saccharomyces cerevisiae seed liquid in a volume ratio of 4:2:1.

[0057] (7) After centrifuging the above-mentioned enzymatic fermentation products, collect the supernatant and spray dry it to obtain black soldier fly water-soluble protein powder.

[0058] The amino acid composition of the black soldier fly water-soluble protein powder prepared by the above method is shown in Table 1.

[0059] Table 1. Amino acid composition of black soldier fly water-soluble protein powder

[0060]

[0061]

[0062] Tests have shown that black soldier fly water-soluble protein powder contains a relatively high amount of aspartic acid, glutamic acid, and histidine, which have a significant impact on the bioactivity of polypeptides.

[0063] We determined the in vitro antioxidant activity of the black soldier fly water-soluble protein powder prepared by the above method. The test results are as follows: Figure 1 As shown, the results indicate that the DPPH free radical scavenging rate gradually increases with the increase of the concentration of black soldier fly water-soluble protein powder. When the concentration reaches 8 mg / mL, the scavenging rate is 86.7%. The black soldier fly water-soluble protein prepared by this invention has good antioxidant effect.

[0064] Comparative Example 1

[0065] A water-soluble protein powder from black soldier fly larvae is prepared according to the following steps:

[0066] (1) Rinse the live black soldier fly larvae with running water to remove impurities from the surface of the larvae;

[0067] (2) The cleaned black soldier fly larvae were steamed in water at 80-90℃ for 30 minutes, then homogenized and dehydrated by centrifuge for 15-20 minutes to obtain black soldier fly larvae solid concentrate.

[0068] (3) Add hexane to the dehydrated black soldier fly solid concentrate at a ratio of 1:3, heat to 50°C, heat for 2 hours, filter the filtrate, and repeat the above operation on the solid concentrate to remove crude fat from the concentrate by defatting 3-5 times.

[0069] (4) Use a centrifuge to remove the defatting solvent and recover the oil to obtain defatted black soldier fly larvae solids and oil;

[0070] (5) The defatted black soldier fly larvae solids are mixed with water at a ratio of 1:4-5 (Kg / L), and a compound enzyme preparation is added at 3% of the weight of the solids. The enzymatic hydrolysis reaction is carried out at a temperature of 50℃ and a time of 4-5h. The enzymatic hydrolysis product is obtained. The compound enzyme preparation is an alkaline protease and a flavor protease in a mass ratio of 1:1.

[0071] (6) After centrifuging the above enzymatic hydrolysis products, collect the supernatant and spray dry it to obtain black soldier fly water-soluble protein powder.

[0072] Experimental Example 1

[0073] Effects of different proteases and compound enzyme preparations on the degree of hydrolysis and peptide yield of black soldier fly larvae solids after treatment

[0074] This experiment used six proteases—neutral protease, trypsin, alkaline protease, flavor protease, papain, and acidic protease—to enzymatically hydrolyze the solids of black soldier fly larvae. The hydrolysis conditions were: a feed-to-water ratio of 1:4-5, a temperature of 50℃, a time of 5 hours, natural pH, and a protease addition of 3%. After hydrolysis, the enzymes were inactivated at 80-90℃ for 10 minutes. The degree of hydrolysis and peptide yield of the hydrolysate were measured, and the results are as follows: Figure 2 As shown. From Figure 2 The results showed that trypsin, alkaline protease, and flavor protease had higher degrees of hydrolysis than neutral protease, papain, and acidic protease. Among them, alkaline protease had the highest degree of hydrolysis at 33.52%, followed by flavor protease at 33.22%. The alkaline protease group had the highest peptide yield after hydrolysis at 27.10%, which was significantly higher than other proteases. Combining the two indicators of degree of hydrolysis and peptide content, alkaline protease was the optimal protease preparation for the method of this invention.

[0075] Experimental Example 2

[0076] Based on the experimental results of Example 1, this invention further investigates the effects of the compound enzyme preparation on the degree of hydrolysis and peptide yield of black soldier fly larvae solids after treatment.

[0077] Different compositions and ratios of compound enzyme preparations were used to perform enzymatic hydrolysis of black soldier fly larvae solids, and the degree of hydrolysis and peptide yield of the hydrolysis products were determined. The compositions of the different compound enzyme preparations are shown in Table 1. The effects of different compound enzyme preparations on the degree of hydrolysis and peptide yield are shown in the table below. Figure 3 , Figure 4 As shown.

[0078] We first investigated the effects of different compound enzyme preparations on the degree of hydrolysis and peptide yield of black soldier fly larvae solids. In this experiment, alkaline protease was mixed with neutral protease, trypsin, flavor protease, papain, and acidic protease at a mass ratio of 1:1 as the enzymatic hydrolysis compound enzyme. Enzyme preparations 1-5 were added at 3% of the weight of the black soldier fly larvae solids, respectively. Enzymatic hydrolysis was carried out at 50℃ for 5 hours, followed by enzyme inactivation at 80-90℃ for 10 minutes after hydrolysis. The degree of hydrolysis and peptide yield of the hydrolysate were then measured. The results of the effects of different compound enzyme preparations 1-5 on the degree of hydrolysis and peptide yield of black soldier fly larvae solids are shown below. Figure 3 As shown. From Figure 3 The results showed that the degree of hydrolysis and peptide yield of enzyme preparation 3 (alkaline protease + flavor protease) were much higher than those of other combinations. Under these enzymatic hydrolysis conditions, the degree of hydrolysis of black soldier fly larvae protein was 38.29% and the peptide yield was 35.32%. Therefore, the present invention selected alkaline protease and flavor protease as the best dual-enzyme combination.

[0079] Based on the above experiments, we further investigated the weight ratio of alkaline protease and flavor protease, as detailed in Table 1. Enzyme preparation 6-10 was added at 3% of the weight of the solid matter from black soldier fly larvae, and the mixture was enzymatically hydrolyzed at 50℃ for 5 hours. After hydrolysis, the enzyme was inactivated at 80-90℃ for 10 minutes, and the degree of hydrolysis and peptide yield were measured. The effects of different compound enzyme preparations 3 and 6-10 on the degree of hydrolysis and peptide yield are shown in the table below. Figure 4 As shown. From Figure 4The results showed that enzyme preparations 3 and 6-8 achieved a degree of hydrolysis and peptide yield of over 30% for black soldier fly protein, while enzyme preparations 9 and 10 achieved yields below 30%. This indicates that alkaline protease and flavor protease, within the weight ratio range of 1-3:1-2 provided by this invention, can achieve good hydrolysis and peptide yield of black soldier fly protein. Among them, enzyme preparation 3 achieved a degree of hydrolysis of 38.29% of the solids from black soldier fly larvae and a peptide yield of 35.32%, which is much higher than other enzyme preparations. This indicates that when the weight ratio of alkaline protease to flavor protease is 1:1, the enzymatic hydrolysis effect on black soldier fly larvae is the best.

[0080] Table 1. Composition and weight ratio of different compound enzyme preparations

[0081]

[0082] Experimental Example 3

[0083] Based on the results of Experiment 2, we further investigated the effects of compound fermentation broth on pH and peptide yield of black soldier fly larvae solids. Enzyme preparation 3 was added at 3% of the weight of black soldier fly larvae solids, and enzymatic hydrolysis was performed at 50℃ for 5 hours. After hydrolysis, the enzyme was inactivated at 80-90℃ for 10 minutes. Following hydrolysis, 3-4% glucose and 15% compound fermentation broth were added according to the volume of the hydrolysate. The fermentation temperature was 35-37℃, and the fermentation time was 20 hours. After fermentation, sterilization was performed at 80-90℃ for 10 minutes, and the pH and peptide yield of the fermentation broth were measured. The compound fermentation broth was prepared with Lactobacillus plantarum seed culture: Bacillus subtilis seed culture: Saccharomyces cerevisiae seed culture in ratios of 1:1:1, 2:2:1, 3:2:1, 4:2:1, and 5:2:1, respectively. The results are as follows: Figure 5 and Figure 6 As shown, when the ratio of *Lactobacillus plantarum* seed culture to *Bacillus subtilis* seed culture to *Saccharomyces cerevisiae* seed culture was 4:2:1, the pH and peptide yield tended to stabilize. At this point, the pH value was 5.66 and the peptide yield was 38.52%.

[0084] Test Example 4

[0085] The pH and peptide yield of the black soldier fly larvae enzymatic hydrolysis or fermentation broth prepared by the methods of Example 2 and Comparative Example 1 were determined, and the results are as follows: Figure 7 As shown, the method of using enzymatic hydrolysis combined with compound probiotic fermentation, compared with simple enzymatic hydrolysis, can significantly reduce the pH value of the fermentation broth, increase the yield of peptides, and improve palatability, thus providing conditions for the application of black soldier fly water-soluble protein powder in animal husbandry.

[0086] Experimental Example 5

[0087] Application of the black soldier fly water-soluble protein powder prepared by this invention in laying hen production

[0088] 1. Materials and Methods

[0089] 1.1 Experimental Design

[0090] Forty-five 58-week-old Dawu Jinfeng laying hens in good condition and with similar weights were randomly divided into three groups, with three replicates per group and 45 hens per replicate. The pre-trial period was one week, and the formal trial period was four weeks. The control group was fed a basal diet, while the experimental groups were fed a basal diet supplemented with 0.5% and 1.0% black soldier fly larvae water-soluble protein powder, respectively. The diets for each experimental group were formulated according to the "NY / T 33-2004 Chicken Feeding Standard," and their composition is shown in Table 2.

[0091] All groups of laying hens were raised and managed under the same conditions, using enclosed chicken houses and three-tiered cages; they had free access to water via nipple drinkers and were fed twice daily (7:30 and 17:30); artificial lighting was provided, with a constant lighting time of 16 hours / day and a light intensity of 10–20 lx; ​​longitudinal negative pressure ventilation was used, with a temperature of 20–25℃ and a relative humidity of 40%–60%; eggs were collected at 2:30 pm daily, the chicken houses were cleaned daily, the chicken houses were disinfected weekly, and manure was removed every two days; and routine disease prevention procedures were followed.

[0092] Table 2. Diet composition for the experiment (air-dried basal diet)

[0093]

[0094]

[0095] Note: The premix provides the following per kilogram of feed: Vitamin A 9800 IU, Vitamin D3 3500 IU, Vitamin E 28 IU, Vitamin K3 2.4 mg, Vitamin B1 1.6 mg, Vitamin B2 7.0 mg, Vitamin B6 4.5 mg, Vitamin B... 12 0.03mg, Biotin 0.18mg, Folic Acid 1.2mg, Niacin 40.0mg, Pantothenic Acid 10.0mg, Iron 90mg, Copper 15mg, Manganese 100mg, Zinc 75mg, Selenium 0.3mg, Iodine 0.8mg, Phytase 1000IU.

[0096] 1.2 Measurement of production performance

[0097] During the trial period, the number of eggs laid, egg weight, number of soft-shelled and broken eggs, and number of abnormal eggs were recorded daily for each group (in replicates). Feed was collected weekly, and the egg production rate, daily feed intake, average egg weight, and feed conversion ratio during the trial period were calculated and statistically analyzed.

[0098] 1.3 Determination of Egg Quality

[0099] Egg weight, albumen height, yolk color, and Haugh units were measured using an automatic egg quality analyzer; eggshell strength was measured using an eggshell strength tester; after peeling off the eggshell membrane, the eggshell thickness at the tip, equator, and blunt end was measured using vernier calipers, and the average of the three measurements was taken as the final value of the eggshell thickness.

[0100] 1.4 Evaluation of Egg Flavor

[0101] The evaluation is based on the egg white color (1-5 points), aroma (1-5 points), egg white texture (1-5 points), and egg yolk texture (1-5 points), and a comprehensive score (0-9 points) is assigned.

[0102] 1.5 Statistics and Analysis

[0103] Experimental data were processed using Excel 2016 and analyzed using SPSS 26.0 software. One-way ANOVA was performed, and Duncan's multiple comparison test was used. P < 0.05 indicated a significant difference, and P < 0.01 indicated a highly significant difference. Results are expressed as mean ± standard deviation.

[0104] 2 Results

[0105] 2.1 Effects of Black Soldier Fly Water-Soluble Protein Powder on Laying Hen Production Performance

[0106] Table 3. Effects of black soldier fly water-soluble protein powder on laying hen production performance.

[0107] Group Egg production rate / % Average egg weight / g Broken egg rate / % Egg ratio Average daily feed intake / g control group <![CDATA[89.63±0.36 b ]]> 60.02±0.45 <![CDATA[1.18±0.06 A ]]> 2.08±0.04 124.47±3.01 0.5% group <![CDATA[90.98±0.43 a ]]> 60.16±0.33 <![CDATA[0.82±0.03 B ]]> 2.02±0.02 121.37±0.81 1.0% group <![CDATA[91.10±0.68 a ]]> 60.27±0.29 <![CDATA[0.81±0.04 B ]]> 2.02±0.04 121.50±1.71

[0108] Note: Different lowercase letters in the same column indicate significant differences (P<0.05), different uppercase letters indicate extremely significant differences (P<0.01), and no label indicates no significant differences (P>0.05). The same applies to the following table.

[0109] Table 3 shows that, compared with the control group, adding 0.5% and 1.0% black soldier fly larvae water-soluble protein powder to the diets of laying hens in the later stages increased the egg production rate by 1.51% (P<0.05) and 1.64% (P<0.05), respectively, and reduced the rate of broken eggs by 30.51% (P<0.01) and 31.36% (P<0.01), respectively. The experimental results indicate that black soldier fly larvae water-soluble protein powder can improve the egg production rate of laying hens, significantly reduce the rate of broken eggs, and improve the economic benefits of laying hen farming enterprises.

[0110] 2.2 Effects of Black Soldier Fly Water-Soluble Protein Powder on Egg Quality in Laying Hens

[0111] Table 4. Effects of black soldier fly water-soluble protein powder on egg quality in laying hens.

[0112]

[0113] Table 4 shows that, compared with the control group, adding 0.5% and 1.0% black soldier fly larvae water-soluble protein powder to the diet of laying hens in the later stages can improve eggshell strength and thickness (P<0.05). The increase in eggshell strength and thickness reduces the proportion of broken eggs.

[0114] 2.3 Effect of Black Soldier Fly Water-Soluble Protein Powder on Egg Flavor

[0115] Table 5. Effects of black soldier fly water-soluble protein powder on egg flavor.

[0116] Group egg white color fragrance protein texture Egg yolk texture Overall score control group 3.40±0.54 3.96±0.32 4.20±0.28 4.10±0.14 7.90±0.26 0.5% group 3.54±0.23 4.24±0.18 4.30±0.21 4.06±0.09 8.26±0.23 1.0% group 3.56±0.25 4.24±0.29 4.30±0.22 4.10±0.38 8.28±0.15

[0117] As shown in Table 4, compared with the control group, adding 0.5% and 1.0% of black soldier fly water-soluble protein powder to the diet of laying hens in the later stage can improve the aroma and total score of eggs, but the difference is not statistically significant.

[0118] 3. Conclusion

[0119] This invention provides black soldier fly water-soluble protein powder that can significantly improve the production performance and egg quality of laying hens in egg-laying hen farming. Adding black soldier fly water-soluble protein powder to the diet of laying hens in the later stages can increase eggshell thickness and eggshell strength, thereby reducing the proportion of broken eggs and increasing the laying rate. It can effectively solve the problem of declining eggshell quality and egg quality in the later stages of laying hens in large-scale chicken farms.

[0120] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing water-soluble protein powder from black soldier fly larvae, characterized in that, The method includes the following steps: (1) Rinse the live black soldier fly larvae with running water to remove impurities from the surface of the larvae; (2) The cleaned black soldier fly larvae were steamed in water at 80-90℃ for 30 minutes, then homogenized and dehydrated by centrifuge for 15-20 minutes to obtain black soldier fly larvae solid concentrate. (3) Add 3-5L of defatting solvent to the dehydrated black soldier fly solid concentrate and defatt it 3-5 times to remove crude fat from the concentrate. (4) Use a centrifuge to remove the defatting solvent and recover the oil to obtain defatted black soldier fly larvae solids and oil; (5) The defatted black soldier fly larvae solids are mixed with 4-5L of water per kilogram, and a compound enzyme preparation is added at 3-5% of the weight of the solids. The enzymatic hydrolysis reaction is carried out at a temperature of 40-50℃ and a time of 4-5 hours to obtain the enzymatic hydrolysis product. The compound enzyme preparation is an alkaline protease and a flavor protease with a mass ratio of 1-3:1-2. (6) After the enzymatic hydrolysis reaction is completed, add 3-4% glucose and 20-30% compound fermentation liquid according to the liquid volume of the fermentation product, and carry out the fermentation reaction. The fermentation temperature is 35-37℃, the fermentation time is 20-24h, and after the fermentation is completed, sterilize at 85-90℃ for 10-15 minutes to obtain the enzymatic hydrolysis fermentation product. The compound fermentation liquid is composed of Lactobacillus plantarum seed liquid, Bacillus subtilis seed liquid and Saccharomyces cerevisiae seed liquid in a volume ratio of 4-8:2-4:1-2. (7) After centrifuging the above-mentioned enzymatic fermentation products, collect the supernatant and spray dry it to obtain black soldier fly water-soluble protein powder.

2. The method for preparing a water-soluble protein powder of black soldier fly larvae according to claim 1, characterized in that, In step (3), the degreasing solvent is one of n-hexane, petroleum ether, and ethanol.

3. The method for preparing a water-soluble protein powder of black soldier fly larvae according to claim 1, characterized in that, In step (6), the amount of the compound fermentation liquid added is 15-20% of the liquid volume of the fermentation product.

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