From Cover Crop to Food Crop: Nutritional Composition and Evidence Gaps Limiting Human Consumption of Pearl Millet in Brazil

Pearl millet (Cenchrus americanus (L.) Morrone, syn. Pennisetum glaucum (L.) R. Br.) is a climate-resilient cereal distinguished from wheat, rice, and oats by a higher lipid content dominated by linoleic acid, essential amino acids, dietary fiber, minerals, and antioxidant compounds. However, its use outside Africa and Asia remains limited; in Brazil it is grown primarily as a cover crop and animal feed, with negligible presence in human diets. This review asks why a nutritious grain produced at this scale fails to enter the human food chain, arguing that its defining nutritional strength is also its main limitation. The lipid fraction triggers rapid hydrolytic and oxidative rancidity post-milling, restricting flour shelf life and impacting downstream processing, formulation, and distribution. We organize the evidence around interacting barriers: sensory acceptance in a population unaccustomed to grain consumption; post-milling lipid instability; nutrient gains and losses across processing, where total and bioaccessible content diverge; the poor dough workability of a gluten-free flour, which leads to blending with other flours and dilutes the attributes that justify its use; and contaminants in pearl millet flour. The challenge is no longer knowing what pearl millet contains, but producing a flour that can withstand distribution, preserve the nutritional properties and gain a place in a food system centered on other crops, a task that requires processing studies, consumer research and evidence generated under Brazilian conditions.