Efficacy of microwave irradiation in enhancing the shelf life of groundnut (Arachis hypogaea L.)

Abstract

This study aimed to investigate the effect of microwave irradiation on quality attributes of groundnut (Arachis hypogaea L.) during the storage period of four months. In this experiment, the groundnut seeds of Devi variety (ICGV-91114) were exposed to power density levels (3 and 5 W/g) and treatment time (60 and 90 s) maintaining the initial moisture content (IMC) at 5 ± 0.1 and 7 ± 0.1% db in packaging materials of low-density polyethylene (LDPE) and polypropylene (PP). With the increase in power level and exposure time, the moisture content and germination percentage were found to decrease. Groundnut kernels at IMC 5% showed lower infestation and samples treated with 3 W/g for 90 s showed a higher percentage of oil yield. The samples treated with 3 W/g for 60–90 s and 5 W/g for 60 s exposure time, stored in PP retained both seed and grain qualities at the end of 4 months. The Principal Component Analysis (PCA) was carried out to define the most appropriate descriptors of quality attributes of the microwave treated groundnut samples during the storage period. The highest significant negative correlation was found between moisture content and oil yield (r = −0.815) as well as between germination capacity and free fatty acid content (r = −0.815) whereas infestation percentage was positively correlated with the moisture content (r = 0.719) of microwave treated groundnut samples during the four months of storage study.