Why do bananas go brown and ripen other fruit? (2024)

FAQs

Why do bananas go brown and ripen other fruit? ›

"Bananas make other fruit ripen because they release a gas called ethene (formerly ethylene)," added Dr Bebber. "This gas causes ripening, or softening of fruit by the breakdown of cell walls, conversion of starches to sugars and the disappearance of acids.

A known process of speeding up ripening is by placing fruits in a paper bag with a banana; the banana in the paper bag will produce more ethylene gas along with the other fruit, and the paper bag will trap the ethylene gas, speeding the ripening.

As bananas ripen, they produce and release ethylene gas, which causes the yellow pigment in the fruit skin to decay and turn brown ( 1 ). But nevertheless, a brown banana is not a useless one, and they're still nutritious too.

Bananas produce a natural plant hormone called ethylene that ripens the fruit. It works by converting starch into sugar, which gives the bananas that soft texture and sweet taste. They start off bright green in color and continue to ripen over time—gradually becoming yellow, then yellow with spots, and finally brown.

During ripening, there is an increase in the breakdown of starch inside the fruit, and a corresponding increase in the amount of simple sugars which taste sweet, such as sucrose, glucose, and fructose. This process is particularly obvious in bananas as they ripen.

A dull, grey color indicates they have been either chilled or overheated during ripening and/or storage. There is no need to be concerned if bananas appear a little greyer than usual. There is nothing wrong with the bananas and is safe to consume.

Melanin is the same dark brown pigment that colors hair, skin and the irises of our eyes. It also turns fruit and vegetables brown." So, oxidized bananas, while they may be less eye-catching than when they're in their sunny, yellow form, are perfectly fine to eat.

You might have noticed that most bananas you find at the supermarket are still a bit green. This is because bananas, like many fruits and vegetables, continue to ripen after being picked. So to give them a longer shelf, bananas are harvested young and delivered to stores while still slightly underripe.

The reason bananas get sweeter as they ripen is that their starch is broken down into sugar. When your body has to break down the starch itself (as it does when you eat a green banana), your blood sugar rises more slowly.

Rotten bananas will often have a fermented or alcohol-like smell. While it's okay if the banana peel is dark brown or even black, if the inside is too, then the fruit is beyond ripe and now on its way to rotten. Another sign that bananas have gone bad is if they start leaking any fluids.

What is the chemical change in a banana turning brown? ›

The chemical change that occurs when a banana peel turns brown in the open air is known as an oxidation reaction. In this process, oxygen reacts with a chemical that is in the peel of a banana called polyphenol oxidase.

As one piece of fruit emits ethylene gas, other climacteric fruits nearby get the message that it's time for them to ripen, too. It's peer pressure, for produce. Because bananas produce copious amounts of ethylene, they nudge neighboring fruits to hop on the ripening-into-deliciousness train.

According to Chiquita's website, separating each banana from the bunch is the most effective way of slowing down the ripening process. The large amount of ethylene gas produced by an intact bunch of bananas will ripen them faster.

Banana ripening gas

The ethene which bananas release can affect many other fruits, such as apples and pears, which is why you should keep the bananas separate from these fruits unless you intentionally want to ripen them quicker. Citrus fruits however, such as oranges and lemons are unaffected by this gas.

A cotton towel or linen cloth can also be used to speed up the ripening of the fruits. First, we need to make sure that the cloth towel is completely clean and soft. Then spread the towel on the table and place soft fruits like peaches, plums, or soft-skinned fruits on it one by one.