Evaluation of Bioprocess-Based Technique for Iron and Zinc Fortification in Red Rice Genotypes

Iron (Fe) and zinc (Zn) deficiencies, globally prevalent nutritional disorders, underscore the need for effective fortification strategies in staple foods like rice. This study evaluates a bioprocess-based technique for single (SF) and double fortification (DF) of two heritage red rice genotypes (Chennangi—CH, Karungkuruvai—KK) to enhance mineral content and bioavailability. Whole rice grains were germinated in sodium iron EDTA and zinc chloride solutions (SF: 50 and 100 mg/L Fe/Zn; DF: Fe + Zn at a 2:1 ratio). Mineral quantification via microwave plasma atomic emission spectrometry (MPAES) revealed that SF significantly increased fortified mineral content but reduced accessibility of the non-fortified mineral. In contrast, DF substantially enhanced both Fe (2-fold) and Zn (7-fold) content while improving bioaccessibility (Fe: 2–2.5x; Zn: 3–7x), supported by reduced phytate levels. Both genotypes exhibited high Zn accumulation and retention. Cooked DF rice has good sensory acceptability and improved cooking characteristics. At daily consumption levels of 30–150 g, DF rice could meet 16–70% of Fe and nearly 100% Zn Recommended Dietary Intake (RDI) across age groups. This simple, scalable bioprocessing method effectively enhances Fe and Zn bioavailability in wholegrains, offering a promising solution to combat micronutrient deficiencies through dietary staples, contributing to Sustainable Development Goals (SDG 2 and 3) by promoting accessible nutrition for healthier populations.