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United States Department of Agriculture

Agricultural Research Service

Research Project: SORTING AGRICULTURAL MATERIALS FOR DEFECTS USING IMAGING AND PHYSICAL METHODS

Location: Foodborne Toxin Detection and Prevention

Title: Low cost real time sorting of in-shell pistachio nuts from kernels

Authors
item Jackson, Eric
item Haff, Ronald

Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: April 13, 2007
Publication Date: July 17, 2007
Citation: Jackson, E.S., Haff, R.P. 2007. Low cost real time sorting of in-shell pistachio nuts from kernels. ASABE Annual International Meeting.

Interpretive Summary: A high speed, non-destructive, low cost sorting machine has been developed to separate pistachio product streams. An optical method was used to sort pistachio kernels from in-shell nuts, and was able to correctly identify 97.9% of kernels and 99.3% of in-shell nuts. By adjusting certain settings, the machine can be made to correctly identify a higher percentage of one type, though with a loss in percentage of the other, or vice versa. Recent research using a commercially available sorting system has reported identification of kernels at 98.8% and in-shell nuts at 99.9%. While these rates are slightly better than those reported here, the cost of this system is on the order of hundreds of dollars, as compared to commercially available sorting systems, which are in the range of tens of thousands of dollars.

Technical Abstract: A high speed, non-destructive, low cost sorting machine has been developed to separate pistachio product streams. An optical method was used to differentiate pistachio kernels from in-shell nuts, with recognition rates of 97.9% for kernels (2.1% false negatives) and 99.3% for in-shell nuts (0.7% false positives). By adjusting the conditions of the method, these values can be manipulated to favor better recognition of one over the other depending on the more favorably desired stream. Recent research using a commercially available sorting system has reported separation of kernels from in-shell nuts with false positives of 0.1% and false negatives of 1.2 %. While these rates are slightly better than those reported here, the cost of this system is on the order of hundreds of dollars, as compared to commercially available sorting systems, which are in the range of tens of thousands of dollars.

Last Modified: 10/1/2014