Restaurants, please don't package to-go/takeaway orders of acidic foods in aluminum containers!
We don't cook acidic foods in reactive metals (like aluminum) because it creates unpleasant tastes and coloration. The same thing happens when we put that food into reactive containers, and by the time the customer gets the food to wherever it's going, it's pretty well ruined (and science seems to look to unfavorably on ingesting aluminum, anyway).
Obvious foods to avoid packaging in aluminum: tomato (including sauces), vinaigrette (though acidic dressings should be on the side anyway to avoid wilting), fish, citrus, berry sauces.