Location: National Peanut Research Laboratory
2017 Annual Report
Objectives
Objective 1: Establish new commercial equipment/methods to reduce labor and time to accurately sample farmers stock and shelled peanut lots and accurately determine peanut quality parameters including, but not limited to, foreign material, damage, oil chemistry, and kernel size distribution.
Sub-objective 1.A. Establish new sampling plans and equipment to obtain representative samples of consistent size from semi-drying trailer loads of farmers stock peanuts.
Sub-objective 1.B. Develop instrumentation systems combining the radio frequency dielectric with spectral properties to measure total oil content and the relative proportions of the oleic and linoleic fatty acids.
Objective 2: Enable use of existing and develop new commercial peanut curing (drying and processing) systems to reduce non-uniformity of moisture in farmers stock and shelled peanuts, and extend quality during storage and transport.
Objective 3: Enable new commercial uses of shelled-peanut bulk packaging and storage systems, utilizing temperature/relative humidity/oxygen modified atmospheres, to control mold and insect damage.
Approach
In a globally competitive market, the United States peanut industry must closely monitor and reduce the costs of producing, marketing, and processing peanuts for the global consumer. Peanut quality and safety are paramount and require considerable labor and capital to ensure that a safe, high quality product is delivered to the intended customer. This project is not limited to a single aspect of handling and processing peanuts, but examines peanut handling and processing on the farm to delivery of raw product to the manufacturer. The overall goal of this project is to reduce the post-harvest processing costs which include the cost of measuring and monitoring quality, quality degradation, and physical loss of product. Specifically, the objectives include: 1) Establish new commercial equipment/methods to reduce labor and time to accurately sample farmers stock and shelled peanut lots and accurately determine peanut quality, 2) Enable use of existing and develop new commercial peanut curing (drying and processing) systems to reduce non-uniformity of moisture in farmers stock and shelled peanuts, 3) Enable new commercial uses of shelled-peanut bulk packaging and storage systems, utilizing temperature/relative humidity/oxygen modified atmospheres.
Progress Report
In order to improve sampling and grading equipment (Objective 1), a pneumatic
sampler normally used during the grading process was instrumented with sensors and
programmable logic controllers to 1) automatically sense when a trailer is present
and ready for sampling, extract a representative sample using official sampling
patterns, 2) reduce that sample to 1800-g official and check samples, and 3) present
the sample for grading by peanut inspectors. The prototype was installed,
operated, and tested at a commercial peanut receiving facility during the 2016
peanut harvest. Tests were conducted at a commercial peanut drying facility that
receives peanuts in semi-trailers that have been re-designed for drying in-shell
peanuts to moisture contents suitable for safe storage. Some trailers were filled
completely; others were partially filled. Samples were taken throughout drying in
each load to determine the variation of moisture content during and upon completion of drying (Objective 2). Data from the constant condition shelf life studies were analyzed, presented at industry and scientific meetings, and submitted for publication (Objective 3).
Accomplishments
1. Alternative storage environments for shelled peanuts. Once the peanut industry began shelling peanuts 12 month out of the year and storing the peanuts in conventional cold storage facilities maintained at 38 degrees F, shellers received complaints from product manufacturers that shelled peanuts were arriving with mold damage in the top of the 1-ton containers. ARS engineers in Dawson, Georgia determined that peanuts packaged during the hot, humid summer months and then placed in 38 degree cold storage were at risk of developing mold in the tops of the bulk containers. ARS engineers from Dawson, Georgia conducted 12-month studies to compare quality changes in peanuts stored at 38, 55, and 70 degrees F. Their research showed no significant changes in peanut quality when stored at 55 degrees and 65% relative humidity. As a result of this research, the peanut industry has modified its Good Management Practices for maintaining and operating cold storage facilities to allow for storage of shelled peanuts up to 55 degrees. At least one major peanut sheller has adopted 55-degree storage for some of its facilities. A cold storage facility could reduce its energy consumption by approximately 50% just by raising the operating temperature from 38 to 55 degrees F.
Review Publications
Sorensen, R.B., Lamb, M.C., Butts, C.L. 2016. Yield response and economics of shallow subsurface drip irrigation systems. Journal of Agricultural Science. 4(1):1-11.
Butts, C.L., Sheppard, H.T., Lamb, M.C. 2017. An automated sample divider for farmers stock peanuts. Applied Engineering in Agriculture. doi:10.13031/aea.11798.
Lamb, M.C., Sorensen, R.B., Butts, C.L., Nuti, R., Davis, J.P., Dang, P.M., Arias De Ares, R.S., Sobolev, V. 2017. Chemical interruption of flowering to improve harvested peanut maturity. Peanut Science. 44(1):60-65.
