| Archidendron pauciflorum | |
|---|---|
 | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Fabales |
| Family: | Fabaceae |
| Subfamily: | Caesalpinioideae |
| Clade: | Mimosoid clade |
| Genus: | Archidendron |
| Species: | A. pauciflorum |
| Binomial name | |
| Archidendron pauciflorum (Benth.) I.C.Nielsen (1984 publ. 1985) | |
| [1] | |
| |
| Synonyms[1] | |
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Archidendron pauciflorum, commonly known asdjenkol,jengkol orjering, is a species of flowering tree in thepea family,Fabaceae. It is native toSoutheast Asia, where the seeds are also a popular dish.[2] They are mainly consumed inIndonesia,Thailand,Myanmar, andVietnam, prepared by frying, boiling, or roasting, and eaten raw.[3] Thebeans are mildly toxic due to the presence ofdjenkolic acid, an amino acid that causes djenkolism (djenkol bean poisoning).[4] The beans and leaves of thedjenkol tree are traditionally used for medicinal purposes, such as purifying the blood.[5] To date,djenkol is traded on local markets only.[6]
Common English names are blackbead, dog fruit,jengkol tree,luk nieng tree andngapi nut.[2] As this plant grows in different countries in Southeast Asia, it has a variety of vernacular names. The common names in Indonesia isjengkol,jinkol,jarung (Sumatra) orjering (Java). It is calledkrakos in Cambodia,jering in Malaysia, and Thailand. Other vernacular names includeluk nieng,cha niang,khang daeng andpha niang. In Myanmar it is calledda-nyin-thee orda-nyin-pen.[2][6][7]
Archidendron pauciflorum is alegumetree with a size of 18–25 m, has a spreading crown andbipinnate leaves (up to 25 cm) and greyish smooth bark.[2][7][8] The young leaves have a wine-red colour and are edible. The flowering time of the tree is between September and January.[9] The white calyx cup-shaped flowers are bisexual and have various yellowish-whitestamens.[2]
Thefruit (legume) of the tree is a woody, glabrous, deep purple pod. Each Pod contains around three to nine round-shapedseeds.[7] The pods are formed falcate or twisted in a wide spiral. Theseed coat of a young seed shows a yellow-green colour and turns dark brown during ripening. Then the ripe fruitdehisces along theventral suture.[6]
The tree is indigenous toprimary andsecondary forests in humid, mountainous, and undulating areas as well as onriver banks from sea level up to 1600 m elevation in Southeast Asian countries such asBangladesh,Indonesia (Sumatra,Sulawesi,Kalimantan),Malaysia,Myanmar, andSouthern Thailand.[2] Djenkol trees grow best in pervious sandy orlateriticsoils and they need a high rainfall guarantee.[2][6]
The Djenkol fruit containsdjenkolic acid. Eating the djenkol fruit is linked to cases ofhematuria. In a study of school children aged 7-11 in Hat-Yai, Thailand who had hematuria, the children were almost four times as likely to have a history of eating djenkol beans. In the cases of eating djenkol, increasing consumption, time since last consumption, or type of preparation (even after adjustment for sex and age) did not change the risk of having hematuria. In that same study, the conclusion was derived that eating djenkol beans may be defined as one of the probable causes of hematuria.[10]
In another report from Indonesia, djenkol consumption can cause hypersaturation of djenkolic acid crystals within the urinary system. That leads to obstructivenephropathy with sludge,stones, or possible spasms. In this report, 96 cases of djenkolism were identified. Recovery for the majority of patients included using hydration, bicarbonate therapy, and pain medication for treatment. Three patients required surgery. Another patient had obstructing djenkolic acid stones and required urethral stinting. Out of the 96 reported cases, four patients died with the final diagnosis as acutekidney failure.[11]
In a different study of Australian acacia seeds (Acacia colei,Acacia elecantha,Acacia tumida, andAcacia saligna), the study focused on processing methods to reduce djenkolic acid in the seeds. The study tested the levels of djenkolic acid in the seeds of each species and reported the levels to be similar to the djenkol bean. The conclusion of that study surmised that djenkolic acid levels can be reduced by over 90% through dry roasting at 180°C. The new lower levels of djenkolic acid were safe for human consumption.[12] However, in the Hat-Yai, Thailand study, different types of preparation did not change the risk of having hematuria.
| Nutritional value per 100 g (3.5 oz) | |||||||
|---|---|---|---|---|---|---|---|
25.67 g | |||||||
| Dietary fiber | 1.76 g | ||||||
1.45 g | |||||||
14.19 g | |||||||
| |||||||
| †Percentages estimated usingUS recommendations for adults.[13] Source:[8] | |||||||
The beans of the Djenkol tree have a crudecarbohydrate content of about 26% which is relatively low compared to other commonlegumes, such ascowpea,kidney bean, andpea which all contain about 60 - 70%. The crudeprotein content instead is about 14.2%.[8] This is higher than that of commoncereals, such aswheat (13%),rye (11%), orrice (7%).[14] The presence of adequate protein and low-fat contents might be perceived as desirable by consumers.[8] When processed to flour, highmoisture content (about 59%) suggests that this seed needs to be further processed to improve its shelf life and overall quality.[8]
Djenkol beans are 3.0 to 3.5 cm in diameter and 1.5 to 2.0 cm thick and have a reddish-brown color. These beans are prepared byfrying, boiling, orroasting and are also eaten raw. They are mainly consumed inThailand,Malaysia,Myanmar, andIndonesia.[3] The seeds of djenkol are mainly used to add flavour to food, although the crushed seeds give off a mildsulfurous odor[7] which is perceived as rather offensive by some people.[15] Young seeds are often eaten raw as so-calledulam.[16] Mature seeds are prepared in different ways:
Different parts of the djenkol tree are applied in traditional medicine inSoutheast Asia. The raw seeds are thought to purify the blood[5][8] or curedysentery.[17] Compresses with young leaves are used for skin problems, and burnt old leaves are believed to relieve itchy feelings. The powder of burnt young leaves is applied to cuts and wounds.[2][18]
Archidendron pauciflorum can also be used fordyeing. The pods of the seeds dye silk purple and the bark of the tree dyes black. The shell is also being used for hair washing, timber as firewood, and for building (e.g. coffins).[2] Due to the content ofdjenkolic acids in the seeds, the raw seed is also being applied to the production of organicpesticides in combination with other plants to kill and prevent the growth of pests.[18]
Djenkol trees have often been spared whenprimary orsecondaryrainforests have been cut down. Otherwise planting distances are 10–15 m.[15] The plant favours well-drained sandy, lateritic or sandy claysoil.[2] is propagated by Seed. Methods for clonal distribution have not yet been found. In nature, Squirrels(Callosciurus notatus) eat the seeds and facilitate their distribution.[15]
A tree produces between 1000 and 4000 seeds per year.[19] The main harvesting time inJava is around July to August and theaftercrop in December to February. Usually, Djenkol is sold in the markets by several seeds. For transport, seeds, in particular young ones, should not be removed from the pods to avoiddesiccation. One way to store the seeds is by processing them into chips (emping).[15] Another possibility however could be its procession toflour. To date, due to the high moisture content, this is hardly done.[8]
Archidendron pauciflorum has several pests in common with other leguminous trees andshrubs such as the pod-borersMussidia pectinicornella andCryptophlebia ombrodelta or thecaterpillars of the leaf-feederEurema blanda, one of the most common butterflies in Java.[15]