Love the simplicity. Good texture, let down by the lighting - especially at the bottom of the shot where there should not be a highlight. An angled light to rake across the surface would have shown the texture more.
Perfect yellow against the blue. Maybe if it weren't so centered and there was more negative space on one side or above and below, it wouldn't appear as such a "target." The light and focus is good. The black dot on the upper part of the lemon is just a touch distrcting to me. Hope this is helpful.
Very nice texture. The lighting is perhaps a bit garish and the composition might be improved by not having the lemon right in the middle of the photo and taking the shot at more of an angle from above, this is just my opinion.