Microscopy, HPTLC, and LC-DAD-Q-ToF validation of nut-based weight-loss dietary supplements, Aleurites moluccanus (candlenut) and Bertholletia excelsa (Brazil nut)

Abstract

Aleurites moluccanus (candlenut) and Bertholletia excelsa (Brazil nut) are marketed as dietary supplements for weight loss. These dietary supplements have been found to sometimes be adulterated with toxic nuts/seeds from Cascabela thevetia, commonly known as yellow oleander or lucky nut. This study emphasizes the key identification parameters to differentiate the genuine and adulterated nuts. Samples were obtained from authenticated sources of the nuts and from commercial sources of dietary supplements. This study examined 38 samples, including voucher and commercial samples. All eight commercial candlenut dietary supplement samples were adulterated. Additionally, two samples sold as Brazil nuts were also found to be adulterated. Other nuts were screened for the presence of Cardiac Glycosides, but none were found to be positive. The presence of yellow oleander was confirmed in all commercial dietary supplement samples marketed as candlenut as well as in commercial samples of Brazil nut. This study provides simple key identification characters using micro-morphology and histochemical localization of cardiac glycosides in the commercial nuts, HPTLC fingerprints, and LC-DAD-Q-ToF analytical parameters to detect and identify adulteration in commercial products.

Keywords:

• Adulteration
• authentication
• cardiac glycosides
• dietary supplements
• food contaminants
• identification
• toxic nuts

Acknowledgments

The scanning electron microscopy analysis was performed at the University of Mississippi GlyCORE Imaging Core, was supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under award number P20GM103460. The authors thank Mr. Jeff Solomon for his reviewing and Language proofreading.

Author contributions

Sebastian John Adams (SJA): Study conception and design, methodology, investigation, micro and macroscopy data curation, and interpretation, writing-original-draft. Bharathi Avula (BA) and Kumar Katragunta (KK): Methodology, data curation, visualization, investigation, and writing of LC-DAD-QToF. Seethapathy G. Saroja (SGS), Jianping Zhao (JZ): Methodology, Data curation, visualization, investigation, and writing of HPTLC analysis. Amar G. Chittiboyina (AGC): Reviewing and Ikhlas A. Khan (IAK): Conceptualization, resources, funding acquisition and guidance. All authors have agreed to the published version of the manuscript.

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This research is supported by the ‘Science-Based Authentication of Botanical Ingredients’ funded by the Center for Food Safety and Applied Nutrition, US Food and Drug Administration grant number 5U01FD004246.