Processing method of enzymolysis corn protein powder

Abstract

The invention discloses a processing method of enzymolysis corn protein powder, and belongs to the technical field of biology. The processing method comprises the following steps: (1) treating corn protein powder with alkali, adding a compound enzyme I, and carrying out I-section enzymolysis to obtain enzymatic hydrolysate; and (2) adding a compound enzyme II and a lactic acid bacteria solution into the enzymatic hydrolysate, carrying out II-stage synchronous enzymolysis and fermentation, and filtering and drying to obtain the enzymolysis corn protein powder. The enzymolysis corn protein powder is prepared by adopting a deep bacterium-enzyme synergistic fermentation method, the protein enzymolysis efficiency is improved, the number of lactic acid bacteria is increased, and the digestion and utilization efficiency and the product taste of the corn protein powder are greatly improved. The feed can be applied to high-end aquatic products, laying fowls and various young animals, the animal production performance can be improved, and the feed cost and the feeding cost are reduced.

Description

Technical Field

[0001] The invention relates to the field of biotechnology, in particular to a method for processing enzymatically hydrolyzed corn protein powder. Background Art

[0002] Corn gluten meal is a byproduct of corn kernels after starch is produced by the food industry or purified by the brewing industry. It has a high protein content, about 62% to 74% protein, accounting for about 65% of dry matter, and is rich in various amino acids, such as methionine, cystine and leucine. In addition, carotene and lutein in corn gluten meal can promote lipid metabolism in broilers. As a high-protein feed raw material, corn gluten meal has application development potential in animal production.

[0003] Although corn gluten meal has a high protein content, its main components are alcohol-soluble protein (68%) and gluten (22%). There is a large area of ​​α-helical structure in the alcohol-soluble protein molecule, which makes it very hydrophobic. Gluten is only soluble in alkaline solution, and the water solubility of the two is poor. Traditional corn gluten meal is made by treating the protein water produced when corn kernels are processed into corn starch using the wet grinding process, and then concentrating, dehydrating, separating, and drying. Due to the differences in processing equipment and production processes, the protein content in corn gluten meal also varies greatly, and the alcohol-soluble protein content is relatively high, which is not conducive to animal digestion and absorption, resulting in greater restrictions on the amount of corn gluten meal used in feed and the objects of use.

[0004] Corn gluten meal can be modified and processed by fermentation and enzymolysis to improve its feeding value. During the fermentation process, the protease produced by microorganisms can decompose the macromolecular protein in corn gluten meal into small molecular peptides and free amino acids, which are easier to be absorbed and utilized by animals. After fermentation, the composition of amino acids in corn gluten meal is more reasonable, supplementing the essential amino acids that were originally lacking, and more in line with the nutritional needs of animals. However, the solid-state fermentation of corn gluten meal also has certain defects. Due to the complexity and uncertainty of the solid-state fermentation process, the quality of fermented corn gluten meal products from different batches is prone to large differences. Generally, the solid-state fermentation cycle is relatively long, which will increase production costs and pose potential pollution risks. The production cycle of enzymatic corn gluten meal is shorter, the quality is more stable, the degree of protein hydrolysis is higher than that of fermented corn gluten meal, and the product value is high. However, there are limitations such as high cost of enzyme preparations, strict requirements for reaction conditions, and large equipment investment. In addition, the amino acid composition of corn gluten meal will not change after enzymolysis, and the balance of amino acids will not improve. Summary of the invention

[0005] The purpose of the present invention is to provide a processing method for enzymatic corn gluten powder to solve the problems existing in the above-mentioned prior art. The present invention adopts a deep bacterial enzyme synergistic fermentation method to prepare enzymatic corn gluten powder, which improves the protein enzymatic hydrolysis efficiency, increases the number of lactic acid bacteria, and greatly improves the digestion and utilization efficiency of corn gluten powder and the product taste. It can be applied to high-end aquatic products, laying poultry and various young animals, can improve animal production performance, and reduce feed costs and breeding costs.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a method for processing enzymatically hydrolyzed corn gluten powder, comprising the following steps:

[0008] (1) treating corn gluten powder with alkali, adding complex enzyme I, performing I-stage enzymolysis, and obtaining an enzymolysis solution;

[0009] (2) adding compound enzyme II and compound bacterial solution to the enzymatic hydrolysis solution to perform stage II simultaneous enzymatic hydrolysis and fermentation, filtering, and drying to obtain the enzymatic hydrolyzed corn gluten powder;

[0010] The complex enzyme I includes alkaline protease and neutral protease; the complex enzyme II includes neutral protease, flavor protease, acid protease and saccharifying enzyme;

[0011] The composite bacterial liquid includes Bacillus coagulans and Streptococcus thermophilus.

[0012] Furthermore, the alkali treatment process is to mix corn gluten meal, alkali and 60-70°C water; the mass ratio of the corn gluten meal, alkali and water is 1:(0.02-0.03):(2-4).

[0013] Optionally, the base includes but is not limited to sodium hydroxide.

[0014] Furthermore, in the complex enzyme I, the inoculation amount of the alkaline protease is 1000-2000U / g, and the inoculation amount of the neutral protease is 500-1000U / g.

[0015] Furthermore, the temperature of the stage I enzymatic hydrolysis is 53°C-60°C, the time is 6-10 hours, and the pH is 8.0±0.2.

[0016] Furthermore, in the complex enzyme II, the inoculation amount of the neutral protease is 800-1000U / g, the inoculation amount of the flavor protease is 300-600U / g, the inoculation amount of the acid protease is 800-1000U / g, and the inoculation amount of the saccharifying enzyme is 100-300U / g.

[0017] Furthermore, in the composite bacterial solution, the ratio of live bacteria of the Bacillus coagulans to the thermophilic Streptococcus is 1:1, and the inoculation amount of the composite bacterial solution is (0.1-5)×10 7 CFU / g.

[0018] Furthermore, the temperature of the stage II simultaneous enzymatic hydrolysis and fermentation is 40°C-50°C, and the time is 18-24h.

[0019] The invention also provides enzymatically hydrolyzed corn protein powder obtained by the processing method.

[0020] The present invention also provides an application of the enzymatically hydrolyzed corn protein powder in preparing animal feed.

[0021] The present invention also provides an animal feed, which contains the enzymatically hydrolyzed corn protein powder.

[0022] The present invention discloses the following technical effects:

[0023] The present invention adopts a deep bacterial enzyme synergistic fermentation method to prepare enzymatic corn gluten powder. Compared with traditional microbial fermentation, deep bacterial enzyme synergistic fermentation can decompose corn gluten powder into smaller molecules, provide better substrates for microbial fermentation, promote the growth and metabolism of microorganisms, and thus improve fermentation efficiency and effect. At the same time, the microbial enzymes produced during the fermentation process can further promote the enzymatic hydrolysis of corn gluten powder, and the two cooperate with each other to jointly improve the nutritional value and functional characteristics of corn gluten powder.

[0024] The present invention improves the protein enzymolysis efficiency (small peptide content and conversion rate) by optimizing the core enzymolysis process, and increases the number of lactic acid bacteria by adding the lactic acid bacteria fermentation process, thereby greatly improving the digestion and utilization efficiency of corn protein powder and improving the product taste. The processing process of the present invention is simple and low in cost. The obtained enzymolysis corn protein powder can be used as a high-quality protein feed raw material to replace high-cost protein raw materials, and is applied to high-end aquatic products, laying poultry and various young animals, which can improve animal production performance and reduce feed costs and breeding costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 The present invention is a process flow chart for preparing enzymatically hydrolyzed corn protein powder;

[0027] Figure 2This is the UV absorption chromatogram of enzymatically hydrolyzed corn gluten meal. DETAILED DESCRIPTION

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0030] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0031] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0032] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0033] Example 1 Enzymatic Hydrolysis Process Optimization

[0034] This example explores the effects of different enzymatic hydrolysis processes on the treatment effect of corn gluten powder. The enzyme preparation is selected from alkaline protease, neutral protease, acidic protease, flavor protease or saccharifying enzyme; the fermentation strain is selected from Bacillus coagulans. The enzymatic hydrolysis scheme is shown in Table 1. The specific process is as follows:

[0035] Take 20 triangular flasks and divide them into 5 groups, with 4 bottles in each group. Add 50g corn gluten powder, 1g sodium hydroxide and 150mL water to each bottle. Add the corresponding protease according to the scheme in Table 1, and then place the triangular flasks in a 45℃ shaker at 150rpm for enzymolysis. Among them, groups C, D and E were enzymolyzed for 6h and the pH of the material was adjusted to 8.0 and the corresponding protease was added. Group E also added saccharifying enzyme and inoculated with 10mL of Bacillus coagulans cultured by MRS. After 30h of enzymolysis, the corn gluten powder was placed in a 90℃ water bath for 15min, and then samples were taken to determine the moisture, pH, acid-soluble protein and crude protein content in the corn gluten powder after enzymolysis in each group.

[0036] The crude protein was determined by the Kjeldahl method. When determining the acid-soluble protein, 15% trichloroacetic acid was used as the extracting solution, and the mixture was shaken well and centrifuged for 5 minutes. The supernatant was taken and the protein content was determined by the Kjeldahl method.

[0037] Table 1 Enzymatic hydrolysis scheme of corn gluten meal

[0038]

[0039] The test results are shown in Table 2. It can be seen that the crude protein content of each group of samples after enzymatic hydrolysis is about 62%, with little difference, but the acid-soluble protein and pH value of each group of enzymatic hydrolysis samples are quite different. The acid-soluble protein content of the material after enzymatic hydrolysis in Group E is the highest, reaching 37.38%, and the acid-soluble protein conversion rate reaches 60%; the pH value is 4.14, the lowest among all groups. Comparing the results of Group B and Group A, it can be seen that the addition of acid protease and flavor protease during enzymatic hydrolysis can increase the acid-soluble protein content of the material after enzymatic hydrolysis. Comparing the results of Group C and Group B, it can be seen that the acid-soluble protein content can be increased by adjusting the pH during enzymatic hydrolysis. Comparing the results of Group D and Group C, it can be seen that the addition of neutral protease during the II stage enzymatic hydrolysis can also increase the acid-soluble protein content of the material after enzymatic hydrolysis. Compared with Group D, saccharifying enzyme and lactic acid bacteria were added to Group E during the II stage enzymatic hydrolysis, which increased the acid-soluble protein content of the material after enzymatic hydrolysis. Therefore, the Group E scheme can obtain the highest acid-soluble protein conversion rate, and subsequent process optimization is carried out based on this scheme.

[0040] Table 2 Effects of different enzymatic hydrolysis schemes on crude protein, acid-soluble protein and pH of enzymatic hydrolysis corn gluten meal (dry basis)

[0041]

[0042]

[0043] Example 2 Screening of fermentation strains

[0044] This example explores the effect of fermentation strains on the treatment effect of corn gluten powder, and the fermentation strains are selected from Bacillus coagulans, Streptococcus thermophilus, Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus casei, Enterococcus faecalis or Pediococcus acidilactici. The specific process is as follows:

[0045] (1) Mix 1000 g corn gluten powder, 20 g sodium hydroxide, and 2000 mL water (60°C) in a ratio of 1:0.02:2.

[0046] (2) Stage I enzymatic hydrolysis

[0047] The premix was added into a 5L fermentation tank, and composite protease (alkaline protease 1000U / g, neutral protease 1000U / g) was added to start timed enzymolysis. The enzymolysis process was maintained at a stirring rate of 150rpm, and the temperature of the material was controlled at 53-55°C. 20% sodium hydroxide solution was added every 2 hours to adjust the pH of the material to 8.0. The total enzymolysis time was 6h.

[0048] (3) Stage II enzymatic hydrolysis and fermentation

[0049] After the I stage of enzymatic hydrolysis, compound protease (flavor protease 300U / g, acid protease 800U / g) and saccharifying enzyme (300U / g) were added and divided into 500mL conical flasks, 200g of enzymatic hydrolysate was added to each bottle, and 5mL of MRS cultured lactic acid bacteria liquid was added respectively. 5mL of MRS culture medium was added to one group as a control, and fermented at 45℃ and 150rpm for 24h.

[0050] (4) Sampling and testing

[0051] Determine the acid-soluble protein, crude protein and lactic acid content in the raw corn gluten meal and the corn gluten meal after enzymatic hydrolysis. Take samples at the end of fermentation to count the number of lactic acid bacteria. Crude protein is determined by Kjeldahl method. When determining acid-soluble protein, use 15% trichloroacetic acid as the extract, shake well, centrifuge for 5 minutes, and take the supernatant to determine the protein content by Kjeldahl method.

[0052] The test results are shown in Table 3. It can be seen that after the inoculation of different lactic acid bacteria in the II stage of enzymatic hydrolysis and fermentation, the acid-soluble protein, lactic acid content and number of live lactic acid bacteria in each group are quite different. Among them, Bacillus coagulans and Streptococcus thermophilus have higher lactic acid bacteria count, lactic acid content and acid-soluble protein content after fermentation than other lactic acid bacteria, while the product indicators of Bacillus coagulans and Streptococcus thermophilus after fermentation and enzymatic hydrolysis are not much different. Therefore, Bacillus coagulans and Streptococcus thermophilus are preferred as fermentation strains, which can greatly improve the acid-soluble protein yield, increase the number of fermented bacteria, and increase the lactic acid content of the product compared with the other four lactic acid bacteria and the group without lactic acid bacteria inoculation.

[0053] Table 3 Effect of inoculation with different lactic acid bacteria on enzymatic hydrolysis of corn gluten meal (dry basis)

[0054]

[0055]

[0056] Example 3 Optimization of inoculum amount of lactic acid bacteria

[0057] This example explores the effect of the inoculation amount of lactic acid bacteria on the treatment effect of corn gluten powder, and the fermentation bacteria are Bacillus coagulans and Streptococcus thermophilus. The specific process is as follows:

[0058] (1) Mix 1000 g corn gluten powder, 20 g sodium hydroxide, and 2000 mL water (60°C) in a ratio of 1:0.02:2.

[0059] (2) Stage I enzymatic hydrolysis

[0060] The premix was added into a 5L fermentation tank, and composite protease (alkaline protease 1000U / g, neutral protease 1000U / g) was added to start timed enzymolysis. The enzymolysis process was maintained at a stirring rate of 150rpm, and the temperature of the material was controlled at 53-55°C. 20% sodium hydroxide solution was added every 2 hours to adjust the pH of the material to 8.0. The total enzymolysis time was 6h.

[0061] (3) Stage II enzymatic hydrolysis and fermentation

[0062] After the I-stage enzymatic hydrolysis, compound protease (neutral protease 800 U / g, flavor protease 600 U / g, acid protease 800 U / g) and saccharifying enzyme (300 U / g) were added and divided into 500 mL conical flasks, with 200 g of enzymatic hydrolysate in each bottle, and lactic acid bacteria were inoculated according to the proportion and addition amount in Table 4, and fermented at 50°C and 150 rpm for 24 h.

[0063] Table 4 Lactic acid bacteria addition amount and inoculation ratio scheme

[0064]

[0065]

[0066] (4) Sampling and testing

[0067] Determine the contents of acid-soluble protein, crude protein, lactic acid, etc. in the raw corn gluten meal and corn gluten meal after enzymatic hydrolysis. Take samples at the end of fermentation to count the number of lactic acid bacteria. Crude protein is determined by Kjeldahl method. When determining acid-soluble protein, use 15% trichloroacetic acid as the extract, shake well, centrifuge for 5 minutes, and take the supernatant to determine the protein content by Kjeldahl method.

[0068] The test results are shown in Table 5. It can be seen that when the inoculation ratio is (0.1-1):(1-0.1), after fermentation and enzymatic hydrolysis, the number of lactic acid bacteria produced in each group is (0.7-1.2)×10 10 CFU / g, much larger than 6.94×10 4CFU / g content; the acid-soluble protein content of each group was greater than 38%, which was also higher than 36.77% of the uninoculated group; the lactic acid content of each group was between 7.5% and 9.0%, much higher than 2.12% of the uninoculated group; the crude protein content of each group was similar, all around 62%. The results showed that the ratio of inoculated Bacillus coagulans to thermophilic Streptococcus was in the range of (0.1-1): (1-0.1), and the inoculation amount was 1×10 6 -1×10 7 CFU / g range, each treatment group can obtain a relatively ideal fermentation effect. When the inoculation ratio of Bacillus coagulans to Streptococcus thermophilus is 1:1, the fermentation and enzymatic hydrolysis effects are the best, and the inoculation amount range is (0.1-5)×10 7 CFU / g have similar excellent effects.

[0069] Table 5 Effects of different proportions and inoculation amounts of lactic acid bacteria on the indicators of enzymatic hydrolysis of corn gluten powder (dry basis)

[0070] Serial number Crude protein% Acid soluble protein% Lactic acid% Lactic acid bacteria count CFU / g Comparison 62.98 36.77 2.12 <![CDATA[6.94×10 4 ]]> 1 63.26 38.33 7.51 <![CDATA[7.69×10 9 <!-- 6 -->]]> 2 62.86 39.06 7.93 <![CDATA[8.01×10 9 ]]> 3 62.85 40.30 8.24 <![CDATA[8.35×10 9 ]]> 4 62.36 40.16 8.43 <![CDATA[1.03×10 10 ]]> 5 61.45 41.47 8.98 <![CDATA[1.21×10 10 ]]> 6 61.61 41.43 8.14 <![CDATA[1.10×10 10 ]]> 7 63.12 39.88 8.25 <![CDATA[9.85×10 9 ]]> 8 62.95 40.27 7.98 <![CDATA[9.39×10 9 ]]> 9 62.88 40.38 7.69 <![CDATA[8.94×10 9 ]]>

[0071] Example 4

[0072] 1. Experimental study on enzymatic hydrolysis of corn gluten powder 1

[0073] 1. Processing method

[0074] (1) Premix dry corn gluten powder, alkali and a small amount of water

[0075] Take 10 kg of corn protein powder, 0.25 kg of calcium hydroxide powder, and 2.5 kg of water, and mix them in a mixer.

[0076] (2) Stage I enzymatic hydrolysis

[0077] Add 20kg of 70℃ hot water to a 50L fermenter, start stirring, slowly add the premixed corn protein powder, stir and mix until the material temperature is 53℃ and pH is 8.9. Then add compound protease (alkaline protease 2000U / g, neutral protease 500U / g) and mix until the enzymolysis starts. The temperature of the enzymolysis process is controlled at 53-55℃. Add 20% sodium hydroxide solution every 2 hours to adjust the pH of the material to 8.0±0.2. The total enzymolysis time is 6h.

[0078] (3) Stage II enzymatic hydrolysis and fermentation

[0079] After the I stage of enzymatic hydrolysis, the temperature was lowered to 45°C, and composite protease was added for the II stage of enzymatic hydrolysis and fermentation. The amount of acid protease and neutral protease added was 1000U / g, and the amount of flavor protease added was 400U / g. A mixed strain of Bacillus coagulans and Streptococcus thermophilus was added, with a live bacterial count ratio of 1:1 and a total inoculation amount of 1×10 7CFU / g. 200U / g of saccharifying enzyme was added. The timing was started from the addition of lactic acid bacteria, compound protease and saccharifying enzyme, and the fermentation and enzymolysis was maintained at 45℃ for 18h. The pH of the fermentation and enzymolysis process was not controlled.

[0080] (4) Spray drying

[0081] After the enzymatic hydrolysis was completed, the temperature was raised to 80°C and maintained for 10 min, after which the enzymatic hydrolyzate was passed through a 100-mesh sieve and spray-dried.

[0082] 2. Detection indicators

[0083] The acid-soluble protein, crude protein and lactic acid contents in the raw corn gluten meal and enzymatically hydrolyzed corn gluten meal were determined, and samples were taken to count the number of lactic acid bacteria at the end of fermentation.

[0084] 2. Experimental study on enzymatic hydrolysis of corn gluten powder 2

[0085] 1. Processing method

[0086] (1) Premix dry corn gluten powder, alkali and a small amount of water

[0087] Take 10 kg of corn protein powder, 0.30 kg of calcium hydroxide powder, and 4.0 kg of water, and mix them in a mixer.

[0088] (2) Stage I enzymatic hydrolysis

[0089] Add 20kg of 70℃ hot water into a 50L fermenter, add the premixed material into the fermenter, stir and mix until the material temperature is 53℃ and pH is 9.1, then add composite protease (alkaline protease 1000U / g, neutral protease 500U / g) and mix until the enzymolysis starts. The temperature of the enzymolysis process is controlled at 57-60℃. Add 20% sodium hydroxide solution every 2 hours to adjust the pH of the material to 8.0±0.2. The total enzymolysis time is 10h.

[0090] (3) Stage II enzymatic hydrolysis and fermentation

[0091] After the I stage of enzymatic hydrolysis, the temperature was lowered to 45 °C, and composite protease was added for the II stage of enzymatic hydrolysis and fermentation. The amount of acid protease and neutral protease added was 800 U / g, the amount of flavor protease added was 300 U / g, and a mixed strain of Bacillus coagulans and Streptococcus thermophilus was added, with a live bacterial count ratio of 1:1 and a total inoculation amount of 1×10 7 CFU / g, and glucoamylase was added at the same time, with an addition amount of 200U / g. The timing started from the addition of lactic acid bacteria, compound protease and glucoamylase, and the fermentation and enzymolysis was maintained at 45℃ for 24h. The pH of the fermentation and enzymolysis process was not controlled.

[0092] (4) Spray drying

[0093] After the enzymatic hydrolysis was completed, the temperature was raised to 80°C and maintained for 10 min, after which the enzymatic hydrolyzate was passed through a 100-mesh sieve and spray-dried.

[0094] 2. Detection indicators

[0095] The acid-soluble protein, crude protein and lactic acid contents in the raw corn gluten meal and enzymatically hydrolyzed corn gluten meal were determined, and samples were taken to count the number of lactic acid bacteria at the end of fermentation.

[0096] 3. Experimental Results

[0097] The test results are shown in Table 6. It can be seen that in the small test 1, after the corn protein powder raw material was fermented and enzymatically processed by this process, the acid-soluble protein (small peptide) increased from 2.07% to 41.47%, which was increased by about 20 times, the lactic acid content increased from 1.28% to 7.84%, the starch content decreased from 17.47% to 8.23%, the crude protein content was 62.85%, and the small peptide conversion rate reached 66.00%; the results of small test 2 were similar to those of small test 1. After fermentation and enzymatic processing, the acid-soluble protein (small peptide) increased from 2.05% to 41.79%, which was also increased by about 20 times, the lactic acid content increased from 1.31% to 8.03%, the starch content decreased from 17.83% to 8.49%, the crude protein content was 63.14%, and the small peptide conversion rate reached 66.19%. The results of the two batches were similar, indicating that the product obtained by the process of the present invention was relatively stable.

[0098] Table 6 Comparison of corn gluten meal before and after enzymatic fermentation in small test (dry basis)

[0099]

[0100] Example 5

[0101] Pilot test of enzymatic hydrolysis of corn gluten meal

[0102] 1. Processing method

[0103] (1) Premix dry corn gluten powder, alkali and a small amount of water

[0104] Take 500 kg of corn gluten powder, 12.5 kg of calcium hydroxide powder, and 125 kg of water, and mix them in a mixer.

[0105] (2) Stage I enzymatic hydrolysis

[0106] Add 1000kg of 70℃ hot water to a 5t fermentation tank, add the premixed material to the tank, stir and mix until the material temperature is 55℃ and pH is 9.0. Then add compound protease (1000U / g alkaline protease, 700U / g neutral protease) and mix until the enzymolysis starts. The temperature of the enzymolysis process is controlled at 55℃±2℃. Add 20% sodium hydroxide solution every 2 hours to adjust the pH of the material to 8.0±0.1. The total enzymolysis time is 10h.

[0107] (3) Stage II enzymatic hydrolysis and fermentation

[0108] After the end of the I stage enzymatic hydrolysis, the fermentation tank was cooled to 45°C, and composite protease was added for the II stage enzymatic hydrolysis and fermentation. The amount of acid protease and neutral protease added was 1000U / g, the amount of flavor protease added was 300U / g, and a mixed strain of Bacillus coagulans and Streptococcus thermophilus was added at the same time, with a live bacterial count ratio of 1:1 and a total inoculation amount of 1×10 7 CFU / g, and glucoamylase was added at the same time, with an addition amount of 100U / g. The timing started from the addition of lactic acid bacteria, compound protease and glucoamylase, and the fermentation and enzymolysis was maintained at 45℃ for 24h. The pH of the fermentation and enzymolysis process was not controlled.

[0109] (4) Spray drying

[0110] After the enzymatic hydrolysis was completed, the temperature was raised to 80°C and maintained for 10 min, after which the enzymatic hydrolyzate was passed through a 100-mesh sieve and spray-dried.

[0111] 2. Detection indicators

[0112] The acid-soluble protein, crude protein and lactic acid contents in the corn gluten meal raw material and enzymatically hydrolyzed corn gluten were determined, and samples were taken to count the number of lactic acid bacteria at the end of fermentation.

[0113] 3. Experimental results

[0114] The test results are shown in Table 7. It can be seen that in the pilot experiment, after the corn gluten meal raw material was fermented and enzymatically processed by this process, the acid-soluble protein (small peptide) increased from 2.07% to 42.03%, an increase of about 20 times, the lactic acid content increased from 1.32% to 7.85%, the crude protein content was 62.45%, the small peptide conversion rate reached 67.30%, and the number of lactic acid bacteria after fermentation reached 1.19×10 10 The results are similar to those in Example 4, indicating that the process of the present invention is stable.

[0115] Table 7 Comparison of corn gluten meal before and after pilot enzymatic fermentation (dry basis)

[0116] sample Corn Gluten Meal Enzymatic corn egg powder Acid soluble protein (small peptide) % 2.07 42.03 Crude protein% 66.47 62.45 Lactic acid% 1.32 7.85 Small peptide conversion rate % / 67.30 Lactic acid bacteria count CFU / g / <![CDATA[1.19×10 10 ]]>

[0117] Example 6

[0118] In order to explore the effect of bacterial enzyme synergistic fermentation treatment on the amino acid content in corn protein powder, the enzymatic corn protein powder prepared in Example 5 was used as a sample to detect the amino acid content. The test results are shown in Table 8. It can be seen that the total amino acid content in the enzymatic corn protein powder prepared by the method of the present invention is slightly reduced, from 63.89% to 59.67%, a decrease of 4.22%. This is because the addition of alkali during the fermentation process "dilutes" the crude protein content. In addition, due to the growth and metabolism of lactic acid bacteria during the fermentation process, the amino acid composition has a greater change than the raw material, and the proportion of total essential amino acids in the total amino acids has slightly decreased, but the overall difference is not large.

[0119] Table 8 Effect of enzymatic fermentation on the amino acid content in corn gluten meal

[0120]

[0121]

[0122] Example 7

[0123] In order to explore the effect of bacterial enzyme synergistic fermentation treatment on the amino acid content in corn gluten powder, the enzymatic hydrolyzed corn gluten powder prepared in Example 5 was used as a sample to analyze the protein molecular weight. The specific process is as follows:

[0124] (1) Sample preparation: Take an appropriate amount of enzymatically hydrolyzed corn gluten powder sample, dissolve it in water to make the final concentration 5 μg / μL, centrifuge it at 4°C, 12000 rcf for 10 min, and prepare the supernatant for loading on the machine.

[0125] (2) Liquid chromatography conditions

[0126] 1) Column temperature is 25°C;

[0127] 2) Flow rate: 0.7 mL / min;

[0128] 3) The injection volume is 10 μL;

[0129] 4) Chromatographic column: BioCore SEC-1205 μm, 7.8×300 mm;

[0130] 5) Mobile phase: 150mmol / L phosphate mobile phase (8.99g anhydrous sodium dihydrogen phosphate, 10.65g anhydrous disodium hydrogen phosphate in 1L water);

[0131] 6) Detection wavelength: UV 214nm.

[0132] Test results such as Figure 2As shown in Table 9, it can be seen that the protein molecular weight distribution of the sample is mainly concentrated between 100-1000Da, accounting for about 63% of the soluble protein, and 25.63% of the soluble protein is hydrolyzed into amino acids with a molecular weight of less than 100Da, and only a small amount of protein has a molecular weight greater than 3000Da, indicating that after fermentation and enzymatic hydrolysis by the method of the present invention, the macromolecular protein in the corn protein powder is mainly decomposed into small peptides with a molecular weight of less than 1000Da.

[0133] Table 9 Molecular weight distribution of enzymatically hydrolyzed corn gluten meal

[0134] Components Molecular weight range Area % 1 ≥10 kDa 0.00 2 5-10 kDa 0.08 3 3-5 kDa 0.44 4 1-3 kDa 10.15 5 0.5-1kDa 25.98 6 0.5-0.1 kDa 37.73 7 0.1kDa 25.62 total - 100

[0135] Example 8

[0136] In order to explore the effect of the enzymatically hydrolyzed corn gluten meal prepared by the method of the present invention replacing fish meal on the growth performance of juvenile sea bass, the enzymatically hydrolyzed corn gluten meal prepared in Example 5 was used as a sample to replace fish meal for experiments.

[0137] Healthy and similar-weight fry of striped seabass were selected and divided into three treatment groups (CK, D1, and D2). Three breeding boxes were set up in each treatment group, and 30 striped seabass fry were raised in each breeding box. The striped seabass fry used in the experiment came from the same batch of fry from the same company. The striped seabass fry with an initial weight of 12.20±1.20g were selected from them, and the experiment began after one week of adaptation. The experimental period was 56 days, and they were fed twice a day at 8:30 and 16:00. During the breeding period, water quality was tested every day. The water temperature was about 28℃, the salinity was 16‰~22‰, the dissolved oxygen concentration was>5.0mg / L, and the ammonia nitrogen concentration was<0.05mg / L. The experimental feed formula and ingredients are shown in Table 10. Among them, CK is a conventional feed; D1 is a feed with 3% enzymatic corn gluten meal added to replace the same amount of fish meal; D2 is a feed with 6% enzymatic corn gluten meal added to replace the same amount of fish meal.

[0138] Table 10 Feed formula and ingredients (%)

[0139]

[0140]

[0141] Measurement indicators and methods: Record and clean the feed amount, feed residue and number of dead seabass in each breeding box every day, calculate the survival rate, measure the weight of each seabass, and calculate the weight gain rate and feed coefficient.

[0142] Calculation method:

[0143] Weight gain rate (%) = (m 1 -m 2 ) / m 2 (1)

[0144] Among them, m 1 is the mass after the test, m 2 The quality before the test.

[0145] Feed coefficient = (R 1 -R 2 ) / (m 3 +m 4 -m 5 )(2)

[0146] Among them, R 1 and R 2 are the amount of feed and residual feed, m 3 is the total mass of the fish at the end, m 4 is the total mass of dead fish, m 5 is the initial total fish mass.

[0147] Statistical analysis and variance analysis of each element index were analyzed using Microsoft EXCEL 2010 and IBM SPSS Statistics 26 software.

[0148] The test results are shown in Table 11. It can be seen that in the conventional sea bass feed formula, the enzymatic corn gluten meal of the present invention is used to replace 3% or 6% of fish meal, and there is no significant difference in the survival rate, weight gain rate, specific growth rate and feed coefficient of sea bass (p>0.05), indicating that the product of the present invention can replace part of the fish meal in the use of sea bass feed, reduce the feed cost, and has no significant effect on the growth index of sea bass.

[0149] Table 11 Effects of enzymatic corn gluten meal on growth performance indicators of Lateolabrax

[0150]

[0151]

[0152] Example 9

[0153] In order to explore the effect of replacing fish meal with different proportions of enzymatic corn gluten meal on the growth performance of Penaeus monodon, an experiment was carried out using the enzymatic corn gluten meal prepared in Example 5 as a sample.

[0154] 900 Penaeus monodon with a body weight of about 13.20±0.10g and healthy and vigorous were selected and divided into three treatments (CK, T1, T2). Three cages were set up in each treatment, and 100 Penaeus monodon were raised in each cage. The content of fish meal and enzymatic corn gluten meal added to each treatment is as follows. The experimental feed formula and ingredients are shown in Table 12. Among them, CK uses fish meal as the main protein raw material; T1 uses enzymatic corn gluten meal to replace 3% of fish meal; T2 uses enzymatic corn gluten meal to replace 6% of fish meal.

[0155] Table 12 Formula and composition of basic feed for Penaeus monodon (%)

[0156]

[0157]

[0158] Determination indicators and methods: Clean and record the number of dead Penaeus monodon in each cage every day, and calculate the survival rate. Measure the weight of each shrimp, and calculate the weight gain rate, specific growth rate and feed efficiency.

[0159] The test results are shown in Table 13. It can be seen that the survival rates of Penaeus monodon in the CK group, T1 and T2 treatment groups were 99.0%, 98.5% and 98.0% respectively, and there was no significant difference in survival rate among the groups. The weight gain rate and specific growth rate of the T2 treatment group were slightly lower than those of the CK group, but there was no significant difference. There was no significant difference in feed coefficient between the T1 and T2 treatment groups compared with the CK group (p>0.05). It shows that the use of the enzymatic corn protein powder of the present invention to replace 3% or 6% fish meal has no significant effect on the growth index of Penaeus monodon, and this product can be used to replace part of the fish meal in feeding to reduce feed costs.

[0160] Table 13 Survival rate and growth index of each group of Penaeus monodon

[0161] Group CK T1 T2 Initial body weight (g) 13.21±0.04 13.25±0.06 13.40±0.11 Final body weight (g) 31.74±1.62 31.92±2.21 31.37±3.22 Survival rate (%) 99.00±1.00 98.50±1.50 98.00±1.00 Weight gain rate (%) 140.21±4.85 141.73±3.59 133.62±7.41 Specific growth rate (%) 1.50±0.04 1.53±0.02 1.47±0.03 Feed Coefficient 1.74±0.03 1.74±0.05 1.79±0.10

[0162] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for processing enzymatically hydrolyzed corn gluten meal, characterized in that: The steps include: (1) treating corn gluten powder with alkali, adding complex enzyme I, performing I-stage enzymolysis, and obtaining an enzymolysis solution; (2) adding compound enzyme II and compound bacterial solution to the enzymatic hydrolysis solution to perform stage II simultaneous enzymatic hydrolysis and fermentation, filtering, and drying to obtain the enzymatic hydrolyzed corn gluten powder; The complex enzyme I includes alkaline protease and neutral protease; the complex enzyme II includes neutral protease, flavor protease, acid protease and saccharifying enzyme; The composite bacterial liquid includes Bacillus coagulans and Streptococcus thermophilus.

2. The processing method according to claim 1, characterized in that: The alkali treatment process is to mix corn gluten powder, alkali and water at 60-70° C.; the mass ratio of the corn gluten powder, alkali and water is 1:(0.02-0.03):(2-4).

3. The processing method according to claim 1, characterized in that: In the complex enzyme I, the inoculation amount of the alkaline protease is 1000-2000 U / g, and the inoculation amount of the neutral protease is 500-1000 U / g.

4. The processing method according to claim 1, characterized in that: The temperature of the stage I enzymatic hydrolysis is 53° C.-60° C., the time is 6-10 h, and the pH is 8.0±0.

2.

5. The processing method according to claim 1, characterized in that: In the complex enzyme II, the inoculation amount of the neutral protease is 800-1000U / g, the inoculation amount of the flavor protease is 300-600U / g, the inoculation amount of the acid protease is 800-1000U / g, and the inoculation amount of the saccharifying enzyme is 100-300U / g.

6. The processing method according to claim 1, characterized in that: In the composite bacterial solution, the ratio of live bacteria of Bacillus coagulans to thermophilic Streptococcus is 1:1; the inoculation amount of the composite bacterial solution is (0.1-5)×10 7 CFU / g.

7. The processing method according to claim 1, characterized in that: The temperature of the stage II simultaneous enzymatic hydrolysis and fermentation is 40°C-50°C, and the time is 18-24 hours.

8. Enzyme-hydrolyzed corn gluten meal obtained by the processing method according to any one of claims 1 to 7.

9. Use of the enzymatically hydrolyzed corn gluten meal according to claim 8 in preparing animal feed.

10. An animal feed, characterized in that: The animal feed contains the enzymatically hydrolyzed corn gluten meal according to claim 8.

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