My wife finds some foods bitter. She calls them green.
I told her she might have a double BITTER gene, just guessing.
She cannot eat blueberries raw, but she likes them cooked.
When cooking them to make a jelly or other as she cooks them and starts to taste them, they become good for her when they START to boil.
She likes clementine oranges. I bought bag. She ate one and it was good for her. Another day I gave here the last one, and she started to eat it, but stopped and said it was bitter. I tried another section of it and found it sweet and good.
Ii thought maybe it had something to do with what she had just eaten before the orange, which was granala she made with very little sugar and sugar free tea.