I microwave mine and then store it in the freezer. I know you can bake it but I am not familiar with the baking temperature or time. It should not change the nutritional value.
The purpose of that is to prevent moths from hatching. About 220F is what I did - stopped doing that and just use egg cartons now, and feed them Repashy Insect Gutload (human grade quality).
I want to bake it because I get mites in the bedding once in a while; not many, just that when I search through the tub, I can see 3 or 4 running around in there. I already put a dish of water beneath the mealworm tub. So I guess these mites (or their eggs) might have come from the organic stuff that I use.