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United States Department of Agriculture

Agricultural Research Service

Title: Efficiency of the Blanching and Color Sorting Process in Removing Aflatoxinfrom Raw Shelled Peanut Lots

Author
item Whitaker, Thomas

Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 7, 1997
Publication Date: N/A

Interpretive Summary: Aflatoxin, produced by several fungi, is a carcinogenic and toxic compound found on several agricultural commodities. The FDA has established maximum levels for food and feed products. The peanut industry inspects all domestic lots of raw shelled peanuts for aflatoxin before the peanuts are sent to a manufacturer of consumer-ready products. Because aflatoxin is associated with damaged kernels, the peanut industry attempts to reclaim peanut lots rejected by the testing program by first removing the red skin from each peanut kernel and then removing damaged kernels from the lot using electronic color sorters. The efficiency of this blanching process at reducing aflatoxin in peanut lots was measured. Results indicated that the blanching process is a very effective method of reducing aflatoxin in raw peanut lots. On the average, almost 91 percent of the aflatoxin in contaminated lots can be reduced by the blanching process. If blanching did not effectively reduce aflatoxin, peanut lots would be crushed for oil which has a much lower economic value than raw peanuts used for consumer-ready products. The blanching process allows the peanut industry to maintain high economic product values and at the same time maintain high consumer safety standards.

Technical 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) that administers the USDA Peanut Marketing Agreement. The aflatoxin concentration of most peanut lots rejected by the PAC sampling plan is reduced by using a blanching process that removes the red skin from meach seed and then damaged or discolored seeds are removed from the lot using electronic color sorters. Comparing aflatoxin sample test results on lots before and after the blanching and color sorting process indicate that the two-step process is an effective method of reducing aflatoxin in contaminated lots. The average aflatoxin reduction among the 5,492 lots blanched and color sorted in 1990 was 90.6%. Sorting the PAC 1990 database of 5,492 lots by peanut market type and grade categories indicated that the percent of aflatoxin reduction varied among the various categories from 81.2 to 97.4%. The percent aflatoxin reduction achieved with the blanching and color sorting steps, while averaging over 90%, was related to the amount of aflatoxin in lots before blanching and color sorting. As the aflatoxin concentration among unblanched lots decreased, the percent aflatoxin reduction achieved by blanching and color sorting decreased. For example, the percent aflatoxin reduction achieved when blanching and color sorting lots initially at 200, 50, and 16 ng/g was about 98%, 93%, and 81%, respectively.

Last Modified: 12/20/2014
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