Mapping and analysis of volatomes from pearl millet (<i>Pennisetum gaucum</i> L.) grains during different storage conditions with solid‐phase microextraction–gas chromatography–mass spectrometry

Abstract

Abstract Background and Objectives Volatile organic compounds (VOCs) are considered biomarkers for the metabolic activities of biological entities. This work analyzed the impact of storage period and temperature (5°C, 25°C, and 45°C) on the VOC profile of pearl millet grains stored for 120 days through headspace gas analysis using solid‐phase microextraction–gas chromatography–mass spectroscopy (SPME‐GC‐MS). Findings The major groups identified in the pearl millet grains belonged to acid, alcohol, aldehyde, alkane, and ester groups. VOC data were analyzed using principal component analysis, partial least square discriminant analysis (PLS‐DA), cluster heat map, and network analysis of metabolite–metabolite interactions. The PLS‐DA could distinctly classify the VOCs generated with respect to different storage conditions. The VOCs generated during storage indicated the four most significant metabolic pathways, that is, fatty acid biosynthesis, cutin, suberine and wax biosynthesis, arginine biosynthesis, and arginine and proline metabolism. Conclusions The SPME‐GC‐MS protocol developed for mapping VOC through this study and the classification protocol developed can be used for developing quality monitoring systems in pearl millet grains. Significance and Novelty Identification of VOCs at a particular period will be helpful for the recommendation of appropriate remedial measures at the right time to avoid the spoilage of grains.