Apples are my daughter's favourite fruit (she takes after her grandfather!) and they are also a great addition the lunchbox thanks to their availability all year round and their budget-friendly price. However they do have a problem of going brown once they are sliced up, so I've tried several methods to stop this and I will share with you my favourite choice!
Why do apples turn brown?
Apples are rich in iron (another bonus) so when they are cut and exposed to air, the iron reacts with enzymes and the oxygen in the air to form Iron oxide, so basically the apple is rusting. This might change the taste and the nutritional value slightly but mostly, it just looks very unappealing to eat, especially to kids.
Before we go into the different methods though I would like to point out 2 other factors which affect browning. Fist is the type of apple: my green grocer suggested I use Golden Apples (the yellowish ones) or Pink Lady, since they brown less than Gala or Granny Smith, and its absolutely true. So if your family likes these apples they are the best choice for lunchboxes. Second is using a sharp knife when slicing. A sharp knife will damage the cells less so there is less oxidation. Below are some other methods that have been tried and tested
Leaving the apple whole
If you leave the apple whole it obviously wont turn brown but many children do not find this handy. You can also slice it up and reconstruct it, holding together with a rubber band. This minimizes the area exposed to the air so less browning. You can use this method of you have place to pack the apple as a whole fruit, such as in the b.box lunchboxes
Slicing under water
By slicing under water, the sliced flesh of the apple never meets the air so you are preventing the oxidation process. I haven't tried this method so I don't know if the effect holds once you remove them from the water and place in the lunchbox.
Juices or Citric Acid
By soaking the slices in water and lemon juice, orange juice, pineapple juice, apple juice or ginger ale, the browning will be drastically reduced. These juices contain citric acid (which you can also buy from the pharmacy in powdered form and mix with water) which prevent the oxidation process. This method works very well but the fruit might take the taste of the juice and taste different. When I used lemon juice in water 50:50 for example, the apple was a bit bitter.
Water and Honey
Stir two tablespoons of honey into one cup of water and soak your apple slices in the mixture for 30 seconds. A compound in honey stops the enzyme responsible for oxidation. This also gives a sweeter taste to the apple though you might be adding sugars and in my opinion its a bit of an expensive solution to use every day.
Using airtight containers
After slicing, an apple kept in an airtight container will brown much slower because you are limiting the exposure to oxygen. I find this really makes a big difference. An apple sitting on her plate and an apple in her lunchbox in the fridge for the next morning will look very different. If i'm preparing the apple for home or outing I use the NomNom Kids Snack Bags or Sandwich Bags (squeeze out the air before closing). If it's for school, I pack straight away into the b.box lunchbox or snackbox or yumbox since both seal tightly. This method works perfectly hand in hand with the method below, which is my favourite method to stop apple from browning.
My Favourite Method
My favourite method is the salt and water method. Mix half a teaspoon of salt in a bowl of 1 cup water. As you slice the apple, place the slices in the bowl straight away and carry on preparing the rest of the packed lunch. After about 3-5 minutes, drain the water, rinse the slices under fresh water to remove the salt, and pat dry. This method really works. I slice the apple in the evening, pack it in the lunchbox, and the it still looks good after 24 hours or more!