Indochina P. latifolius, P. odoratissimus Linn P. amaryllifolius

Xoi Dua La Dua (Coconut Sweet Sticky Rice with Fragrant Leaf Flavor)
"Check out the natural green of Xoi Dua La Dua, isn’t it beautiful? I not only love the color of la dua (fragrant leaf) but also its exquisite
aroma and tang. Waking up in the morning smelling the steam of Xoi Dua La Dua is just reviving. Forget about Donkin’ or Krispy Kreme
donuts, just give me a handful of Xoi Dua La Dua with a cup of coffee and I am all set for the morning".(D. Truong from My Tho, Vietnam).

"The leaves’s aroma is distinct and hard to describe, somewhat nutty, reminiscent to fresh hay and definitely pleasant. A similar scent is found in some aromatic rice varieties grown in South East Asia. (e.g., Thai jasmine rice) Its actually the aroama you smell when a breeze passses through a rice field close to harvest time. This is one of the reasons why South East Asians throw a small blade in to their pot when they cook rice from the previous harvest, presumably to restore the newly harvested fragrance that has faded". (from the eGullet Society for Culinary Arts & Letters)

Lá Dua Tea

Lá Dua leaves produce a healthy & invigorating anti-oxidant herbal tea helpful in rejuvenating and nourishing the body. The tea has a cooling effect which helps to maintain the heart and liver in good condition and helps relieve fever and soothe sore throats. It is also good for the treatment of internal inflammations, urinary infections, colds, coughs, measles, bleeding gums and skin diseases. In folklore, a decoction of the tips of fresh or dried prop roots is used as a diuretic. Poultices of fresh leaves mixed with oil are used for headaches, while pulverized dried leaves are used to facilitate wound healing and its oil is considered a stimulant, antispasmodic and antiseptic. The Lá Dua leaves contain essential oils, alkaloids, glycosides and tannin.

Cosmetic & Aromatic Uses

It is also used in traditional aromatic bath & spa soaps that produce a unique fragrant scent. La Dua is said to be a restorative, deodorant, indolent and phylactic (serving to protect especially against disease), promoting a feeling of wellbeing, and acting as a counter to tropical lassitude (debility, fatigue, or diminished energy). It's also a breath sweetener and an effective organic food preservative.

Another interesting and useful attribute to this herb is that roaches tend to dislike the compounds of La Dua leaves. In Asia, leaves can be distributed as a safe organic natural repellant to rid roaches by sprinkling La Dua leaves in infested areas.

Mid-eastern Indians use the flower of this plant in making perfume, while in Thailand, the leaves are often used as flavorful wrappers for morsels of food, as the leaves will leave their aroma in the food – though the leaves themselves are too tough for eating.

Culinary Uses*

In cooking, the leaf is used in cake, which is similar to the American sponge cake. The La Dua leaf has also been used in rice and making different type of curries. La Dua leaves are used in Southeast Asian cooking to add a distinct aroma to rice and curry dishes such

as Nasi lemak, Kaya preserves, and desserts such as sweet cake. For festive holidays and ceremonies, La Dua is used with the essences of rose to flavor spicy rice dishes such as Biryani. La Dua leaf is used in flavoring sweet desserts and rice dishes in Indochina Asian cuisines.

Chemical Components

The best candidate is 2-acetyl-1-pyrroline (2AP), which was found in the leaves at levels of about 1ppm and which also occurs in aromatic rice cultivars such as Basmati & Thai Jasmine; another possibility is ethyl formiate, which is also common to both rice and La Dua leaves.

Background History

In ancient times, the leaves were used for making thatched huts and women’s grass skirts. Strips of the leaves are used in making woven baskets throughout Indo-china used to serve rice or other food items. The botanical provides materials for housing, clothing and textiles, food, medication, decorations, fishing, religious uses and the manufacture of handbags & mats, hand woven from the dried leaves.

Lá Dua P. latifolius, P. amaryllifolius, P.Odoratissimus Roxb botanical

The Lá Dua botanical offers a pleasant scent widely used in Indochina (southeast Asia; Vietnam, Laos, Cambodia, Thailand, Myanmar (Burma), and the mainland territory of Malaysia) to give flavour to sweet rice and other desert dishes. Before cooking, just  add a few leaves to your steamed rice and the rice will become even more fragrant than Basmati orJasmine rice!

In Thai gai hor bai toey cuisine leaves are used as fragrant wrappers.

La Dua chicken, gai hor bai toey, is a classical recipe and an eternal favorite in restaurants: Marinated chicken bits are wrapped in leaves and deep-fried in a wok. Although the leaves are too hard to eat, they impart a most exotic aroma to the meat.

All over South East Asia, La Dua leaves find their most important culinary application in desserts: In Thailand, iced drinks from young coconuts with La Dua flavour are popular, and in Indonesia, theleaves are made into ice cream like concoctions (espandan, see also  vanilla on the topic of ice creams). Furthermore, La Dua leaves appear more frequently in sweet puddings or custards based on sticky (glutinous) rice. For these concoctions, glutinous rice is boiled with water, palm sugar and La Dua leaves to yield a heavy mass that becomes semi-solid on cooling. Before serving, thick coconut milk is sprinkled over it. It is often possible to substitute La Dua by vanilla or nutty flavours (e.g., hazelnut extract) in these recipes, although the flavours are not too similar.

Main constituents

The flavour component of leaves is not well known. It is speculated that the flavor is a volatile product of oxidative degradation of a yellow carotenoid pigment that forms only when the plant withers. In that respect, there are similarities to saffron and rose, which also contain carotenoid-derived aroma compounds.

The best aromatic candidate is 2-acetyl-1-pyrroline (2AP), which was found in P. amaryllifolius Roxb leaves at levels of about 1 ppm (Cereal Chemistry, 70, 381, 1993 and which also occurs in aromatic rice cultivars; another possibility is ethyl formiate, which is also common to both rice and La Dua leaves (Naturwissenschaften, 71, 215, 1984).

Yet another study found 3-methyl-2-(5H)-furanone as main volatile compound in La Dua leaves, besides 3-hexanol, 4-methylpentanol, 3-hexanone and 2-hexanone (Flavor and Chemistry of Ethnic Foods, [Proceedings of a Meeting held during the 5th Chemical Congress of

North America], Cancun, Nov. 11-15, 1997 (1999)).  The leaves also contain piperidine-type alkaloids (pandamarine, pandamerilactones) with pyrroline-derived structures (Phytochemistry, 34, 1159, 1993)

On distillation, the leaves do yield traces of an essential oil, but it is unclear to which extent the volatile oil contributes to the flavour.

In Sri Lankan & Vietnamese La Dua leaves (p. Latifolius, allegedly synonym to p. Amaryllifolius), the following aroma components have been identified in concentrations less than one microgram per kilogram (ppb) fresh material: styrene 0.62,  formylthiphene 0.76, linalool 0.29, β-caryophyllene 0.55, β-farnesene 0.18, 1,2-dimethoxybenzene 0.15 and β-selinene 1.24 ppb. (Phytochemistry, 21, 1653-1657, 1982)

Origin

Other than its flower yielding relatives, Lá Dua is not known in the wild state. Today, it is distributed over Southern India peninsular, Indochina, Indonesia, and Western New Guinea. The family Pandanaceae comprises approximately 600 species that are widely distributed in tropical and subtropical regions. Thirty-six species have been recorded in India, among which P. odoratissimus Linn. and P. amaryllifolius Roxb. are being exploited commercially. In p.odoratissimus, the flowers are scented, while in p. amaryllifolius & p.latifolius the leaves are scented. Male flowers are extremely rare, and there is no scientific description of a female flower for this species. The only known instances of flowering plants occurred on the Moluccas archipelago, and it is plausible that the species evolved there. The species is, however, unlikely to have evolved from hybridization, as is shares its chromosome number (2n=60) with most other representatives of the genus. It is also interesting to note that Indochina Amaryllifolius is the only species with fragrant leaves. Taken together, the combined lack of a wild population and the large distribution imply a long tradition of cultivation.

(exerpts from Gernot Katzer's Spice Dictionary)

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