Curcuma Longa

Turmeric, Curcuma longa L., rhizomes, ground turmeric, turmeric oils, turmeric oleoresin, curcuminoids, curcumin, sesquiterpenes, marker compounds, adulteration, standardization.

Dried Whole Rhizome Preparation: mother rhizomes (egg-shipped primary rhizomes) and finger rhizomes (cylindrical and multibranched secondary rhizomes) are usually boiled separately for about 40-60 min under slightly alkaline conditions in copper, galvanized iron or earth vessels and then sun-dried on bamboo mats for 10-15 days to reduce the moisture to 10-11% Harvest: usually 7-9 months after planting during January-March Appearance: orange-brown, pale yellow or red-yellow Chemical Composition: may contain 3-15% cucuminoids and 1.5 to 5% essential oils.

Uses Medicine (Rhizoma Curcumae Longae) and process of other turmeric products Ground Turmeric Preparation: Powder is prepared from dried finger rhizomes (60-80 mesh) Appearance: yellow or red-yellow powder Chemical Composition: The contents of active ingredients curcuminoids and essential oils may decrease during the process and exposure to light, it is appropriate to pack the powder in a UV protective container (e.g., fiber hard drums, glass packs, etc.) Uses Spice: as alone or in curry powder and pastes dye: for food, textile, cosmetic Medicine: e.g., in Ayurveda, Chinese medicine Dietary supplement Turmeric Oils Preparation: Extract from dried rhizomes (ground turmeric) or leaves by steam distillation or supercritical CO2 extraction Chemical Composition: essential oils from leaves is usually dominated by monoterpenes while the oil from rhizomes mainly contains sesquiterpenes Appearance: yellow to brown viscous liquid Refractive Index: 1.4850-1.5250 Flash Point: 78°C Solubility in Water: insoluble Uses Spice, Medicine & Dietary Supplement Turmeric Oleoresin Preparation: Extract from dried rhizomes by solvent extraction with aceone, dichloromethane, 1,2- dichloroethane, methanol, ethanol, isopropanol and light petroleum (hexanes) or supercritical CO2extraction.

Graded by the content of curcuminoids or color value Chemical Composition: 37-55% curcuminoids and up to 25% essential oil Appearance: yellow-dark reddish brown oily fluids Refractive Index: 1.4850-1.5250 Flash Point: 78°C Solubility in Water: insoluble Uses Food Coloring, Medicine & Dietary Supplement Curcumin Preparation: obtained by solvent extraction from ground turmeric rhizomes and purification of the extract by crystallization.

The suitable solvents include aceone, carbon dioxide, ethanol, ethyl acetate, hexane, methanol, , isopropanol Chemical Composition: the product is often the mixture of curcumin and its demethoxy- and bisdemethoxy- derivatives in turmeric in varying proportions. The three major curcuminoids may account no less than 90%.

Minor compounds may include oils and resins naturally occurring in turmeric rhizomes Appearance: yellowish to orange red crystalline powder Molecular Formula: C21H20O6 Molecular Weight: 368.38 Solubility in Water: insoluble Uses Medicine & Dietary Supplement Variations of Essential Oils There are significant variations in both content level and constituents of essential oils of turmeric rhizomes with geographical locations.

Among the 27 accessions North Indian plains at Lucknow, India, the percentage essential oil content in the fresh rhizomes varied between 0.16% and 1.94% (on a fresh weight basis) [101].

Although usually sesquiterpenes, particularly Ar-turmerone (99), -turmerone (100) [83], and -turmerone (101) are major compounds in turmeric oils in Asia, presence of other compounds in C. longa often vary with various locations.

By using GC-MS analysis, Chowdhury and his coworkers identified 54 compounds of essential oils from the “yellow type” of C. longa while only 39 compounds were detected from the “red type” growing in Bangladesh.

The essential oil in “yellow type” were dominated by ar-tumorone (99) (27.78%), turmerones (100 and 101) (17.16%), curlone (141) (13.82%), 2-carene (73) (4.78%), zingiberene (124) (4.37%) and - sesquiphellandrene (136) (5.57%), but the “red type” oil mainly contained carvacrol (43) (21.14%), citral (13.91%), methyleugenol (229) (7.31%), geraniol (86) (6.99%), menthol (46) (5.11%) and caryophyllene oxide (168) (4.14%).

However, there is no significant difference was observed in essential oil composition between T3C turmeric and Hawaiian red turmeric [79]. Unlike those from Asia, interestingly, turmeric oils from Brazil contained 50-80% of ar-turmerone (99), (Z)--atlantone (137), and (E)--atlantone (138) [81, 92].

(Z)--atlantone (137) and (E)--atlantone (138) are only found in the turmeric from Brazil. Without information of which cultivars or varieties were used in these studies, however, it is impossible to determine the difference caused by geographical or genetic variation. Constituent of essential oil varies with different species of Curcuma [119- 125].

For example, curcumene, a minor compound in C. longa, is the major constituent (approx. 65%) of the essential oil of Javanese turmeric (C. xanthorrhiza) [46].