From field to shelf: A review on tackling anti-nutritional factors and rancidity in millets for a sustainable future

Millets are increasingly recognized as nutritionally rich, climate-resilient grains with immense potential to support global food and nutrition security. They are high in fibre, essential amino acids, B-vitamins, and minerals such as iron, calcium, and zinc, making them particularly valuable in addressing micronutrient deficiencies. Despite their nutritional richness and climate resilience, the wider dietary adoption of millets is constrained by two major challenges: anti-nutritional factors that reduce nutrient bioavailability and post-harvest rancidity that impairs sensory quality, shortens shelf life, and limits consumer acceptability. ANFs including phytic acid, tannins, oxalates, and enzyme inhibitors reduce the bioavailability of key nutrients by binding minerals or interfering with digestion. Rancidity, predominantly in milled millet flour, results from enzymatic and oxidative lipid degradation, leading to undesirable flavours, nutrient loss, and reduced shelf life. Traditional food processing methods such as soaking, fermentation, roasting, and germination have shown substantial effectiveness in lowering ANF content while preserving or enhancing nutritional quality. Modern innovations, including extrusion processing, pulsed electric fields, and improved packaging, further contribute to shelf-life extension and quality retention. Recent advances in biotechnology, including CRISPR/Cas9 genome editing, RNA interference, and DNA-free editing, offer targeted solutions to reduce phytic acid levels and limit rancidity at the genetic level. Additionally, AI-based predictive models now provide real-time insights into rancidity development and storage optimization. This review synthesizes biochemical, technological, and genetic strategies for reducing anti-nutritional factors and mitigation rancidity in millets. Through integrated strategies, millets can be repositioned as sustainable, nutrient-dense staples suitable for modern food systems and changing global dietary needs.