How to get unknown food stains out of a cotton t-shirt

Stains usually come out in the wash but these are stubborn. I think they're from a pizza I had because when I was leaving a friend pointed to my t-shirt and sure enough there were splotches across my chest.

So I've tried the usual - Tide Oxy spray stain removal with a wash. Nothing. Then I tried a combo of the Tide spray remover plus Oxi laundry detergent soaked on the spots then washed. Again, nothing. Now I'm soaking the spots in a mixture of papaya digestive enzimes and Tide spray remover and Dawn.

What else is there?