Separation of Shells from Walnut Meats Using Magnetic Methods

ABSTRACT THE purpose of this research was to study the feasibihty of using iron powder and magnetic fluid to remove shells from walnut meats. Privately developed methods and equipment, utilizing nontoxic glue and iron powder, were used to coat whole walnuts with iron powder. Alternately, a 1:1 mixture, consisting of 125 mL of water and 125 mL of magnetic fluid with 10 g nontoxic gelatin powder, was used to coat walnuts for the magnetic fluid treatment. Coated (both iron powder and magnetic fluid) nuts were cracked in a commercial nut cracker. Treatments were repHcated five times. Control walnuts were not treated with iron powder or magnetic fluid. Cracked walnuts (including the control) were conditioned over the permanent magnetic drum separator two times. Analyses were done to determine percentage shells and membranes removed along with percentage walnut meats recovered. Iron analyses were carried out on walnut meats. Both iron powder and magnetic fluid removed essentially all shells from walnut meats. However, both require Food and Drug Administration approval as food additives.