Method for identifying authenticity of some feed raw materials

Part of the feed raw material identification method 1, wheat bran: often found mixed with talc powder, rice bran and other identification methods: insert the hand into the wheat bran to extract, if the hands stick with white powder and not easy to shake off, it means that it is mixed with talc powder, if it is easy to shake off, it is residual flour. Then grab a handful of bran with your hand and rub it hard. If the bran forms a ball, it is pure bran. When you wipe your hand, it is mixed with rice chaff. If it is slippery in the palm of your hand, it means there is talc powder. Second, soybean meal (cake): often mixed with sediment, chopped corn or 5% to 10% stone powder, reducing the protein content of soybean cake.  identification method: 1. Immersion: 25 g of sample was soaked in a glass containing 250 ml water for 2-3 h, then stirred gently with a wooden stick, it could be seen that the soybean meal or broken cake was delaminated with sediment, the upper layer was cake, and the lower layer was sediment.  2. Iodine identification: take a small number of samples on a clean porcelain plate, spread thin and smooth, drop a few drops of iodine on it, over 1 min, if any substance turns blue-black, it is mixed with corn, wheat bran, rice husk and so on.  3. Testing method of raw and cooked soybean meal: cooked soybean cake is often used as raw material, because raw soybean cake contains antitrypsin, saponin and other substances, which affect the palatability and digestibility of livestock and poultry. The method is to take 0.1g urea, add distilled water to 100ml, add it to 45 ℃ water and heat it for 1 h, then soak the red litmus test paper into this solution. If the litmus test paper turns blue, it shows that the soybean meal is raw, otherwise it is cooked. Third, fish meal: which is often mixed with cottonseed cake, rapeseed cake, urea, sand and other sundries.  identification method: 1. Sensory test: standard fishmeal particles of the same size, you can see a large number of loose fish muscle fibers and a small amount of fish bones, fish scales, etc., the color is light yellow, yellowish brown or yellowish brown, with a sense of looseness, no caking, no sticky, fishy smell, no peculiar smell. two。 Odor detection: put 20g of sample into a conical bottle, add proper amount of water, add it and heat it for 1520 min. If you can smell ammonia after opening the lid, it is mixed with urea.  3. Water immersion method: put a small amount of samples into a test tube or a large glass, add an appropriate amount of water, fully oscillate and rest, the mixed sand and gravel will sink to the bottom, and cotton cakes and feather powder will float on the surface. Fourth, bone meal: good bone meal contains calcium 23% 26%, phosphorus 12% 14%. The adulterated bone powder contains insufficient phosphorus due to the addition of stone powder, shell powder, fine sand and so on.  identification method: 1. Intuitive method: pure bone powder is grayish white powder or granular, with inherent smell; adulterated bone powder color is white. two。 Dilute hydrochloric acid solution: put the sample into dilute hydrochloric acid solution, such as pure bone powder will make a "rustling" sound for a short time, there are no air bubbles on the surface of bone powder particles, and finally all dissolve and become turbid; there is a very small amount of organic matter floating on the surface of hydrochloric acid solution of degummed bone powder; there are more floating substances on the surface of steamed bone powder and raw bone powder, but there is no above chemical phenomenon on false bone powder.  3. Fire burning method: take a small number of samples into the test tube, barbecue on the fire, the real bone powder produces steam, and then produces the pungent smell of burning hair, while the adulterated bone powder produces less steam and smell, and the false bone powder has no vapor and odor. the undegummed metamorphic bone powder has a peculiar smell. 5. Methionine: it is often mixed with starch, glucose powder, stone powder and so on, but the content of amino acid is only 50%, which is much lower than the national standard.  identification method: 1. Sensory examination: true methionine is pure white or yellowish, glossy crystal, sweet taste; fake yellow or gray, very few flash crystals, strange taste, astringent feeling.  2. Burning method: 1 g sample was placed in a constant weight porcelain crucible, carbonized before the electric furnace, and then burnt in a high temperature furnace at 550 ℃ for 1 h. The one with ash less than 0.5% is true methionine.  3. Solution: 1 g sample is dissolved in 50 ml distilled water, if it can be completely dissolved, it will be true, otherwise it will be false. These things are very practical Collection-- collection is too practical to thank you-- useful, worth learning. O (∩ _ ∩) O Thank you for communicating more and making progress together. -- these things are very practical and collected-- good information! Simple and practical! I have a collection of studies-is there anything else? Send it out for everyone to learn-- the material is very practical, thank you for sharing, collecting-- simple, useful and practical. -- not bad, it can be collected and used in practice-- simple and practical, collected, thank you!