IntroductionWhenever we cut an apple, we consume it before it turns brown. What we usually do when we don’t want it to turn brown as fast, is submerge it in salt water. This made me wonder why apples turned brown in the first place, and if different varieties of apples had different browning rates. As it turns out, apples turn brown as a result of a reaction between enzymes released by the inner pulp of apples and the oxygen in the air, which is extremely reactive.
Normally, the outer skin of the apple acts to protect this pulp from damage, but when this layer is damaged, the cells in the pulp release enzymes to react with the oxygen to oxidise the damaged cell in order to form a protective layer that stops infection. It is this process that causes apples to brown. Adding salt takes away moisture from the apple, exposing the pulp to less oxygen, meaning less oxidation to cause browning. |
Aim |
To find out which variety of apple is the most resilient to turning brown, and how much salt affects each of their browning rates.
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Hypothesis |
The sweetest-tasting apple variety will turn brown first, with the saltiest-tasting variety turning brown last.
The salted counterparts of each apple will last longer than the unsalted ones. |