Abstract
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.