CONTROLLED ATMOSPHERE STORAGE OF FARMERS STOCK PEANUTS

Goals / Objectives
The objective of this cooperative research is to determine the feasibility of using insulated concrete domes for storing peanuts using ambient, refrigerated, and low oxygen storage techniques.

Project Methods
Four 12-ft diameter insulated concrete domes will be filled with approximately 5 tons of farmers stock peanuts each. One dome will be aerated with ambient air. The second dome will be sealed after initial tempering with ambient air and cooled to 50F or less using refrigeration equipment. A third dome will be sealed after initially tempering and flushed with nitrogen until less than 5% oxygen remains. The fourth storage unit will combine refrigerated storage and low oxygen atmosphere. Environmental conditions such as ambient temperature and relative humidity and conditions inside the dome including oxygen concentration, temperature, and relative humidity will be measured throughout the storage period. Indicators of peanut quality such as single kernel moisture and kernel size distributions, aflatoxin, and peroxide values and free fatty acids will be measured before and after storage. Tests will be repeated for 5 harvest seasons. Peanuts will be stored in a 5000-ton capacity monolithic dome in Rochelle, GA. Peanut quality will be monitored before and after storage through random sampling. Storage environment will be monitored using temperature sensors throughout the storage period.

Progress 02/28/04 to 02/27/09

Outputs
Progress Report 4d Progress report. This research is conducted through a non-funded cooperative agreement with Doster Warehouse. During the spring of 2004, Doster Warehouse constructed two 122-ft diameter domes to store farmer stock peanuts. A third dome was constructed prior to harvesting the 2005 peanut crop, and equipment installed to remove excessive foreign material from the peanuts prior to storage. The National Peanut Research Laboratory installed sensors to measure temperature in two vertical transects of the dome stuctures. Temperature and humidity data were transmitted wirelessly to the office of the cooperator then could be securely accessed via the world wide web. Each dome was filled with approximately 5500 tons of farmer stock peanuts by mid-October. Aeration fans were operated to remove the excess heat and moisture. Peanuts have been stored from harvest through July with minimal detrimental changes in peanut quality. This research parallels research conducted on 1/10- scale domes by engineers at the National Peanut Research Laboratory. Peanuts from the 2004 and 2005 crops have been stored in both the commercial and 1/10-scale domes. Tests to evaluate the quality of peanuts after storage are underway.

Impacts
(N/A)

Publications

Progress 10/01/04 to 09/30/05

Outputs
4d Progress report. This research is conducted through a non-funded cooperative agreement with Doster Warehouse. This report serves to document research conducted under a Non-funded Cooperative Agreement with Doster Warehouse. Additional details of research can be found in the report for the parent CRIS 6604-41430-002-00D. During the spring of 2004, Doster Warehouse constructed two 122-ft diameter domes to store farmer stock peanuts from the 2004 crop. The National Peanut Research Laboratory installed sensors to measure temperature in two vertical transects of the dome stuctures. Each dome was filled with approximately 5500 tons of farmer stock peanuts by mid-October. Aeration fans were operated to remove the excess heat and moisture until the end of December 2004. A nitrogen generator was used to inject high purity nitrogen into the domes to reduce and maintain the oxygen level with the dome below 5%. These peanuts have been stored through the first week in August 2005 with no apparent detrimental changes in peanut quality. This research is a commercial scale test of tests conducted on a smaller scale by engineers at the National Peanut Research Laboratory. 2004 crop peanuts will be unloaded from the controlled atmosphere domes at the end of August 2005. Samples will be sent to independent laboratories to conduct flavor, chemical, and germination tests.

Impacts
(N/A)

Publications

Progress 10/01/03 to 09/30/04

Outputs
4. What were the most significant accomplishments this past year? A Non-funded Cooperative Agreement was signed with Doster Warehouse, Rochelle, GA to collaborate on developing management strategies for controlled atmosphere storage of farmers stock peanuts. Two 122-ft diameter monolithic domes were constructed by the cooperator in Rochelle, GA and instrumented by ARS engineers. These commercial warehouses will be aerated according to a mutually agreed upon protocol and the resulting peanut quality will be determined and compared to the quality at load-in. Four 12-ft monolithic domes were constructed and transported to Dawson, GA for replicated storage studies at the National Peanut Research Laboratory. Instrumentation in the 1/10th scale domes will record the temperature profile, O2 concentration, and relative humidity in each of the domes. One dome will be aerated using only ambient air. A second dome will be sealed and the temperature controlled using an in-line air conditioning unit. The third dome will be held at ambient temperature, but the O2 concentration will be maintained at less than 5%. The fourth dome will be chilled and low oxygen storage conditions maintained.

Impacts
(N/A)

Publications