I am doing a project on bananas on why they turn black brown after a while. I want to know the biology and chemistry of it.
Some fruits tend to brown when they are cut and exposed to air.
We are familiar with the way in which pale-coloured fruit and vegetables such as apples, bananas, and potatoes quickly turn brown if air is allowed access to a cut surface. When the polyphenolic substance are oxidised by the action of phenolase, browning occurs. This is similar to the changes which occur during the drying of tea leaves. Browning can be prevented by avoiding contact of oxygen with the substrate. A number of means are available to limit the activity of the phenol oxidase enzyme.