The role of Soy Lecithin in aquatic feed processing
Soy lecithin has excellent physiologicaland surfacting effect, and is a natural and high-efficiency nutritionaladditive. Adding soya lecithin to feed can enhance, wetting, dispersing andsurfing activity, provide bile amines, phosphorus, inositol, choline and fattyacids and other nutrients, improve feed energy, nutritional value, improve feedconversion rate, reduce feed coefficient; Sex, has the effect of inducing food,helps animals to digest and absorb fats and fat-soluble vitamins, protectsunsaturated acids in feed, promotes animal growth and development, improves thesurvival rate of young animals, improves the production performance of aquaticanimals, prevents fatty liver, enhances disease resistance ; improve thephysical quality and yield of granulation, reduce feed loss and energyconsumption when extruded, prevent dust flying and feed grading, reduce theloss of water-soluble nutrients in aquatic feed, improve drift and depositionin aquatic feed, reduce feed waste and water pollution, and provide unknowngrowth factors.
Inthe role of aquatic feed processing
Lecithins are added to the feed and premix,can play a bonding role, reduce dust flying and automatic grading during feedprocessing, and maintain the effect of feed mixing uniformity.
Lecithin molecules have hydrophilic andoil-pro-oil 2 groups, so it is a good fat emulsifier. Lecithin can can inhibitthe loss of fat in bait, increase the absorption of fat by animals, promotegrowth, and improve the conversion rate of bait. For prawns, we can make up forthe reduction of fat digestion due to lack of bile, prevent the high mortalityrate of young shrimp, and improve the survival rate.
Lecithins can not only emulsify fat inwater, but also have an effect on water-insoluble components. Lecithins act asa way to prevent sedimentation against insoluble components suspended inemulsions. Usually the grain feed in the water will expand, and often scattereddrift away and subsidence to the bottom, which will cause waste of feed andwater quality pollution. The use of a special lecithin product suitable forfish and crustaceans can improve the wear resistance of grain feed, enhance thecondensation in the water after the expansion of the feed, thus improving thedrift and settlement of this situation, conducive to the suspension of feed inwater and convenient for fish and shrimp consumption.
Lecithins have good lubricity, which canreduce the loss of feed during extrusion molding, reduce the wear of feedequipment, improve grain yield and particle quality. At the same time, it alsoreduces the energy consumption in the granulation process, and can reduce thetemperature of the product to a minimum, so the particles can quickly cooldown, the risk of mold is also reduced, which is particularly important forbagged products.
5, Lipidbody encapsulation agent
Using the properties of lecithindouble-layer film, it can be made into a lipid body that contains a variety ofwater-soluble and fat-soluble substances. Therefore, the current processors usethis characteristic of lecithins to bury the feed package into particulatefeed, specially fed fish fry, crustaceans and shellfish larvae during thefeeding period. Feed particles buried by lipids can be suspended in water andmaintain its stability, and it is easy to be swallowed by seedlings such asfish and shrimp, and the nutrients in the feed are easily digested andabsorbed.
Applicationin aquatic feed
1, Promotegrowth, improve survival rate
A large number of studies have shown that lecithinscan effectively promote the growth of aberdeen fish and improve their survivalrate. Researchers at the University of Belgium, using carp, sea bass anddalinas as experimental fish, were fed lecithins to feed 10 experiments, andfound that lecithins had a growth-promoting effect on young fishers, and foundthat the growth and mortality of carp feeding lecithin-free feed decreased andmortality was high. Phosphatidylcholine and phosphatidyl inositol inositolinositol inositol inositol inositol to improve the growth and survival rate ofcarp starting to feed is obvious, but only the addition of choline or inositolin microfeed did not produce significant effect, it was found that choline andinositol can not replace phosphatidylcholine and phosphatidyl inosiol; Comparedwith foreign countries, China's application of lecithins in aquatic productsstarted late, feed formula contains 2% soybean modified lecithins, making feedbaiting is particularly good, fish growth speed. Different contents of lecithinsare added to the feed, and with the increase of lecithin level in the feed, thegrowth performance is on the rise. Adding soybean lecithins to aberdeen feedcan play a good role in promoting the growth of aberdeen fish and improvingtheir survival rate, especially for some valuable fish species, can reduce theeconomic risk of their breeding. However, depending on the type of fish,attention should be paid to the change of the added amount. Lecithins in feedcan promote the use of cholesterol in crustaceans and improve the growth andsurvival rate of crustaceans. The addition of lecithins (e.g. soy lecithins) tofeed promotes the metabolism of cholesterol in shrimps, especially from theliver and pancreas to the lymphatic. The addition of soybean lecithin to shrimpfeed can promote growth, improve feed efficiency and survival rate, and alsopromote the digestion of protein in feed and improve utilization rate.According to research by the National University of Singapore, adding a massscore of 1% degrease to female crab diet can significantly improve the hatchingrate of crab eggs and the survival rate of young crabs, while adding sufficientamounts of lecithin to the early day food of the farmed crabs plays a key rolein the smooth shelling.
2, Improvebody fat composition
Adding the appropriate amount of soybean lecithinto the feed can improve the slaughter rate, reduce abdominal fat and improvethe meat quality. Because soy lecithins contain a certain amount of unsaturatedfatty acids, such as carbon pentaerate (EPA) and carbon hexaleic acid (DHA),the content of these unsaturated fatty acids in fish after-harvesting lipidswill increase accordingly. When soybean lecithins with a mass fraction of 5%were added to the feed, the EPA and DHA levels of grass fish increasedsignificantly after feeding 52d. Similar effects were found in the body fatcomposition of other fish such as carp, real slugs and high-headed slugs, whichshowed that soybean lecithins were a catalyst for improving the quality ofwater products. With the increase of lecithin level in the feed, the whole fat andneutral fat content in the mussel fish body were increased, the ratio of20:5n-3 and whole n-3 fatty acid content in neutral fat was increased, and thepolar fat content in whole fish was reduced, and the ratio of almost all n-3fatty acids in polar fat was reduced. Adding soy lecithin son to feed canimprove body fat, reduce crude fat content, and accordingly improve thenutritional value of fish and improve the taste of food. The nutritional fattyliver of fish seriously affects its own growth and reduces the meat quality andresistance. The physiological reason of fatty liver syndrome is mainly the lackof lecithins, because lecithins are very important to fat metabolism, lecithinmolecules have emulsified properties, contain ingested cholesterol, in theblood to regulate the transport and deposition of fat, cholesterol. Animalssynthesize lecithins in the liver and can continuously transfer these fatsoutside the liver by forming lipoproteins. Lipoprotein is a compound of lecithins,cholesterol and triglycerides, if there is not enough lecithins, lipoproteincan not be formed, the liver will be filled with fat. If thin liver tissue issoaked in fat, other important chemical processes and synthesis cannot becarried out smoothly, so that other relevant functions of the body will beaffected. Therefore, a certain amount of lecithins is added to the feed, sothat the synthesis of lipoprotein seisopa can be carried out with fat in theliver. Feeding soybean lecithin feed can increase the fat transport capacity oflipoprotein and reduce fat deposition. Lecithin can improve the absorption oflipids in fish by its emulsified properties, making up for the deficiency ofits bile secretion, and the researchers believe that lecithins can promote thedigestion and absorption of lipids. With the increase of soybean lecithin levelin the feed, serum triglycerides and serum total cholesterol showed asignificant downward trend. Therefore, from the aspect of improving the healthlevel of fish, in the young fish and rapid growth stage, the appropriateaddition of a certain amount of lecithins in the feed has a certain practicalsignificance.
3.Reduce the incidence of fish malformations
Japan's Kanazawa and other reports, in thereal mackerel, stone bass, halibut, fennel and other fish fry culture feedingspecial round worms and other biological feed, the resultof is deformed anddyslest and other phenomena, especially after the consumption of this feed ofthe spectre rate (especially the body side bend) as high as 18% to 80%. If theegg yolk lecithin or soybean lecithin is added to the pestic seisile, theincidence of side bending of the fragrant fish can be reduced to 0 to 5%. TheBelgian Aquatic Research Institute fed Japanese prawn larvae with particulatefeed with lecithin choline, with a feed perversion rate of 76% with a massscore of 3%, significantly higher than the prawns fed for commodity materials(41%) and the larvae in the control group (48%). Soybean lecithin feed canreduce the incidence of animal malformation in aquatic products, which is verynecessary for the production of seedlings.
Feeding soybean lecithins can improve thetolerance of real mackerel larvae and plaques to water temperature, salinity,low dissolved oxygen and exposure to air, and improve the survival rate ofseedlings. Feed the striped slugs, white slugs and hybrid slugs (including EPAand DHA) and coy bait (without lecithins) at a water temperature of 20 degreesC to compare their cold resistance; The mortality rate of the bait group was50% to 90%, while the fish fed natural bait did not find death, which was dueto the content of unsaturated fatty acids in natural bait snare 13% higher thanthat of the bait, indicating that the high content of unsaturated fatty acidsin natural baiting could improve the coldness of fish. Using lecithinas as theopening bait of the Daling mackerel, it was found that it did not affect thestress of salt resistance of the daring mackerel. When the daling mackerelgrows to 20 days later, replacing the brine completely with lecithin bait canlead to serious stress problems. The Belgian Aquaculture Research Institutefound that japanese prawns had good growth and anti-stress performance in feedwith a lecithin choline mass score of 1.5%, and that the effect of adding amass score of 6.5% to the feed was similar to that of non-fat soybeans. Addingsoybean lecithins to feed can enhance the environmental adaptability of aquaticanimals and reduce mortality.
5, Improvefeed conversion rate, reduce feed coefficient and cost
The head fat was the largest fed with theaddition of 7% rapeseed oil lecithin feed, while visceral fat accounted for thesmallest proportion of weight, and its health was found to be the best by thecolor of the liver. The addition of 2% modified soybean lecithins in carp baitwas 30.7% higher than that of the control group, the bait coefficient was 0.21%lower, and the feed cost was reduced by 9.63%. The improved soybean lecithinwith a mass fraction of 2% was added to The Nile Rogite, the weight gain rateof the test group increased by 43%, the protein efficiency increased by 31.3%,the daily weight gain increased by 66.1%, and the feed coefficient decreased by31.4%, and the breeding effect was very obvious. Adding soybean lecithins tofeed can effectively improve feed conversion rate, reduce feed coefficients andcosts, increase economic benefits, combine the above role, play a large numberof breeding effects.
Adding soy lecithins to feed can play apartial role in replacing fat, but whether it can be completely replacedremains to be seen. Some lecithins may be involved in the permeation pressureregulation of migratory fish, and the eel in the water environment conversionprocess, with the decline of salinity, the PE of the crucible can be maximizedstability, and can recover quickly after the stability of environmentalsalinity. This suggests that the eels may rely on PE to complete the mediationactivities of osmosis pressure. The addition of different levels of soybean lecithinsin the feed caused the activity of superoxide dismutase in the mussels toincrease with the increase of lecithin levels in the feed.