When you cut an apple oxygen immediately starts attacking it, leaving you with a less than appetizing brown hue. Many people use lemon juice or specialty powders to try to stop this from happening, but these items aren’t always on hand. The items that are usually around are drink packets and Emergen-C. The citric acid in both products, as well as lemon and orange juice, is what helps prevent browning.
Simply make packets as labeled and then soak fruit for just a minute. Do not rinse. Then store in the refrigerator or pack in a lunch. This trick also works for pears, bananas, and other browning fruits. When I make fruit salad, I like to use a little freshly squeezed orange juice if I have it, but this is always my “in a pinch” go to trick.