quimica das coisas


Some of the most sublime pleasures we have in life exist only thanks to chemistry! To prove it, today we speak of chocolate!

The chocolate we eat today is the result of a long process of discovery, experience and innovation. Over the next few minutes, we’ll learn about some important steps that make it so delicious!

You may not know this, but the cacao bean that is harvested from the fruit is far from having the aroma and flavour we associate with chocolate.

The first essential process for the formation of the substances responsible for cocoa flavour is the fermentation of these seeds, which involves several chemical reactions. What is important to remember is that it’s during this process that the seed’s storage protein begins to be broken down into its constituent amino acids.

The next step is roasting, which allows for the evaporation of water and also of some compounds of the cocoa beans with unpleasant smell and taste.

But the real beauty of roasting is the chemical cascade of reactions that  occur between the amino acids formed in fermentation and the sugars in the grain. Such reactions lead to the compounds responsible for flavour and taste of chocolate (aldehydes, esters, ketones, furans)) and also form the compounds which give the brown colour to the grain! Chocolate brown!

Before we can enjoy the delights of chocolate, there is still one last step: crystallization. The main responsible for the texture of chocolate, cocoa butter, can crystallize in six different ways, a property known as polymorphism.

Polymorphism is a different arrangement of molecules to form a solid state. But various physical properties such as colour, brightness and melting temperature result of this arrangement. Of the six possible forms of polymorphism for chocolate, only one has the features that consumers appreciate: it has a silky surface, a smooth texture and it melts on the tongue.

Unfortunately, this tastier form is not the most stable one.  And the ultimate challenge for chocolate makers is to ensure that all the chocolate crystallizes in the right way. This can only be achieved through a cycle of heating and cooling with carefully controlled temperatures.

If you leave your chocolate in the heat it will lose its special features and be insipid and difficult to melt in the mouth.

Keep your chocolate at the right temperature, to avoid wasting the pleasures of chemistry!