Preparation method of high-fat high-emulsibility corn enzymolysis protein for feed

Abstract

The invention relates to the technical field of feed processing, and provides a preparation method of high-fat and high-emulsibility corn enzymolysis protein for feeds, which comprises the following steps: S1, weighing corn protein raw materials, adding water, uniformly stirring, heating, adjusting the pH value to 8.5-9.5, then adding alkaline protease, and carrying out enzymolysis at a certain temperature for a period of time to obtain corn protein enzymolysis liquid; s2, fat is added into the corn protein enzymatic hydrolysate treated in the step S1, stirring continues for a period of time, and turbid liquid is obtained; s3, homogenizing the turbid liquid treated in the step S2 through a high-pressure homogenizer to obtain emulsion with finer particles; and S4, carrying out spray drying on the emulsion obtained in the step S3 to obtain the high-fat and high-emulsibility corn enzymolysis protein. The preparation method disclosed by the invention can be used for solving the problems of excessive external fat addition, processing difficulty, non-uniform fat distribution, fat leakage and the like in the feed processing process.

Description

Technical Field

[0001] The invention relates to the field of feed, and in particular to a method for preparing high-fat and high-emulsification corn enzymatically hydrolyzed eggs for feed. Background Art

[0002] In order to achieve higher feed conversion efficiency and faster growth rate for aquatic products and broilers, it is usually necessary to increase the energy level of feed. Fat, as a high-energy substance, is an important form of energy supplement. The 2011 edition of NRC "Nutritional Requirements of Fish and Shrimp" recommends that the fat content of shrimp feed is 5-6%, and the fat content of fish feed needs to reach 5-20% depending on the variety; GB / T19664-2005 "Technical Regulations for Commercial Broiler Production" recommends that the fat content of broiler feed needs to reach 3-5%. The fat content of conventional plant feed raw materials is 1-20%, and the energy needs cannot be met by the combination of raw materials alone, and additional fat is often required. However, the additional addition of fat will bring difficulties in granulation to feed processing. In order to alleviate the difficulty of granulation, the prior art generally adopts the method of adding part of the fat by post-spraying after granulation, but it will face problems such as poor oil adsorption effect and oil leakage.

[0003] For example, the Chinese patent with publication number CN208387844U discloses a two-stage modulator for aquatic feed. The first modulator is connected to the oil supply system to achieve the ratio molding of the high-fat content aquatic feed packaging raw materials. The second modulator achieves full mixing and adsorption of fat, solving the problem of insufficient fat content and uneven fat distribution in aquatic feed. The Chinese patent with patent publication number CN209031196U discloses a high-fat aquatic feed puffing machine, which is puffed after two temperings, realizing the production of aquatic feed with high fat content and uniform fat distribution. The above patents only use fat and raw materials for tempering and then adsorption. Due to the lack of emulsification of the raw materials and weak tempering strength, there are problems such as low fat content in the product, poor fat stability, and fat leakage during the granulation process.

[0004] Therefore, there is no ideal method for adding fat externally in the industry. How to introduce an appropriate amount of fat into the feed to meet the needs of feed use and alleviate the problems in feed processing is particularly important. This patent enzymatically hydrolyzes part of the protein that should be added to the formula into small molecule peptides with a molecular weight of 150-1000Da in advance, and uses its good emulsifying properties to fully emulsify the added fat. After drying, it is made into a uniformly dispersed protein fat powder, and is evenly introduced into the feed according to the required amount of the formula. It can solve the problems faced in the feed processing process, such as excessive addition of external fat, difficult processing, uneven fat distribution, and fat leakage. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a high-fat and high-digestibility corn protein hydrolysate for feed, wherein the corn protein hydrolysate has a fat content of ≥20%, good fat stability, an emulsion stability index ESI increased by about 30-35 times, and an oil leakage rate of ≤0.1% during the granulation process, which can solve the problems of excessive fat addition, processing difficulties, uneven fat distribution, fat leakage, etc. faced in the feed processing process. The inventor found in the research process that: the part of the protein that should be added in the formula is hydrolyzed in advance into a small molecule peptide with a molecular weight of 150-1000Da, and the good emulsification property is used to fully emulsify the added fat, and after drying, it is made into a uniformly dispersed protein fat powder, and is evenly introduced into the feed according to the required amount of the formula, so that the additional fat addition amount can be reduced, thereby alleviating the problems in feed processing.

[0006] Therefore, the embodiments of the present invention are implemented by the following technical solutions:

[0007] A method for preparing high-fat and high-emulsification corn enzymatic protein for feed, which is prepared by the following steps:

[0008] S1: Weigh corn protein raw material, add water at a ratio of raw material weight to water weight = 100:200, stir evenly, heat to 58-62°C, adjust pH to 8.5-9.5, add alkaline protease with an enzyme activity of 200000U / g at a ratio of raw material weight to alkaline protease weight = 100:0.3-0.5, maintain the temperature at 58-62°C for enzymolysis for 6 hours;

[0009] S2: Add fat to the material treated in step S1 at a ratio of raw material weight to fat weight of 100:25-50, and continue stirring for 30 minutes to obtain a suspension;

[0010] S3: homogenizing the suspension treated in step S2 by a high-pressure homogenizer at a pressure of 400±50 bar to obtain an emulsion with finer particles;

[0011] S4: spray drying the emulsion obtained in step S3, with an air inlet temperature of 200±10° C. and an air outlet temperature of 90±10° C., to obtain the high-fat corn enzymatic protein powder.

[0012] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects:

[0013] The preparation method of the present invention first performs enzymatic hydrolysis on the corn protein raw material to improve the water solubility of the protein, fully expose the hydrophilic and hydrophobic groups, wherein the content of small molecule peptides with a molecular weight of 150-1000Da accounts for ≥34% of the protein percentage, greatly improving its emulsification performance; then fat is introduced to fully mix it with the protein emulsion, and then homogenized by a high-pressure homogenizer, on the one hand, the unhydrolyzed particles are torn into particles with smaller particle size under high pressure and high shear force, further improving its emulsification performance, and on the other hand, the material and fat are fully emulsified; after drying, a corn enzymatic protein powder product with uniform fat dispersion is obtained, and the fat content is high, the stability is good, and it is easy to process. The corn enzymatic protein prepared by the present invention has a small molecule peptide content with a molecular weight of 150-1000Da accounting for ≥34% of the protein percentage, a fat content of ≥20%, and good fat stability, the emulsion stability coefficient is increased by about 30-35 times, and the oil leakage rate during the granulation process is ≤0.1%. Therefore, adding fat-rich corn enzymatic protein powder to feed can reduce the amount of additional fat added while meeting feed usage needs, and solve problems faced in feed processing such as excessive addition of external fat, poor oil adsorption, uneven fat distribution, and fat leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 This is the corn enzymatic protein A prepared in Example 1 of the present invention.

[0016] Figure 2 The stratification of the liquid of corn enzymatic protein A prepared in Example 1 of the present invention before drying;

[0017] Figure 3 The stratification of the dried powder of corn enzymatic protein A prepared in Example 1 of the present invention after re-dissolution;

[0018] Figure 4 The stratification of the corn enzymatic protein A prepared in Example 1 of the present invention after the liquid was left for 24 hours before drying;

[0019] Figure 5 This is the stratification of the dried powder of corn enzymatic protein A prepared in Example 1 of the present invention after it was redissolved and left for 24 hours. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0021] Example 1

[0022] This embodiment provides a high-fat and high-emulsification corn protein hydrolysate for feed, the preparation process of which includes the following steps:

[0023] S1: Raise the temperature of the water storage tank to 65°C, and weigh 1000kg of water into the enzymolysis tank, weigh 400kg of corn gluten powder and put it into the enzymolysis tank, start stirring, set the temperature to 60°C, weigh 8.5kg of sodium hydroxide, dissolve it in 8.5kg of water, and slowly add it to the enzymolysis tank until the pH value of the solution reaches 9.0, then weigh 1.6kg of alkaline protease and add it to the enzymolysis tank, maintain the temperature at 60±1°C, and continue enzymolysis for 6h;

[0024] S2: Weigh 120 kg of fish oil and add it to the material treated in step S1, and continue stirring for 0.5 hours to obtain a suspension;

[0025] S3: homogenizing the suspension treated in step S2 by a high-pressure homogenizer at a pressure of 400±50 bar to obtain an emulsion;

[0026] S4: spray drying the emulsion obtained in step S3, maintaining the air inlet temperature at 200°C and the air outlet temperature at 90°C, to obtain a powdered fat-rich corn protein A. Figure 1 shown.

[0027] Experimental Example 1

[0028] In this experimental example, various indicators of corn protein powder raw material and corn enzymatic protein A prepared in Example 1 were tested, and the results are shown in Table 1:

[0029] Table 1 Detection indexes of corn gluten meal and corn protein A

[0030]

[0031] It can be seen from the results in Table 1 that the present invention can produce corn enzymatic protein powder with high fat content.

[0032] Experimental Example 2

[0033] In this experimental example, the stratification of corn protein A prepared in Example 1 was observed, including the stratification of the liquid before drying and the stratification of the powder after drying and re-dissolving. Figure 2-5 shown.

[0034] in Figure 2 is the stratification of the liquid before drying, Figure 3 This is the stratification of the dried powder after re-dissolution. Figure 4 This is the stratification of the liquid before drying after 24 hours. Figure 5 This is the stratification of the dried powder after it is re-dissolved and left for 24 hours.

[0035] Depend on Figure 2-5 It can be seen that the high-fat and high-emulsifying corn protein A prepared by the present invention has good fat emulsification effect, good emulsification stability and uniform fat distribution.

[0036] Experimental Example 3

[0037] This experimental example measures the emulsification stability coefficient of corn protein powder and corn protein hydrolyzate A prepared in Example 1.

[0038] Take 50g of material, add 150ml of water to mix evenly, and centrifuge to obtain supernatant; take 20ml of supernatant, add 20g of fish oil, and homogenize with a high-speed homogenizer at 8000rpm for 1 minute to make an emulsion; use a pipette to take 100ul of emulsion from the bottom, add it to 10ml0.1% SDS buffer and mix evenly; add 100ul of pure water to 10ml0.1% SDS buffer as a blank control, and measure the absorbance A1 at a wavelength of 500nm; after 10 minutes, take 100ul of emulsion again, dilute it in the same way, and measure the absorbance A2 at a wavelength of 500nm; calculate the emulsification stability index ESI according to the following formula.

[0039] ESI=A1×t / (A1-A2), where t is 10min.

[0040] The measured emulsion stability coefficients are shown in Table 2.

[0041] Table 2 Emulsification stability coefficient of corn protein powder and corn protein hydrolysate A

[0042]

[0043] As can be seen from Table 2, the emulsification stability coefficient of the corn enzymatic protein A prepared by the present invention is increased by 31.5 times.

[0044] Experimental Example 4

[0045] This experimental example measures the oil leakage rate of pellet feed made according to the feed formula of corn protein powder and corn enzymatic protein A prepared in Example 1.

[0046] The control group was pelletized by mixing corn gluten meal, fish oil and corn flour in a ratio of 30:6:74; the experimental group was pelletized by mixing enzymatic corn gluten meal A and corn flour in a ratio of 36:74. The pellet feeds were weighed and recorded as B1; they were placed on oil-absorbing paper and left at room temperature for 24 hours, and the pellet feeds were weighed again and recorded as B2; the oil leakage rate was calculated according to the following formula.

[0047] Oil leakage rate = (B1-B2) / B1×100%.

[0048] The measured oil leakage rates are shown in Table 3.

[0049] Table 3 Oil leakage rate after granulation of corn protein powder and corn protein A

[0050]

[0051] As shown in Table 3, when the corn enzymatic protein A prepared by the present invention is uniformly mixed with corn flour at a ratio of 36% and then granulated, the oil leakage rate is reduced by 96.8%.

Claims

1. A method for preparing high-fat and high-emulsification corn protein hydrolysate for feed, characterized in that: The following steps are involved: S1: Weigh corn protein raw material, add water at a ratio of raw material weight to water weight = 100:200, stir evenly, heat to 60±1°C, adjust pH to 8.5-9.5, add alkaline protease with an activity of 200000U / g at a ratio of raw material weight to alkaline protease weight = 100:0.3-0.5, maintain the temperature at 58-62°C for enzymolysis for 6 hours; S2: Add fat to the material treated in step S1 at a ratio of raw material weight to fat weight of 100:25-50, and continue stirring for 30 minutes to obtain a suspension; S3: homogenizing the suspension treated in step S2 by a high-pressure homogenizer at a pressure of 400±50 bar to obtain an emulsion with finer particles; S4: spray drying the emulsion obtained in step S3, with an air inlet temperature of 200±10° C. and an air outlet temperature of 90±10° C., to obtain the high-fat and high-emulsification corn enzymatic protein.

2. The method for preparing high-fat and high-emulsification corn protein hydrolysate for feed according to claim 1, characterized in that: In S2, the fat includes one or more of fish oil, soybean oil, rapeseed oil, cottonseed oil, sunflower seed oil, corn oil, rice oil, etc.

3. A method for preparing high-fat and high-emulsification corn protein hydrolysate for feed, characterized in that: The content of small molecule peptides with a molecular weight of 150-1000Da accounts for ≥34% of the protein percentage, the fat content is ≥20%, the fat stability is good, the emulsion stability index ESI is increased by about 30-35 times, and the oil leakage rate during the granulation process is ≤0.1%.

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