First, "mayim shelanu"! Now, the time component of eating. Plus the quantity component of eating. And the fact that terumah and non-kodshim do not combine to make that volume. Also, the combination of bread soaked in wine. How does this compare to meat and milk? Or rather, why isn't meat/milk the example that is brought to begin with? [What's What: Ta'am ke-Ikar] Note the rule against extrapolating from an innovation. So instead of meat and milk, the Gemara moves to kilayim, as a prohibited food. And then the requirement to get rid of the vessels of the non-Jews, or purifying them before use.