Why does the beaten fruit stir?

2000/09/27 Elhuyar Zientzia

• Biokimika

When we get a blow, the skin of human beings is stirred, and the same thing happens with the fruit: when it hits it, it is shaken.

But in one and the other case why it is different, of course. Human blows are a consequence of the rupture of small veins and the irruption of blood under the skin. But the fruit hit, why is it brown?

Fruit cells contain hundreds of enzymes inside. These include the enzyme called POLYPHENOL OXIDASE or THYROSINASE, which produces moraton. When the cells of the fruit are complete, this enzyme is in place, but by beating them, the walls of the cells and their internal structure break. As a result, oxygen enters the cells and the aforementioned enzyme THYROSINASE oxidizes the phenolic components with oxygen. Because many of the oxidized organic compounds that form as a result of the reaction are brown, the beaten area also stops, that is, it is brushed.

When dividing the fruit into knives the same thing happens: the walls and tissues of the cells break and the fruit darkens. Citric acid, for example, is easily oxidizable and can be used to keep the fruit without biting, since it is the one that catches all the oxygen available around it. Therefore, the apple pieces will last longer if we put them before in lemon juice without getting dark. Immersed in water we can get the same result