As soon as apple is cut, its open surface begins an immediate contact with air and turns brown. Every bite made on apple is a cut surface. The first opening is already brown before the next bite is made.
What if you want to serve apples to your visitors? Serving whole apples is fine. Turning brown while biting is of no big deal. However, there is a problem in serving slices. The apples are all brown before the visitors get them. Perhaps no one will get.
There are ways to prevent apple browning. I gonna test few of them.
1) I cut the apples under water. The purpose is to prevent air contact to apple surface. I kept one slice soaked in water for two minutes.
2) I squeezed one calamansi juice in a glass of water. It was enough to make it slightly acidic. I dipped one apple slice for two minutes.
3) I mixed 1/4 teaspoon of salt in a glass of water. It is claimed that saltiness prevents apple browning. I dipped one sliced for two minutes.
4) I dipped another slice in recently boiled water for one minute – more than this is too much.
I tapped the slices dry and placed on plate for observation.
From left to right – hot water treatment / blanching, soaked in calamansi / acid solution, dipped in salty water / saline solution and dipped in water.
The affect done by blanching is very noticeable, The flesh turned slightly brown and the peel became pale. The rest still have slight brown complexion but are still good looking. Hot water treatment is an obvious looser.
Dipping in acid solution gave a slightly acidic taste. The same is true with saline solution, a slightly salty taste. While plain water preserved the natural apple taste.
Cutting apples underwater and soaking for two minutes are enough.