Is there anything more simple and refreshing than a lemon? We have an eye on this iconic fruit every day, but after a closer look we might never see it in the same way again.
Small, yellow, fragrant. Give these three clues to anyone and they will certainly answer ‘lemon'. It is one of the most popular and well-known fruits, due to its use in kitchens all over the world. This is why we all know its organoleptic characteristics and properties so well. But what many people ignore is that a lemon represents a small chemical laboratory, which we are going to visit today.
First of all, the lemon is a citrus fruit, which recent genetic studies trace back to a cross between bitter orange and cedar. This would also be confirmed by the history of the fruit, which is recent: official records only begin during the Song dynasty, between 960 and 1279. Considering how old citrus fruits are, the lemon is merely a youngster.
When we think of the appearance of a lemon, the first thing that comes to mind is its beautiful colour, that characteristic yellow. But an unripe lemon is actually green. In this phase of immaturity, the colour of the fruit is given by chlorophyll alone, which is precisely green. With maturation, carotenoids develop, a group of orange-yellow coloured molecules. And those that exist in lemons, not surprisingly, are the most yellow: these are carotene and cryptoxanthin. A good way to check that a lemon is ripe, flavourful and juicy is to make sure its colour is a beautiful intense yellow.