COLOR SORTING OF LIGHTLY ROASTED AND DESKINNED PEANUT KERNELS TO DIMINISH AFLATOXIN CONTAMINATION IN COMMERCIAL LOTS

Moistened peanut kernels were inoculated with conidia of Aspergillus parasiticus, and moistened but uninoculated kernels were incubated at ambient temperature for 35 days. Glucose, free fatty acid, free threonine, proline, glycine, alanine, leucine, tyrosine, phenylalanine, lysine, histidine, and arginine contents increased in both types of peanuts, whereas sucrose, free glutamic acid, aspartic acid, valine, and serine contents decreased. When the incubated kernels were roasted at 160 degrees C for 15 min, discoloration of infected, manually deskinned kernels was detected by color sorting. The average aflatoxin contents in the discolored sublets of kernels inoculated with A. parasiticus and uninoculated lots were 18 200 and 12.5 ppb, respectively. When this process was applied to a commercial line, the aflatoxin content in the discolored sublets of 30 200-kg lots ranged from undetected to 976 ppb. Aflatoxin was not detected in kernels of unblemished sublets.