Not sure what to make of these trusses

Can anybody suggest what might be going on with the white discoloration on these trusses that I found in an inspection today? See photos below… Possibly from trusses getting damp before installation?
Thanks for any replies

It’s possibly mold from during storage. The pattern certainly matches what it would look like if trusses were stacked and bundled and getting rained on. If there were a chronic moisture problem in the attic after construction, it would be odd to see mold only on the trusses. If it’s not identifiable and you need to know your only real option is to test it.

I agree, it looks like the result of something that happened while they were stacked. It may just be that they were left in a stack exposed to sun and weather for a while before they were installed. Was there a residue of any kind?