Matrix-controlled iron bioavailability in unrefined whole-pulse low-moisture extrudates

This is the authors' abstract. We don't add key points for this paper.

Iron deficiency remains one of the most prevalent micronutrient deficiencies globally, disproportionately affecting populations that rely on plant-based diets. Although pulses are widely consumed staple foods and often contain substantial amounts of iron, iron concentration alone is a poor predictor of nutritional value because absorption is strongly constrained by the food matrix after processing these pulses. Here, we show that unrefined pulse composition exerts a dominant influence on cellular iron uptake in extruded foods, often outweighing the effects of total iron concentration and processing method. Using low-moisture extrusion to produce shelf-stable, ready-to-eat foods from unrefined pulse flours, we observed wide variation in cellular iron uptake among pulse types despite comparable iron contents, with Caco-2 cell ferritin formation ranging from 0.81 ± 0.04 to 32.17 ± 0.31 ng ferritin/mg cell protein. This variation was most strongly associated with flavonoid composition: a low level of inhibitory flavonoids, together with a low phytate-to-iron molar ratio, characterized the samples with the highest iron uptake, whereas abundant enhancer flavonoids contributed only when inhibitory flavonoids were scarce. Extrusion improved cellular iron uptake only modestly relative to traditional porridge preparation. Together, these findings highlight matrix-controlled bioavailability as a key factor in plant-based iron delivery and identify yellow bean-based puffed snacks as a promising, consumer-friendly strategy for improving dietary iron intake.