Quick Facts
- Kesari dal (Lathyrus sativus) is banned for sale in many Indian states but still contaminates toor dal supply chains — it causes lathyrism, a paralytic disease with no cure
- Lathyrism affects thousands of people in Bihar, MP, and UP annually — caused by the neurotoxin BOAA (beta-N-oxalyl-amino-L-alanine) in kesari dal
- Metanil yellow (acid yellow 36) is an industrial textile dye used to make yellow-split dals appear fresher and more vibrant — it is a carcinogen banned as a food additive
- Artificial colour coating on whole dals is used to make old, inferior quality dals appear brighter and fresher — detected by rubbing the dal on white paper
- Adulteration rates in loose dal purchased from open bins are significantly higher than in packaged, branded dal from FSSAI-licensed processors
- Kesari dal can be identified visually under a magnifying glass — it has a distinctive triangular seed shape different from the oval toor dal seed
The Kesari Dal Crisis — A Paralysis Cause
Kesari dal (grass pea, Lathyrus sativus) is a cheap, drought-resistant legume that grows in harsh conditions. It contains BOAA (beta-N-oxalyl-amino-L-alanine) — a neurotoxin that causes lathyrism when consumed regularly.
What lathyrism does:
- Causes irreversible damage to the spinal cord
- Results in spastic paralysis of the lower limbs — victims drag or cannot use their legs
- Has no treatment or reversal — the paralysis is permanent
- Primarily affects the poor who eat kesari dal as a primary protein source during food scarcity
Why it enters the food supply: Kesari dal looks similar to toor dal when split and polished. It is significantly cheaper (₹20–40/kg vs ₹80–120/kg for toor). Unscrupulous traders blend it into toor dal, particularly in drought years when dal prices spike.
States most affected: Bihar, Madhya Pradesh, Uttar Pradesh, Chhattisgarh
Legal status: Kesari dal is banned for sale in many Indian states under the Prevention of Food Adulteration Act and state-specific orders. However, enforcement remains difficult.
Other Dal Adulterants
Metanil yellow dye: Applied to split dals to make them appear fresh and vibrant. Old or stored dals lose their bright colour — dye restores the appearance. Metanil yellow is an industrial dye (not food grade) associated with neurotoxicity and carcinogenicity in animal studies.
Artificial colour coating: Whole dals are coated with artificial food colour (or non-food dyes) to make them appear higher quality. Detected by rubbing on white paper — the colour transfers.
Polishing with oil or mineral oil: Dals are polished to give a shiny appearance. Permitted edible oils are fine; mineral oil (non-food grade) used for the same purpose is harmful.
Inferior quality substitution: Cheap varieties sold as premium varieties (e.g., ordinary masoor sold as red malka masoor at a premium price).
Home Tests for Dal Adulteration
Home Test: Rubbing Test — Artificial Colour Detection
Steps
- 1 Take a handful of dal in your palm
- 2 Rub the dal vigorously between your palms for 30 seconds
- 3 Examine your palms for colour transfer
Pure / Pass
Genuine dal leaves no colour on your hands. Natural colour is bound within the dal seed coat and does not rub off.
Adulterated / Fail
Adulterated dal with artificial colour coating leaves coloured residue on your palms. Red, yellow, or orange colour on your hands indicates dye coating.
Home Test: Water Test — Artificial Colour Detection
Steps
- 1 Add a handful of dal to a glass of water
- 2 Stir for 30 seconds
- 3 Observe the colour of the water
Pure / Pass
Water with genuine dal remains clear or turns very lightly coloured (natural pigment from the seed coat) — the colour is subtle and even.
Adulterated / Fail
Water with artificially coloured dal turns distinctly coloured (yellow, orange, red) quickly — the synthetic dye is water-soluble and leaches out rapidly.
Home Test: Hydrochloric Acid Test — Metanil Yellow Detection
Steps
- 1 Dissolve a small amount of dal in water
- 2 Add a few drops of hydrochloric acid (dilute) or concentrated vinegar
- 3 Observe colour change
Pure / Pass
Pure dal shows no dramatic colour change with acid.
Adulterated / Fail
Dal with metanil yellow turns pink or magenta with acid — metanil yellow is an acid indicator and changes colour in acidic solution. This is the same response as turmeric adulterated with metanil yellow.
Home Test: Visual Test — Kesari Dal Identification
Steps
- 1 Examine a sample of toor dal under good light (use a magnifying glass if available)
- 2 Look for seeds that are different in shape from the standard oval/round toor dal shape
- 3 Kesari dal seeds are distinctly angular and wedge-shaped
Pure / Pass
All seeds are uniformly oval, similar in shape and size — consistent with genuine toor dal.
Adulterated / Fail
You see some seeds that are distinctly triangular or wedge-shaped with a different surface texture — these may be kesari dal. Sort and remove them, and consider reporting to FSSAI.
Dal Adulteration — Adulterants and Health Impact
| Adulterant | Target Dal | Health Effect | Detection |
|---|---|---|---|
| Kesari dal (Lathyrus) | Toor dal primarily | CRITICAL — lathyrism (permanent paralysis) | Visual test; BOAA chemical test |
| Metanil yellow | All yellow/split dals | HIGH — carcinogenic, neurotoxic | HCl/acid test — turns pink |
| Artificial colour | All dals | Moderate — depends on dye used | Rubbing test; water test |
| Inferior varieties | Premium dal categories | Low toxicity — quality fraud | Cooking test; visual examination |
| Mineral oil polish | Whole dals (urad, chana) | Moderate — petroleum toxicity | Paper absorbency test |
Kesari dal is the only adulterant with a catastrophic, irreversible health effect — it warrants particular vigilance for toor dal.
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Organic Toor Dal
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Q How do I know if my toor dal has kesari dal in it?
How do I know if my toor dal has kesari dal in it?
The most reliable home method: spread dry toor dal on a white plate in good light. Look carefully at the shape of individual seeds. Toor dal seeds are oval, round at both ends. Kesari dal (Lathyrus sativus) seeds are distinctly wedge-shaped or triangular — one end is pointed, the seed has a different curvature. You may see a few mixed in with thousands of genuine seeds. A magnifying glass helps significantly. For lab-confirmed testing, BOAA (the neurotoxin in kesari dal) can be tested by food testing laboratories — FSSAI-accredited labs can perform this test.
Q If I accidentally ate kesari dal once, will I get lathyrism?
If I accidentally ate kesari dal once, will I get lathyrism?
No — lathyrism results from chronic, high-level consumption of kesari dal as a major dietary staple over months to years. A small accidental exposure from adulterated dal consumed occasionally at normal quantities is unlikely to cause lathyrism. The disease affected rural poor who ate kesari dal as their primary protein source during famines. The neurotoxin BOAA has a cumulative effect — the disease typically manifests after sustained high intake. If you discover your dal is adulterated, stop using it and buy from a verified source. No special medical action is needed for a single accidental exposure.
Disclaimer: This article is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your doctor or a qualified healthcare provider before making dietary changes, especially if you have a medical condition.