Method for reducing content of insoluble dietary fibers in oil tea meal

Abstract

The invention provides a method for reducing the content of insoluble dietary fibers in oil tea meal, and relates to the field of feed processing. The invention provides a treatment-chemical-enzyme-bacterium combined modification method so as to achieve the purposes of reducing the insoluble dietary fiber content of the oil-tea meal and increasing the crude protein content of the oil-tea meal at the same time. Wherein fiber tissues of plant cell walls can be quickly destroyed by a physical method; in the chemical method, weak acid and weak base are used for destroying a fiber structure between cellulose, and the contact area of an enzyme system and cellulose is increased; chemical bonds in cellulose macromolecules can be directionally decomposed by an enzyme system method; the oil-tea meal treated by a treatment-chemical-enzyme method is relatively loose in structure and contains a lot of nutrient substances, aspergillus niger with strong cellulose degradation capability and bacillus secreting a variety of cellulase are added, dietary fibers of the oil-tea meal can be continuously degraded, and saccharomycetes capable of consuming glucose and synthesizing protein are added, so that the dietary fibers of the oil-tea meal can be continuously degraded. The degradation efficiency of cellulase can be improved, and the protein content of the oil-tea meal can also be improved.

Description

Technical Field

[0001] The invention relates to the field of feed processing, in particular to a method for reducing the content of insoluble dietary fiber in oil-tea camellia meal. Background Art

[0002] Camellia oleifera meal is a byproduct of camellia oil extraction. It is rich in nutrients such as crude protein, fat, and polysaccharides. It also contains a variety of active substances such as saccharoterpenoids and some trace mineral elements. It has the functions of promoting animal growth and development, regulating immune function, etc. It is a feed resource with great development potential. An important difficulty in developing camellia oleifera meal feed resources is that the cellulose content in camellia oleifera meal is extremely high, and its composition is mainly insoluble dietary fiber (IDF), while the content of soluble dietary fiber (SDF) is relatively low, resulting in a low nutritional value of camellia oleifera meal. It is not good to use it directly as a feed raw material and needs to be improved to a certain extent.

[0003] Dietary fiber (DF) is a carbohydrate that cannot be hydrolyzed by intestinal digestive enzymes. It is divided into SDF and IDF according to water solubility. SDF has a wider range of physiological activities and higher nutritional value than IDF. Therefore, people often modify IDF and convert IDF into SDF to increase the content of SDF. At present, there are few research reports on reducing the content of IDF in tea seed meal, and a mature production process has not been formed.

[0004] Domestic and foreign research on cellulose degradation mostly uses chemical treatment methods, using strong acids or strong bases to break the chemical bonds between cellulose. This method is fast and has high degradation efficiency, but it is easy to cause a large loss of nutrients in camellia oleifera meal, which in turn reduces the feeding value of camellia oleifera meal. There are also many other methods for extracting dietary fiber from straws. For example, CN 105029452 A mentions a method for extracting dietary fiber from wheat straw, which mainly uses ultrasound-assisted enzymolysis + microbial anaerobic fermentation to obtain dietary fiber. The enzyme system uses a large amount of enzymes, the fermentation time is long, and nutrients such as protein and fat are removed, which is not suitable for the improvement of camellia oleifera meal dietary fiber.

[0005] Therefore, it is particularly important to find a degradation method with fewer side effects, which can not only greatly reduce the IDF content in tea oil cake, but also minimize the loss of other nutrients, such as protein denaturation. Summary of the invention

[0006] The purpose of the present invention is to provide a method for reducing the IDF content in tea oil cake, which can not only greatly reduce the IDF content in tea oil cake, but also minimize the loss of other nutrients, and even increase the content of nutrients such as protein to a certain extent. The present invention provides such a method.

[0007] The present application provides a method for reducing the IDF content in tea seed cake, comprising the following processing steps:

[0008] Enzymatic hydrolysis: mixing the tea seed meal powder after acid hydrolysis and alkaline hydrolysis with an enzymatic hydrolysis system and performing enzymatic hydrolysis, wherein the enzymatic hydrolysis system comprises a mixed enzyme system and an enzymatic hydrolysis aid, wherein the mixed enzyme system comprises at least one of cellulase, hemicellulase and ligninase;

[0009] Microbial fermentation: The enzymatically hydrolyzed tea oil meal powder is mixed with a fermentation system and aerobic fermentation is performed for 2-3 days; the fermentation system includes a mixed bacterial system and a fermentation aid, the mixed bacterial system includes Aspergillus niger and auxiliary bacteria, and the auxiliary bacteria are Bacillus subtilis and Saccharomyces cerevisiae;

[0010] Anaerobic fermentation and preservation of finished products: Add lactic acid bacteria to the tea seed cake powder after microbial fermentation, seal the container, and perform anaerobically fermentation for 5 to 7 days to obtain the finished product.

[0011] The tea seed meal is crushed, screened and chemically hydrolyzed before enzymatic hydrolysis;

[0012] Crushing: Crush and sieve the tea seed meal to reduce the particle size of the tea seed meal powder and increase the surface area.

[0013] Chemical hydrolysis: Taking advantage of the property that cellulose will crack in acidic and alkaline environments, the camellia oil meal is hydrolyzed with alkali solution to weaken the hydrogen bonds between cellulose and hemicellulose, and the ester bonds between hemicellulose and lignin; the camellia oil meal is then hydrolyzed with acid to decompose the β-1,4-glycosidic bonds in cellulose and reduce the degree of polymerization of cellulose.

[0014] Furthermore, in the alkaline hydrolysis, the camellia oleifera meal powder is soaked in an alkaline solution with a pH value of 9.0 to 13.0, and then washed and dried after hydrolysis for 12 to 18 hours;

[0015] In the acid hydrolysis, the oil tea meal powder after alkali hydrolysis is soaked in an acid solution with a pH value of 0.5-3.5, heated to 98-102° C., hydrolyzed for 2-3 hours, and then washed with water and dried;

[0016] In the enzymolysis, the enzymolysis aids include a shielding agent, CaSO4 and an acetic acid solution; the mass ratio of the tea seed meal, the mixed enzyme system, the shielding agent, CaSO4 and the acetic acid solution is 1000:(1-5):(1-5):(0.5-1):(5000-10000), the pH value of the acetic acid solution is 3.0-5.0; the enzymolysis temperature is 40-60°C, and the enzymolysis time is 9-12h; after enzymolysis, the water content is dehydrated to 40-60%, and the shielding agent includes a non-ionic surfactant (such as tea saponin, etc.) and hydrolyzed soy protein;

[0017] In the microbial fermentation, the fermentation aid includes bran, brown sugar and urea; the mass ratio of the camellia meal powder, the mixed bacteria system, the bran, the brown sugar and the urea is 1000:(0.1-0.5):100:10:10; the camellia meal powder and the fermentation aid are mixed, the mixed bacteria system is added, the water content is adjusted, and the temperature of the mixture is controlled at 30-38°C under the condition of constant humidity for aerobic fermentation for 2-3 days;

[0018] During the anaerobic fermentation and storage of the finished product, 0.1 wt % lactic acid bacteria is added to the tea-leaf meal powder after aerobic fermentation by microorganisms, and the mixture is sealed and anaerobic fermented for 5 to 7 days at a temperature of 30 to 38° C. to obtain the finished product.

[0019] Furthermore, in the mechanical crushing step, a 10-18 mesh (particle size 1.0-2.0 mm) sieve is used to filter the tea seed meal powder.

[0020] Furthermore, the pH value of the acidic solution is 2.0-3.0; the pH value of the alkaline solution is 9.0-11.0.

[0021] Furthermore, in the alkaline hydrolysis step, the alkaline solution: tea oil meal powder = (2-4): 1.

[0022] Furthermore, in the acid hydrolysis step, the ratio of acidic solution to camellia oleifera meal powder is (5-10):1.

[0023] Furthermore, the mixed enzyme system in the enzymatic hydrolysis step is a composition of cellulase, hemicellulase and ligninase in a mass ratio of (6-10):(1-2):1.

[0024] Furthermore, the activity of the cellulase is ≥ 200,000 u / g, the activity of the hemicellulase is ≥ 100,000 u / g, and the activity of the ligninase is ≥ 100,000 u / g.

[0025] Furthermore, in the microbial fermentation product, the water content of the fermentation material is 50-60%.

[0026] Furthermore, the viable count of the Aspergillus niger is ≥10 billion cfu / g; the Bacillus subtilis is a high-producing cellulase Bacillus with a viable count of ≥100 billion cfu / g; and the viable count of the Saccharomyces cerevisiae is ≥20 billion cfu / g.

[0027] Furthermore, the mixed bacteria system needs to be activated with warm water at 25-35° C. for 0.5-1.0 h before use.

[0028] Furthermore, in alkaline hydrolysis, the alkaline solution is preferably ammonia water, and the liquid-to-solid ratio is preferably (3-4):1; in acid hydrolysis, a dilute sulfuric acid solution is preferably used, and the liquid-to-solid ratio is preferably 5:1.

[0029] Mechanically crushing and screening the oil-tea camellia meal can reduce the particle size, destroy the crystal structure of cellulose, and increase the surface area. In this application, the oil-tea camellia meal powder with a particle size of 1.0-2.0 mm can be achieved with a small pulverizer, and there is no need to use an ultrafine pulverizer, which is conducive to reducing the pulverization cost. If ultrafine pulverization is used, the water absorption of the oil-tea camellia meal powder is strong, the drying cost is high, and the material loss during filtration will also be greater.

[0030] The preferred pH value, treatment time and treatment concentration of the acidic solution and alkaline solution of the present application can enable the weak acid and weak base to destroy the fiber structure between cellulose, increase the contact area between the enzyme system and cellulose, and thus increase the soluble dietary fiber content. On the other hand, low-concentration chemical reagents also reduce their damage to nutrients such as protein and vitamins.

[0031] In alkaline hydrolysis, cellulose is relatively stable in alkaline solution, but OH - It can weaken the hydrogen bonds between cellulose and hemicellulose, as well as the ester bonds between hemicellulose and lignin. During acid hydrolysis, the β-1,4-glycosidic bond between the two glucose monomers in cellulose is sensitive to acid and will break when exposed to acid, reducing the degree of polymerization of cellulose.

[0032] In order to improve the efficiency of enzymatic hydrolysis, shielding agents such as non-ionic surfactants (such as tea saponin) and hydrolyzed soy protein can be added to prevent the ineffective adsorption of enzymatic products such as oligosaccharides, cellobiose and glucose, as well as lignin on cellulase; and metal ions (such as Ca 2+ ) to activate the activity of the enzyme; using organic acid (such as acetic acid) solution to maintain the acidic environment required for enzymatic hydrolysis is more effective than inorganic acid solution.

[0033] The strains used in the present application are Aspergillus niger with strong cellulose decomposition ability, Bacillus subtilis that can secrete a variety of cellulases, and Saccharomyces cerevisiae that can synthesize microbial proteins using oligosaccharides such as glucose, all of which are aerobic bacteria, so aerobic fermentation is adopted.

[0034] Beneficial effects:

[0035] The present invention proposes a "physical-chemical-enzyme-bacteria" combined modification method to achieve the goal of greatly reducing the IDF content of tea oil meal and increasing the crude protein content of tea oil meal to a certain extent. This combined modification method is simple to operate, cost-controlled, and has great application potential; the physical method has a very strong effect and can quickly destroy the fibrous tissue of the plant cell wall, which is suitable for preliminary modification; the chemical method uses weak acid and weak alkali to destroy the fiber structure between cellulose and increase the contact area between the enzyme system and cellulose; the enzyme system method can directionally decompose the chemical bonds inside the cellulose macromolecule. After the "physical-chemical-enzymatic hydrolysis" treatment, the tea oil meal has a loose structure and contains a lot of nutrients, which is suitable as a hotbed for microbial fermentation. Adding Aspergillus niger with strong cellulose degradation ability and Bacillus that can secrete a variety of cellulases can continue to degrade the IDF of tea oil meal. If yeast that can consume glucose and synthesize protein is further added, the degradation efficiency of cellulase can be improved, and the protein content of tea oil meal can be increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The present invention is a flowchart of a method for reducing the content of insoluble dietary fiber in camellia oleifera meal according to Example 1. DETAILED DESCRIPTION

[0037] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments.

[0038] Example 1, a method for reducing the content of insoluble dietary fiber in tea seed meal, the processing method is as follows Figure 1 , comprising the following preparation steps:

[0039] Crushing:

[0040] After the tea oil meal is removed from the impurities, it is crushed with a grinder and filtered with a 15-mesh sieve. The fiber debris and foreign matter that still cannot pass the sieve after the second crushing are removed, and those that pass the sieve can be used as tea oil meal materials.

[0041] Alkaline hydrolysis:

[0042] Take ammonia water with a pH value of 9.2 and immerse the material in a ratio of liquid: solid = 3:1. Soak it for 15 hours at room temperature and pressure. Filter it with a filter screen with a mesh size of 200 or above to remove the waste liquid. Then wash the material with clean water until it is neutral and air-dry it.

[0043] Acid hydrolysis:

[0044] Take a dilute sulfuric acid solution with a pH value of about 2.0, mix the materials in a ratio of liquid: solid = 8:1, heat the materials to 100°C under normal pressure, hydrolyze for 2.5 hours and then cool to room temperature, filter with a filter screen with a mesh size of more than 200, rinse the residue with distilled water that is 10 times the weight of the residue, filter, and air-dry.

[0045] Enzymatic hydrolysis:

[0046] ① Prepare a mixed enzyme system by mixing cellulase, hemicellulase and ligninase in a ratio of 8:1:1;

[0047] ② Mix the components in the following proportions: 1000g of camellia meal, 5g of mixed enzyme system, 2.5g of hydrolyzed soy protein, 0.5g of CaSO4 powder, and 10L of acetic acid solution (pH value is 4.0±0.2);

[0048] ③ Control the enzymatic hydrolysis temperature to 50°C (in other embodiments, the enzymatic hydrolysis temperature can be any temperature between 50°C and 60°C), the enzymatic hydrolysis time to 10 hours, during which continuous stirring is performed, and ultrasonic oscillation is intermittently used at a frequency of 20 KHz for 20 minutes per hour;

[0049] ④ After enzymatic hydrolysis, let it settle for 1.5 hours, filter out the supernatant, and dehydrate the solid material at the bottom by centrifugation at 1500 rpm to a water content of 55-60%;

[0050] Microbial fermentation:

[0051] ① Aspergillus niger, Bacillus subtilis and Saccharomyces cerevisiae are prepared into a mixed bacterial system in a ratio of 3:2:10;

[0052] ②Mix the components in the following proportions: 1000g of camellia meal, 100g of bran, 10g of brown sugar, 10g of urea, and 0.5g of mixed bacteria. Note that the mixed bacteria must be activated with a small amount of warm water (30°C) for 1.0h before use.

[0053] ③ Adjust the moisture content of the material to 60% (in other embodiments, the moisture content of the fermented material can be any value in the range of 60-65%), the material temperature to 35°C, and aerobic fermentation for 3 days, during which the material needs to be turned over continuously and the temperature and humidity of the material are maintained stable.

[0054] Anaerobic fermentation and finished product preservation:

[0055] The materials were placed in a fermentation bag with a breathing valve, lactic acid bacteria (added amount 0.1 wt %) were added, the bag was sealed, the air was exhausted, the material temperature was controlled at 35°C, and anaerobic fermentation was performed for more than 6 days.

[0056] Example 2, a method for reducing the IDF content in tea oil cake, is different from Example 1 in that the mixed bacteria system in the microbial fermentation step is changed to 4.0 g / kg cellulase, and the material temperature is 50°C.

[0057] Example 3, a method for reducing the IDF content in tea oil cake, is different from Example 1 in that, in alkaline hydrolysis, ammonia water with a pH value of 12 is used for soaking for 15 hours; and in acid hydrolysis, a sulfuric acid solution with a pH value of 0.69 is used for hydrolysis for 2.5 hours.

[0058] Example 4, a method for reducing the IDF content in tea oil cake, differs from Example 1 in that the mixed enzyme system in the enzymatic hydrolysis step is a combination of cellulase and hemicellulase in a mass ratio of 10:1.5; the mixed bacterial system in the microbial fermentation step is a combination of Aspergillus niger, Bacillus subtilis and Saccharomyces cerevisiae in a mass ratio of 1:3:10.

[0059] Example 5, a method for reducing the IDF content in tea oil meal, which is different from Example 1 in that an ultrafine grinder is used to grind the tea oil meal to pass a 100-mesh sieve.

[0060] Example 6, a method for reducing the IDF content in tea oil cake, is different from Example 1 in that hydrolyzed soy protein and CaSO4 powder are not added in the enzymatic hydrolysis.

[0061] Comparative Example 1, a method for reducing the IDF content in camellia oleifera meal, is different from Example 1 in that alkaline hydrolysis and acid hydrolysis are not used; the camellia oleifera meal is crushed to pass through a 100-mesh sieve.

[0062] Comparative Example 2 is a method for reducing the IDF content in tea oil cake. The difference from Example 1 is that during the microbial fermentation, aerobic fermentation is not performed, but lactic acid bacteria are directly added and anaerobic fermentation is performed for more than 6 days.

[0063] Comparative Example 3, a method for reducing the IDF content in tea oil meal, is different from Example 1 in that after microbial fermentation, sealed anaerobic storage is not adopted, lactic acid bacteria are not added, but the meal is only bagged and placed for more than 6 days.

[0064] Index detection:

[0065] The tea oil meal was treated by the method of reducing the IDF content in the tea oil meal according to Example 1 to Example 6 and Comparative Example 1 to Comparative Example 2, respectively, and the insoluble dietary fiber (IDF) content, soluble dietary fiber (SDF) content, crude protein (CP), crude fat (CF) content, viable bacteria count and aflatoxin (AFT) of the tea oil meal prepared after the treatment were tested.

[0066] Table 1: Comparison of indicators of each embodiment group and comparative example group

[0067] IDF (%) SDF(%) CP (%) CF (%) Number of viable bacteria (billion cfu / g) AFT (μg / kg) Before treatment 58.93 5.67 9.18 1.10 ＜0.01 0.05 Example 1 31.94 30.05 15.04 0.76 12.46 0.38 Example 2 38.32 26.24 8.30 0.80 1.66 0.13 Example 3 27.40 38.40 14.91 0.36 13.92 0.25 Example 4 33.13 28.52 14.68 0.74 10.29 0.30 Example 5 30.23 37.60 14.64 0.66 14.03 0.40 Example 6 34.65 27.45 14.38 0.81 10.19 0.45 Comparative Example 1 36.84 25.26 13.67 0.78 9.04 0.36 Comparative Example 2 35.70 26.40 13.11 0.80 3.32 0.34 Comparative Example 3 28.43 32.27 15.31 0.73 16.86 8.64

[0068] The reference standards for the determination methods of each indicator are: CP refers to GB / T 6432-2018; CF refers to GB / T 6433-2006; IDF and SDF refer to GB / T 22224-2008; the number of viable bacteria is determined by the plate colony count method; AFT refers to NY / T 2071-2011.

[0069] Advantages of this solution:

[0070] The "physical-chemical-enzyme-bacteria" combined treatment process of the present invention can greatly reduce the IDF content in tea oil meal, with a degradation rate of 45.8%, and greatly increase the crude protein content, with an increase of 63.8%.

[0071] The treatment process of this application is gradual and the treatment effect is good. Physical crushing reduces the chemical bonds between cellulose in oil tea meal, enzymatic decomposition decomposes the particle size of chemical particles such as hydrogen bonds and glycosidic bonds, the chemical method further breaks the fiber structure and violent bonds, and the microbial fermentation method improves the degradation speed and efficiency.

[0072] The nutritional value of camellia oil meal is greatly improved through the method of the present application. On the one hand, the present scheme converts part of IDF into SDF, which directly improves the structural composition of dietary fiber of camellia oil meal; on the other hand, yeast uses camellia oil meal as the main carbon source to produce a large amount of microbial protein that is easier to digest and absorb, thereby improving the protein content and protein quality of camellia oil meal.

[0073] The cost of this application plan is controllable. According to the market price of bacteria and enzymes, processing 1 ton of tea cake material will cost about 13 yuan for energy, 2 yuan for chemical reagents, 7 yuan for enzymes, and 8 yuan for bacteria, totaling 30 yuan.

[0074] The cellulase hydrolysis efficiency of this scheme is high because the tea saponin naturally present in the oil-tea camellia meal acts as a surfactant, the added shielding agent, activator and other promoting substances can also improve the cellulase activity, and the acetic acid that maintains the acidic environment can also improve the cellulase hydrolysis efficiency.

[0075] The microbial fermentation speed of the method in the present application is relatively fast. Aspergillus niger, Bacillus subtilis, and yeast all have a higher proliferation rate in an aerobic environment, while Bacillus subtilis and yeast have a higher fermentation speed in an anaerobic environment. Therefore, aerobic fermentation is first performed for about 3 days, and then switched to anaerobic fermentation, which is faster than directly entering anaerobic fermentation.

[0076] This scheme uses lactic acid bacteria anaerobic fermentation for preservation. On the one hand, it greatly reduces the risk of mildew, and the aflatoxin content meets the feed hygiene standards, extending the shelf life. On the other hand, it can also produce lactic acid and improve the flavor of tea meal.

[0077] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for reducing the content of insoluble dietary fiber in tea-leaf meal, characterized in that: The processing steps include: Enzymatic hydrolysis: mixing the camellia oleifera meal powder after acid hydrolysis and alkaline hydrolysis with an enzymatic hydrolysis system for enzymatic hydrolysis, wherein the enzymatic hydrolysis system comprises a mixed enzyme system and an enzymatic hydrolysis aid, wherein the mass ratio of the camellia oleifera meal powder to the mixed enzyme system is 1000:(1-5), and the mixed enzyme system comprises at least one of cellulase, hemicellulase, and ligninase; Microbial fermentation: The enzymatically hydrolyzed camellia meal powder is mixed with a fermentation system and then aerobic fermentation is performed for 2-3 days; the fermentation system includes a mixed bacterial system and a fermentation aid, the mass ratio of the camellia meal powder to the mixed bacterial system is 1000:(0.1-2), the mixed bacterial system includes Aspergillus niger and auxiliary bacteria, and the auxiliary bacteria are Bacillus subtilis and Saccharomyces cerevisiae; Anaerobic fermentation and preservation of finished products: Add lactic acid bacteria to the tea seed cake powder after microbial fermentation, seal the container, and perform anaerobically fermentation for 5 to 7 days to obtain the finished product.

2. The method for reducing the content of insoluble dietary fiber in tea seed meal according to claim 1, characterized in that: In the alkaline hydrolysis, the tea seed meal powder is soaked in an alkaline solution with a pH value of 9.0-13.0, and then washed and dried after hydrolysis for 12-18 hours; In the acid hydrolysis, the oil tea meal powder after alkali hydrolysis is soaked in an acid solution with a pH value of 0.7-3.5, heated to 98-102°C, hydrolyzed for 2-3 hours, and then washed and dried; In the enzymolysis, the enzymolysis aids include a shielding agent, CaSO4 and an acetic acid solution; the mass ratio of the tea seed meal, the mixed enzyme system, the shielding agent, CaSO4 and the acetic acid solution is 1000:(1-5):(1-5):(0.5-1):(5000-10000, the pH value of the acetic acid solution is 3.0-5.0; the enzymolysis temperature is 40-60°C, and the enzymolysis time is 9-12h; after enzymolysis, the water content is dehydrated to 40-60%, and the shielding agent includes a non-ionic surfactant and hydrolyzed soy protein; In the microbial fermentation, the fermentation aid includes bran, brown sugar and urea; the mass ratio of the camellia oleifera meal, the mixed bacteria system, the bran, the brown sugar and the urea is 1000:(0.1-0.5):100:10:10; the camellia oleifera meal and the fermentation aid are mixed, the mixed bacteria system is added, the water content is adjusted, and the temperature of the mixture is controlled at 30-38°C for aerobic fermentation for 2-3 days; During the anaerobic fermentation and storage of the finished product, 0.1 wt % lactic acid bacteria is added to the tea-leaf meal powder after aerobic fermentation by microorganisms, and the mixture is sealed and anaerobic fermented for 5 to 7 days at a temperature of 30 to 38° C. to obtain the finished product.

3. The method for reducing the content of insoluble dietary fiber in oil-tea camellia meal according to claim 2, characterized in that: In the mechanical crushing step, a 10-18 mesh screen is used to filter the tea seed meal powder; in the microbial fermentation product, the water content of the fermented material is 50-60%.

4. The method for reducing the content of insoluble dietary fiber in oil-tea camellia meal according to claim 2, characterized in that: The pH value of the acidic solution is 2.0-3.0; the pH value of the alkaline solution is 9.0-11.

0.

5. The method for reducing the content of insoluble dietary fiber in oil-tea camellia meal according to claim 4, characterized in that: In the alkaline hydrolysis step, the alkaline solution: tea seed meal powder = (2-4):

1.

6. The method for reducing the content of insoluble dietary fiber in oil-tea camellia meal according to claim 4, characterized in that: In the acid hydrolysis step, the acidic solution: tea seed meal powder = (5-10):

1.

7. The method for reducing the content of insoluble dietary fiber in oil-tea camellia meal according to claim 2, characterized in that: The mixed enzyme system in the enzymatic hydrolysis step is a composition of cellulase, hemicellulase and ligninase in a mass ratio of (6-10):(1-2):

1.

8. The method for reducing the content of insoluble dietary fiber in oil-tea camellia meal according to claim 7, characterized in that: The activity of the cellulase is ≥200,000 u / g, the activity of the hemicellulase is ≥100,000 u / g, and the activity of the ligninase is ≥100,000 u / g.

9. The method for reducing the content of insoluble dietary fiber in tea-leaf meal according to claim 2, characterized in that: The mixed bacterial system in the microbial fermentation step is a composition of Aspergillus niger, Bacillus subtilis and Saccharomyces cerevisiae in a mass ratio of (2-4):(1-2):

10.

10. The method for reducing the content of insoluble dietary fiber in tea-leaf meal according to claim 9, characterized in that: The viable bacteria count of the Aspergillus niger is ≥10 billion cfu / g; the viable bacteria count of the Bacillus subtilis is a high-producing cellulase Bacillus with a viable bacteria count of ≥100 billion cfu / g; and the viable bacteria count of the Saccharomyces cerevisiae is ≥20 billion cfu / g.

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