Sodium nitrate has a bitter aftertaste to me. A bit like baking soda. I can usually taste it then I check the labels and sure enough I see 'preservative (252)'.
Interesting. After this comment I mentioned it to a family member who is in natural medicine and diet (no fan of preservatives themselves) and they were surprised that I could taste it. So Maybe there is a genetic component. I mean it's more like an aftertaste than a taste but it's obvious to me. Like if you eat pancakes with too much baking soda in them, it leaves a kind of numbing effect and slight bitterness on the tongue... Or maybe that's genetic too haha.
If you constantly experience a bitter taste when eating foods you should speak to your doctor. It can be a sign of an infection or liver issues.