What is the tolerance temperature to dry fish feed containing vitamin C in an oven? It means at what level of temperature, we can recommend to dry fish feed containing vitamin C? What is destroying temperature for vitamin C in fish feed?
Engineering tool box recommend drying fish feed at 70 degrees C to 110 degrees C for half an hour to one and a half hour. https://www.engineeringtoolbox.com/drying-temperatures-time-d_132.html
The higher end of the range may destroy the vitamin C. The fish feed is not usually damaged by normal amounts of vitamin C.
"Vitamin C is the most easily destroyed vitamin there is. It is destroyed by oxygen, heat (above 70 degrees) and it leaks out." http://www.dietitian.com/vitaminc.html#.W0_8NvZFzIU
Maybe the vitamin could be added after the feed is dried.