We had an arbovitee cut down.Can we put the mulch on our apple&peach t

If it came down due to some pest or infection, NO!

I would not recommend that,as there were most likely insects that attack the arborvitae

"The loss of nitrogen can be a problem, however, for vegetables and annuals, so do not use fresh wood chips, particularly sawdust size chips, in the home vegetable garden or as mulch around annuals. The fresh chips can be placed around established trees and shrubs to a depth of 3 or 4 inches"

igrow.org/gardens/gardening/can-i-use-fresh-wood-and-bark-mulch/

"it is recommended that you stockpile the chips for three to six months before using them. If your pile is large, be sure to turn it several times during this period to ensure good aeration to aid decomposition. This should allow acidic compounds to dissipate as well as partially decompose the chips, so that heat and acidity will not harm your plants."

https://macon.ces.ncsu.edu/2017/02/fresh-wood-chips-as-mulch/

Reading for you to consider:

http://www.gardensalive.com/product/wood-mulch/you_bet_your_garden

http://www.reformationacres.com/2014/05/5-things-you-should-know-about-wood-chip-mulch.html

http://homeguides.sfgate.com/pine-bark-mulch-problems-49460.html

https://www.newgarden.com/notes/what-is-the-best-mulch

http://www.finegardening.com/mulch-healthy-garden

If it were me, I'd set them aside for the 6 months, turning as directed and then use appropriately.

I agree with Robyn. Fresh garden or tree chips can burn a plant because it gets hot while it is decomposing. Better to compost the chips first then use them.