Long before basmati became India’s global export, farmers in the Himalayan Terai were growing a black-husked, salt-tolerant rice called kalanamak. Kalanamak has been cultivated from around 600 BC in the Kapilvastu region and in parts of eastern Uttar Pradesh and Nepal, where the locals called it scented black pearl and considered it Buddha’s gift.
Kalanamak has a distinctive aroma, and dense micronutrient content. Kalanamak from the Siddharthnagar district was given a Geographical Indication tag in 2020. The Food and Agriculture Organization recognised it as a special variety of world rice.
However, no one has checked whether its quality changes with location. Does growing kalanamak in different conditions and locations change its composition and health benefits?
To find out, researchers from the Homi Bhabha National Institute collaborated with other institutions in India.
During the kharif season of 2024, they sowed kalanamak at two blocks just 20 km apart in the Siddharthnagar district: Birdpur and Shohratgarh. Rice grains harvested from both locations were compared.
To estimate the levels of essential minerals, the researchers acid-digested the samples in a microwave digester and used inductively coupled plasma-optical spectroscopy to analyse calcium, magnesium, iron and zinc content.
Compared to polished rice, micronutrient content was much higher in brown rice. Compared to Shohratgarh rice, the Birdpur rice sample had higher levels of magnesium, calcium, iron, zinc and phosphorus in both brown and milled forms.
To measure antioxidant potential, the researchers assayed radical scavenging on methanolic extracts of the rice samples. Both rice samples showed strong, dose-dependent free radical scavenging activity.
To measure intracellular reactive oxygen species levels, splenic lymphocytes from mice were treated with rice extracts and stained with a dye, a cell-permeable, non-fluorescent chemical probe. When analysed using flow cytometry, both extracts showed depletion in the levels of intracellular reactive oxygen species in a dose-dependent manner. Birdpur rice showed more distinctive inhibitory effects than Shohratgarh rice, suggesting that it is better at reducing reactive oxygen in cells.
To measure aromaticity, the researchers crushed milled rice and treated it with potassium hydroxide solution to release the aroma. A trained panel of food scientists evaluated the aroma on a four-point scale. Birdpur rice was found to be more fragrant than both Shohratgarh rice and the control Pusa Basmati 1.
The complete range of metabolites in the brown rice was identified using ultra-high-performance liquid chromatography tandem mass spectrometry. Around fifteen major aroma-producing compounds were identified. Birdpur rice had a higher abundance of diverse aroma compounds.
The researchers analysed the biosynthetic origins of the detected metabolites, using MetaboAnalyst, a computer-based analytical tool. They identified four major metabolic pathways linked to the aroma of kalanamak. The enrichment of these pathways was more significant in Birdpur rice.
Thus, the research established that kalanamak’s profile is chemically distinct but sensitive to local growing conditions besides its genetic potential. Kalanamak is a strategic genetic resource for breeding nutrient-rich aromatic rice varieties. But only if cultivators account for where, not just what, they are planting.
The research covers samples harvested in one kharif season and grown at two locations. Will the results be different if the samples were taken from rice grown in the rabi season? This question is yet to be settled.
Though kalanamak rice is reported to have cardiovascular and skin-health benefits, this heritage grain is disappearing. High-yield hybrid varieties have displaced its cultivation,
Should we not take steps towards understanding and preserving kalanamak – the Buddha’s gift?
Journal of Food Biochemistry, 2026(1)
DOI: 10.1155/jfbc/6588161
Reported by Aritha Chandrasekar
Sastra Deemed to be University, Thanjavur
This report was written in a workshop for capacity building of PhD scholars
organised by scienceandmediaworkshops.
The reports on this site are free-to-use for Indian media houses.
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