The technology of the post-additive additive of the enzyme.

OA_show ('533');1Introductionenzyme preparation sedienzyme seise is a biological product produced by microorganisms, since 1975 the American feed industry for the first time as an additive used as an additive in the feed and achieved remarkable results, feed enzyme preparations have been increasingly paid attention to by the world's aquaculture industryBut at the same time, with the development of animal husbandry, antibiotics, hormones and drug additives are widely used in feed, animal food pollution and harmful substances residues are becoming more and more serious, feed safety problems are becoming more and more prominentAt present, many countries are trying to increase the management of feed additives, Western Europe, Japan, the United States and other countries have issued a series of laws in the feed to prohibit or limit the use of antibiotics, hormones and drug additivesIn May 1999, China issued the Regulations on the Management of Feed and Feed Additives, especially the recently published Standard of The Determination of Clenbuterol Hydrochloric Acid in Feed"Natural, green, pollution-free, no residue" has become the theme of the development of animal husbandry in the 21st centuryEnzyme preparation as a kind of high-efficiency, non-toxic side effects and environmental protection of "green" feed additives in the livestock and poultry industry has a broad application prospects, is gradually replacing commonly used drug additives, to achieve additives "green."feed safety is a major event related to food safety and the interests of the masses, and is the focus of the whole societyIn recent years, some European countries due to feed safety issues such as "dioxin" and "mad cow disease" caused huge economic losses, and triggered serious political events, so that the whole of Europe's livestock production and food industry in the international competition has been at a disadvantage for a long timeWith China's accession to the WTO approaching, the production of non-residual, non-polluting natural "green" animal products is an urgent taskThe core problem of realizing "greening" of animal products is to use less or no pharmaceutical additives such as antibiotics, and to apply "green" biotechnology products such as enzymes and microbial preparations to solve the problems of prevention of diseases in animal husbandry production and the improvement of production performanceFeeding enzyme preparation as a new type of "green" environmental protection additive, its efficacy characteristics are:(1) supplement animal endogenous enzyme deficiencies, improve feed compensation; (2) decomposing plant cell walls to promote the digestion and absorption of nutrients;(3) eliminate the anti-nutrition factors in feed, improve the conversion rate of feed, and (4) to enhance the resistance of animals to disease, improve the survival rate of livestock and poultry; (5) reduce the discharge of nitrogen and phosphorus, reduce environmental pollution 2 Changes in the activity of enzymes in the process of granulation enzymes as a protein, have all the physical properties of proteins, and like all proteins, enzymes are sensitive to environmental factors Temperature, pH, moisture, strong acids, strong alkalis, ultraviolet rays, and storage processes all have a great impact on enzyme activity As feed plants are increasingly equipped with thermal processing equipment such as puffers, extrusion conditioners or other types of accent equipment, and short-time processing equipment at high temperatures Feed is subjected to the strong effects of temperature, pressure and moisture during granulation, extrusion and puffing, which destroys most of the efficacy of thermal microcomponents such as enzyme preparations the optimum temperature of general enzyme activity is 30-45 degrees C, and the enzyme becomes denatured and loses activity when it exceeds 60 degrees C However, the temperature of graining and puffing process can reach 120-150 degrees C or more, and mixed with high humidity, high pressure Under these conditions, most enzymes lose their activity The above expansion processing of pig feed, mainly based on barley and wheat, is carried out, wherein the relative activity of phytoase with high thermal sensitivity in various processing processes is shown in Table 1 Israelsen reported that the activity retention rate of phytoase was zero at 110 degrees C; Van der Poel reported that the activity of beta-glucanase and cellulase was no longer detectable at 110 degrees C Gradient reported a significant decrease in amylase activity at 80 degrees C Gradient et al (1993) pointed out that the degree of change in enzyme activity caused by granulation is related to the type of enzyme preparation and the granulation process If the enzyme preparation is "packed" treatment, made into microcapsules, the thermal stability of the enzyme is improved, on the one hand, to prevent the damage of heat, humidity, acid and alkali in the process of feed processing, on the other hand, to avoid the enzyme preparation in the stomach liquid as a protein degradation and inactivation If the grain temperature exceeds 85 degrees C, it should be sprayed with liquid enzyme preparation on the cooled granule material, so as to avoid the adverse effects of high temperature steam on enzyme activity moisture content also has a great influence on the activity of enzyme seis After the "pack" treatment of the feeding enzyme preparation, under dry conditions, 90 degrees C heating 30min will not inactivate, but at the same temperature to supply steam, the enzyme will quickly inactivate from the above can be seen, granulation, puffing process temperature, pressure and moisture, etc have a great influence on the activity of enzyme preparations Therefore, granulation, puffed liquid enzyme preparation spraying technology is increasingly favored Granulation, puffing enzyme is the liquid enzyme preparation in the feed granulation, puffing added to the feed technology, so as to avoid the feed pre-treatment and granulation, expansion process of the loss of the effective ingredients of additives 3 The advantages of the post-adding technology (1) can protect the thermal microcomponents such as enzyme preparations from the damage of thermal processing, reduce the amount of these components added, thereby reducing production costs (2) set the addition of trace components such as enzyme preparations in granulation or puffing, the use of offline spraying process, is conducive to the user's needs to add, so as to meet the user's requirements (3) can do "sell-to-spray", always provide users with fresh products (4) By adopting the offline spraying process, feed plants can not only save the number of finished warehouses, but also replace expensive micro-ingredient strains systems that take up large space, thereby reducing the one-time investment in feed plants NextPage 4 The development of enzyme post-addition technology and the status quo the application of enzyme post-addition technology in the feed industry, starting with amino acids, greases and other liquid addition technology With the deepening of animal nutrition and the continuous improvement of feed safety calls, people realize the necessity and urgency of protecting thermal microcomponents such as enzyme preparations, reducing environmental pollution and producing fresh feed World-class equipment manufacturers such as Buhler in Switzerland, Kahl and Chevita in Germany, Finnfeads in the United States, Sprout-Matador in Denmark, Schranwen in Belgium and Wijnveen in the Netherlands are investing in the development of liquid sprayers, and new products are being introduced the domestic understanding of post-liquid spraying began in the late 1980s, and the emergence of liquid sprayers only in recent years Today, manufacturers are few and far between There are two main models: one is a vertical centrifugal atomization sprayer represented by the LC-50 sprayer of the Institute of Livestock And Livestock Machinery of the Chinese Academy of Agricultural Mechanization, and the other is a horizontal liquid sprayer modeled on the DMWT series of early products from Buhler, Switzerland 5 Liquid enzyme preparation post-addition technology due to the superiority of post-liquid spraying, domestic and foreign feed producers have adopted this process to add enzyme preparations and other thermal micro-components 5.1 different post-addition methods 5.1.1 directly add suspension or colloid KvtKva (1987) reported that will contain a small amount of biologically active substances (including vitamins, enzymes, microbial agents, etc.) combined into the feed after granulation, the biologically active substance is first mixed with an inert substance carrier into a liquid, forming a uniform suspension, suspension through a device can be transformed into a form that can be acting on the pellet, forming a uniform film covering the surface of the pellet Lavery (1996) also reported a method of componenting components such as enzymes into particles: mixing the added substance with a viscous colloid and then with feed particles The particles that cover the colloid are basically uniform and the contamination of the mixer is very small, and its addition is about 2-40 kg These two addition methods are more suitable for small batch production of feed or farm self-processing 5.1.2 Spray added liquid at present, domestic and foreign reports on thermal micro-component liquid rear addition is not much, and mainly concentrated in several major industrial developed countries in Europe and the United States Several of today's more representative liquid addition systems are described below: Amandus Kahl of Germany is a pioneer in the development of post-add-on add-on technology, and the core of its liquid addition system is the rotary spray adder Rotospray The middle of the machine is equipped with a set of high-speed rotating disk, when the turning disk high-speed rotation, can be 1 ml of liquid feed raw materials can be divided into 10 million particles of fog, sprayed on the top-down particles or puffed feed around the transfer The machine structure is simple, the spray effect is good, the distribution is even According to the data, when used to add phytoase, the uniformity of the liquid distribution of the coefficient of variation is less than 10%, when the flow of particles is 5-20t/h, the liquid material sprayed on the particle feed more than 98% Schranwen of Belgium and Finnfeads of the United States have jointly developed a new spray-additive system The system uses a pump to deliver liquid enzymes at a measured flow rate to an aerosoled nozzle, which is located above a rotating disk that receives grain feed from an impact weighing device and allows the material to stay on it by about 30s Due to the rotation of the disc, coupled with the constant flipping of a pulp wheel to the grain feed, all particles can be sprayed Novo Nordisk (1993) developed a liquid spray system that meets the requirements of the feed granulation liquid enzyme formulation It is mainly composed of a high-precision metering pump, which will be the exact amount of liquid enzyme preparation, by the air pressure nozzle spray, and the output of the pump can be adjusted according to the feed Daniso has also developed an enzyme spray system that sprays liquid enzyme preparations onto the surface of the particle feed, which guarantees accuracy and safety of additions when adding liquid enzyme preparations, and which also produces a range of liquid enzyme preparations Danish company Sprout-Matador developed the Micro Fluid System MFS in 1999, which is mainly used to add trace liquid components such as enzymes to particles The spray dose of the system can reach 10g per ton of feed, and its coefficient of variation (CV) is less than 10% Because the MFS system saves time by adjusting the spray according to different feed types and formulationchanges Its liquid addition accuracy can reach more than 98% of the .5,16,17 BASF jointly developed a new Advanced Liquid Enzyme Application System (PPA System) in 1999 The system focuses on its accuracy, and the spray dose of the system can reach 83 ml per ton of feed The system has the characteristics of spray accuracy (-1.5%) and small coefficient of variation (CV 10%) In order to avoid blocking and dust problems, the system adopts the characteristics of containment, self-cleaning and fault self-exclusion The PPA system uses a PLC control panel to control automatic feeding or individual control China's Agricultural Mechanization Science Institute in 2000 to develop a liquid spraying system LC50S The core equipment of the system is the liquid sprayer When working, the material disc and the liquid disc start at the same time, stay on the dry material on the material plate, under the action of centrifugal force and gravity, are thrown in the range of 360 degrees C, and form a downward flow of uniform dry material curtain At the same time, liquids such as enzymes in the liquid tank are pumped into a high-speed rotating liquid disc and then thrown upward under the action of centrifugal forces, thus forming an upward liquid curtain The two reverse-moving curtains fall into the mixing chamber after full contact with the help of the blades in the spray chamber and flow out of the material port after further mixing in the mixing chamber NextPage 5.2 after the choice of adding points particles not cooled to add enzymes and other thermal micro-components, will also cause the loss of thermal components, so the addition of the added point generally selected after the particle cooling, there are 3 available (1) Injection equipment Some feed plants themselves are equipped with grease-encapsulating, add-on spray system does not need to modify the process (2) spiral conveyor using the method of installing spray on the spiral conveyor, can save equipment cost input, the deficiency is the mixing uniform effect is poor, the coefficient of variation is generally greater than 20% (3) Liquid sprayer such equipment is generally installed in the particle cooler, such as Taiwan ChemGen's swing nozzle, it is a barrel-shaped equipment, its center has a hollow rotating shaft, from the top through the top cover until close to the bottom plate, under which there is a liquid shunt disc, can be rotated at high speed On its about 30-60cm has a slightly large feed turntable attached to the hollow hinge, the speed is slow, when operating grainy from the upper fall on the feed turntable, is evenly swept to the surrounding round barrel wall, skimping down the liquid transfer disc outside the edge of the fall to the bottom plate At the same time, the liquid is sprayed on the liquid shunt plate by the hollow hinge, and the centrifugal force of its high-speed rotation is evenly sprayed to the feed curtain falling on the outer edge of the surrounding 6 Problems 6.1 accuracy liquid metering mainly has two kinds of flow metering and weight metering, most of which use the lower-cost flow metering method, the accuracy range of the flow meter is generally .25% to 0.5% Simultaneous flow meter correction is usually set up after the flow meter a bypass to detect the flow, but due to the actual spray line resistance and the bypass resistance used to detect inconsistent, resulting in correction time In order to achieve the required accuracy, the flow of liquids and feed should be very coordinated, the spray system should be able to handle large volumes of material, and should reflect changes in feed flow in a very short period of time However, in the actual production, the accuracy of dynamic control of material flow is not very high, which affects the flow control of liquid additives, making the accuracy of the addition of liquid enzyme preparations difficult to meet the set requirements 6.2 Uniformity the uniformity of the spray effect can be measured by a coefficient of variation Uniformity is influenced by many factors, especially the atomization effect and feed particle size At present, commonly used atomization methods include pressure atomization, centrifugal atomization, air flow atomization and ultrasonic atomization, among which pressure atomization, centrifugal atomization is the most extensive Pressure atomization is not well controlled during the production process, the pressure is significantly reduced at the end of atomization, and spray uniformity is affected Similarly, feed particle size largely affects the uniformity of spraying In general, particle sizes can expect better uniformity, so care must be taken to minimize particles in particle feed 6.3 Easy to peel general rear added, liquid.