No more brown apples?

The longer an apple retains its beautiful colour, the better it is - especially for the food industry. Therefore, the industry works intensely on inhibiting the "browning" of fruits. Chemists of the University of Vienna around Annette Rompel moved a step closer to this ultimate goal. Everybody knows this phenomenon: After slicing an apple, it loses its appetising white colour very quickly, which does not only scare off children. Although browned fruit is not harmful, we unwillingly eat "old-looking" fruit and throw away huge quantities of fresh products each year. The reason for this ugly colouring is a chemical reaction, which is due to the catalysis caused by the enzyme tyrosinase. Actually, this "browning" is a defence mechanism of plants.