Sandalwood is a class of woods from trees in the genus Santalum. The woods are heavy, yellow, and fine-grained, and, unlike many other aromatic woods, they retain their fragrance for decades. Sandalwood oil is extracted from the woods for use. Sandalwood is often cited as one of the most expensive woods in the world. Both the wood and the oil produce a distinctive fragrance that has been highly valued for centuries. Consequently, some species of these slow-growing trees have suffered over-harvesting in the past. Read about the Sandalwood tree below explained by Pritish Kumar
True sandalwoods
Sandalwoods are medium-sized hemiparasitic trees, and part of the same botanical family as European mistletoe. It originates from Malayan Peninsula, and was brought to India and other places by the vast Indian and Arab mercantile networks and Chinese maritime trade routes until the sixteenth century CE. The sandalwood of this region — Malayan Peninsula as the primary trading center of that time, supported most consumption of sandalwood in East Asia, Arab and India, before the commercialization of sandalwood plantation (Santalum spicatum) in Australia and China .
Although the sandalwood in Peninsular Malaysia is still considered have the best and original quality in terms of religion and alternative medicine, Indian sandalwood (Santalum album) and Australian sandalwood (Santalum spicatum) are marketed as the notable members of this group today by merchants because of its stable sources; others in the genus also have fragrant wood. These are found in India, Nepal, Bangladesh, Pakistan, Sri Lanka, Australia, Indonesia, Hawaii, and other Pacific Islands.
Unrelated plants
Various unrelated plants with scented wood and also referred to as sandalwood, but not in the true sandalwood genus:
1)Adenanthera pavonina – sandalwood tree, red or false red sandalwood
2)Baphia nitida – camwood, also known as African sandalwood
3)Eremophila mitchellii – sandalwood; false sandalwood (also sandalbox)
4)Myoporum platycarpum – sandalwood; false sandalwood
5)Myoporum sandwicense – bastard sandalwood, false sandalwood
6)Osyris lanceolata – African sandalwood
7)Osyris tenuifolia – east African sandalwood
Production
Producing commercially valuable sandalwood with high levels of fragrance oils requires Indian sandalwood (S. album) trees to be a minimum of 15 years old – the yield, quality and volume are still to be clearly understood. Yield of oil tends to vary depending on the age and location of the tree; usually, the older trees yield the highest oil content and quality.
Australia is the largest producer of S. album, with the majority grown around Kununurra, in the far north of the state by Quintis (formerly Tropical Forestry Services), which in 2017 controlled around 80 per cent of the world’s supply of Indian sandalwood and Santanol. India used to be the world’s biggest producer, but it has been overtaken by Australia in the 21st century. Over-exploitation is partly to blame for the decline.
This country sandalwood (S. spicatum) is grown in commercial plantations throughout the wheatbelt of Western Australia, where it has been an important part of the economy since colonial times. As of 2020 WA has the largest plantation resource in the world.
Sandalwood is expensive compared to other types of woods, so to maximize profit, sandalwood is harvested by removing the entire tree instead of sawing it down at the trunk close to ground level. This way wood from the stump and root, which possesses high levels of sandalwood oil, can also be processed and sold.
Australian sandalwood is mostly harvested and sold in log form, graded for heartwood content. The species is unique in that the white sapwood does not require removal before distilling the oil. The logs are either processed to distil the essential oil, or made into powders for making incense. Indian sandalwood, used mainly for oil extraction, does require removal of the sapwood prior to distillation. As of 2020, Australian Sandalwood oil sells for around US$1,500 per 1 kilogram (2.2 lb), while Indian Sandalwood oil, due to its higher alpha santalol content, is priced at about US$2,500 per kg.
Sandalwood is often cited as one of the most expensive woods in the world, along with African blackwood, pink ivory, agarwood and ebony.
Uses
Fragrance
Sandalwood oil has a distinctive soft, warm, smooth, creamy, and milky precious-wood scent. It imparts a long-lasting, woody base to perfumes from the oriental, woody, fougère, and chypre families, as well as a fixative to floral and citrus fragrances. When used in smaller proportions in a perfume, it acts as a fixative, enhancing the longevity of other, more volatile, materials in the composite. Sandalwood is also a key ingredient in the “floriental” (floral-ambery) fragrance family – when combined with white florals such as jasmine, ylang ylang, gardenia, plumeria, orange blossom, tuberose, etc.
Sandalwood oil in India is widely used in the cosmetic industry. The main source of true sandalwood, S. album, is a protected species, and demand for it cannot be met. Many species of plants are traded as “sandalwood”. The genus Santalum has more than 19 species. Traders often accept oil from closely related species, as well as from unrelated plants such as West Indian sandalwood (Amyris balsamifera) in the family Rutaceae or bastard sandalwood (Myoporum sandwicense, Myoporaceae). However, most woods from these alternative sources lose their aroma within a few months or years.
Isobornyl cyclohexanol is a synthetic fragrance chemical produced as an alternative to the natural product.
Sandalwood’s main components are the two isomers of santalol (about 75%). It is used in aromatherapy and to prepare soaps.
Distillation
Oil is extracted from Sandalwood through distillation. Many different methods are used, including steam distillation, water distillation, CO2 extraction, and solvent extractions. Steam distillation is the most common method used by sandalwood companies. It occurs in a four-step process, incorporating boiling, steaming, condensation, and separation. Water is heated to high temperatures (60–100 °C or 140–212 °F) and is then passed through the wood. The oil is very tightly bound within the cellular structure of the wood, so the high heat of the steam causes the oil to be released.
The mixture of steam and oil is then cooled and separated so that the essential oil can be collected. This process is much longer than any other essential oil’s distillation, taking 14 to 36 hours to complete, but generally produces much higher quality oil. Water, or hydro, distillation is the more traditional method of sandalwood extraction which involves soaking the wood in water and then boiling it until the oil is released. This method is not used as much anymore because of the high costs and time associated with heating large quantities of water.
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