Comprehensive Assessment of Millet Quality and Safety: Nutritional Characteristics, Processing Effects, Contaminant Detection and Emerging Analytical Technologies
Abstract
Millets contribute to dietary diversification, but their nutritional value and suitability for food use depend on species, processing, storage and contaminant control. This narrative review integrates nutritional composition, antinutritional factors, processing effects, biological and chemical hazards, regulatory requirements, and analytical technologies. Targeted searches of bibliographic records, publisher websites and official standards were combined with source-level checking of quantitative claims. Evidence was distinguished by study design, grain species, food or feed use, and analytical matrix. Millets provide starch, protein, fibre, minerals and phenolic compounds, although composition and glycaemic response cannot be generalised across products. Soaking, germination, fermentation, milling and thermal processing can improve selected nutritional or functional attributes while causing nutrient losses or introducing additional hygiene requirements. Historical and more recent surveys demonstrate mycotoxin contamination in pearl millet, but their sampling frames do not support national prevalence estimates. Evidence on edible-grain metal contamination and many emerging hazards remains insufficient for broad comparative safety claims. Chromatographic and immunochemical methods support contaminant testing, whereas optical sensing, biosensors and machine learning require application-specific validation. Direct hyperspectral evidence for millet cultivar classification should not be interpreted as validation for toxin detection. Effective quality assurance therefore requires representative sampling, verified commodity-specific limits, preventive process controls, and traceable analytical results. Priority research needs include comparable occurrence surveys, bioavailability studies and externally validated screening methods for millet-based foods.