We've all been there. “I don't like that” (hasn't tried it), “I don't eat x” (varies day by day), or just out-right refusal to eat certain foods. I used to let this stress me out, I now realise it is part of the development of independence, asserting own personality or just taking some control. Or perhaps they just don't like something, which hey this is ok too!
I hate wasting food, but realise that you do need to present certain foods over and over before they are even tried – but it is worth the persistence, you do win some (not all, let's be realistic!) in the end.
However, the best way I have found to get fussy or 'refusal' eaters to try something is to involve them in the preparation or cooking of a meal. It is amazing.