Even some of the most agreeable young eaters will turn their noses up at fruit that's turning brown. No matter how fresh the apple, once you slice it oxygen hits the flesh and it starts to oxidize, or turn brown. To keep your culinary critic from sending the fruit course back, all you need to do is give it a hit of acidulated water before bagging it up.

Acidulated water is just a fancy name for H2O spiked with a harmless edible acid such as lemon or lime juice. To make the solution, pour a quart of water into a clean mist bottle and add two tablespoons of lemon or lime juice to it (bottled is fine). After slicing the apples just give them a quick spritz with the mixture and pack them up. Then you can stash the mister in the fridge for another day. It works for peaches, pears, and avocados as well.

Way 2:

 keep our cut apples fresh we put them in a pan and fill it with pinapple juice, it works great and gives the apples a nice flavor.