Overview[1]
L-ascorbic acid (VC) is an essential nutritional vitamin in the process of animal growth and reproduction, and has a wide range of physiological functions. In many known metabolic processes of the body, VC participates in the synthesis of hormones in the body, the metabolism of tyrosine and cholesterol, and the composition of the redox system in the body. The presence of easily oxidizable groups in the VC structure makes VC unstable. VC can be decomposed and deactivated under conditions such as air, light, water, minerals and higher temperatures. Therefore, when VC is used alone as a feed additive, 80% to 98% of the active ingredients are destroyed during the processing and storage of feed. For example, 25% to 50% of crystalline VC is destroyed during the mixing and preparation process, 30% to 60% is destroyed during soaking and sinking in water, and the storage loss at room temperature is 10% to 15% per week. In this way, aquatic animals The amount of VC that can be absorbed in the feed is very small. In response to these problems, Hebei Institute of Chemical Industry has developed L-ascorbic acid-2-phosphate with a potency greater than 35%, and has put it into industrial production at Hebei Yuanzheng Pharmaceutical Co., Ltd. Compared with the 25% L-ascorbic acid-2-phosphate currently sold on the market, this Korean LG product has a higher VC utilization rate, basically replacing the 25% potency L-ascorbic acid-2-phosphate product. .
Stability[2]
L-ascorbic acid-2-phosphate can withstand harsh conditions such as high temperature, high pressure, and high humidity during feed processing. Its ability to withstand the complex environment during feed storage is much greater than that of crystalline VC, For coated VC, whether in the granulation process or the conditioning and puffing process, the preservation rate of L-ascorbic acid-2-phosphate is higher than 90%, which is significantly higher than other types of VC.
Preparation[1]
A method for producing feed additive L-ascorbic acid-2-phosphate. The method uses vitamin C as raw material, uses calcium hydroxide suspension to implement alkalization under nitrogen protection, and uses sodium trimetaphosphate to implement esterification. oxidation, aging in a low-oxygen aging room, and drying with nitrogen hot air to obtain L-ascorbic acid-2-phosphate.
1) Alkalization process: Put 500Kg of purified water into the alkali kettle, add 250Kg of calcium hydroxide, stir and make it fully dissolved; add 720Kg of purified water into the esterification kettle, and control the temperature below 15°C. While stirring, add one ten thousandth of EDTA-2Na (mass ratio to calcium hydroxide, add 500kg of vitamin C and 30kg of calcium chloride after 5 minutes, replace with nitrogen twice (evacuate until the pressure in the kettle is -0.09MPa, and pass in nitrogen) When the pressure in the kettle reaches 0.05MPa (one replacement), keep the pressure in the esterification kettle at 0.05MPa; start dripping the calcium hydroxide suspension, and control the temperature below 20°C until the pH is between 11 and 12.5, stop dripping Add.
2) Esterification process: The temperature is controlled between 20 and 25°C, and 370kg of sodium trimetaphosphate is quickly put into the esterification kettle. After 5 minutes, the temperature of the material liquid is raised to about 35°C, and the material is discharged until it becomes stainless. Original hot melt adhesive steel material truck imported from Germany.
3) Curing process: Transport the materials to the low-oxygen curing room, and control the temperature at around 30°C for 19 hours.
4) Drying process: After the nitrogen hot air dryer is turned on, adjust the inlet air temperature to 220°C and the outlet air temperature to within the range of 115°C. Start feeding the matured L-ascorbic acid-2-phosphate. The chopped ester is evenly fed into the dryer, and the feeding speed can be adjusted appropriately according to the inlet and outlet air temperature. Finally, the dried L-ascorbic acid-2-phosphate is collected through a cyclone separator.
Application
L-ascorbic acid-2-phosphate (also known as vitamin C-2-phosphate, Vc-2-phosphate) is a highly stable L-ascorbic acid derivative that has appeared in the international market in recent years. It is composed of L -Ascorbic acid is produced by phosphoric acid esterification. Because the hydroxyl group at the 2-position of L-ascorbic acid molecule is esterified, it has high tolerance and stability to high temperature, water, and oxygen, acid, and alkali in the air. It enters the organism and is hydrolyzed and dephosphorylated under the action of phosphatase. The base is converted into L-ascorbic acid, which has the same biological activity as vitamin C.
Main reference materials
[1] Stability study of high potency L-ascorbic acid-2-phosphate
[2] CN201610256991.9 A production method of L-ascorbic acid-2-phosphate
[3] CN200410012588.9 A method for preparing L-ascorbic acid-2-phosphate and its salts
