Art Smith finds it's best not to use aluminum for acidic products, like tomatoes. The acid can cause the metal to leak from the pan, and you will taste it in your food. He also never cooks or beats eggs in an aluminum pan, because it causes discoloration.
Art suggests shopping around to look for pots and pans that are lined with stainless steel. They are more expensive, but you'll like the results, and you won't taste any metal in your food. And even if you do have lined pots and pans, place your food in storage containers with labels.