New things require new words that accurately describe them.
To the chancellery official on duty on that Thursday the 1st of September 1718, trufelier must have occurred as the perfect term to indicate the freshly created office at the court of the landgrave of Hesse-Kassel. Three syllables, concise and unequivocal, the solemn ending -lier somehow reminding of romanic raffinement.
Trufelier: The one who goes for truffles.
The neologism did not happen to last. The word does not appear in the Brothers Grimm dictionary of ancient German nor in other authoritative dictionaries of the time.
Before, it did not exist, and then it never resurfaced – as if the word itself was a mushroom.
Besides the Brothers Grimm dictionary of ancient German, I have checked:
DU CANGE (1678/1688) – LA CURNE (1875) – LE LITTRÉ (1874) – FURETIÈRE (1708) –DICTIONNAIRE DE L´ACADÉMIE Française (1732) – OUDIN (1640) – GUIZOT (1848)