Hull Adhesion Characteristics of Early-split and Normal Pistachio Nuts

The hull adhesion properties of early-split and normal pistachio nuts were studied to determine the feasibility of separating early-split nuts from normal nuts by their hulling characteristics. The hulls of pistachio nuts were found to adhere more tightly to the shells of early-split nuts than to normal nuts. Laboratory hulling tests on pistachio nuts harvested in 1993 indicated that under controlled conditions, 98% of the normal nut hulls were removed while only 9% of the early-split hulls were removed.