Product dehydration unit comprising a chamber (1), an air suction member (4) contained in the chamber, a product receptacle (13) housed in the chamber and provided with an upper opening (25), an air-permeable and water-permeable bottom of a cassette (9) facing said upper opening, said cassette containing moisture adsorption means, and a seal (32) extending between a perimeter of the bottom of thecassette (9) and an edge (26) of the receptacle (13) defining the opening.