What methods are there for identifying the authenticity of feed ingredients?
Methods for identifying the authenticity of some feed ingredients
Methods for Identifying the Authenticity of Some Feed Ingredients 1.Wheatbran: talc powder, rice bran and other substances are often found mixed in
Identification method: insert the hand into thewheatbran and pull it out. If white powder sticks to the hand and is not easy to shake off, it indicates talc powder has been mixed in; if it shakes off easily, it is residual flour. Then grab a handful ofwheatbran and rub it hard. If thewheatbran forms a ball, it is purewheatbran; if there is a swelling feeling when rubbing the hand, rice husk bran has been mixed in; if there is a relatively slippery feeling when holding it in the palm, it indicates talc powder.
2. Soybean meal (cake): sediment, crushed corn or 5%-10% stone powder are often mixed in, reducing the protein content of soybean cake.
Identification method: 1. Water soaking: take a 25 g sample, place it in a glass cup containing 250 ml of water and soak for 2-3 h, then stir gently with a wooden stick. It can be seen that the soybean meal or crushed cake separates into layers from the sediment; the upper layer is cake meal, and the lower layer is sediment.
2.Iodine test:Place a small amount of sample on a clean porcelain dish, spread it thin and flat, and drip a few drops of iodine tincture on top. After 1 min, if some substance turns blue-black, it indicates corn,wheatbran, rice husk, etc. have been mixed in.
3.Raw and cooked soybean meal test method:Cooked soybean cake is commonly used as a raw material, not raw soybean cake, because raw soybean cake contains antitrypsin, saponin and other substances, which affect the palatability and digestibility for livestock and poultry. The method is to take 0.1 g of urea, add distilled water to 100 ml, stopper it and warm it in 45 °C water for 1 h, then immerse red litmus paper in this solution. If the litmus paper turns blue, it indicates the soybean meal is raw; otherwise it is cooked.
3. Fish meal: cottonseed cake, rapeseed cake, urea, sand grains and other impurities are often mixed in.
Identification method: 1. Sensory test: standard fish meal has uniform particle size, and a large amount of loose fish muscle fibers as well as a small amount of fish bones, fish scales, etc. can be seen. The color is light yellow, yellow-brown or yellow-brown, and when pinched by hand it feels loose, does not clump, is not sticky, has a fishy smell, and has no off odor.
2.Odor test:Take a 20 g sample and place it in a conical flask, add an appropriate amount of water, stopper it, and heat for 15-20 min. After opening the lid, if an ammonia smell can be detected, it indicates urea has been mixed in.
3.Water soaking method:Take a small amount of sample and place it in a test tube or large glass cup, add an appropriate amount of water, shake fully, and let it stand. The mixed-in sand and stones will sink to the bottom, while cotton cake, feather meal, etc. will float on the water surface.
4. Bone meal: good bone meal contains 23%-26% calcium and 12%-14% phosphorus. Adulterated bone meal has insufficient phosphorus due to the mixing in of stone powder, shell powder, fine sand, etc.
Identification method: 1. Visual method: pure bone meal is grayish-white powder or granular, with its inherent odor; adulterated bone meal is whitish in color.
2.Dilute hydrochloric acid dissolution method:Place the sample into a dilute hydrochloric acid solution. If it is pure bone meal, it will emit a short "shasha" sound, no bubbles will form on the surface of the bone meal particles, and finally it will all dissolve and become turbid; the hydrochloric acid solution of degelatinized bone meal has a very small amount of organic matter floating on the surface; steamed bone meal and raw bone meal have more floating matter on the surface, while fake bone meal shows none of the above chemical phenomena.
3.Burning method: take a small amount of sample and place it in a testtube, hold it over a fire and burn it. Real bone meal produces steam and then a pungent smell of burning hair, while adulterated bone meal produces less steam and odor, fake bone meal produces no steam or odor, and non-degelatinized deteriorated bone meal has an off odor.
5. Methionine: starch, glucose powder, stone powder, etc. are often mixed in, so that the amino acid content reaches only 50%, greatly lower than the national standard.
Identification method: 1. Sensory inspection: real methionine is pure white or slightly yellow, glossy crystals, and tastes sweet; fake methionine is yellow or gray, with very few shiny crystals, and has a strange taste and astringent feel.
2. Ignition method: take a 1 g sample and place it in a constant-weight porcelain crucible, first carbonize it on an electric furnace, then place it in a high-temperature furnace and ignite it at 550 °C for 1 h. That with an ash content below 0.5% is real methionine.
3. Dissolution method: take a 1 g sample and dissolve it in 50 ml of distilled water. If it can fully dissolve, it is real; otherwise it is fake.
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--------------------------------------
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--------------------------------------
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--------------------------------------
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--------------------------------------
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--------------------------------------
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--------------------------------------
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Identification method: insert the hand into thewheatbran and pull it out. If white powder sticks to the hand and is not easy to shake off, it indicates talc powder has been mixed in; if it shakes off easily, it is residual flour. Then grab a handful ofwheatbran and rub it hard. If thewheatbran forms a ball, it is purewheatbran; if there is a swelling feeling when rubbing the hand, rice husk bran has been mixed in; if there is a relatively slippery feeling when holding it in the palm, it indicates talc powder.
2. Soybean meal (cake): sediment, crushed corn or 5%-10% stone powder are often mixed in, reducing the protein content of soybean cake.
Identification method: 1. Water soaking: take a 25 g sample, place it in a glass cup containing 250 ml of water and soak for 2-3 h, then stir gently with a wooden stick. It can be seen that the soybean meal or crushed cake separates into layers from the sediment; the upper layer is cake meal, and the lower layer is sediment.
2.Iodine test:Place a small amount of sample on a clean porcelain dish, spread it thin and flat, and drip a few drops of iodine tincture on top. After 1 min, if some substance turns blue-black, it indicates corn,wheatbran, rice husk, etc. have been mixed in.
3.Raw and cooked soybean meal test method:Cooked soybean cake is commonly used as a raw material, not raw soybean cake, because raw soybean cake contains antitrypsin, saponin and other substances, which affect the palatability and digestibility for livestock and poultry. The method is to take 0.1 g of urea, add distilled water to 100 ml, stopper it and warm it in 45 °C water for 1 h, then immerse red litmus paper in this solution. If the litmus paper turns blue, it indicates the soybean meal is raw; otherwise it is cooked.
3. Fish meal: cottonseed cake, rapeseed cake, urea, sand grains and other impurities are often mixed in.
Identification method: 1. Sensory test: standard fish meal has uniform particle size, and a large amount of loose fish muscle fibers as well as a small amount of fish bones, fish scales, etc. can be seen. The color is light yellow, yellow-brown or yellow-brown, and when pinched by hand it feels loose, does not clump, is not sticky, has a fishy smell, and has no off odor.
2.Odor test:Take a 20 g sample and place it in a conical flask, add an appropriate amount of water, stopper it, and heat for 15-20 min. After opening the lid, if an ammonia smell can be detected, it indicates urea has been mixed in.
3.Water soaking method:Take a small amount of sample and place it in a test tube or large glass cup, add an appropriate amount of water, shake fully, and let it stand. The mixed-in sand and stones will sink to the bottom, while cotton cake, feather meal, etc. will float on the water surface.
4. Bone meal: good bone meal contains 23%-26% calcium and 12%-14% phosphorus. Adulterated bone meal has insufficient phosphorus due to the mixing in of stone powder, shell powder, fine sand, etc.
Identification method: 1. Visual method: pure bone meal is grayish-white powder or granular, with its inherent odor; adulterated bone meal is whitish in color.
2.Dilute hydrochloric acid dissolution method:Place the sample into a dilute hydrochloric acid solution. If it is pure bone meal, it will emit a short "shasha" sound, no bubbles will form on the surface of the bone meal particles, and finally it will all dissolve and become turbid; the hydrochloric acid solution of degelatinized bone meal has a very small amount of organic matter floating on the surface; steamed bone meal and raw bone meal have more floating matter on the surface, while fake bone meal shows none of the above chemical phenomena.
3.Burning method: take a small amount of sample and place it in a testtube, hold it over a fire and burn it. Real bone meal produces steam and then a pungent smell of burning hair, while adulterated bone meal produces less steam and odor, fake bone meal produces no steam or odor, and non-degelatinized deteriorated bone meal has an off odor.
5. Methionine: starch, glucose powder, stone powder, etc. are often mixed in, so that the amino acid content reaches only 50%, greatly lower than the national standard.
Identification method: 1. Sensory inspection: real methionine is pure white or slightly yellow, glossy crystals, and tastes sweet; fake methionine is yellow or gray, with very few shiny crystals, and has a strange taste and astringent feel.
2. Ignition method: take a 1 g sample and place it in a constant-weight porcelain crucible, first carbonize it on an electric furnace, then place it in a high-temperature furnace and ignite it at 550 °C for 1 h. That with an ash content below 0.5% is real methionine.
3. Dissolution method: take a 1 g sample and dissolve it in 50 ml of distilled water. If it can fully dissolve, it is real; otherwise it is fake.
--------------------------------------
These things are very practical, saved.
--------------------------------------
Saved, too practical, thank you
--------------------------------------
Useful, worth learning, O(∩_∩)O thank you
--------------------------------------
Everyone should communicate more and make progress together.
--------------------------------------
These things are very practical, saved.
--------------------------------------
Good material! Simple and practical! Saved for learning
--------------------------------------
Is there anything else? Post it so everyone can learn
--------------------------------------
The material is very practical, thanks for sharing, saved
--------------------------------------
Simple, useful, and very practical.
--------------------------------------
Not bad, can be saved and used in practice
--------------------------------------
Simple and practical, saved, thanks!