Here comes the science bit.
The truffle, one of the many species of the genus Tuber, is the reproductive fruiting body of a subterranean fungus. In other words, the truffle is an underground fungus with the shape of a tuber. Truffles need trees. They must live in symbiosis with certain trees and shrubs in order to form. When an animal smells the pungent truffle and breaks it apart spores are released. These spores travel to the tree and ‘inoculate’ the roots of the tree by means of filaments or hyphae which interact with the roots and form mycorrhizae.
By this means the tree gives nutrients to the fungi, and in turn receives mostly water and minerals.
When certain environmental conditions occur, a number of hyphae will intertwine and create the truffle. Unlike fungi which grow above ground the truffle spores cannot be dispersed by wind. It is for this reason that nature has given them with a strong smell, perceptible only when they mature. This strong smell attracts insects and mammals that feed on truffles and as they disperse the spores and the lifecycle begins again.
The white truffle, which consists of a meaty mass (glebe) and a harder part (peridium), is made up mainly of water (approximately 80 %), fibres, mineral salts (potassium, sodium, magnesium, calcium, iron, copper and zinc) and by those organic substances that gets from the tree it lives in simbiosis with. The peridium has a colour that varies from white to yellowish and the glebe is whitish with brown grains.