3,375. The Bracha on Eating Terumah
Terumos 15:21
Pursuant to the previous halacha, the laws regarding eating terumah and mixing it with other things apply equally to terumah gedolah, terumas maaser, challah and bikkurim. Each of these is nullified in a mixture 101 times its original volume, and they all combine with one another. If rendered ritually unclean, they must be burned. The laws of terumas maaser from doubtfully tithed produce are the same as those for terumas maaser from definitely untithed produce except that it is not punishable with lashes.
Terumos 15:22
When a kohein eats terumah, he should recite the appropriate bracha for that food, followed by the bracha “Who sanctified us with the holiness of Aaron and commanded us to eat terumah." We have a tradition – and the Rambam says that it has been observed – that kohanim recite this bracha even when eating challah that was taken from dough outside of Israel. This is because even eating holy foods from Israel is like performing the Temple service, as per Numbers 18:7 “I give you your priestly service as a gift.”