Summary by @tldr:

Michel de Nostre Dame, a Provencal doctor better known under name of Nostradamus, was the first to insist that sugar had valuable properties for preserving foods when he published his "Traite des confitures" in 1555 (Fauque, 2002).
At present, Brazil has the highest rate of consumption of sugar, followed by Australia, Thailand, and the European Union.
White refined sugar is one of the main conservatives: it keeps jams, marmalade for long time; in medicine it is added to many syrups and tablets to make them less bitter.
When a School of pastry cooking in France asked him to initiate its' students into sugar work, he was delighted to share his passion and soon devoted himself entirely to teaching.
Thus as you can see sugar is not only a white cube to make our tea sweet but very interesting thing to investigate.