Nutrient variability and food potential of indigenous rice landraces (Oryza sativa L.) from Northeast India

Abstract

Rice is major staple food of Nagaland, northeast India. A comprehensive nutrient assessment of 23 rice landraces from Nagaland (brown, ~5 % and ~10 % polished) was carried out. The mean nutrient content of brown rice was: protein 7.6 ± 0.5 %, fat 2.65 ± 0.39 %, total dietary fibre 5.24 ± 0.52 %, ash 1.28 ± 0.11 % and carbohydrate 69.84 ± 1.28 %. The range of water soluble-vitamin was thiamine 0.19–0.35, riboflavin 0.04–0.07, niacin 2.48–3.77, pyridoxine 0.43–2.39, and pantothenic acid 0.03–0.11 mg/100 g. A relatively large coefficient of variation was observed for iron (25 %), manganese (28 %), copper (32 %), calcium (13 %), and phosphorus (11 %) among 23 varieties of brown rice. Nutrient density score (NDS) was 16, 11, and 8 for brown rice, ~5 % and ~10 % milled rice, respectively. The NDS score identified eight rice landraces as superior. Nutrient losses due to milling ranged from 14 % to 69 %. By far, brown rice has the best potential for nutrient supply, but limiting milling to ~5 % can substantially improve rice grains' nutrient content. Rice exhibited the most crucial nutrient contributor to the RDA. Significantly higher TDF and lower phytate contents found in these rice landraces. The study highlights the importance of rice landraces to help select important traits and breed superior germplasm to improve rice grain nutrient considerably especially in the face of climate change.