Peanut Quality Improvement Through Controlled Curing1

Abstract

Abstract Peanut curing must proceed fast enough to avoid mold problems and harvest delays, and yet proceed slow enough to avoid milling quality loss. A new dryer heat control method, termed drying rate control (DRC), was developed to better meet the above criteria. DRC was tested and compared with humidistat control (HC) and conventional control (CC) using a bulk simulation model and laboratory curing tests. Airflow rates of 5, 10, and 15 m3/min/m3 were used. Simulation studies incorporated five years of actual weather data from Suffolk, Va. Laboratory curing tests were done on nine lots of peanuts over two years. Average curing times were the same for CC and DRC, but averaged 17% longer with HC. Estimated fuel costs were nearly the same for CC and DRC, but were 14% less for HC. Mold risk, percent splits in the grade sample, and volatile organic matter concentrations were nearly the same for all heater control methods. Percent skin slippage in ELKs, measured with a subjective test, averaged approximately 30% less with DRC and HC as compared to CC. In summary, HC resulted in better peanut quality than CC with lower fuel cost, but increased curing time. DRC resulted in better peanut quality than CC with similar curing time and similar fuel cost.