The capsule includes: a cup defining an internal volume and closed at the top by a lid fixed to an upper edge; a sealing disc fixed internally to the cup on a lower edge, adapted to divide the internal volume into a containing volume for the food product to be infused or dissolved, and a mixing volume for optimal mixing of the food substance in the extraction fluid, said sealing disc, being adapted to seal the containing volume tightly at the base and then to detach from the lower edge due to the pressure exerted by the fluid; a mixing element positioned in the cup between the sealing disc and the lower wall, adapted to create vorticity in the fluid to allow a correct mixing of the food substance.