Urad Dal (Black Gram): Nutrients, What Research Shows and Safety

Urad dal is the seed of black gram, Vigna mungo (pea family), a cousin of the mung bean. It is eaten as a dal (a cooked split-pulse dish), ground into batters for idli, dosa and similar foods, and made into fritters and snacks. People eat it mainly for plant protein and fiber. This page covers the food as eaten, puts cooking and safety first, and notes plainly where the research is thin: the USDA database has no item for it, and we found no trials of urad dal in people.

Read this first

• Cook it; do not eat dry black gram raw. Raw legumes in general hold the highest lectin levels, and Harvard says soaking and wet-heat cooking inactivate most lectins. [7] The evidence on black gram itself is mixed: in a 2021 laboratory survey, lectin activity was not detected in raw "urid" (black gram) by the method used, unlike raw black and lima beans. [2] But an idli study reports hemagglutinating activity (the lectin test) and trypsin inhibitor activity in the raw ingredients, reduced by 100% and 58% in the finished idli. [3] We read no report of poisoning from urad dal, and no study that fed people raw black gram.
• Allergy: in a study of 355 asthma and rhinitis patients in India with a history of legume allergy, immune-test cross-reactivity was found among kidney bean, peanut, black gram and pigeon pea. [4] If you have a peanut or legume allergy, ask your allergist. For trouble breathing or swelling of the face or throat, call 911 (or your local emergency number). [11]
• Evidence in one line: pooled trials of pulses as a group show small cholesterol and weight effects; we found no trial of black gram itself. [8] [9]
• USDA has no item for it. Numbers below come from a 2026 lab paper on raw black gram, not from USDA.

What is in it (USDA values)

USDA FoodData Central has no item for urad dal or black gram in the file we used, so there are no USDA values. We use one 2026 peer-reviewed paper that analyzed raw black gram (the abstract and text we read do not say whether it was whole seed or dal) [1]. Values are percent by weight of the raw material, which equals grams per 100 g. We did not convert or invent anything; the paper gives no vitamin or mineral values we could read.

Another 2026 paper compared flours and reported higher tannin (2.55 mg per g) and phytic acid (7.89 mg per g) in black gram than in moth bean; its tannin figure differs from the first paper's, as expected for different samples and methods. [5] Because values vary this much, treat all numbers as approximate. The first paper had no external funding. [1] Plant compounds: tannins and phytic acid are described above; they are measured in the raw seed, and Harvard says the mineral-blocking effects of legume antinutrients are suggested by animal and cell studies, with very limited human research. [7]

What research says

Eaten as food vs tested in the lab. The pooled trials involved cooked pulses as food. The fermentation work measured chemicals in batters, not health. Observational findings show an association, not proof.

How much is a normal serving

USDA lists no household portion for urad dal. The NHS counts 80 g of beans and pulses as one portion and says they count only once a day toward 5 A DAY, however much you eat. [13] The cholesterol trials used a median of about 130 g of pulses a day. [8] This is information, not a prescription.

Safety, allergy and medicines

• Raw or undercooked. Raw legumes hold the highest lectin amounts and cooking with wet heat inactivates most. [7] Health Canada notes lectins occur in many legumes and that illness has mostly followed undercooked red kidney beans. [14] The FDA says PHA, the lectin of raw or undercooked beans, can cause nausea, severe vomiting and diarrhea; it does not name black gram. [15] The 2021 laboratory survey did not detect lectin in raw black gram, but its authors say the method is not harmonized, there is no agreed toxic threshold, and high activity does not necessarily mean toxicity. [2] Our reading: cook black gram fully, as the sources advise for other beans.
• Antinutrients. Tannins, phytic acid and trypsin inhibitors are measured in raw black gram and reduced by soaking, fermenting and cooking. [1] [3]
• Fermented batters. In idli the same study found biogenic amines rose by 339%. [3] We read no source linking these to symptoms in people; for histamine and fermented foods see idli and dosa.
• Allergy. See legume allergy and cross-reactivity. Peanut is a legume; see peanuts. Food allergy can cause hives, swelling and trouble breathing; anaphylaxis is a medical emergency, call 911. [11]
• Kidney disease, medicines, pregnancy, children: we read no source on these for urad dal and have no USDA mineral values. See foods, kidney disease, potassium and oxalates, food and medicine interactions and foods in pregnancy, and ask a clinician.
• If someone gets sick after eating legumes: see poisoning: what to do first.

Choosing, storing and food safety

• Soaking and cooking: we found no black-gram-specific time from an official body. Health Canada's soak (at least 5 hours) and vigorous boil (at least 10 minutes) is written for dry red kidney beans, and the FDA's 5-hour soak and 30-minute boil for beans; neither names black gram. [14] [15] A lab study took about 50 minutes to cook whole seeds. [12] Cook until fully soft; follow your national authority.
• Slow cookers: Harvard says raw beans simmered at low heat may keep their lectins. [7] Bring to a boil first.
• Mold in stored pulses: a 2026 review says fungal infection generally lowers the quality of pulse seeds; discard moldy seeds. [16]

Related pages

• Idli and dosa
• Lectins in beans: cooking dried beans safely
• Mung beans
• Pigeon peas
• Soaking and cooking times for dried beans and lentils
• Legumes as food: what trials found
• Sprouting, soaking and fermenting grains and legumes