Nutritional value, phytochemical composition, and biological activities of edible Curcuma species: A review

Enhancing the solubility and potency of tetrahydrocurcumin as an anti-cancer agent using a β-cyclodextrin inclusion complex approach

Curcuminoids originating from turmeric roots are renowned for their diverse pharmacological applications, particularly as a natural anticancer agent. Unfortunately, harnessing the full potential of curcumin derivatives in cancer therapy has been impeded by its inherent limitations, specifically instabilities owing to poor solubility, leading to low systemic bioavailability under normal physiological circumstances. To circumvent this, a novel organic-based drug delivery system employing physically adsorbed β-cyclodextrin (βCD) as an excipient was developed in this study. This resulted in improved aqueous dispersion coupled with anticancer enhancements of tetrahydrocurcumin (THC) at a molar ratio of 2:1. Encapsulation of this agent was confirmed by physicochemical characterisation using UV-vis spectroscopy, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and both in vitro and in vivo approaches. Through the presence of an inclusion complex, a higher aqueous dispersion (65-fold) resulting in a higher drug content and an elevated release profile was achieved. Athymic nude (Nu/Nu) mice exposed to this treatment displayed improvements in tumour regression compared to stand-alone agents, consistent with in vitro cytotoxicity assays with an SI value > 10. The inclusion complex further enhanced apoptosis, as well as anti-migration and anti-invasion rates. Mechanistically, this formulation was consistent in terms of caspase 3 activation. Furthermore, the inclusion complex exhibited reduced systemic toxicity, including reduced inflammation in vital organs as examined by hematoxylin and eosin (H&E) staining. This study also revealed a notable sequential reduction in serum levels of tumour markers, including carcinoembryonic antigen (CEA) and mouse Cytochrome P450 1A2 (CYP1A2), correlating with a significant decrease in tumour bulk volume upon treatment commencement. These compelling findings highlight the potential of this formulation to empower insoluble or poorly soluble hydrophobic agents, thus offering promising prospects for their effective utilisation in colorectal cancer (CRC) chemotherapy.

Phytochemical Profiling and Assessment of Antidiabetic Activity of Curcuma Angustifolia Rhizome Methanolic Extract: An In Vitro and In Silico Analysis

Curcuma angustifolia Roxb. is a plant with medicinal potential, traditionally used to treat different diseases. The present study aimed to determine the antidiabetic activity of C. angustifolia rhizome in vitro and in silico. The methanolic extract of C. angustifolia rhizome was analyzed by FTIR and GC-MS to determine the phytochemicals present. The antidiabetic potential of the extract was evaluated by different assays in vitro. The extract inhibited both α-amylase and α-glucosidase enzymes and the glucose diffusion through the dialysis membrane in a concentration-dependent manner with IC50 values of 530.39±0.09, 293.75±0.11, and 551.74±0.3 μg/ml respectively. The methanolic extract also improved yeast cell's ability to take up glucose across plasma membranes and the adsorption of glucose. The findings were supported by molecular docking studies. The results showed that the methanol extract of C. angustifolia rhizome has significant antidiabetic activity and thus can be also studied to isolate the potential compound with antidiabetic activities.

In-vivo anti-hyperglycemic effect of herbal extracts Tribulus terrestris (L) and Curcuma amada (R) on streptozotocin-induced diabetic rats and its associated histopathological studies

Dia/betes is a serious health concern in many countries with high blood glucose, obesity, and multiple organ failures in late stages. Treating diabetes with effective drugs is still a challenging issue since most of the available diabetic drugs are not effective in combating diabetes, especially in secondary disease complications like obesity, retinopathy, and nephropathy associated with diabetes. Hence search for effective antidiabetic medication, especially from natural sources is mandatory with no adverse side effects. In the present study, a combined herbal aqueous extract of Tribulus terrestris and Curcuma amada was administered to diabetic-induced rats for 37 days. During experimentation, the mean blood glucose level was estimated and at the end of the experiment on the 37th day, the animal was sacrificed and observed for weight gain, plasma insulin, glycogen, glycated hemoglobin, urea, and creatinine level. The results revealed that TT and CA extract-treated diabetic groups significantly lowered the mean blood glucose level followed by increased glycogen and insulin level. Urea, creatinine, and HbA1c levels were considerably reduced in TT and CA-treated diabetic animals as compared to that of antidiabetic drug Glibenclamide-treated groups. TT and CA-treated diabetic animals showed considerable net body weight gain at the end of the experimental day. A concluding remark of the study shows that TT and CA herbal extract is effective against diabetes and it can be considered as an antidiabetic agent in ayurvedic medicine practice.

Biophysical Evaluation of Water-Soluble Curcumin Encapsulated in β-Cyclodextrins on Colorectal Cancer Cells

Curcumin (CUR), a curcuminoid originating from turmeric root, possesses diverse pharmacological applications, including potent anticancer properties. However, the use of this efficacious agent in cancer therapy has been limited due to low water solubility and poor bioavailability. To overcome these problems, a drug delivery system was established as an excipient allowing improved dispersion in aqueous media coupled with enhanced in vitro anticancer effects. Different analyses such as UV-vis spectroscopy, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), solubility and dissolution assays were determined to monitor the successful encapsulation of CUR within the inner cavity of a β-cyclodextrin (β-CD) complex. The results indicated that water solubility was improved by 205.75-fold compared to pure CUR. Based on cytotoxicity data obtained from MTT assays, the inclusion complex exhibited a greater decrease in cancer cell viability compared to pure CUR. Moreover, cancer cell migration rates were decreased by 75.5% and 38.92%, invasion rates were decreased by 37.7% and 35.7%, while apoptosis rates were increased by 26.3% and 14.2%, and both caused caspase 3 activation toward colorectal cancer cells (SW480 and HCT116 cells). This efficacious formulation that enables improved aqueous dispersion is potentially useful and can be extended for various chemotherapeutic applications. Preliminary toxicity evaluation also indicated that its composition can be safely used in humans for cancer therapy.

Fermented Curcuma longa L. Prevents Alcoholic Fatty Liver Disease in Mice by Regulating CYP2E1, SREBP-1c, and PPAR-α

We examined the efficacy of fermented Curcuma longa L. (FT) on the development of alcoholic fatty liver in mice and investigated the underlying mechanism. The protective potential of FT against ethanol-induced fatty liver was determined using C57BL/6 male mice allocated into four groups (8 mice/group). Control groups received either distilled water or 5 g/kg body weight (b.w.) per day ethanol for 8 days. Treatment groups were administered either 300 mg/kg b.w. per day of milk thistle or FT before receiving ethanol. FT contained a higher amount of caffeic acid and tetrahydrocurcumin than C. longa. FT pretreatment significantly suppressed the elevated hepatic lipid droplets associated with ethanol ingestion. In comparison with ethanol-treated control, FT pretreated mice showed inhibited cytochrome P4502E1 (CYP2E1), sterol regulatory element-binding protein-1 (SREBP-1c), and acetyl-CoA carboxylase production but elevated AMP-activated protein kinase, peroxisome proliferator-activated receptor-alpha (PPAR-α), and carnitine palmitoyltransferase 1 (CPT-1) levels. Taken together, FT is a promising hepatoprotectant for preventing of alcoholic fatty liver through modulating fatty acid synthesis and oxidation.

A Comprehensive Review on the Therapeutic Potential of Curcuma longa Linn. in Relation to its Major Active Constituent Curcumin

Curcuma longa Linn. (C. longa), popularly known as turmeric, belongs to the Zingiberaceae family and has a long historical background of having healing properties against many diseases. In Unani and Ayurveda medicine, C. longa has been used for liver obstruction and jaundice, and has been applied externally for ulcers and inflammation. Additionally, it is employed in several other ailments such as cough, cold, dental issues, indigestion, skin infections, blood purification, asthma, piles, bronchitis, tumor, wounds, and hepatic disorders, and is used as an antiseptic. Curcumin, a major constituent of C. longa, is well known for its therapeutic potential in numerous disorders. However, there is a lack of literature on the therapeutic potential of C. longa in contrast to curcumin. Hence, the present review aimed to provide in-depth information by highlighting knowledge gaps in traditional and scientific evidence about C. longa in relation to curcumin. The relationship to one another in terms of biological action includes their antioxidant, anti-inflammatory, neuroprotective, anticancer, hepatoprotective, cardioprotective, immunomodulatory, antifertility, antimicrobial, antiallergic, antidermatophytic, and antidepressant properties. Furthermore, in-depth discussion of C. longa on its taxonomic categorization, traditional uses, botanical description, phytochemical ingredients, pharmacology, toxicity, and safety aspects in relation to its major compound curcumin is needed to explore the trends and perspectives for future research. Considering all of the promising evidence to date, there is still a lack of supportive evidence especially from clinical trials on the adjunct use of C. longa and curcumin. This prompts further preclinical and clinical investigations on curcumin.

Phytochemical properties and functional characteristics of wild turmeric (Curcuma aromatica) fermented with Rhizopus oligosporus

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Wild turmeric (Curcuma aromatica) was fermented with R. oligosporus.

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Curcuminoid fermented for 5 days and phenolic compound of all fermented wild turmeric increased.

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The l-carnitine content of fermented wild turmeric was newly synthesized.

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The antioxidant activities were enhanced 1.47-fold after fermentation for 3 days.

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Anti-inflammatory, anti-melanogenic, and anti-obesity effects improved with fermentation.

This study investigated the effect of solid-state fermentation of wild turmeric (Curcuma aromatica) with Rhizopus oligosporus, a common fungus found in fermented soy tempeh, on phytochemical and biological properties. Ultra-performance liquid chromatography–tandem mass spectrometry showed that fermented wild turmeric has higher concentrations of curcumin, demethoxycurcumin, bisdemethoxycurcumin, phenolic compounds and total flavonoid-curcuminoid after fermentation for 1-, 3-, and 5-day relative to non-fermented turmeric. The l-carnitine content reached 242 µg g⁻¹ extract after fermentation for 7-day. Wild turmeric had 1.47- and 2.25-fold increases in ORAC and FRAP, respectively, after 3-day fermentation. The inhibitory effects of fermented wild turmeric on lipid accumulation from 3T3-L1 cells, nitric oxide production from lipopolysaccharide-stimulated RAW264.7 murine macrophages, and melanin formation by B16F10 mouse melanoma cells with α-MSH increased 1.08-, 1.44-, and 1.52-fold, respectively, after 3-day fermentation. Based on these results, fermented wild turmeric product can be used as a functional ingredient in the cosmeceutical and nutraceutical industries.

Design and Characterization of Silver Nanoparticles of Different Species of Curcuma in the Treatment of Cancer Using Human Colon Cancer Cell Line (HT-29)

BACKGROUND

Cancer is a deadly disease responsible for worldwide mortality; usually, middle- and low-income countries have been more affected by cancer and are responsible for 70% of deaths. The present study was performed with the aim to design silver nanoparticles using three species of Curcuma, i.e., Curcuma longa, Curcuma aromatica, and Curcuma caesia.

METHODS

The rhizomes of different plants were extracted with ethanol. The rhizome extracts were used to prepare silver nanoparticles. It was optimized at different pH, silver ion concentrations, and concentrations of plant extracts. The anticancer activity of prepared nanoparticles of C. longa, C. aromatica, and C. caesia was evaluated on a human colon cancer cell line (HT-29) using sulforhodamine B (SRB) assay.

RESULTS

The percentage yield of C. longa, C. aromatica, and C. caesia was 11.34 g, 15.45 g, and 12.67 g, respectively. The results exhibited that the prepared nanoparticles were smooth and spherical. All the nanoparticles of rhizome extracts rescued the viability of HT-29 cells in a different extent. HT-29 cells were sensitive to prepared nanoparticles that induce more cytotoxicity towards cancer cells.

CONCLUSION

Thus, the prepared silver nanoparticle of Curcuma species through green synthesis may help treat cancer with low toxicity.

Turmeric Oil: Composition, Extraction, Potential Health Benefits and Other Useful Applications

The turmeric essential oil of Curcuma species has extensively more useful properties due to its rich phytochemical profile. The concentration of volatile chemical constituents varies according to their type of applied plant part (i.e., root, rhizome, leaves, and flower) for extraction and type of the adopted extraction method. Novel extraction and purification methods, subcritical CO2 , supercritical CO2 , pressurized liquid extraction, and molecular distillation are found to be more efficient for good recovery of this volatile oil, along with increased concentrations of specified compounds. Not only have the curcuminoid compounds had a broad potential in the field of pharmacology but also the turmeric oil is found to have great applicability in treating several diseases and disorders. Turmeric oil possesses good antioxidant, antimicrobial, anticancer, anti-hyperlipidemic anti-inflammatory, anti-diabetic, and hepato-protective properties. Apart from medicinal fields, this oil has also a great future in the cosmetics, pesticide, and food industries due to its rich chemical profile. The present review focuses on providing information about turmeric oil in terms of its physicochemical properties, chemical composition, and available traditional extraction techniques, as well as available novel extraction options, actual health benefits, and other useful applications. It is hoped that the reported information is helpful for further discovery in the area of food, pharmaceutical, and cosmeceutical applications.

Therapeutic Promises of Medicinal Plants in Bangladesh and Their Bioactive Compounds against Ulcers and Inflammatory Diseases

When functioning properly, the stomach is the center of both physical and mental satisfaction. Gastrointestinal disorders, or malfunctioning of the stomach, due to infections caused by various biological entities and physiochemical abnormalities, are now widespread, with most of the diseases being inflammatory, which, depending on the position and degree of inflammation, have different names such as peptic or gastric ulcers, irritable bowel diseases, ulcerative colitis, and so on. While many synthetic drugs, such as non-steroidal anti-inflammatory drugs, are now extensively used to treat these diseases, their harmful and long-term side effects cannot be ignored. To treat these diseases safely and successfully, different potent medicinal plants and their active components are considered game-changers. In consideration of this, the present review aimed to reveal a general and comprehensive updated overview of the anti-ulcer and anti-inflammatory activities of medicinal plants. To emphasize the efficacy of the medicinal plants, various bioactive compounds from the plant extract, their experimental animal models, and clinical trials are depicted.

Immunomodulatory Effects and Mechanisms of Curcuma Species and Their Bioactive Compounds: A Review

Curcuma species (family: Zingiberaceae) are widely utilized in traditional medicine to treat diverse immune-related disorders. There have been many scientific studies on their immunomodulating effects to support their ethnopharmacological uses. In this review, the efficacy of six Curcuma species, namely, C. longa L., C. zanthorrhiza Roxb., C. mangga Valeton & Zijp, C. aeruginosa Roxb. C. zedoaria (Christm.) Roscoe, and C. amada Roxb., and their bioactive metabolites to modulate the immune system, their mechanistic effects, and their potential to be developed into effective and safe immunomodulatory agents are highlighted. Literature search has been carried out extensively to gather significant findings on immunomodulating activities of these plants. The immunomodulatory effects of Curcuma species were critically analyzed, and future research strategies and appropriate perspectives on the plants as source of new immunomodulators were discussed. Most of the pharmacological investigations to evaluate their immunomodulatory effects were in vivo and in vitro experiments on the crude extracts of the plants. The extracts were not chemically characterized or standardized. Of all the Curcuma species investigated, the immunomodulatory effects of C. longa were the most studied. Most of the bioactive metabolites responsible for the immunomodulating activities were not determined, and mechanistic studies to understand the underlying mechanisms were scanty. There are limited clinical studies to confirm their efficacy in human. Of all the bioactive metabolites, only curcumin is undergoing extensive clinical trials based on its anti-inflammatory properties and main use as an adjuvant for the treatment of cancer. More in-depth studies to understand the underlying mechanisms using experimental in vivo animal models of immune-related disorders and elaborate bioavailability, preclinical pharmacokinetics, and toxicity studies are required before clinical trials can be pursued for development into immunomodulatory agents.

The Genus Curcuma and Inflammation: Overview of the Pharmacological Perspectives

The Curcuma genus has been extensively used for therapeutic purposes in traditional or folk medicine worldwide, including for its anti-inflammatory activity. Curcuma spp.'s active constituents, such as alkaloids, flavonoids, and terpenoids, can act on various targets in the signaling pathway, restrain pro-inflammatory enzymes, lower the production of inflammatory cytokines and chemokines, and reduce oxidative stress, which subsequently suppresses inflammatory processes. Preclinical and clinical studies have reported the predominant anti-inflammatory activity of several Curcuma species. This review provides an overview of the anti-inflammatory effects of different extracts, preparations, and bioactive components in this genus. This analysis may provide a scientific basis for developing new and alternative methods for the isolation of a single entity from this genus to attenuate inflammatory conditions. The Curcuma genus is waiting for researchers interested in developing safe and efficient anti-inflammatory agents for further investigation.

Hypoglycemic Activity of Curcuma mangga Val. Extract via Modulation of GLUT4 and PPAR-γ mRNA Expression in 3T3-L1 Adipocytes

Background

There would be over 600 million people living with diabetes by 2040 as predicted by the World Health Organization. Diabetes is characterized by raised blood sugar and insulin resistance. Insulin regulates the influx of glucose into the cell by upregulating the glucose transporter type 4 (GLUT4) expression on the plasma membrane. Besides, PPAR-γ also controls the metabolism of glucose in adipose tissues. Curcuma mangga Val., denoted as C. mangga, is a native Indonesian medicinal plant that has many beneficial effects, including an antidiabetic potential.

Purpose

In this research, we aimed to disclose the hypoglycemic activity of ethanol extract of C. mangga (EECM) in 3T3-L1 fibroblasts-derived adipocyte cells in regulating glucose uptake as confirmed by the GLUT4 and PPAR-γ gene expression.

Methods

The uptake of glucose was determined using radioactive glucose, while the gene expression of GLUT4, PPAR-γ, and β-actin was quantified using mRNA segregation and real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR).

Results

We discovered that EECM interventions (200 and 50 μg/mL) increased glucose uptake in lipid-laden 3T3-L1 cells by 14.75 and 8.86 fold compared to the control non-insulin, respectively (p < 0.05). At the same doses, they also increased GLUT4 mRNA expression by 8.41 and 11.18 fold compared to the control non-insulin, respectively (p < 0.05). In contrast, EECM interventions (200 and 50 μg/mL) showed lower levels of PPAR-γ mRNA expression compared to the control metformin, indicating the anti-adipogenic potentials of EECM.

Conclusion

EECM showed hypoglycemic activity in lipid-laden 3T3-L1 cells by improving glucose ingestion into the cells, which was mediated by increased GLUT4 expression and downregulated PPAR-γ expression.

A comparative account of the traditional healing practices of healers and non-healers in the Kiudang area of Brunei Darussalam

ETHNOPHARMACOLOGICAL RELEVANCE

In this study, we compare the traditional medicinal knowledge and associated spiritual practices of healers with that of non-healers, to understand the relevance of healers in contemporary times. Given that Brunei Darussalam is well-known for its forest cover, the study also aims to understand the number of species collected from the forests, compared to those from human influenced habitats.

MATERIALS AND METHODS

A total of six specialist healers from Belait, Tutong, Dusun and Iban communities, and seven non-healers who had personal experience in self-medication using medicinal plants participated in the study. We identified the specialist healers through purposive sampling, on the basis of their reputation in the locality, while the non-healers were those experienced in self-medication, recommended by the healers. Informants were interviewed at their residences, followed by collection trips to the plant habitats. We classified the total recorded ailments into 15 disease categories. We then compared the medicinal uses cited by healers to those mentioned by non-healers, as well as with prior published records from Brunei Darussalam. We also compare the habitats of species cited by both healers and non-healers to understand the dependency of the local pharmacopoeia on forests and human-influenced habitats.

RESULTS

Our study records 175 medicinal plants belonging to 85 families, the majority of which (92) were exotic to Borneo. There were 110 species collected from disturbed, human influenced habitats such as roadsides, agricultural fields, secondary and degraded forests, and homestead lands, while 58 species were collected from the forests surrounding Kiudang. Majority of the plants used by both healers and non-healers were collected from human-influenced habitats, indicating that the local pharmacopoeia could be a disturbance one. Most of the medicinal plants recorded in this study were used to treat chronic, but non-life threatening conditions. Ailments affecting the digestive system were the most targeted group with 67 species used. All medicinal uses with more than one citation were recorded from healers. Medicinal uses cited by healers also had greater correspondence with prior published reports from Brunei Darussalam. Healers believe that combining medicinal plants can produce a synergistic effect. Our study found that traditional knowledge related to healing practices is mostly transmitted vertically from parents to children. We also show that a ritual gift (pikaras) and invocations characteristic of the beliefs of the healers play an important role in facilitating healing.

CONCLUSION

Our study adds further evidence to prior studies that the medicinal plants and healing practices in the Kiudang region could be considered as disturbance pharmacopoeia. Healers with their knowledge on both therapeutic and spiritual aspects of healing continue to play an important role in local healthcare.

The Role of Histone Acetylation and the Microbiome in Phytochemical Efficacy for Cardiovascular Diseases

Cardiovascular diseases (CVD) are the main cause of death worldwide and create a substantial financial burden. Emerging studies have begun to focus on epigenetic targets and re-establishing healthy gut microbes as therapeutic options for the treatment and prevention of CVD. Phytochemicals, commonly found in fruits and vegetables, have been shown to exert a protective effect against CVD, though their mechanisms of action remain incompletely understood. Of interest, phytochemicals such as curcumin, resveratrol and epigallocatechin gallate (EGCG) have been shown to regulate both histone acetylation and microbiome re-composition. The purpose of this review is to highlight the microbiome-epigenome axis as a therapeutic target for food bioactives in the prevention and/or treatment of CVD. Specifically, we will discuss studies that highlight how the three phytochemicals above alter histone acetylation leading to global changes in gene expression and CVD protection. Then, we will expand upon these phytochemicals to discuss the impact of phytochemical-microbiome-histone acetylation interaction in CVD.

The Cancer Chemopreventive and Therapeutic Potential of Tetrahydrocurcumin

In recent decades, cancer has been one of the leading causes of death worldwide. Despite advances in understanding the molecular basis of tumorigenesis, diagnosis, and clinical therapies, the discovery and development of effective drugs is an active and vital field in cancer research. Tetrahydrocurcumin is a major curcuminoid metabolite of curcumin, naturally occurring in turmeric. The interest in tetrahydrocurcumin research is increasing because it is superior to curcumin in its solubility in water, chemical stability, bioavailability, and anti-oxidative activity. Many in vitro and in vivo studies have revealed that tetrahydrocurcumin exerts anti-cancer effects through various mechanisms, including modulation of oxidative stress, xenobiotic detoxification, inflammation, proliferation, metastasis, programmed cell death, and immunity. Despite the pharmacological similarities between tetrahydrocurcumin and curcumin, the structure of tetrahydrocurcumin determines its distinct and specific molecular mechanism, thus making it a potential candidate for the prevention and treatment of cancers. However, the utility of tetrahydrocurcumin is yet to be evaluated as only limited pharmacokinetic and oral bioavailability studies have been performed. This review summarizes research on the anti-cancer properties of tetrahydrocurcumin and describes its mechanisms of action.

A 1 H-NMR spectroscopic method for the analysis of thermolabile chemical markers from the essential oil of black turmeric (Curcuma caesia) rhizome: application in post-harvest analysis

INTRODUCTION

Curcuma caesia (black turmeric), an essential oil-bearing rhizomatous herb has been a part of ethnomedicinal practices in India and southeast Asian countries since ancient time. Oleochemical profile of black turmeric has been investigated previously by gas chromatography coupled to mass spectrometry (GC-MS) technique from different geographical regions showing a large variation in the identity as well as abundance of the constituents.

OBJECTIVES

To develop an analytical method for the reliable analysis of essential oil from black turmeric rhizome through identified chemical markers and to show the credibility of the developed method on real samples.

METHODS

The essential oil of black turmeric was analysed through proton nuclear magnetic resonance (¹ H-NMR) based method using an internal standard.

RESULTS

Four thermolabile sesquiterpene markers were unambiguously identified from the essential oil of black turmeric rhizome. GC-MS based analysis produced an erroneous identification of the constituents. A standardised ¹ H-NMR spectroscopy based method was developed for the qualitative and quantitative analysis of the identified chemical markers. The developed method was further utilised for analysing the variation in oleochemical profile across multiple batches of harvest and the rhizomes subjected to different post-harvest storage or drying conditions.

CONCLUSION

The identified marker molecules and developed ¹ H -NMR spectroscopic method might prove to be a useful tool for the analysis of essential oil and quality control of this endangered crop material. Also, the present study provided information on the preferred drying and storage condition of black turmeric rhizome prior to the extraction of essential oil.