Evaluation of Methods to Change Specific Gravity of Pecans and Pecan Weevils

Abstract

ABSTRACT PECAN pieces and pecan weevil larvae were subjected to two vacuum levels (low and high vacuum) followed by exposure to three fluids (water, brine (sp. gr. 1.1), helium gas) for four different times (5, 10, 20 and 40 min for water and brine, and 1, 2, 4 and 8 min for helium) to enlarge the density difference between pecan pieces and larvae for enhancing density separation of these two materials. The most significant change in the specific gravity distributions were found when the pecan pieces and larvae were immersed in water or brine for 20 to 40 min after subjecting them to a high level of vacuum. However, none of the treatments altered the specific gravity of pecans and larvae adequately to enhance separation due to density difference.