Metabolite Profiling of Methanolic and Aqueous Extracts of Rice and Black Gram Pulse consumed in Indian Subcontinent by Untargeted LC-MS/MS

Rice (Oryza sativa L.) and black gram (Vigna mungo (L.) Hepper) are widely consumed dietary staples in India and represent important sources of nutrients and bioactive phytochemicals. The present study aimed to characterize and compare their phytochemical compositions using an untargeted liquid chromatography–tandem mass spectrometry (LC-MS/MS) metabolomics approach. Methanolic and aqueous extracts were prepared by maceration and subjected to qualitative analysis using a SCIEX QTRAP mass spectrometry system operated in enhanced mass scan–enhanced product ion (EMS–EPI) mode with information-dependent acquisition (IDA) under positive and negative electrospray ionization conditions. The acquired mass spectral data were processed using SCIEX OS software for tentative compound identification and characterization. The analysis revealed 62 and 91 putatively identified compounds in rice and black gram, respectively, representing diverse chemical classes, including phenolic compounds, flavonoids, organic acids, and other bioactive metabolites. Rice exhibited spectral features assigned to genipin, and citric acid, jasmonic acid, and nigerose. In contrast, black gram exhibited a chemically diverse profile comprising flavonoids such as kaempferol, vitexin, robinin, luteolin, and puerarin, together with citric acid. The complementary positive and negative ionization modes facilitated the detection of chemically diverse metabolites, providing broader qualitative coverage of the investigated food matrices. In addition to phytochemical characterization, the analysis revealed tentative matches to pharmaceutical-related compounds, indicating the potential application of untargeted metabolomics for preliminary contaminant screening. These findings demonstrate the utility of LC-MS/MS-based metabolomics for comparative chemical profiling of commonly consumed food grains and provide a foundation for future.