My 17 week old Pitbull pup

Question
Ok so my dog is pretty well trained, except I have obvious trouble when around lots of distractions because he gets so excited. But that is another topic. My problem is I recently got him these nice flavored chew treats and he knows that I control EVERYTHING and has never had a issue with me just taking things from him because I always praise him when he willingly just gives things up, but with these chews as soon as I went near him he because SUPER aggressive, hair on back standing up, lips snarling, he looked ready to attack and I said "NO!" and took the chew and he bit me. I was very mad and I really want to fix this, there is no reason he should be aggressive like that.

Any suggestions? I have been coming up to him with treats and showing the treats and taking the chews with no problems but with out treats he goes crazy again. I want to be able to do this with out bribing him, what if a stranger goes to pet him when he has a chew? Please help, thanks.

P.S. he is going through training classes and is on his second one, he is showing a little aggression toward adult dogs, but plays very proper with the other dogs in his puppy classes.

Answer
I have this problem with my own dog as well,and as a result after trying 'trade offs' and failing,she is no longer allowed to chews

But what you can try first before banning him from having chews,is to spray him with water when he growls and said 'no' loud and firm-that does work with most dogs,but if it doesn't,you too may be forced to take them away for good as it can lead to trouble,some dogs tend to be aggressive only with hard toys,so sometimes you have to only give them softer toys,like stuffed animals ect

It might also help if you ask your trainer,as he/she might be able to help you if they see the problem,they can show you how to correct it