Related su Ma'aserot 5:9

One who takes terumah from the threshing floor needs to have in mind (lit., "direct his heart on") what is in the stubble, what is in the straw, what is on the sides, [and] what is on the threshing floor [itself]. One who takes terumah on the winepress needs to have in mind [the volume of] what is in the [discarded] grape skins, and what is in the [discarded] grape seeds. One who takes terumah on an olive tank needs to have in mind what is in the pomace (i.e., the pulp that remains from the olives after the oil is squeezed). If he doesn't intend, it is a stipulation of the court that he takes terumah on the whole.