Rancidity in pearlmillet (Pennisetum glaucum): biochemical mechanisms, genetic variability and mitigation strategies

Abstract

Pearlmillet is a nutritionally rich and climate-resilient cereal crop widely cultivated in arid and semi-arid regions. However, its utilization in processed food systems is limited by the rapid development of rancidity in the flour after milling. Rancidity in pearlmillet flour is predominantly enzymatic, initiated by endogenous triacylglycerol lipases that release free fatty acids, followed by oxidative reactions mediated by lipoxygenase and non-enzymatic pathways, resulting in the formation of volatile compounds responsible for development of off-flavour during storage. Although numerous studies have independently investigated biochemical indicators, genetic variability and processing-based mitigation strategies, the available information remains fragmented and lacks an integrated synthesis linking enzymatic mechanisms with genetic regulation and technological interventions. Recent advances in metabolomics, transcriptomics and functional genomics have improved understanding of lipid catabolism and flavour deterioration in pearl millet flour. However, these findings have not yet been comprehensively evaluated in the context of breeding and industrial processing. Integration of biochemical understanding, genetic improvement and optimized post-harvest processing strategies is essential for enhancing flour shelf stability and expanding the utilization of pearl millet in modern food systems.