Why does a freshly cut apple change colour after a while?

Answer 1

Oxidation - to prevent this happening place fresh cut apples and pears into a bath of 2 cups ice water and 1 teaspoon lemon, lime or orange juice to prevent browning for up to 12 hours this is also advisable if baking the same.

Answer 2

Apples and other produce (e.g., pears, bananas, peaches, potatoes) contain an enzyme (called polyphenol oxidase or tyrosinase) that reacts with oxygen and iron-containing phenols that are also found in the apple. The oxidation reaction basically forms a sort of rust on the surface of the fruit. You see the browning when the fruit is cut or bruised because these actions damage the cells in the fruit, allowing oxygen in the air to react with the enzyme and other chemicals.

The reaction can be slowed or prevented by inactivating the enzyme with heat (cooking), reducing the pH on the surface of the fruit (by adding lemon juice or another acid), reducing the amount of available oxygen (by putting cut fruit under water or vacuum packing it), or by adding certain preservative chemicals (like sulfur dioxide).

On the other hand, using cutlery that has some corrosion (as is seen with lower quality steel knives) can increase the rate and amount of the browning by making more iron salts available for the reaction.

Answer 3

Oxidation of Iron content. Other fruits do change their color. Mostly it is oxidation or some kind of chemical reactions. Even it is because if the knife we use might not be stainless steel and the iron gets rust in presence of moisture and oxygen. Cutting apples with such knife is a possible cause.

A drop or two of lemon juice on a cut apple should help you prevent oxidation quickly.

Answer 4

hi mamta,
the reason why an apple changes colour when it is cut is because an apple contains iron and when the cut apple is exposed to air it reacts with the oxygen in the air which is why the apple starts to brown or change colour.

Answer 5

its because the starch content present in the apple which is responsible for its sweet taste....forms a golden brown layer on the freshly cut surface...

Answer 6

Dear Friend !!

Apple contains iron, when we cut the apple the iron(Fe) is exposed to air which contains oxygen, when they react (Oxidation) Ferrous Oxide is formed (Fe2O) is formed which is red in colour

Hence apple turns red.

Answer 7

In simple language, any fruit or vegetable that turns blackish after sometime after cutting it, contains Iron. So if you are suffering from iron defeciency, try and eat apples, bananas, pears etc.

Answer 8

Apple contain millions of cells that when they are exposed to oxygen, they die and the apple turns brown. It's like a chemical reaction.

Answer 9

Orange :)

Answer 10

hi,
its because of ENZYMATIC BROWNING, where cell of the fruit is exposed to oxygen in the air and result is a darkening of the flesh.So to avoid that soak the fruit in the citric acid like lemon juice to slow down the process..