Abstract: There is provided an apparatus for splitting closed pistachio nuts in a controlled manner such that the longitudinal sutures of the nuts will be cracked open. The apparatus includes a cylindrical housing with a mandrel mounted for rotation therein to provide an annulus into which nuts can be introduced. According to various features of the apparatus, the pistachio nuts are rotated, oriented and then split along their sutures in the annulus and subsequently discharged through an opening in the housing. There is also provided a continuous process of treating closed shell pistachio nuts which includes the step of removing the denser foreign particles from the closed shell nuts by flotation; and a soaking step so that the shells of the unopened pistachio nuts will be saturated with water to provide a degree of shell flexibility such that when pressure is applied to the suture of the shell to effect splitting, the shell will flex rather than crack.

Abstract: A machine for hulling nuts having a rotationally driven horizontal disc provided with an upwardly disposed abrasive surface; a cylindrical casing coaxially related to the disc, closely spaced from its periphery, and provided with a discharge opening; a cover closing the casing above the disc and provided with a supply opening adjacent to the discharge opening; and a plurality of blades spaced around the disc and extending generally radially across it to guide nuts deposited in an unhulled condition on the disc through the supply opening in a path around the disc and alternately centrally and peripherally of the disc toward the discharge opening, the hulls being abraded from the kernals as the nuts traverse the path and being urged centrifugally from the disc to fall between it and the casing while the separated kernels exit through the discharge opening.