Influence of microwave irradiation on lipid oxidation and acceptance in peanut (Arachis hypogaea L.) seeds

The purpose of this study was to evaluate the occurrence of lipid oxidation in peanut (Arachis hypogaea L) seeds which were heated by microwave irradiation. Peanut seeds were exposed to microwaves for 0, 2.5, 3.5, 4.5, 5.5 and 6.5 min at frequency of 2,450 MHz, 450 watts microwave oven. The quality characteristics of peanut seed (moisture content and color values), extracted peanut oils (PV, TBA, p-anisidine, FFA) and acceptance test were analyzed. Moisture contents and color values (L*) of seeds significantly decreased (P <0.05), whereas a* and b* values increased (P <0.05) from 0 – 6.5 min of heating time. The PV, p-anisidine and FFA of the extracted oils significantly increased (P <0.05) whereas TBA values were not significantly (P >0.05). Lower acceptance in all attributes was observed in the samples heated at 6.5 min, than in other samples. The results indicated that microwave irradiation on peanut seeds contributed to lipid oxidation and acceptability.