Twin-screw extrusion of vitamin D3/iron-blend granules in corn and lentil composite flours: Stability, microstructure, and interaction of vitamin D3 with human osteoblast cells

Abstract: Vitamin D3 (VD3) and iron-blend granules were blended with corn and lentil composite flour (75/25, w/w) and fed into a pilot-scale twin-screw extruder to produce ready-to-eat snacks. The morphology and microstructure of extruded snacks were examined using scanning electron microscopy with energy-dispersive X-ray (SEM–EDX), X-ray powder diffraction, and FT-IR. Differential scanning calorimetry and thermogravimetric analysis measured the melting temperature and thermal stability of the extrudates. SEM and FT-IR analysis demonstrate that micronutrients are mixed well in formulations used in extrudates at high shear and high temperatures. The SEM–EDX exhibited the presence of iron, whereas high performance liquid chromatography measurements confirmed the significant retention of VD3 in the extruded snacks. The interaction between VD3 and human osteoblast cells was studied using live imaging and the MMT assay. Overall, for the first time, VD3 and Fe²⁺ blend granules have been used in an extrusion platform, which has significant potential for the intervention of VD3 and iron deficiencies. Practical Application: For the first time, we reported the use of VD3/iron-blend granules in extruded products. The findings of this work demonstrated the thermal stability and capability of providing adequate quantities of VD3 and iron in corn flour/lentil flour/VD3-iron blend extruded snacks. Furthermore, the interaction of VD3 with osteoblast cells highlights the potential health benefits of the extrudates.