Effect of Drying Methods on Peanut Quality during Storage.

Storage is an important step after peanut harvest and drying. Many factors could affect the peanut quality during storage. The quality change differences of peanut after being dried by solar radiation and at 35°C, 40°C, 45°C, 50°C during later storage were investigated, including moisture content (MC) and germination percentage (GP) of peanut kernels, acid value (AV), peroxide value (PV), iodine value (IV), vitamin E (VE) content and fatty acid composition (FAC) of extracted peanut oil. And the impact of four storage conditions, air-room temperature (A-RT), air-low temperature (A-LT), vacuum-room temperature (V-RT) and nitrogen-room temperature (N-RT) on peanut quality after 10 months' storage were also studied in this paper. The results revealed that drying conditions had only a little influence on peanut quality during later storage. Peanut dried by solar radiation was more easily oxidized than that dried under other drying conditions. The effects of storage time were much greater. The GP, AV, PV, VE content and FAC, showed significantly changes along with storage. GP and VE content decreased, AV and PV increased, and some linoleic acid was oxidized to oleic acid after 10 months' storage. In addition, A-LT exhibited best performance in keeping peanut quality than A-RT, V-RT and N-RT, which demonstrated that low temperature was more advantageous for peanut storage than controlled atmosphere. These results above would provide useful information and reference for the peanut storage to apply in food industry.