How about another fruit? Like grapes.... Or cherry.... Any other. If not, arranging some other apple so it won't be alone and or try to take a shot on not just full apple by eat it a bit, or just using knifes to peel it.

If not, you can try to shot apple without applying grayscale effect in it. That might be a good idea too, to use one or two of lamp in the side of the apple, so it will give clearer texture. And applying try to not just placing some water in the top, try to make the water all round the apple so it will give the total fresh outlook.