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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Quality and Safety Assessment Research Unit » Research » Publications at this Location » Publication #320848
Title: Assessing the utility of microwave kernel moisture sensing in peanut drying

Author
item Lewis, Micah
item Trabelsi, Samir
item NELSON, STUART - Retired ARS Employee

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/28/2016
Publication Date: 8/1/2016
Citation: Lewis, M.A., Trabelsi, S., Nelson, S. 2016. Assessing the utility of microwave kernel moisture sensing in peanut drying. Applied Engineering in Agriculture. 32(6):707-712.

Interpretive Summary: World-wide production of peanuts totals approximately 29 million metric tons annually. The United States is the world’s third largest producer with about 1.9 million metric tons per year. Peanut production in the United States has increased yearly for the last decade. At harvest, peanuts must be dried to 10.49 percent moisture content or less for sale and for safe storage to prevent the development of mold and aflatoxin. Energy and labor for peanut drying are significant costs in the marketing of peanuts. A microwave moisture sensor has been developed, tested and proven for determining kernel moisture content without shelling the peanut pods, making it useful for monitoring kernel moisture content in real-time during peanut drying. Presently, in the peanut industry, peanut pods (unshelled peanuts) have to be shelled for kernel moisture content determination with the official moisture meter. This makes kernel moisture content determination laborious and limits efficiency during peanut drying. For field testing during the 2013 and 2014 peanut harvest seasons, a microwave moisture sensor was placed in several 45-ft drying semitrailers at a buying point in central Georgia to monitor kernel moisture content as the peanuts dried. A comparison was also performed with the official moisture meter. Overall evaluation demonstrated that the accuracy of the microwave moisture sensor and its provision of in-shell kernel moisture content would make it highly effective in the peanut drying process. Implementation of the microwave kernel moisture sensor in the drier control systems could produce significant savings in costs of drying and improve final product quality with benefits for producers, buyers, processors, marketers and the consuming public.

Technical Abstract: Presently, in the peanut industry, peanut pods (unshelled peanuts) have to be shelled for kernel moisture content determination with the official moisture meter. This makes kernel moisture content determination laborious and limits efficiency during peanut drying. For field testing during the 2013 and 2014 peanut harvest seasons, a microwave moisture sensor was placed in several 45-ft drying semitrailers at a buying point in central Georgia to monitor kernel moisture content as the peanuts dried. Laboratory investigation of the accuracy of the portable microwave moisture sensor showed that peanut kernel moisture content can be determined from measurements on unshelled peanuts with a standard error of performance = 0.55% moisture content when compared to the reference oven-drying method. A comparison was also performed between the microwave sensor and the official moisture meter during field testing. Results showed that there was a 2.3% difference in initial kernel moisture content determination and a 0.8% difference in ending kernel moisture content determination between the two. Overall evaluation demonstrated that the accuracy of the microwave moisture sensor and its provision of in-shell kernel moisture content would make it highly effective in the peanut drying process.