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ARS Home » Northeast Area » Beltsville, Maryland (BHNRC) » Beltsville Human Nutrition Research Center » Methods and Application of Food Composition Laboratory » Research » Publications at this Location » Publication #421104
Research Project: Farm to Table Factors: Impact of Production, Processing, and Preparation on Food Composition

Location: Methods and Application of Food Composition Laboratory

Title: Comparative untargeted and targeted metabolomics investigation of turmeric dietary supplements and rhizomes

Author
item SINGH, JABSHIR - Orise Fellow
item TAREQ, FAKIR - University Of Maryland
item Luthria, Devanand - Dave

Submitted to: Foods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2024
Publication Date: 12/24/2024
Citation: Singh, J., Tareq, F.S., Luthria, D.L. 2024. Comparative untargeted and targeted metabolomics investigation of turmeric dietary supplements and rhizomes. Foods. 14. https://doi.org/10.3390/foods14010007.
DOI: https://doi.org/10.3390/foods14010007

Interpretive Summary: Curcuma longa L., or turmeric, is a perennial herb also known as golden spice belonging to the family Zingiberaceae, commonly used in Asian food curries and dietary supplements. In the present study, we analyzed bioactive curcuminoids content in nine most popular turmeric dietary supplements (DS), three ground powdered samples, three dried rhizome powders. The results showed that the total curcuminoids content, the volatile component, and the percent ratio of the three prominent curcuminoids, bisdesmethoxycurcumin (BMC), desmethoxycurcumin (DMC), and curcumin (CUR), also varied remarkably. Analysis of curcuminoids from DS in neutral and acidic solution demonstrated that all curcuminoids (BMC, DMC and CUR) existed in the keto and enol forms and their concentrations changed with pH. This study will be of significant interest to manufacturers, consumers, and pharmacologists to accurately understand the bioactivities of three curcuminoids in different isomeric forms.

Technical Abstract: In the present study, we analyzed bioactive curcuminoids content in eight capsules (DS-1-DS-7 and DS-9), one tablet (DS-8), and three ground turmeric samples (DS-10-DS-12), and three ground turmeric rhizomes (TR-1, TR-2, and TR-3). The initial screening with infrared and ultraviolet-visible spectroscopy coupled with principal component analysis (PCA) revealed distinct differences between the samples analyzed. Hence, targeted and untargeted analyses were performed using ultra-high-performance liquid chromatography and gas chromatography coupled with mass spectrometry detections. The results showed that the total curcuminoids content (ranged from 1.3 to 69.8 mg/100 mg) and the volatile component (ranged from 0.7 to 9.1 mg/100 mg). The percent ratio of the three prominent curcuminoids, bisdesmethoxycurcumin (BMC), desmethoxycurcumin (DMC), and curcumin (CUR), also varied remarkably as compared to the expected ratio (BMC:DMC:CUR: 1:2:6) as described in the literature. The three prominent volatiles identified in most samples were ar-turmerone, turmerone, and curlone Results demonstrated significant differences in the volatile compound levels among the DS and dried rhizome samples. The non-targeted analysis resulted in the identification of over 40 compounds including, bioactives such as piperine, phenolic acids, and amino acids. A disintegration study was performed on limited DS according to the United States Pharmacopeia protocol. The results revealed that all the selected DS passed the disintegration test. Analysis of curcuminoids from DS in neutral and acidic solutions demonstrated that all curcuminoids (BMC, DMC, and CUR) existed in the keto and enol forms and their concentrations changed with pH. This study will be of significant interest to manufacturers, consumers, and pharmacologists to accurately understand the bioactivities of three curcuminoids in different isomeric forms.