Location: National Peanut Research Laboratory
2019 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
Analysis of spatial variability of peanut grade factors in semi-drying trailers shows that the spatial distribution of foreign material and loose shelled kernels (LSK) is highly correlated to spatial variation moisture content and split kernels (Objective 1a). Data analysis of commercial drying data shows a need for continued education of personnel loading trailers and operating the dryers to improve drying uniformity (Objective 2). A 9-month test showed that storing shelled peanuts using hermetic storage systems may not be feasible because of reduced germination and some mold growth. The mold that was identified has very little published data regarding its preferred environment and is very difficult to grow in laboratory cultures.
Accomplishments
1. Hermetic storage of shelled peanuts. Purdue Improved Crop Storage (PICS) is a hermetic storage system using two layers of an impermeable plastic bag to store grain and other commodities in developing nations to reduce losses to insects and rodents. The efficacy of the PICS system for storing shelled peanuts is unknown and ARS researcher in Dawson, Georgia, conducted a 9-month study to determine its suitability for storing shelled peanuts in developing countries. Carbon dioxide levels increased rapidly as expected in the PICS bags serving to kill any insects that may have initially been in the peanuts. Losses to insect and rodent damage was heavy in the burlap/jute bags used as the control. Some of the PICS bags were damaged by rodents. The peanuts stored in the PICS bags had reduced seed germination and a very slow-growing mold that had not been previously identified on peanuts. This work has demonstrated that shelled peanuts should not be stored in hermetically sealed bags at/or above 7% moisture content.
Review Publications
Butts, C.L., Sorensen, R.B., Lamb, M.C. 2018. Unloading farmers’ stock warehouses with a peanut vac. Peanut Science. https://doi.org/10.3146/0095-3679-45.2.87.
Butts, C.L., Valentine, H. 2019. Building on our past to engineer the future. Peanut Science. 46(1A):82-90. https://doi.org/10.3146/0095-3679-46.1A.82.
