Shrinkage of Farmers Stock Peanuts During Storage1

Abstract

Abstract A3-yr study was conducted during crop years 1989–91 to determine the value loss (shrinkage) experienced during long-term storage of farmers stock peanuts. Typical warehouses used to store each of the three major peanut market types were selected in each of the peanut production regions of the United States. Peanuts were purchased and stored according to conventional operating procedures for at least 60 d, unloaded, and hauled to the shelling plant (regrade). The loan value of the peanuts was determined using the 1990 Peanut Loan Schedule based on official grades and weights at load-in, bailout, and the shelling plant. Data from samples shelled at the National Peanut Research Laboratory Pilot Shelling Plant were used to determine the difference between outturns estimated from the official grade and the actual shelling outturns after storage. The 3-yr average change in value from load-in to regrade for runner peanuts was −2.04%; Spanish peanuts was −2.81%; and Virginia peanuts was −4.17%. Increases in foreign material and loose shelled kernels due to handling during loading and unloading, and changes in the kernel size distribution contributed equally to the value loss for the runner peanuts. Moisture loss to levels below 7% was responsible for approximately 20% of the value loss in both the Spanish and Virginia peanuts. Redistribution of kernel size, primarily the increase in split kernels, resulted in approximately 25% of the loss experienced in virginia-type peanuts. An increase in foreign material percentage accounted for approximately 50% of the Virginia peanut value loss. Increased foreign material and loose shelled kernels accounted for approximately 66% of the loss experienced in the Spanish peanuts. The total kernel weight obtained when the peanuts were shelled averaged 1.5% less than that estimated from the official grades at the time of original purchase. All market types had decreased outturn of whole edible kernels and increased split kernels. A net decrease in edible kernel outturns of 1.3% was observed.