Screening of Eight Biofortified Rice Varieties Based on Total Content of Zinc and Iron as Well as Its Uptake by Caco-2 Cells: An In Vitro Cellular Model

Zinc (Zn) and iron (Fe) are two essential micronutrients that help the body to maintain its normal physiology and metabolism. Rice is the most important staple crop because it nourishes approximately half of the world's population. The present study was intended to screen a set of eight rice varieties for total grain Zn and Fe content along with their uptake in differentiated Caco-2 cells. The total grain Zn and Fe content, as well as their bioaccessibility, was determined using inductively coupled plasma mass spectrometry (ICP-MS) techniques. The Caco-2 cell-based fluorescence assays and ferritin synthesis assays were used to determine Zn and Fe uptake, respectively. The transcriptional expression of micronutrient transporters has been analyzed in Caco-2 cells in response to the uptake of Zn and Fe from in vitro digested rice samples. The findings of this study revealed a comparative analysis of two prominent micronutrient contents in eight different varieties of polished rice. DRRDhan 48 (4.93 ± 0.10 mg/kg), Zinco Rice (4.65 ± 0.01 mg/kg), and Protozin (4.43 ± 0.03 mg/kg) were shown to have low phytate content, and high grain Zn content (32.49 ± 2.8, 27.9 ± 1.8, 26.7 ± 1.2 mg/kg, respectively), as well as significantly greater Zn uptake in differentiated Caco-2 cells. The outcome of this study provides an easy and convenient approach for the screening of food items or cereals based on micronutrient uptake.