Eficiency of the Blanching and Electronic Color Sorting Process for Reducing Aflatoxin in Raw Shelled Peanuts1

Abstract

Raw shelled peanut lots produced in the United States are inspected for aflatoxin using a sampling plan designed by the Peanut Administrative Committee (PAC). The aflatoxin concentration of most peanut lots rejected by the PAC sampling plan is reduced by using a blanching process that removes the testa or seed coat from the seed and then removing damaged or discolored seeds from the lot using electronic color sorters. Comparing aflatoxin sample results on lots before and after the blanching process indicates that the two-step process is effective for reducing aflatoxin in contaminated lots. The average aflatoxin reduction among the 8911 lots blanched and color sorted over 5 crop yr (1990 to 1994) was 89.9%. The blanching process was equally efficient in reducing aflatoxin for all peanut market types and grades represented in the data base. The average total weight loss among all 8911 lots blanched over the 5 crop yr was 16.8%. Both the percentage aflatoxin reduction and the percentage total weight loss that resulted from blanching was related to the amount of aflatoxin in unblanched lots. As the aflatoxin concentration among unblanched lots decreased, the percentage aflatoxin reduction and the percentage total weight loss associated with the blanching process both decreased.