Turmeric is a true wonder of Natural Medicines, and it also shares the same wonderful qualities as a spice.
By Aruna Shukla – Jadibuti Association of Nepal.
Turmeric (Curcuma Longa), a true wonder of folk medicine, is indigenous across southern Asia. It is related to ginger botanically, but also shares the same qualities as a spice and potent healer. In Sanskrit it is known as “Haridra”, which translates to mean “elixir for the skin”. This bright orange root has been used since the birth of the Asian healing arts to successfully treat illness of all kinds, and shall continue to do so into the future.
Turmeric increases bile content and its secretion. It is used to treat build up in the gallbladder, liver and in intestines, as well as to strengthen the individual organs. It is also used to support digestion and to increase digestive flora. Due, in part, to turmeric’s liver healing qualities it also has a potent healing effect on the blood. On the one hand it is a blood purifier, but it also increases the production of blood, and raises its hemoglobin content. This is especially useful for fevers, during which many people suffer from low hemoglobin levels. Turmeric can also help to lower the body’s blood sugar count, and is so used in the treatment of diabetes.
Genus – Curcuma
Family – Zingiberaceae
Order – Zingiberales
Scientific- Curcuma longa
English – Common turmeric, Indian saffron, Turmeric
Indian & Nepalese – Haldi, Besar
Dutch – Geelwortel, Indiase geelwortel, Koenjit, Kurkuma, Tarmeriek
Spanish – Cúrcuma
French – Curcuma, Safran des Indes
German – Gelber Ingwer, Gelbwurzel, Gilbwurzel, Kurkuma, Kurkume
Italian – Curcuma, Zafferano delle indie
- Turmeric is a rhizomatous herbaceous perennial plant of the ginger family, Zingiberaceae. It is native to tropical Indian Subcontinent and needs temperatures between 20 °C and 30 °C (68 °F and 86 °F) and a considerable amount of annual rainfall to thrive. Plants are gathered annually for their rhizomes, and propagated from some of those rhizomes in the following season.
- Turmeric is native to the monsoon forests of south east Asia. It is a perennial herb to 1m tall with underground rhizomes. It produces tall, very beautiful, white flower spikes, if clumps are left undisturbed for a year. The flower is so attractive that it is worth growing for this alone. It requires a well-drained soil, frost-free climate and 1000 to 2000mm of rain annually or supplementary irrigation. It thrives best on loamy or alluvial fertile soils and cannot stand waterlogging. Heavy shade will reduce the yield but light shade is beneficial.
- The most important chemical components of turmeric are a group of compounds called curcuminoids, which include curcumin (diferuloylmethane), demethoxycurcumin, and bisdemethoxycurcumin. The best studied compound is curcumin, which constitutes 3.14% (on average) of powdered turmeric. In addition there are other important volatile oils such as turmerone, atlantone, and zingiberene. Some general constituents are sugars, proteins, and resins.
- Plant turmeric in September or October, into a warm soil. The rhizomes should be planted 5-7 cm deep. It is often planted on ridges, usually about 30-45 cm apart and with 15-30 cm between plants. The crop is planted by setts (small rhizomes) with one or two buds. Approximately 1,700 kg of setts are required to one hectare. Expected yield would be 13 to 35 tonnes/ha of fresh turmeric. In cooler areas of Australia turmeric can be grown in glasshouses. Like all herbaceous perennials clumps of turmeric need to be broken up and fresh pieces planted every 3 to 4 years.
- It is basically a tropical herbaceous plant. It is perennial by nature. The soil required for turmeric has to be fertile and well drained. It also requires sufficient amount of heat as well as moisture. Basically it grows well in summer months and tends to die in winter. For those living in tropics, you can plant turmeric in any of the season but for those not living in tropics, it is best to plant in spring season. You can plant fresh roots of turmeric directly in the soil also. Once planted, it takes around two months to grow. Once the plant turns a bit dry, you can dig it up. However, if it is not dried fully and you have dug it up, then it is best to boil the roots and then keep them in direct sunlight for drying. These days dehydrator is also used for drying the turmeric roots.
The temperature required for growing turmeric is around 20°c- 30°. Rainfall of around 1500 mm per annum is said to be good for the turmeric plant to grow well. The kinds of soil in which turmeric thrives well are loamy soil, black soil, and clayey soil. If there is water stagnation or alkalinity then it becomes quite tough for the turmeric plant to stand well. It might suffer from loss of yield.
One plant is able to yield as much 700 grams of turmeric. For preservation purpose, if the turmeric is fresh then you need to store in refrigerator while the dried ones can be stored without refrigerator also. You can cultivate turmeric organically also.
- Turmeric readiness for harvest is indicated by the drying of the plant and stem, approximately 7 to 10 months after planting, depending on cultivar, soil and growing conditions. The rhizome bunches are carefully dug out manually with a spade, or the soil is first loosen with a small digger, and clumps manually lifted. It is better to cut the leaves before lifting the rhizomes. Rhizomes are cleaned from adhering soil by soaking in water, and long roots are removed as well as leaf scales. Rhizomes are then further cured and processed, or stored for the next year’s planting. Rhizomes for seed purposes must be stored in well ventilated rooms to minimize rot, but covered with the plant dry leaves to prevent dehydration.
They can also be stored in pits covered with sawdust, sand, or panal (Glycosmis pentaphylla) leaves that may act as insect repellent.
The Indian Institute of Spice Research recommends the following fungicides as a prestorage dip treatment for rhizome seeds: quinalphos at 0.075%, and mancozeb at 0.3%. Studies indicate that bulbs (mother rhizomes) are preferred to fingers as a seed stock.
Post harvest handling: curing, drying and polishing
- Turmeric rhizomes are cured before drying. Curing involves boiling the rhizomes until soft. It is performed to gelatinize the starch for a more uniform drying, and to remove the fresh earthy odor.
During this process, the coloring material is diffused uniformly through the rhizome. Recommendations as to the acidity or alkalinity of the boiling water vary by author. The Indian Institute of Spice Research, Calicut, Kerala, and the Agricultural Technology Information Center simply recommend boiling in water for 45 min to one hour, until froth appears at the surface and the typical turmeric aroma is released.
They report the color deteriorates as a result of overcooking, but that the rhizome becomes brittle when under cooked. Optimum cooking is attained when the rhizome yields to finger pressure and can be perforated by a blunt piece of wood.
Boiling in alkaline water by adding 0.05% to 1% sodium carbonate, or lime, may improve the color. For the curing process, it is important to boil batches of equal size rhizomes since different size material would require different cooking times. Practically, fingers and bulbs are cured in separate batches, and bulbs are cut in halves. Cooking may vary from one to four or six hours, depending on the batch size Curing is more uniform when done with small batches at a time. It is recommended to use perforated containers that allow smaller batches of 50 to 75 kg, which are immersed in the boiling water; by using this method, the same water may be used for cooking several batches. Curing should be done two or three days after harvest, and should not be delayed to avoid rhizome spoilage. The quality of cured rhizomes is negatively affected for material with higher initial moisture content. Benefits of curing turmeric include reduction of the drying time, and a more attractive product (not wrinkled) that lends itself to easier polishing. However, it was reported that while the total volatile oil and color remained unchanged, curcuminoid extractability might be reduced. The curing by boiling process has the advantage of sterilizing the rhizomes before drying. Slicing the rhizomes reduces drying time and yield turmeric with lower moisture content as well as better curcuminoid extractability.
Grinding and milling
- Grinding is a simple process involving cutting and crushing the rhizomes into small particles, then sifting through a series of several screens. Depending on the type of mill, and the speed of crushing, the spice may heat up and volatiles be lost. In the case of turmeric, heat and oxygen during the process may contribute to curcumin degradation. Cryogenic milling under liquid nitrogen prevents oxidation and volatile loss, but it is expensive and not widespread in the industry.
Ground spices are size sorted through screens, and the larger particles can be further ground.
- Turmeric pigment is highly unstable as compared to the yellow synthetic colorant, tartrazine.
However, if protected from light and humidity, the curcuminoid pigments in turmeric powder and oleoresin are stable. Therefore, turmeric rhizomes and powder should be stored away from light and in a very dry environment. Additionally, all water or ethanol solvent should be removed from the oleoresin to assure pigment stability
Turmeric in Nepal
- Turmeric is grown in higher altitudes of the Himalayan region, and like ginger it is said to have a unique richness of flavor and aroma compared to turmeric cultivated elsewhere.
As well as being used for culinary purposes, Turmeric is widely used as a medicinal ingredient in Ayurveda treatment. Ayurveda is a science of natural medicines followed religiously throughout the Indian sub-continent, including Nepal, and gradually being recognized and trusted throughout much of the world.
Turmeric, like other varieties of turmeric, is a natural antiseptic and a medicinal plant. The use of Turmeric helps in digestion of food and it also reduces high cholesterol levels. In typical Nepali foods which are oil rich, the use of Turmeric off-sets some of the negative effects of consuming oily food. Turmeric has been used as an antiseptic from ancient times and has great healing power when it is applied as an ointment on cuts, wounds, and burns. Turmeric ointment is also used to treat chicken pox and small pox.
Turmeric is not generally cultivated in Nepal as a cash crop, but many people in villages grow it for their daily consumption. In fact turmeric, a close kin of Turmeric, is imported to meet the bulk of day to day consumption in Nepal.
Turmeric (and turmeric) belongs to the ginger family, they are perennial plants which grow in tropical climates, so Nepal, India and other South Asian countries are major producers.
In Nepal approximately 4325 hectares of arable land is dedicated to growing Turmeric resulting in an annual production of approximately 35,500 metric tonnes.
Sunsari and Sarlahi are two districts in Nepal identified by the ODOM study sponsored by FNCCI as the areas in Nepal best suited for Turmeric production.
- Turmeric has a long list of medicinal values and it cures many diseases. The main organs that turmeric treats are the skin, heart, liver and lungs. It is a natural antiseptic and antibacterial agent, useful in disinfecting cuts and burns. Turmeric is also used for epilepsy and bleeding disorders, skin diseases, to purify the body-mind, and to help the lungs expel Kapha. Turmeric has been known to treat and cure Anemia, cancer, diabetes, digestion, food poisoning, gallstones, indigestion, IBS, parasites, poor circulation, staph infections, and wounds. It helps to regulate the female reproductive system and purifies the uterus and breast milk, and in men it purifies and builds semen. It reduces fevers, diarrhea, urinary disorders, insanity, poisoning, cough, and lactation problems in general and also fight against allergies.
Courtesy of Jadibuti Association of Nepal (JABAN)