The Change of Insect Damaged Kernels, Acid Value and Oil Content of Peanut Seeds Infested by Plofia Interpunctella (Hübner)

Peanut is an important oil protein resource, which is susceptible to pest infection and damage during storage. Plodia interpunctella (Hübner) is one of the important pests in peanut storage, and its impact on peanut storage quality is worthy of attention and research. The rate of insect damaged kernels (IDK), acid value and oil content of peanut seeds were investigated when infested by P. interpunctella larvae with density of 0, 2, 6, 12 individuals/kg peanut seeds after different days, at 20, 25 and 30 ℃. When peanut kernels were infested by different P. interpunctella larvae densities at the same temperature, the rate of IDK and acid value significantly increased, and the oil content significantly decreased. At 30 ℃, when infested by 12 individuals per kg of larvae for 20 days, the rate of IDK of peanut seeds increased from 0.00% to 19.67%, the acid value increased from 0.57 mg/g to 2.25 mg/g, and the oil content decreased from 48.71% to 47.31%. When peanut kernels were infested by the same insect density at different temperatures, the rate of IDK, acid value and oil content changed significantly. When peanut kernels were infested by 12 individuals/kg larvae for 30 days at 20, 25 and 30 ℃ respectively, the rate of IDK of the samples were 14.00%, 18.33% and 21.33%, respectively, and the acid value was 0.82, 2.17 and 2.60 mg/g, the oil contents were 47.60%, 47.09% and 47.01%, respectively. The results suggested that the IDK, acid value and oil content significantly increased with the increase of insect infestation time, larvae development, insect density and temperature, while the oil contents significantly decreased.