Economic viability and production challenges of black turmeric in Odisha's Eastern Ghats Highlands: A focus on its therapeutic potential

Introduction

Black turmeric (Curcuma caesia Roxb.), popularly called as Kali Haldi a perennial rhizomatous plant belonging to the Zingiberaceae family. This underutilized medicinal herb, holds significant value across Asia for its potent therapeutic properties and is increasingly recognized for its potential in traditional healing practices with a diploid chromosome number (2n = 42), is endangered in Southeast Asia. It is native to North-East and central India, distributed to Java, Myanmar and rarely found in Madhya Pradesh, Jharkhand, Chhattisgarh, Orissa and other parts of South India. This species is commonly found along with the coastal areas and river alluvial soils extending up to midlands of Kerala and South Karnataka in wild form (Sabu, 2006) [28] . It is characterized by its distinctive dark purple to black rhizomes, which set it apart from the more common yellow turmeric (Curcuma longa). This plant contains various bioactive compounds, particularly in its rhizomes and leaves, which are used in traditional medicine as natural alternatives to pharmaceutical treatments for various diseases Due to its therapeutic properties, black turmeric is often referred to as "Chemical Goldmine" and holds significant economic value (Joy et al., 1998) [15] . Kanglom et al. (2023) investigated the phytochemical composition, antioxidant, and antibacterial properties of black turmeric (Curcuma caesia) and found it to be a rich source of antioxidants and antimicrobial compounds, making it valuable for health benefits and applications in the pharmaceutical and food industries. Additionally, black turmeric possesses a range of therapeutic properties, including antioxidant, anti-tumor, anti-inflammatory, hepatoprotective, and carminative effects (Gantait et al., 2011) [11] , contributing to its significant economic value. All parts of the plant-leaves, roots, bulbs, and rhizomes-are used in Ayurvedic, Unani, and Siddha medicine (Pandey & Chowdhary, 2003) [23] . The rhizomes of C. caesia are traditionally used in the treatment of various ailments and metabolic disorders like leukoderma, asthma, tumors, piles, bronchitis, rheumatic arthritis/joint pain, gastric problem, cut/injury to stop bleeding, inflammation, fever, cough, infection, allergy, snake bite, insect bite, toothache, vomiting, impotency, cancer, relax muscle, menstrual disorder, aphrodisiac, inflammation, gonorrheal discharges etc. in Indian system of medicine (Das et al., 2013; Pathan et al., 2013) [8,24] . The rhizome is also known for its antioxidant and antimutagenic (Devi et al., 2015) [9] . Its pungent smell is due to essential oil rich in camphor and starch, with the volatile oil containing 30 components, including camphor (28.3%) and ar-turmerone (12.3%) as major constituents. The rhizomes are used for a range of therapeutic effects, such as smooth muscle relaxation, treating hemorrhoids, leprosy, asthma, epilepsy, and cancer, as well as for their anti-inflammatory and aphrodisiac properties (Arulmozhi et al., 2006; Sasikumar, 2005) [3,26] . The diverse chemical composition contained in this plant contributes to various biological activities, which may be beneficial for the health, food, and cosmetic industries. It is the rarest and most expensive rhizome in the Curcuma family, yet its potential remains largely underexplored, with limited awareness of its value. The present study investigates the therapeutic uses and socio-economic impact of black turmeric in the local communities of Koraput, Odisha, emphasizing its economic potential and the challenges in production and marketing. Koraput, located in the Eastern Ghats region between 17°40' and 20°07' north latitude and 81°24' and 84°02' east longitude, is an agro-biodiversity hotspot with a predominantly tribal population. The district's altitude ranges from 1500 to 3000 meters above sea level, with an average annual rainfall of 1,567 mm, mostly received between June and September. The environment is ideal for black turmeric cultivation, which thrives in warm, humid climates and moist deciduous forests with clayey soils. Black turmeric is planted from April to August, with rhizomes (about 20 g) placed three inches deep. The crop is ready for harvest when the leaves turn yellow and fall, typically in December or January. The goal of this research is to provide a comprehensive understanding of the challenges in black turmeric cultivation, marketing, and its therapeutic benefits. This valuable information is the key that can be used for the development of drugs, functional food ingredients, and food product it can be used in fresh form or processed into different products.

Botanical characteristics

The plant is usually erect, with a height ranging from 0.5 to 1.0 m. It consists of an underground, large, ovoid, tuberous rhizome (often referred to as the rootstock) and an erect aerial shoot with leaves and reproductive parts. The leaves are broadly lanceolate or oblong with a deep violet midrib, arising from the underground stem, and have a strong camphoraceous scent. The leaves are generally found in groups of 10-20. In the middle region, the lamina displays deep ferruginous purple-colored clouds. The flowering bracts are green with a ferruginous tinge. The flower petals can be deep pink or red in colour and typically appear in June or July. The calyx is 10-15 mm long, obtuse, and 3toothed, whereas the corolla is long and tubular with a pale yellow lip that is 3-lobed and semi-elliptical. The rhizome is sessile, covered with adventitious roots, root scars, and warts, and is laterally flattened. The inner part of the rhizome is bluish-black in color, about 2-6 cm in diameter, and emits a characteristic sweet camphoraceous odor due to the presence of essential oils like eucalyptol and camphor. It has a bitter and hot taste with a pungent smell (Pandey et al., 2003; Das et al., 2013) [23,8] . The fruits are seed-bearing structures enclosed in a capsule.

Black Turmeric: Phyto-Constituents & Therapeutic Uses:

Curcuma caesia is a valuable source of unique natural products for the therapeutics development against various diseases.

The multiple phtyoconstituents like curcumminoids, oil content, flavonoids, phenolics, amino acids, protein and high alkaloids, found in the rhizome, are responsible for the antimicrobial, antitumor, anxiolytic, antiinflammatory, antiulcer, CNS depressant, locomotor depressant and antioxidant activities (Karmakar et al., 2013) [17] . Pharmacologically blood purifying activity (Arulmozhi et al., 2006) [3] , bronchodilating activity (Paliwal et al., 2011), anthelmintic activity (Gill et al., 2011) [13] , antibacterial activity (Rajamma et al., 2012) [25] , anti-ulcer activity (Das et al., 2012) [27] were reported by several workers. The diverse chemical composition of Black Turmeric (Curcuma caesia) contributes to various biological activities beneficial for the health, food, and cosmetic industries. Gaikwad et al. (2023) [12] identified components such as alkaloids, triterpenoids, steroids, saponins, tannins, flavonoids, cardiac glycosides, proteins, amino acids, carbohydrates, fats, and fixed oils in different extracts (methanolic, chloroform, petroleum ether, and water). The unique color of black turmeric rhizomes is due to the presence of anthocyanins, specifically cyanidin, as reported by Pandey et al. (2003) [23] . The characteristic pungent smell of Black Turmeric (Curcuma caesia) rhizomes is due to the essential oil, which is rich in camphor and starch. The volatile oil components of the rhizomes were analyzed by GC-MS by Pandey et al. (2003) [23] . The volatile rhizomes oil of contains 30 components that make up 97.48% of the oil. Major constituents include camphor (28.3%), ar-turmerone (12.3%), (Z)-ocimene (8.2%), 1,8-cineole (5.3%), elemene (4.8%), borneol (4.4%), bornyl acetate (3.3%), curcumene (2.82%), and ar-curcumene (6.8%) as reported by Mehendra Kumar et al. (2014) [9] .

Antioxidant response and cellular protection

C. caesia, rich in flavonoids, phenols, and curcuminoids, has demonstrated strong antioxidant properties through its free radical scavenging activity. The essential oil of its leaves and rhizome extract are considered excellent natural sources of antioxidants, which can be utilized in cosmetics and pharmaceuticals (Caleja et al.)

Anticancer response

The methanolic extract of C. caesia rhizome mitigates the toxicity induced by cyclophosphamide, a chemotherapeutic agent, in bone marrow cells by reducing micronuclei formation. Additionally, it helps prevent hepatotoxicity and nephrotoxicity associated with cyclophosphamide treatment, suggesting its potential as a supportive supplement in cancer therapy with cyclophosphamide (Devi & Mazumdar, 2016) [10] .

Neuro pharmacological response:

A study by Karmakar revealed that the rhizome of C. caesia exhibits analgesic, anticonvulsant, muscle relaxant, and locomotor depressant effects, suggesting its potential as an antidepressant and a promising agent for improving brain health.

Smooth Muscle Relaxant and Anti-asthmatic Activity:

Arulmozhi et al. (2006) [3] found that Curcuma caesia demonstrates smooth muscle relaxant and anti-asthmatic properties, offering potential benefits for asthma prevention.

Anti-ulcer activity: Das et al. (2012) [27] found that the ethanol extract of C. caesia rhizome reduces gastric acid and free acidity while increasing mucus production, suggesting its potential as an effective anti-ulcer agent, comparable to ranitidine.

Anti-diabetic effects: Some studies suggest that curcuminoids in black turmeric may help regulate blood sugar levels.

Aphrodisiac:

In traditional systems, it is considered an aphrodisiac and is used to address sexual health issues.

Anti-fungal activity: Banerjee and Nigam (1984) [4] identified the antifungal properties of C. caesia rhizomes, while Borah et al. found that its essential oil, also present in the leaves, inhibits the growth of Aspergillus niger, Saccharomyces cerevisiae, Aspergillus fumigatus, and Candida albicans.

Anti-Bacterial activity: Kumar et al. (2014) [21] reported that C. caesia rhizome extracts exhibit antibacterial activity against Gram-positive bacteria like Bacillus cereus, Bacillus subtilis, and Streptococcus agalactiae. Additionally, Angel Gabriel Rajamma et al. (2012) [25] explored the antioxidant and antibacterial properties of oleoresins from nine Curcuma species, while Pandey and Gupta (47) found that rhizome extracts were more effective than stem and leaf extracts in inhibiting bacterial growth.

Black turmeric: Ayurvedic Healing Properties

The rhizomes of black turmeric have long been recognized for their wealth of health-promoting compounds, which have formed the basis of traditional medicinal practices for centuries. These medicinal plants are utilized extensively worldwide to treat a wide range of chronic as well as acute illnesses, and are considered the backbone of traditional medicine. The rhizomes are used as stimulants, antidiarrheal, diuretic, anti-emetic, wound cleanser and in treating various skin disorders in India, Indonesia, Thailand and Malaysia (Vairappan et al., 2013) [29] . In different regions, black turmeric is used to treat specific conditions, such as stomachache, typhoid, and pneumonia. Its rhizome powder is also used as a face pack, and its paste is applied to relieve migraine, snake and scorpion bites, and wounds (Chadalavada et al., 2017) [6] . Black turmeric (Curcuma caesia) is highly valued in Ayurveda for its medicinal properties. Its fresh rhizomes are known for their effectiveness in treating diarrhea, stomach aches, and gastrointestinal disorders. It has strong antiinflammatory, analgesic, and anti-helminthic properties, making it beneficial in treating conditions like rheumatic arthritis, epileptic seiures and worm infections. The rhizome paste is also applied to wounds for quick healing and to stop bleeding. Additionally, black turmeric is used in the treatment of respiratory issues like bronchitis, cough, fever, and tonsillitis, and is considered an aphrodisiac and remedy for leprosy, epilepsy, and even cancer. Both dried rhizomes and leaves of Curcuma caesia are used in treating piles, leprosy, asthma, cancer, wounds, impotency, fertility issues, toothache, vomiting, and allergies. Crushed fresh rhizomes, applied as a paste on the forehead, relieve migraines, while also aiding digestion, supporting liver and kidney function, and alleviating sprains, bruises, and menstrual disorders.

Results and Discussion

The study investigates the challenges and prospects of black turmeric cultivation in the Koraput region, focusing on the Dasmantpur block, a key area for production. Using analytical methods like percentage analysis and Garrett's The data presented in Table 3 highlights the key marketing challenges faced by black turmeric farmers in koraput region. The most critical issue is market accessibility, which directly impacts farmers' ability to sell their crops and secure a stable income. Market price variation ranks second, as fluctuating prices create financial instability and hinder long-term planning. The third concern, the role of middlemen, reveals that while intermediaries assist with distribution, their involvement often results in higher costs and reduced profits for farmers. Lack of transportation ranks fourth, signaling logistical difficulties. Finally, lack of storage facilities is ranked lowest, indicating it is a concern but less critical in comparison to issues affecting market access and pricing. Overall, the rankings emphasize that the most pressing marketing challenges directly influence the profitability and sustainability of black turmeric production.

Conclusion

C. caesia (black turmeric) holds significant potential as a natural complementary and alternative health therapy, offering promising applications in both the pharmaceutical and nutraceutical industries. However, its potential remains largely underexplored, with limited awareness of its value.

To unlock this potential, the implementation of scientific agronomic practices is critical for optimal cultivation and enhanced production. Farmers in Koraput, who grow black turmeric, face various challenges related to production, marketing, technology, social issues, and finance. Addressing these systemic barriers through targeted policies and support mechanisms is essential for the sustainable growth of black turmeric cultivation and the improvement of farmers' socio-economic well-being. Given its bioactive compounds and therapeutic potential, C. caesia could become a key medicinal plant. However, further research is necessary to identify valuable germplasm and develop breeding techniques that could increase its productivity. This crop has the potential to provide financial security and improve the livelihoods of the local tribal communities in Koraput.

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