Effect of Feed Process on Activity of Enzyme Population

LIMA Fish Feed Machine,Chicken Feed Machine


Enzyme is a catalyst having a very high catalytic efficiency, and its catalytic efficiency is 107 to 1013 times higher than inorganic catalyst, but the catalytic activity of the enzyme is extremely susceptible to regulation of various physical and chemical factors. , Such as temperature, pH, moisture, pressure, ultraviolet lines, have a large impact on enzyme activities. At present, the mass production of particle feed and puffed feed has become a development trend in the world feed industry. According to incomplete statistics, more than 70% of foreign feed products are treated with thermal processing (conditioned, granulated or puffed). Feeds have a strong role in temperature, pressure, and humidity during granulation, extrusion, and puffing, challenges the activity of the enzyme preparation in the feed finished product. Although the enzyme preparation can be performed after granulation [1] or pre-enzymatic [2], it increases the amount of addition to obtain the amount of activity in the final product. It is the easiest way to use the easily economical economy of the enzyme preparation, so it is necessary to study this problem on the effect of the feed process to the activity of the enzyme preparation, and the causes of the effects and the degree of the effect can be more accurate to ensure the amount of enzyme preparation.

1. Features affecting the enzymatic process

The main destructive effect on the enzyme preparation in the feed process process is mainly granulation and puffed. These two integrated effects involving high temperatures, high humidity and extrusion on feeding enzyme preparations are a severe test.

1. Formation process During the granulation process, it is necessary to add 4 to 5% of steam to prevent the material, so that the material is 10 ¡ã C. Further, the friction between the material and the pressure roller, the pressure mold and the mold hole can also increase the material to 5 to 20 ¡ã C, so that the particulate temperature is 70 to 90 ¡ã C, even 100 ¡ã C after granulation. In general, the temperature of the tuning is not less than 70 ¡ã C, in order to make the powder are more fully gelatinated, there is also a certain gelatinization time, and if the conditions are allowed, it is best to keep the powder in the tuning tetranes or more, It is generally not less than 6 s, and the material moisture content required to achieve the best granulation effect is between 15.5 to 17.5% [3].

1.2 Expanded work sequences in the extruded infusion process, the temperature can be as high as 200 ¡ã C, but the feed is short (5 to 10 s) at such a high temperature. When machining a floating feed, the addition of steam and water reaches 8% of the feed, the extrudate has the following properties when reaching the die: final pressure is 3.45 ¡Á 103 ~ 3.75 ¡Á 103 kPa, temperature 125 ~ 138 ¡ã C, moisture 25 ~ 27%. In the production of the bodily feed, a small amount of steam is added in the conditioner, and then water is added. The final moisture of the mixture exits the regulator is usually 20 to 24%. The temperature of the mixture reaches 70 to 90 ¡ã C at the exit of the tile, and the moisture content of the extrudate reaches 28 to 30%. When producing fish feed, the pressure at the extruder die is usually 2.63 ¡Á 103 ~ 3.04¡Á 103kpa. Non-puffed completely ripened aquatic feed, extrudate temperature outside the extruder die is 120 ¡ã C [4].

II. Factors affecting enzyme activities Enzyme is a bio-catalyst, which is sensitive to temperature, humidity, pressure, and other factors such as other proteins (GUUS, etc., 2000). The temperature during the granulation expansion can reach 100 to 200 ¡ã C, accompanied by high humidity (causing a higher moisture activity in the feed), high pressure (changed by the spatial multi-dimensional structure of the enzyme protein), under this condition, large The activity of most enzyme preparations will be affected from varying degrees. 2.1 Temperature There are two aspects of temperature on the enzyme activity: on the one hand, the temperature increases can increase the key of the substrate molecule, and the molecular collision probability is improved, thereby accelerating the reaction rate; The temperature rose to a certain degree, the enzyme protein is gradually denatured, and the activity is lost. The main source of feed enzyme preparations and optimal temperatures are shown in Table 1 below.


Table 1 Main source of feed enzyme preparations and optimal temperatures [5] [6] [7] sources of enzyme Optimal Temperature / ¡ã C Non-intrinsic enzyme cellulase Green Pecusa 45 ~ 65 Wood 45 ~ 50 Cantewolds 45 ~ 50 Black Mildew Mold 45 ~ 55 Half Sublaboratures 40 ~ 55 Wooden Musica 40 ~ 50 Pectuff Enzyme root 40 ~ 50 black utensil 40 ~ 50 phytase Black Mercuffle 40 ~ 50 m Kewei 40 ~ 50 Tannin Enzyme Flower 40 ~ 50 Black Mercuffle 40 ~ 50 ¦Â-glucanase 55 ~ 70 Wooden Mild 50 ~ 60 Digestive Enzyme Protease AS1398 Bacillus 35 ~ 40 Bacillus 45 ~ 50 Sugarization Enzyme Black Mercuffle 50 ~ 60 Swings 55 ~ 65 Amplase Black Mildew Nugget 55 ~ 70 Barley and Wheat Foundation Diet After Hot Processing, The relative activity of the acid enzyme is shown in Table 2 [8]. Israelsen (1995) reported that the active residence rate of 1.0 ¡ã C is zero. VanderPoel reported that the activity of beta-glucanase and cellulase at 110 ¡ã C was no longer detected; Gradient reported that the amylase was significantly reduced at 80 ¡ã C. Clayton (1999) believes that such as above 85 ¡ã C, a liquid enzyme preparation should be sprayed into a cooled particles, thereby avoiding the adverse effects of high temperature steam on enzyme activity [9]. Table 2 The relative activity of the relative active step temperature / ¡ã C phylase in the expansion process is 27.9 100%.After 80.5 76% of the granulation, 70 47% of the expansion was 79 12% p.Spring (1996) after the expansion of the granulation, 79 12% P.SPRING (1996) was determined to determine different granulatures, bacterial amylase, fungal amylase and penthen gathering. Effect of sugar enzyme activity. The test sample is a barley-wheat-bean-type feed containing different enzyme preparations, and the granulation temperature is 60 ¡ã C, 70 ¡ã C, 80 ¡ã C, 90 ¡ã C and 100 ¡ã C, respectively. The results show that the cellulase, phenantanase and fungal amylase are still stable at 80 ¡ã C, but at 90 ¡ã C loss of 90% (P u003c0.05). Bacterial amylase is more stable, still has 60% vitality at 100 ¡ã C [10]. COWAN and RASMUSSEN (1993) were measured in the solution of enzyme activity in solution in solution, where the determination results of the pentan glycase were similar to those of P. Spring (1996) [11]. However, under granulation conditions, there are different results under solution, Gadient et al. (1993) reported that during the thermal solution treatment, if the critical temperature does not exceed 75 ¡ã C, the activity of carbohydrase is not affected [12]. Nunes (1993) reported that when the granulation steam temperature was higher than 60 ¡ã C, the activity of the pentananase was significantly reduced [13]. The difference in this result may be due to the difference in heat resistance of the enzyme-free measurement method or the heat resistance of the enzyme preparation of different strains. Determination of granulated enzyme activities is a disputeable problem because there is currently no uniform determination of highly diluted enzyme activity methods in an enzyme feed.

Gadient et al. (1993) believed that the degree of enzyme activity loss was significantly affected by the type of enzyme preparation, and the amylase was significantly reduced at 80 ¡ã C. The phytase is reduced by 50% or more after granulation through 70 to 90 ¡ã C [8]. COWAN (1993) reported that the survival rate of untreated ¦Â-glucanase was only 10% in the feed after 70 ¡ã C granulation. Inborr (1994) reported that the beta-glucanase was injected at a temperature of 75 ¡ã C, and the survival rate was 64%, while the survival rate of the granulation of 90 ¡ã C was only 19% [14]. Feed processing modulation has a balance between the digestibility of feed, the damage of the enzyme activity, and the improvement of the increase in the digestibility of the feed. Bedford et al. (1998) Test showed that the activity of xyllase in the diet was gradually declining with the increase of feed processing temperature, but the feeding test found that the production performance of the meat chicken is preferably 82 ¡ã C, and the temperature is low. The production performance has decreased at or above 82 ¡ã C, and the correlation between the feed conversion and the activity of the feed enzyme is not significant. And all process temperatures reducing the viscosity of the intestinal contents of the meat chicken, and the viscosity is maximized at 95 ¡ã C, which can also reflect the use of hot processing and enzyme preparations in improving the digestibility of feed digestibility. Michael (1997) is reported, taking corn, soybean meat chicken, powderThe body weight and feed efficiency of 45 days after the absorbate were increased by 5% and 1.77% higher than the freezed control group, while the same formulation of the particles of the same formulation was only 4% higher than the control group. And 1.23% [15]. This also suggests that the actual production performance of animals should be used as the effectiveness of the test enzyme preparation in actual production.

2.2 Pressure and Shear Force The pressure of the pressure on the enzyme molecule has been more than 40 years, but it has attached importance to the effect of pressure on the interaction of enzymes and substrates in recent years. Experiments have shown that pressurization can improve the activity of the enzyme, and the pressure on the enzyme can also be improved. It is generally believed that the protein changes its volume, conformational and active portion under the influence, and the laser Raman spectrophotometry can detect this phenomenon. If the reaction rate is slowed, the activation volume is increased, that is, a dissociation reaction; in turn, it is a bonded reaction. In the test conditions, the pressure can be precisely controlled, but the pressure of the feed granulation process is difficult to accurately grasp, and there is still a lot of difficulties in accurately determining the pressure on the activity of the diluted enzyme during granulation or puffing. There are less research on the loss of enzymes in the shear force. There is a shear force in the process of agitation, mixing, vibration, extrusion, and the like before granulation. Inactivation in the agitation process is mainly a surface phenomenon, which is not equal to the heating and chemical action of the enzyme. The agitation acts to expose the peptide chain in the gas-liquid interface and deploy, although the number of peptide chains exposed to the gas-liquid interface (including the gas bubbles produced in the liquid) is small relative to the total peptide chain, but its effect is not negligible. Because the agitation will continue to produce a new interface results in a more peptide chain, the enzyme is difficult to react with the substrate. The effects of shear force on the activity of the enzyme activity were studied by experiments. The test results show that the cellulase activity decreases with the increase in shear strength and the time of time, and the hydraulic reducing activity is slower at low shear strength, and after the shear strength is high, it is mixed for 10 min. The activity is quickly lowered. Dramatic shear forces during granulation and puff may be a cause of enzymatic loss, but there is currently lack of sufficient data to confirm this.

2.3 Humidity

The moisture content also has a great effect on the activity of the enzyme preparation. The protein is degenerate under the presence of the surface tension, and the polypeptide of the protein often loles, particularly the gas-liquid interface, in particular a gas-liquid interface, which is also a cause of polyprophydrogen solution in the two-phase interface. After the packaged feed enzyme preparation, heating at 90 ¡ã C is not inactive under dry conditions, but the vapor is supplied at the same temperature, and the enzyme preparation will be quickly deactivated [17]. Also related to moisture content associated with moisture content can also cause protein degeneration. The hydrogen bond plays an important role in the spatial conformation of the enzyme. When the system contains a large amount of free water, the hydrogen bond inside the enzyme molecule is destroyed.Role, the conformation of the enzyme molecule is prone to change, and the enzyme is easily deactivated. At a certain temperature, the relationship between the moisture content and moisture activity in the forage composite enzyme and the moisture activity is indicated by the adsorption of water, although this relationship is not a primary line relationship, but the total trend is that the moisture content is higher. The greater the moisture activity. The denaturation of the enzyme protein is significantly increased at higher moisture activity. When the moisture content of the sample is reduced to 10%, the temperature rose to 60 ¡ã C, the lipase begins to be inactivated, and when the moisture content is 23%, there is a significant deactivation in normal temperature. For most enzyme preparations, the moisture activity is lowered to 0.3 or less in close neutral pH and lower temperatures, which can prevent detergent of enzyme degeneration and microbial growth, thereby saving more enzyme activity. After the enzyme protein passes through certain stabilization, the environment with high moisture can still be stored sufficient activity, but the loss is still present [18].

NBSP; Enzyme inhibitors, enzyme activator, etc. can significantly change the catalytic activity of the enzyme. Metal ions will not only affect the activity of the enzyme, but also affect the stability of the enzyme. CO2 +, Mn2 + plasma usually increases the activity of D-glucose alkases; Cu2 +, Fe2 +, Al3 +, Hg2 +, Zn2 +, Ca2 + have different degrees of inhibiting catalytic activity; Hg2 +, PB2 + can cause enzymes to deactivate, It should therefore be avoided in contact with enzymes. In addition, the additive in the feed also has an effect on the enzyme, such as the role of PO43-root enzyme activity, other inhibitory effects such as CO32-, CL-, SO42-, NO3-oral ions affect, organic matter such as urea and Guanidin or the like can cause protein degeneration, but the denaturation caused by urea is often reversible. For cellulases, methadealdehyde and potassium iodate can cause inactivation, but cysteine, potassium with red chromates, activate it, can increase the ability of cellulase hydrolyzate CMC to about 20%. In addition, there are natural inhibitors of many enzymes in the feed feedstock, which are some non-specific inhibitors, such as tannins in plants with a strong ability to bind proteins, which can make enzymes, heparin, penicillin, etc. Antibiotic can also affect the activity of many enzymes. For cellulase, the phenols in the plant are inhibitors. During the feed processing, the enzyme preparation is inhibited to inhibit metal ions or substances that inhibit the enzyme activity in the feed feedstock, and the conditions of granulation and puffed high temperature, high pressure, high humidity conditions Next, it is more likely to react with it, so such factors should have a role in the loss of enzyme, but there is no research report on such factors on enzyme in the process.

III. Development direction

In summary, temperature, pressure, and moisture, etc. during granulation, pressure and moistureThe activity has a great influence, and there is currently, the feed industry is currently adding the following processes to add feeding enzyme preparations: 1) Use carriers or coated agents, such as adsorption of liquid cellulase and ¦Â-glucanase to some kind The pelletized enzyme preparation can be maintained at 90 ¡ã C to maintain 95% activity at 90 ¡ã C with a packaged dosage package. Although the packaged enzyme preparation can reduce the impact of processing temperature on its effect, how to ensure that it is released in time in a suitable part in the animal digestive tract, and the maximum catalytic effect may be the most worth considering of the package. question. 2) After the granulation, the enzyme preparation is sprayed to the surface of the cooled particulate feed to avoid the adverse effects of high temperature in the feed molding process. The post-spray technology completely avoids the damage to the enzyme, but it is necessary to install a new spraying equipment, and the technical requirements are also higher, so the corresponding cost is also high, and the accuracy of the spray is not high, uniformity is difficult to control. Factors that are easy to peel off after spraying, oxidation, and increased powder, increased the problem that should be resolved in the future.

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