Tamarind

Tamarind is a large tree, usually 10–25 m tall (up to 30 m), with a wide, dense vase- to dome-shaped crown up to 12 m across; the trunk may reach 7.5 m in girth, the bark is grey-brown and fissured, and the hard dark-red heartwood is sharply demarcated from the pale yellow sapwood. The leaves are alternate, even-pinnately compound with 10–20 small elliptic–ovate leaflets mostly under 2 cm long, bright green and slightly paler beneath; the tree is nearly evergreen but may shed some leaves in the dry season. The small five-petalled flowers, about 2.5 cm across, are yellow with orange–red streaks and borne in clusters (racemes) near the branch tips, usually at the start of the dry season. The fruit is an indehiscent pod 5–15 cm long with a brittle brown shell (Asian types have longer pods with 6–12 seeds; African and West Indian types have shorter pods with 1–6 seeds), containing a sticky reddish-brown pulp that is sweet-sour depending on the cultivar and surrounds flat, glossy brown seeds. A deep taproot makes the tree drought-tolerant as well as tolerant of salt-laden wind and poor soils, and a mature tree may yield up to 225 kg of fruit a year.

According to Kew's Plants of the World Online the currently accepted native range of Tamarindus indica is just the Comoros and Madagascar; in practice the species has been carried and become naturalised across tropical Africa (regarded by many authors as its centre of domestication in the Sudanian savanna belt), India and South Asia, Southeast Asia, the Middle East (Oman, Yemen) and, from the 16th century, Mexico, Central America, the Caribbean and South America. India is the largest producer and consumer, and tamarind is also widespread across Southeast Asia, where in Vietnam it is planted along roads, at temples, in home gardens and in the southern deltas. The species grows in the seasonally dry tropical biome on soils ranging from clay and loam to sand, including acidic types, and tolerates salt-laden coastal winds.

Tamarind's chemistry is dominated by tartaric acid, the main organic acid at roughly 8–18% of the dry pulp by weight, which gives the characteristic sourness; citric and malic acids and a little acetic acid accompany it. The pulp is also rich in reducing sugars (glucose, fructose), fibre, pectin and polyphenols — notably procyanidins, epicatechin and catechin with antioxidant activity. Mineral-wise, 100 g of pulp supplies about 628 mg potassium, 92 mg magnesium and 2.8 mg iron together with thiamine (vitamin B1), plus trace volatile aroma compounds such as 2-acetylfuran and furfural. The seeds contain about 27% protein and 10.9% oil (rich in linoleic acid), and the kernel is rich in the polysaccharide xyloglucan, which makes 'tamarind kernel powder' a gelling, stabilising and textile-sizing agent. The heartwood contains tannins and other phenolics that help resist insects.

In cooking, the pulp is the souring agent for Vietnamese sour soup and dipping sauces, for South Asian curries and chutneys and for industrial sauces such as Worcestershire, HP and barbecue sauce; tamarind is also made into preserves, candy, syrups and drinks (classically the Middle Eastern tamr hindi). Young leaves and flowers are edible, the seeds are roasted for food and oil, and the wood is used for furniture, turnery and charcoal. Medically, the review by Kuru (Asian Pacific Journal of Tropical Biomedicine, 2014) catalogues the laxative, antimicrobial, antioxidant, anti-inflammatory, antidiabetic and hepato- and cardio-protective actions reported for tamarind parts. Later studies continue to note antidiabetic, anti-obesity and lipid-modulating potential, and a 2025 study published a complete genome assembly of tamarind (about 809.5 Mb across 12 pseudochromosomes with more than 30,700 protein-coding genes), opening the way for breeding and bioactive-compound work.

On safety, the pulp is regarded as a safe food and, being rich in organic acids, needs care mainly in people with a sensitive stomach, acid reflux or those on anticoagulants, since the acids and polyphenols may add to their effects; strongly concentrated tamarind drinks are best taken through a straw to limit enamel erosion. Seeds must be soaked and cooked before eating, and a few people are allergic to tamarind. Small children and people with kidney impairment should use it in moderation, and it should not replace medical treatment. For conservation, the IUCN Red List assesses Tamarindus indica as Least Concern and the species is not listed in CITES; nevertheless the genuinely wild populations in the Comoros and Madagascar are shrinking through habitat loss, while cultivated genetic resources are maintained mainly as local landraces that are subject to genetic erosion, so in-situ conservation and germplasm banking are warranted.