Preparation method and application of microcapsule coated lysine

Abstract

The application discloses a preparation method and application of micro-capsule coated lysine. The preparation method is as follows: (1) uniformly mixing lysine raw materials with palm oil, atomizing small liquid drops by using a nozzle system, and forming particles by cooling; (2) putting the obtained particles into a fluidized bed coating machine, spraying encapsulating agents (i.e. coating materials) to uniformly cover the outer surfaces of the particles, and forming a micro-capsule structure. The content of the final product micro-capsule coated lysine is as high as 72%. The two-step method is used to combine the spray cooling technology and the fluidized bed coating technology, the prepared micro-capsule coated lysine particles are small and uniform, the slow-release effect is good, the rumen bypass rate is high, and the growth performance and production efficiency of ruminants can be improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of livestock feed processing, and particularly relates to a preparation method and application of microencapsulated lysine. BACKGROUND

[0002] Amino acids, as one of the important nutritional components of ruminants, play an important role in the body's nutritional metabolism, immune function, growth performance and production performance. Ruminants have a different digestive system from monogastric animals. The dietary protein and amino acids are decomposed by rumen microorganisms in the rumen, and only a small amount reaches the small intestine and is absorbed and utilized by the body. Therefore, they are usually added in the form of rumen-protected amino acids.

[0003] A large number of studies have shown that lysine is one of the most important limiting amino acids for ruminants, and the order of limitation usually depends on its relative content in rumen non-degradable protein and animal species and feed composition. Therefore, supplementing rumen-protected lysine in the feed is a way to optimize the production performance of ruminants and reduce nitrogen excretion.

[0004] Rumen-protected technology is a special processing method for nutrients, which can reduce the degradation of nutrients in the rumen or release them slowly, so that they can be digested and absorbed in the true stomach or small intestine of ruminants. Among them, the microencapsulation technology is a kind of rumen-protected technology that is widely used in ruminant nutrition in recent years, has an advanced production method and good rumen-protected effect. This technology uses special equipment to coat the film material on the surface of the nutrient, which can ensure that the nutrient is not degraded in the rumen and is released, digested and absorbed in the true stomach or small intestine of ruminants.

[0005] In the microencapsulation technology, spray drying or spray cooling method is often used for particle preparation. Spray cooling and spray drying are the same device, but the air supply process is opposite. Spray cooling initially sends the melt, and then sends cold air to the specified temperature to cool and solidify the carrier to encapsulate the nutrients; spray drying sends the suspension, and finally dry stage sends hot air to blow off water and other unnecessary liquids. Spray drying consumes a lot of energy, and the thermal efficiency is not high. When producing small particle products, about 20% of microparticles are entrained in the waste gas, and high-efficiency separation devices need to be selected, the auxiliary devices are relatively complex, and the cost is relatively high. The energy consumption of spray cooling is relatively low, because it mainly relies on water molecules to be atomized to dissipate heat, rather than a large amount of electricity. The spray cooling system is simple to operate and easy to implement, and when producing small particle products, microparticles are concentrated in the cooling chamber, which is convenient for collection.

[0006] Fluidized bed coating technology is a high-efficiency and continuous particle coating technology, which can realize uniform mixing between materials and coating agents, so as to obtain uniformly coated products. Compared with traditional particle coating technology, fluidized bed coating technology has better coating uniformity and can effectively improve the coating quality. Bottom spraying and top spraying are two common process types of fluidized bed. In the top spraying process, the coating liquid and the particle movement direction are opposite, so the distance from the spray gun outlet to the particle surface is relatively increased, the hot air inlet volatilizes the droplet medium, which may affect the viscosity and spreading film properties of the droplet, and even cause a large amount of spray drying of the coating liquid if the process control is not good. In the bottom spraying process, the coating liquid and the particle movement direction are the same. The spray gun sprays from the bottom of the fluidized bed upward, uniformly sprays the coating liquid on the surface of the particles, and the particles contact with the hot air during the rising process to complete the drying. Therefore, the coating effect of the bottom spraying process is better than that of the top spraying process. SUMMARY

[0007] The present application aims to overcome the shortcomings of the prior art and provide a preparation method and application of microencapsulated lysine.

[0008] In order to achieve the above-mentioned purpose, the technical scheme provided by the present application is as follows:

[0009] The preparation method of the microencapsulated lysine comprises the following steps:

[0010] (1) mixing lysine raw materials with palm oil, stirring uniformly in a homogenizer tank to form a liquid raw material; the mass percentage content of the palm oil in the liquid raw material is 20-30%;

[0011] (2) conveying the liquid raw material to the nozzle of a spray device through a conduit, atomizing the liquid into small droplets by the nozzle, and naturally falling and cooling the small droplets in a cooling chamber to form particles;

[0012] (3) collecting the particles obtained in step (2) by using a cyclone separator;

[0013] (4) putting the particles collected in step (3) into a fluidized coating machine, spraying the encapsulating agent onto the fluidized core particles by using a bottom spraying method, and then filtering and screening to obtain the microencapsulated lysine.

[0014] Preferably, the mass percentage content of the palm oil in the liquid raw material is 25%.

[0015] Preferably, step (1) is to mix the lysine raw materials with the palm oil and then stir in the homogenizer tank at 4 standard atmospheres for 60 min.

[0016] Preferably, the parameters of the atomization device during the atomization in step (2) are controlled as follows: feed viscosity 500 mPa·s, atomization pressure 0.2 MPa, atomization cooling temperature 4℃, and atomization time 15 s.

[0017] Preferably, the parameters of the fluidized bed coating machine in step (4) are set as follows: air inlet temperature 50℃, material temperature 60℃, and atomization pressure 0.2 MPa.

[0018] Preferably, the encapsulating agent in step (4) is gelatinized corn starch and sodium carboxymethyl cellulose, wherein the sodium carboxymethyl cellulose is the inner coating and the gelatinized corn starch is the outer coating; and the mass ratio of the gelatinized corn starch to the sodium carboxymethyl cellulose in the encapsulating agent is 55:45.

[0019] Preferably, the filtering and screening in step (4) is performed through a 40-mesh screen.

[0020] More preferably, the microencapsulated lysine has a particle size of 0.40±0.05 mm. It is detected that the content of the microencapsulated lysine in the final product is as high as 72%.

[0021] The microencapsulated lysine prepared by the above method can be used to prepare a feed for ruminants; the ruminants are cattle or sheep.

[0022] The application will be further described below:

[0023] The application first uses a two-step method of spray cooling and fluidized bed to prepare the microencapsulated lysine which is not digested in the rumen, and determines the optimal parameters. The microencapsulated lysine prepared by the method has a small particle size (0.40±0.05 mm) and uniform particle size, has a good effect of not being digested in the rumen, improves the utilization rate of nutrients by ruminants, and has a low production cost. The results of in vitro fermentation and nylon bag test show that the degradation rate of the microencapsulated lysine is less than 16% in 8 h, and the coating effect is good; the results of microbial flora analysis show that the relative abundance of Prevotella and Succiniclasticum increases with the increase of fermentation time, which can degrade the coating materials of the microencapsulated lysine, i.e. sodium carboxymethyl cellulose and gelatinized corn starch, and plays an important role in the precise release of the microencapsulated lysine; adding the microencapsulated lysine prepared by the application to the diet has no significant effect on the daily feed intake of ruminants, but can improve the daily weight gain, thereby reducing the feeding cost. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 Effect of microencapsulated lysine on the beta diversity of microbial community in rumen fluid fermentation system under in vitro fermentation conditions;

[0025] Figure 2Effect of microencapsulated lysine on rumen fluid fermentation system of the horizontal microbial community under in vitro fermentation conditions. DETAILED DESCRIPTION

[0026] The microencapsulated lysine is prepared by the following method:

[0027] (1) The lysine raw material is mixed with palm oil and stirred in a homogenizer tank at 4 atmospheres for 60 min to form a liquid raw material, and the mass percentage content of the palm oil in the liquid raw material is 25%;

[0028] (2) The liquid raw material is transported to the nozzle of a spraying device through a conduit, the nozzle atomizes the liquid into small droplets, the small droplets naturally fall and cool in a cooling chamber to form particles, and the parameters of the atomization device are controlled as follows: feed viscosity 500 mPa·s, atomization pressure 0.2 MPa, atomization cooling temperature 4℃, and atomization time 15 s;

[0029] (3) The particles obtained in step (2) are collected by a cyclone separator;

[0030] (4) The particles collected in step (3) are put into a fluidized coating machine, a bottom spraying method is used to spray the encapsulating agent (gelatinized corn starch and sodium carboxymethyl cellulose, mass ratio 55:45) onto the fluidized core particles, and then the particles are filtered and sieved through a 40-mesh screen to obtain the microencapsulated lysine with a particle size of 0.40±0.05 mm; the parameters of the fluidized coating machine are set as follows: inlet air temperature 50℃, material temperature 60℃, and atomization pressure 0.2 MPa.

[0031] In vitro digestion rate determination: the solid-phase chyme of fattening sheep stays in the rumen for 8 h, and a large amount of chyme is degraded by rumen microorganisms. In order to evaluate the rumen bypass effect of the product of the present application, the rumen fluid of Hulun Buir sheep is taken for in vitro fermentation test, and the rumen digestion rate at four time points of 2 h, 4 h, 6 h and 8 h is determined. The test results are shown in Table 1.

[0032] Table 1 In vitro digestion rate of microencapsulated lysine at different digestion times

[0033]

[0034] The results show that the digestion rate of the microencapsulated lysine prepared by the present application is 12.24% at 6 h and 15.06% at 8 h, and the digestion rate is low, which indicates that the rumen bypass effect of the product is good.

[0035] Rumen bacterial community diversity analysis under in vitro fermentation conditions: the rumen fluid of Hulun Buir sheep is taken for in vitro fermentation test, and the rumen bacterial community diversity at four time points of 2 h, 4 h, 6 h and 8 h is analyzed. The test results are shown in Table 2. Figure 1It can be seen that the dispersion P value is 0.722, indicating that there is no significant difference among the samples in the group, indicating that the application effect of the product is stable within 8 hours; the adonis P value is less than 0.05, indicating that there is a significant difference between the groups, that is, the microbial flora changes when the rumen microorganism degrades the microcapsule coated lysine.

[0036] From the attached Figure 2 It can be seen that after the in vitro fermentation starts, the relative abundance of Prevotella and Succiniclasticum increases. Prevotella is the dominant genus in the rumen of ruminants and plays an important role in the digestion of starch, cellulose and protein, and Succiniclasticum can ferment various sugars. It can be inferred that these two bacteria can degrade the coating materials of the microcapsule coated lysine, carboxymethyl cellulose sodium and gelatinized corn starch, and play an important role in the precise release of the microcapsule coated lysine

[0037] In order to evaluate the stability of the product in the rumen, Hulun Buir sheep were used as test animals, and the rumen digestibility of the microcapsule coated lysine product was determined by the nylon bag method at 2, 4, 6 and 8 hours after the sample was added. The test results are shown in Table 2.

[0038] Table 2 Determination of the rumen digestibility of the product of the present application in Hulun Buir sheep by the nylon bag method

[0039]

[0040]

[0041] The results show that the microcapsule coated lysine prepared by the present application has a 6h digestion rate of 9.62% and an 8h digestion rate of 14.46%, and the digestion rate is low, indicating that the product has good stability in the rumen.

[0042] The effect of adding microcapsule coated lysine on the growth performance of Hulun Buir sheep was determined: 60 healthy Hulun Buir sheep with similar age were randomly divided into 3 groups, including a control group, a test 1 group and a test 2 group. The control group was fed with conventional feed in the sheep farm, the test 1 group was supplemented with a commercial rumen bypass lysine product of a certain company when feeding each sheep, and the test 2 group was supplemented with the product of the present application, and the addition amount was 15g / day, and the test period was 90 days. The test results are shown in Table 3.

[0043] Table 3 Effect of adding microcapsule coated lysine on the growth performance of Hulun Buir sheep

[0044]

[0045] The same row of data without letters indicates that there is no significant difference (P>0.05), and different lowercase letters indicate that there is a very significant difference (P<0.01)

[0046] The results show that the daily feed intake of the ruminants is not significantly affected by adding the rumen-protected lysine product; the daily weight gain of the group in the test 1 is significantly higher than that of the control group (P<0.01), and correspondingly, the feed conversion ratio is reduced from 6.57 to 6.13 (P<0.01), which indicates that the commercial rumen-protected lysine product can improve the growth performance of the mutton sheep; more notably, the daily weight gain of the group in the test 2 is extremely significantly increased by 19.7% and 12.8% (P<0.01) respectively compared with the control group and the group in the test 1, and the feed conversion ratio reaches the lowest value of 5.37 (P<0.01), which indicates that the use effect of the product of the application is superior to that of the product of a certain company, and can significantly reduce the feeding cost of the farm.

Claims

1. A method for preparing microencapsulated lysine, mainly using lysine as a feed core, and using gelatinized corn starch and sodium carboxymethyl cellulose as coating materials to coat the lysine, characterized in that, The method comprises the following steps: (1) mixing lysine raw material with palm oil, stirring uniformly in a homogenizer tank to form a liquid raw material; the mass percentage content of the palm oil in the liquid raw material is 25%; (2) conveying the liquid raw material to the nozzle of a spraying device through a conduit, atomizing the liquid into small droplets by the nozzle, and allowing the small droplets to fall naturally and cool in a cooling chamber to form particles; the parameters of the atomization device during atomization are as follows: feed viscosity 500 mPa·s, atomization pressure 0.2 MPa, atomization cooling temperature 4℃, and atomization time 15 s; (3) collecting the particles obtained in step (2) by using a cyclone separator; (4) putting the particles collected in step (3) into a fluidized coating machine, spraying an encapsulating agent onto the fluidized core particles by using a bottom spraying method, and then performing filtration and screening to obtain microencapsulated lysine, wherein the particle size of the microencapsulated lysine is 0.40±0.05 mm, the degradation rate of the microencapsulated lysine is less than 16% in 8 h; the encapsulating agent is gelatinized corn starch and sodium carboxymethyl cellulose, wherein the sodium carboxymethyl cellulose is an inner coating, and the gelatinized corn starch is an outer coating; the mass ratio of the gelatinized corn starch to the sodium carboxymethyl cellulose in the encapsulating agent is 55:

45.

2. The method for preparing microencapsulated lysine as described in claim 1, characterized in that, Step (1) is to mix the lysine raw material with the palm oil and then stir in the homogenizer tank for 60 min under 4 atmospheres.

3. The method for preparing microencapsulated lysine as described in claim 1, characterized in that, In step (4), the parameters of the fluidized coating machine are set as follows: air inlet temperature 50℃, material temperature 60℃, and atomization pressure 0.2 MPa.

4. The method for preparing microencapsulated lysine as described in claim 1, characterized in that, In step (4), the filtration and screening are performed through a 40-mesh screen.

5. The microencapsulated lysine prepared by the method according to any one of claims 1 to 4 for use in the preparation of feed for ruminants.

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