Excellent idea for this challenge, it really works well.
The lighting on this shot very soft, exactly what a person needs when shooting fruit like this. The thing that I find missing with the lighting is depth. The top and front of the fruit is illuminated perfectly; but, for food images such as this one, I find that lighting from above and slightly behind helps to add more dimension to round fruits. Lighting from above and slightly behind keeps the hot spots (not that yours are bad) to a minimum and gives the bottom of the fruit a bit of light causing a slight silhouette effect. I suggest playing around with it (if you want to) and you’ll see what I mean.
The composition is pretty straightforward. I don’t know what you could have done to improve it, but it leaves me a bit flat.
Looks like you may have some hot pixels, such a shame we cant clone. Anyways, the light reflections are good and miminal, something I often find annoying with fruit, especially the shiny kind. There feels like just the smallest amount of tilt with the apples higher than the oranges, otherwise it could be the heavier amount of shadow on the apples that are making it look like that. I'm assuming you had the light closer to the oranges, which is probably why they are more prominent and the apples are more in shadows. I like the shadows, it gives the feeling of much more dramatic lighting. The shadows on the bottom of the oranges just looks a little odd. Overall I like it, but there seems to be something missing and I'm not sure what.
You have your bases covered with two literalisms. Ooh, I just made one... LOL. The hard part of this challenge, in my opinion, was to illustrate the challenge and also to come up with a compelling photo. I think the composition and lighting here could have been more interesting, but this comparese favorably to others who did the same thing.
Wow. You killed two birds with one stone in this challenge. ;) I love the contrast of the different fruits and the black background worked very well with this. Get rid of those few hot pixels on the bottom right and this photo will be ready for a print.