How to Stabilize Vitamin C for Aquaculture Feed
Pure Vitamin C is unstable and when subject to feed processing of any sort it loses stability rapidly. Vitamin C is very unstable. It oxidizes rapidly when exposed to air and heat.
Vitamin C is required by fish, as they lack the ability to synthesize this vital nutrient. Some Vitamin C is provided by dietary ingredients, however, supplemental Vitamin C is required under several situations. In supplementing Vitamin C to fish, adjustments must be made to accommodate for the losses that occur during feed processing and storage, and also losses that occur because of leaching of Vitamin C into water. Chemically and physically stabilized forms of Vitamin C exist to counter these losses of Vitamin C and are used extensively in the industry.
The preferred form of Vitamin C to use depends on feed processing conditions and to the species fed. For cold pelleting diets, coated Microencapsulated Vitamin C, which is physically stabilized using high quality microencapsulation technology, is preferred. Enzymes present in a feed matrix can cleave the phosphate groups off chemically stabilized vitamin C and thereby lowering its overall stability. For steam pelleted diets, both technologies can be effective with the coated Microencapsulated Vitamin C providing more benefits especially for species such as shrimp with short gastrointestinal tract. For species with short gastrointestinal tract coated Microencapsulated ascorbic acid is more bioavailable than chemically derived Vitamin C. This is because in chemically stabilized Vitamin C there is incomplete cleavage of the phosphate esters of the Vitamin C molecule which causes decreased bioavailability.
Raw Vitamin C is unstable, loses its potency when subjected to feed processing, heat and air. It oxidizes rapidly. Coated Microencapsulated Vitamin C is a stabilized form of Vitamin C that can withstand the rigors of feed processing and remains intact when fed – it does not leach out in water.