A compound protein feed of camellia seed meal and walnut meal and its preparation method

Abstract

This invention discloses a composite protein feed of camellia oil meal and walnut meal and its preparation method, belonging to the field of feed technology. The preparation method of this composite protein feed of camellia oil meal and walnut meal includes the following steps: S1: removing impurities from camellia oil meal, crushing, sieving, and extracting; filtering, and performing Soxhlet extraction on the filter cake using a solvent; drying to obtain detoxified camellia oil meal; S2: removing impurities from walnut meal, crushing, and sieving to obtain improved walnut meal; S3: mixing the detoxified camellia oil meal, improved walnut meal, and a compound enzyme preparation evenly to prepare fermentation raw material; S4: mixing the fermentation raw material, fermentation substrate adjuster, and fermentation inoculum evenly, and fermenting. The method for preparing a composite protein feed of camellia oil meal and walnut meal provided by this invention comprehensively degrades anti-nutritional factors in camellia oil meal and walnut meal through physicochemical detoxification, enzymatic hydrolysis, and microbial fermentation processes, increasing the effective viable bacteria count in the fermentation products, and producing a high-protein, easily digestible composite protein feed of camellia oil meal and walnut meal.

Description

Technical Field

[0001] This invention relates to the field of feed technology, and in particular to a compound protein feed of camellia seed meal and walnut meal and its preparation method. Background Technology

[0002] Protein feed refers to feeds such as soybeans, oilseed cakes, and fishmeal with a natural moisture content of <45%, crude fiber content of <18% in dry matter, and crude protein content of ≥20%. Protein feeds can be classified into four main categories based on their source: plant-based protein feeds, animal-based protein feeds, single-cell protein feeds, and non-protein nitrogen feeds. Soybean meal is currently the most important protein feed in livestock farming, accounting for approximately 25% of feed costs. With rising soybean meal prices and increased farming costs, there is an urgent need to find alternatives to reduce dependence on soybean meal as a raw material.

[0003] Camellia oil meal, a byproduct of camellia seed oil extraction, yields approximately three times the amount of camellia oil. It is rich in nutrients such as crude protein, crude fat, and crude fiber, and contains 10 essential amino acids. Its amino acid composition closely matches the needs of livestock and poultry, making its nutritional value comparable to rice bran and buckwheat. More importantly, camellia oil meal also contains active substances such as tea polyphenols, tea seed polysaccharides, and glycoterpenes, as well as trace minerals such as calcium, magnesium, iron, manganese, zinc, and copper, which significantly promote animal growth, development, and the immune system. Studies have found that glycoterpenes extracted from camellia oil meal have excellent antibacterial and antiviral effects; even small amounts can significantly improve livestock and poultry production performance (Chen Xiao, 2015). Therefore, camellia oil meal has great development potential.

[0004] However, despite the high utilization value of camellia oil meal, mature feed technology for camellia oil meal has not yet been developed domestically or internationally. The main difficulty lies in the high levels of anti-nutritional factors in camellia oil meal, with tea saponins being the most abundant. This gives camellia oil meal a pungent and bitter taste, affecting animal appetite. In addition, although camellia oil meal has a rich amino acid composition, the total content is not high, while the cellulose content is very high, making it unsatisfactory to directly develop camellia oil meal into protein feed.

[0005] Walnut meal, a byproduct of walnut kernel oil extraction, contains 30-50% protein and is rich in amino acids, including all eight essential amino acids (with high levels of glutamic acid, aspartic acid, and arginine). It also contains polysaccharides, polyphenols, and vitamins, making it a high-quality protein resource. However, the residual walnut oil in walnut meal is highly susceptible to oxidative rancidity, leading to a deterioration in flavor and mold growth, significantly shortening its shelf life. Furthermore, walnut meal contains small amounts of anti-nutritional factors such as tannins and phytic acid, which can inhibit the activity of intestinal digestive enzymes and interfere with protein absorption in animals. Summary of the Invention

[0006] Walnut meal is rich in nutrients such as crude protein, lipids, cellulose, and minerals, providing abundant carbon, nitrogen, and inorganic salts for microbial growth and reproduction. Therefore, walnut meal can also serve as a nutrient source for microbial fermentation. Combining camellia oil meal with high-protein walnut meal can improve the feedability of camellia oil meal and extend the storage time of walnut meal.

[0007] The main challenge in developing a new protein feed by combining camellia oil meal and walnut meal is reducing anti-nutritional factors. The mainstream treatment method is microbial fermentation, which utilizes microorganisms to proliferate in large numbers on the meal substrate and secrete enzymes to degrade anti-nutritional factors in the meal. This not only effectively removes various anti-nutritional factors but also transforms other feed components into more easily digestible and absorbable nutrients, thus significantly improving feed digestibility.

[0008] Although microbial fermentation can significantly improve the nutritional value of oilseed meals and produce high-quality protein feed, long-term experiments have shown that the fermentation rate of camellia oil meal is very low. The main reason is that tea saponins in camellia oil meal have extremely strong antibacterial properties. In camellia oil meal substrates with high concentrations of tea saponins, the growth and metabolism of most microorganisms are very slow. The number of microbial communities after fermentation is also low, making it difficult to produce protein feed with a high number of effective viable bacteria and high microbial protein content.

[0009] To address the problems existing in the prior art, the present invention aims to provide a method for preparing a compound protein feed of camellia oil meal and walnut meal through a combination of physicochemical detoxification, enzymatic hydrolysis, and microbial fermentation.

[0010] This invention discloses a method for preparing a compound protein feed of camellia seed meal and walnut meal, comprising the following steps:

[0011] S1 Camellia oleifera meal detoxification: Remove impurities from camellia oleifera meal, crush and sieve; extract with solvent; filter, and extract the filter cake with solvent using Soxhlet extraction until the extract is clear and transparent; dry to obtain detoxified camellia oleifera meal;

[0012] S2 Improved Walnut Meal: Walnut meal is cleaned of impurities, crushed, and sieved to obtain improved walnut meal;

[0013] S3 Add compound enzyme preparation: Mix the detoxified camellia seed meal, the improved walnut meal and the compound enzyme preparation evenly to make fermentation raw material;

[0014] S4 Microbial Fermentation: The fermentation raw materials, fermentation substrate modifier and fermentation agent are mixed evenly and fermented to obtain a compound protein feed of camellia oil meal and walnut meal.

[0015] After crude extraction using an extractor and secondary extraction using a Soxhlet extraction system, the residual tea saponin in the camellia oil meal has reached a safe level (<1%).

[0016] Furthermore, in step S1, the sieving is done through a 10-20 mesh sieve; 75wt% aqueous ethanol is used as the solvent for extraction and Soxhlet extraction; the extraction temperature is 40-50℃, the solid-to-liquid mass ratio is 1:(5-10), the extraction time is 2-3h, and the material is allowed to settle for 0.5h before extraction.

[0017] 75wt% aqueous ethanol, containing 25wt% water, becomes a highly polar solvent, capable of dissolving both polar and weakly polar components. Its extraction efficiency for tea saponins and tea seed polysaccharides is far higher than that for anhydrous ethanol.

[0018] Furthermore, in step S2, the sieving is done through a 10-20 mesh sieve; the sieved walnut meal is also subjected to a brief microwave puffing treatment.

[0019] Microwave puffing utilizes microwave heating technology to rapidly vaporize the moisture inside the material, generating immense internal pressure that causes the material's structure to expand and form a loose, porous structure. After microwave puffing, walnut meal undergoes partial breakdown of its macromolecular structure and protein denaturation, making it easier to digest. It also provides some of the carbon and nitrogen sources needed for the early stages of fermentation, facilitating the implantation of fermentation microorganisms.

[0020] Furthermore, the moisture content of the sieved walnut meal is controlled at 20-25wt%; the microwave puffing power is 800-1200W, the frequency is 2000-3000MHz; the material spreading thickness is 8-12mm, and the puffing time is 10-15s.

[0021] Furthermore, in step S3, the compound enzyme preparation includes cellulase, phytase, and ligninase.

[0022] The compound enzyme preparation has cellulase activity ≥100,000 U / g; phytase activity ≥50,000 U / g; and ligninase activity ≥50,000 U / g.

[0023] Furthermore, the fermentation raw materials also include plant carbon black and yeast powder; in the fermentation raw materials, the mass ratio of the detoxified camellia seed meal, the improved walnut meal, the compound enzyme preparation, the plant carbon black and the yeast powder is (45-70): (25-45):1: (0.2-0.7): (0.2-0.7).

[0024] Enzyme preparations can accelerate the degradation of crude fiber and other substances; plant carbon black can adsorb heavy metals, mycotoxins and other toxic and harmful substances in walnut meal; yeast powder can supplement essential amino acids, B vitamins and dietary fiber and other nutrients.

[0025] Furthermore, in step S4, the fermentation substrate adjuster includes one or two of wheat bran and corn flour; the fermentation agent includes auxiliary materials and live bacteria; the live bacteria include Aspergillus niger, Saccharomyces cerevisiae, Lactobacillus plantarum, Bacillus subtilis, and Bacillus coagulans.

[0026] Fermentation substrate modifiers provide nutrients for the growth of microorganisms in the early stages of fermentation. Microbial fermentation using Aspergillus niger, Saccharomyces cerevisiae, Lactobacillus plantarum, and Bacillus spp. allows Aspergillus niger to degrade the fibrous structure of camellia seed meal, promoting feed digestibility. Furthermore, yeasts produce small-molecule proteins such as microbial proteins, further increasing the protein content and quality of the fermented meal. In addition, highly active beneficial microorganisms such as Bacillus subtilis and Bacillus coagulans can regulate the intestinal flora structure of animals, promoting intestinal health.

[0027] Furthermore, the preparation method of the fermentation agent involves mixing live bacteria and sterile water at a mass ratio of 1:10 to form a homogeneous mixture. Then, each component is added at a ratio of 50g corn flour, 10g peptone, and 1-5g sodium chloride per liter of the mixture, and mixed thoroughly. The pH of the solution is adjusted to 4-5 using citric acid. The mixture is then prepared at a temperature of 30-35℃, a stirring speed of 1-1.5 rpm, and a sterile air ventilation rate of 1.0-1.5 m³ / h. 3 Under the condition of / min, the fermentation agent is activated for 2.0-3.0h to obtain the fermentation agent; the mass ratio of the fermentation raw material, fermentation substrate modifier and fermentation agent is (8-12):1: (7-11).

[0028] Among the live bacteria, the number of live Aspergillus niger is ≥25 billion CFU / g; the number of live Saccharomyces cerevisiae is ≥10 billion CFU / g; the number of live Lactobacillus plantarum is ≥10 billion CFU / g; the number of live Bacillus subtilis is ≥5 billion CFU / g; and the number of live Bacillus coagulans is ≥5 billion CFU / g.

[0029] Furthermore, in step S4, fermentation is carried out first with aerobic fermentation, followed by anaerobic fermentation; the conditions for aerobic fermentation are a temperature of 30-33℃, a rotation speed of 0.5-1.0 rpm, and a sterile air ventilation rate of 0.8-1.0 m³ / h. 3 / min, fermentation time 24-36h; anaerobic fermentation conditions are: air removal, fermentation at 28-32℃ for 72-84h.

[0030] Aerobic fermentation followed by anaerobic fermentation can increase the crude protein and acid-soluble protein content in protein feed, while reducing the crude fiber content.

[0031] This invention provides a method for preparing a compound protein feed of camellia oil meal and walnut meal. Through physicochemical detoxification, enzymatic hydrolysis, and microbial fermentation processes, the anti-nutritional factors in camellia oil meal and walnut meal are comprehensively degraded, while the number of effective live bacteria in the fermentation products is increased, further increasing the content of microbial protein, small peptides, amino acids and other small molecules, and finally producing a high-protein, easily digestible compound protein feed of camellia oil meal and walnut meal. Detailed Implementation

[0032] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments.

[0033] Example 1

[0034] Preparation of a compound protein feed consisting of camellia seed meal and walnut meal:

[0035] S1 Camellia Oil Powder Detoxification: After removing impurities, crushing, and passing through a 10-20 mesh sieve, the camellia oil powder is fed into a rotary extractor for coarse extraction. The process uses a countercurrent multi-stage contact method with the following parameters: solvent 75wt% aqueous ethanol, solid-liquid ratio 1:7, extraction temperature 45℃, and extraction time 2.5h. After extraction, the mixture settles for 0.5h, with the clear mixture discharged from the top and the moist solid residue from the bottom. The moist solid residue is then partially filtered into a plate and frame filter to form a filter cake. The filter cake is then transferred to a fully automated Soxhlet extraction system for a second extraction with 75wt% aqueous ethanol until the extract is clear and transparent, with an extraction time of 1.5h. After extraction, the moist residue is transferred to an evaporator to evaporate the water and solvent, yielding detoxified camellia oil powder.

[0036] S2 Improved Walnut Meal: After removing impurities, crushing, and passing the walnut meal through a 10-20 mesh sieve, the walnut meal is fed into a microwave puffing device for puffing. The process parameters are: controlling the moisture content of the walnut meal to 20-25 wt%, puffing power to 1000 W, frequency to 2450 MHz, material thickness to 10 mm, and puffing time to 15 s, to obtain improved walnut meal.

[0037] S3 Added compound enzyme preparation: Cellulase, phytase, and ligninase are mixed evenly to obtain a compound enzyme preparation, in which cellulase activity ≥100,000 U / g; phytase activity ≥50,000 U / g; and ligninase activity ≥50,000 U / g. Detoxified camellia seed meal, improved walnut meal, compound enzyme preparation, vegetable carbon black, and yeast powder are mixed evenly according to the mass ratio in Table 1 to prepare fermentation raw materials.

[0038] Table 1. Proportioning of Fermentation Raw Materials

[0039] Detoxified Camellia Oil Powder 590 Improved walnut meal 390 Compound enzyme preparations 10 Vegetable carbon black 5 yeast powder 5

[0040] S4 Microbial Fermentation: Live bacteria and sterile water are added to the fully automated fermentation system at a mass ratio of 1:10. Auxiliary materials are added, and the pH is adjusted to 4.0-5.0 using citric acid solution. Sterile air is then introduced for activation. The activation process parameters are: temperature 33℃, stirrer speed 1.2 rpm, and aeration rate 1.3 m³ / h. 3 / min, activation time 2.5h, to obtain fermentation agent.

[0041] The composition and number of live bacteria (powder) are as follows: Aspergillus niger live bacteria count ≥ 25 billion CFU / g; Saccharomyces cerevisiae live bacteria count ≥ 10 billion CFU / g; Lactobacillus plantarum live bacteria count ≥ 10 billion CFU / g; Bacillus subtilis live bacteria count ≥ 5 billion CFU / g; Bacillus coagulans live bacteria count ≥ 5 billion CFU / g.

[0042] The composition and dosage of the excipients are as follows: 50 g / L corn flour, 10 g / L peptone, and 3 g / L NaCl.

[0043] Aerobic fermentation: After activation, according to the material composition and ratio in Table 2, add the fermentation raw materials, fermentation substrate conditioner (wheat bran), and fermentation inoculum into the fully automatic fermentation system. After mixing evenly, adjust the rotation speed to 0.8 rpm and the sterile air ventilation rate to 0.9 m³ / h. 3 / min, fermentation time 24h, aerobic fermentation.

[0044] Table 2. Mixture ratio during fermentation

[0045] Fermentation raw materials 500 bran 50 Fermentation agent 450

[0046] Anaerobic fermentation: After the aerobic fermentation is completed, the material is released and put into an anaerobic fermentation bag. The bag is sealed and the air is exhausted. The material temperature is controlled at 30℃. After anaerobic fermentation for 72 hours, the finished product is a compound protein feed of camellia seed meal and walnut meal.

[0047] Example 2

[0048] The only difference between Example 2 and Example 1 is that the walnut meal was not microwave-expanded in step S2.

[0049] Example 3

[0050] The only difference between Example 3 and Example 1 is that in step S4, the walnut meal is not subjected to aerobic fermentation, but only anaerobic fermentation.

[0051] Comparative Example 1

[0052] The difference between Comparative Example 1 and Example 1 is that the proportions of the fermentation raw materials in step S3 are shown in Table 3.

[0053] Table 3. Proportioning of Fermentation Raw Materials

[0054] Detoxified Camellia Oil Powder 980 Compound enzyme preparations 10 Vegetable carbon black 5 yeast powder 5

[0055] Comparative Example 2

[0056] The difference between Comparative Example 2 and Example 1 is that the proportions of the fermentation raw materials in step S3 are shown in Table 4.

[0057] Table 4. Proportioning of Fermentation Raw Materials

[0058] Improved walnut meal 980 Compound enzyme preparations 10 Vegetable carbon black 5 yeast powder 5

[0059] Comparative Example 3

[0060] The difference between Comparative Example 3 and Example 1 is that in step S1, the camellia oil meal is not detoxified.

[0061] Performance testing:

[0062] The fermentation raw materials of Examples 1-3 and Example 1, as well as the protein feeds obtained in Comparative Examples 1-3, were subjected to performance tests: crude protein was tested according to the standard GB / T 6432-2018; crude fiber was tested according to the standard GB / T 6434-2022; acid-soluble protein was tested according to the standard NY / T 3801-2020; viable cell count was tested using the plate colony count method; amino acid composition was tested according to the standard GB 5009.124-2016; and aflatoxin was tested according to the test standard NY / T 2071-2011. The test results are shown in Table 5.

[0063] Crude protein (%) 21.93 32.45 30.85 24.34 10.84 45.37 27.81 Crude fiber (%) 35.79 24.33 26.76 33.29 37.44 18.89 28.99 Acid-soluble protein (%) 1.38 7.17 6.75 3.07 2.12 8.46 6.21 viable bacteria count (cfu / g) 330 <![CDATA[2.1*10 9 ]]> <![CDATA[1.86*10 9 ]]> <![CDATA[8.5*10 7 ]]> <![CDATA[7.5*10 8 ]]> <![CDATA[6*10 9 ]]> <![CDATA[1.03*10 9 ]]> Aflatoxin (μg / kg) 6.7 5.8 8.3 4.6 2.3 145.4 5.4 Aspartic acid (%) 2.232 4.397 4.196 2.701 0.885 4.865 3.683 Glutamic acid (%) 5.077 9.444 8.428 6.956 2.270 10.895 7.870 Cysteine ​​(%) 0.215 0.403 0.399 0.293 0.112 0.464 0.325 Valine (%) 0.740 1.154 1.309 1.028 0.487 1.457 1.139 Methionine (%) 0.416 0.807 0.782 0.599 0.033 1.045 0.790 Isoleucine (%) 0.529 0.968 1.010 0.672 0.415 1.002 0.851 Leucine (%) 0.960 1.527 1.632 1.152 0.985 1.680 1.700 Phenylalanine (%) 0.465 0.781 0.842 0.688 0.537 0.780 0.930 Lysine (%) 0.560 1.053 0.913 0.823 0.507 1.002 1.081 Threonine (%) 0.621 0.627 0.658 0.646 0.283 1.202 0.664 Serine (%) 1.004 1.024 1.195 1.065 0.381 2.104 1.044 glycine (%) 0.882 0.971 1.050 0.927 0.305 1.806 1.032 Alanine (%) 0.867 1.075 1.067 0.954 0.461 1.663 0.911 Tyrosine (%) 0.260 0.273 0.273 0.260 0.086 0.540 0.281 Histidine (%) 0.483 0.531 0.531 0.512 0.114 1.087 0.560 Arginine (%) 2.823 3.049 2.851 2.936 0.519 6.579 2.964 proline (%) 0.761 0.936 0.868 0.822 0.285 1.541 0.807 Total hydrolyzed amino acids (%) 18.896 29.020 28.004 23.033 8.665 39.711 26.633

[0064] Table 5 Performance Test Results

[0065] As shown in Table 5, the protein feed from Example 1, after fermentation, showed a significant increase in both crude protein and small peptide content. The crude protein content increased from 21.93% to 32.45%, an increase of 47.97%; the acid-soluble protein content increased from 1.38% to 7.17%, an increase of over four times, demonstrating extremely significant effects. Furthermore, compared to the old microbial fermentation method for camellia seed meal, the new method greatly improved the fermentation speed and the number of viable bacteria after fermentation, reducing the fermentation time from 14 days to 4 days and the number of viable bacteria from 10... 7 ~10 8 CFU / g increased to 10 8 -10 10 cfu / g.

[0066] Examples 1-3 and Comparative Example 1 show that when camellia seed meal and walnut meal are used in combination, the crude protein and acid-soluble protein content of the protein feed prepared by using camellia seed meal alone is greatly increased, while the crude fiber content is greatly reduced.

[0067] Compared with Comparative Example 2, the combined use of camellia seed meal and walnut meal in Examples 1-3 resulted in a decrease in crude protein content and acid-soluble protein content compared to protein feed prepared from walnut meal alone, but a significant reduction in aflatoxin content.

[0068] Compared with Example 2, the crude protein content and acid-soluble protein content in the protein feed were both increased after the walnut meal was extruded. Compared with Example 3, the crude fiber content in the protein feed was greatly reduced and the crude protein and acid-soluble protein content were significantly increased after aerobic and anaerobic fermentation.

[0069] Compared with Comparative Example 3, after the walnut meal was detoxified, the crude protein content and acid-soluble protein content of the obtained protein feed increased, while the crude fiber content decreased.

[0070] The cost of this application is controllable. Although some production equipment needs to be purchased in the early stage, the cost is relatively controllable after stable production. For every ton of mixed meal protein feed produced, in addition to the raw material cost of walnut meal and camellia meal, there are also energy costs, water-containing ethanol solvent loss costs, compound enzyme preparation and compound microbial preparation costs, labor costs, etc., totaling about 200-240 yuan.

[0071] The product is positioned not only as a compound protein feed of camellia oil meal and walnut meal, but also as a microbial preparation product. Compared with the original market price of 1200-1500 yuan / ton for camellia oil meal and 1400-1500 yuan / ton for walnut meal, the market price of the mixed meal after microbial fermentation can reach 1600-1800 yuan, with a profit increase of about 5%-10%.

[0072] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for preparing a compound protein feed of camellia seed meal and walnut meal, characterized in that, Includes the following steps: S1 Detoxification of Camellia Oil Powder: Camellia oil powder is cleaned, crushed, and sieved; solvent extraction is performed; filtration is conducted, and the filter cake is subjected to Soxhlet extraction with solvent until the extract is clear and transparent; drying is performed to obtain detoxified Camellia oil powder, wherein the sieving is done through a 10-20 mesh sieve; 75wt% aqueous ethanol is used as the solvent for extraction and Soxhlet extraction; the extraction temperature is 40-50℃, the solid-to-liquid mass ratio is 1:5-10, the extraction time is 2-3 hours, and sedimentation is performed for 0.5 hours after extraction. S2 Improved Walnut Meal: Walnut meal is cleaned of impurities, crushed, sieved, and microwave-expanded to obtain improved walnut meal; S3 Add compound enzyme preparation: Mix the detoxified camellia seed meal, the improved walnut meal and the compound enzyme preparation evenly to make fermentation raw material; S4 Microbial Fermentation: The fermentation raw materials, fermentation substrate modifier and fermentation agent are mixed evenly and fermented to obtain a compound protein feed of camellia oil meal and walnut meal. The fermentation agent includes auxiliary materials and live bacteria. The live bacteria include Aspergillus niger, Saccharomyces cerevisiae, Lactobacillus plantarum, Bacillus subtilis and Bacillus coagulans. During fermentation, aerobic fermentation is carried out first, followed by anaerobic fermentation. The fermentation raw materials also include plant carbon black and yeast powder; in the fermentation raw materials, the mass ratio of the detoxified camellia seed meal, the improved walnut meal, the compound enzyme preparation, the plant carbon black and the yeast powder is 45-70:25-45:1:0.2-0.7:0.2-0.

7.

2. The method for preparing a compound protein feed of camellia seed meal and walnut meal according to claim 1, characterized in that, In step S2, the sieving is done through a 10-20 mesh sieve.

3. The method for preparing a compound protein feed of camellia seed meal and walnut meal according to claim 2, characterized in that, The moisture content of the sieved walnut meal is adjusted to 20-25wt%; the microwave puffing power is 800-1200W and the frequency is 2000-3000MHz; the material is spread to a thickness of 8-12mm and the puffing time is 10-15s.

4. The method for preparing a compound protein feed of camellia seed meal and walnut meal according to claim 1, characterized in that, In step S3, the compound enzyme preparation includes cellulase, phytase and ligninase.

5. The method for preparing a compound protein feed of camellia seed meal and walnut meal according to claim 1, characterized in that, In step S4, the fermentation substrate modifier includes one or both of wheat bran and corn flour.

6. The method for preparing a compound protein feed of camellia seed meal and walnut meal according to claim 5, characterized in that, The fermentation agent is prepared by mixing live bacteria preparation and sterile water at a mass ratio of 1:10 to form a homogeneous mixture. Corn flour, peptone, and sodium chloride are added per liter of the mixture at a ratio of 50g, 10g, and 1-5g, respectively. The mixture is then thoroughly mixed, and the pH is adjusted to 4-5 using citric acid solution. The mixture is then maintained at a temperature of 30-35℃, a stirring speed of 1-1.5 rpm, and a sterile air ventilation rate of 1.0-1.5 m³ / h. 3 Under the condition of / min, the fermentation agent is activated for 2.0-3.0h to obtain the fermentation agent; the mass ratio of the fermentation raw material, fermentation substrate modifier and fermentation agent is 8-12:1:7-11.

7. The method for preparing a compound protein feed of camellia seed meal and walnut meal according to claim 1, characterized in that, In step S4, the aerobic fermentation conditions are: a temperature of 30-33℃, a rotation speed of 0.5-1.0 rpm, and a sterile air ventilation rate of 0.8-1.0 m³ / h. 3 / min, fermentation time 24-36h; anaerobic fermentation conditions are: air removal, fermentation at 28-32℃ for 72-84h.

8. A compound protein feed consisting of camellia seed meal and walnut meal, characterized in that, It is prepared by the preparation method described in any one of claims 1-7.