Level of natural hepatotoxin (Indospicine) contamination in Australian camel meat

ABSTRACT

Camel meat production for human consumption and pet food manufacture accounts for a relatively small part of overall red meat production in Australia. Reliable statistical data for the Australian production and consumption of camel meat are not available; however, it is estimated that 300,000 feral camels roam within the desert of central Australia, with an annual usage of more than 3000 camels for human consumption, 2000 for pet food manufacture and a smaller number for live export. Despite a small Australian camel meat production level, the usage of camel meat for pet food has been restricted in recent years due to reports of serious liver disease and death in dogs consuming camel meat. This camel meat was found to contain residues of indospicine, a non-proteinogenic amino acid found in certain Indigofera spp., and associated with mild to severe liver disease in diverse animals after dietary exposure to this hepatotoxin. The extent of indospicine-contaminated Australian camel meat was previously unknown, and this study ascertains the prevalence of such residue in Australian camel meat. In this study, indospicine levels in ex situ (95 samples collected from an abattoir in Queensland) and in situ (197 samples collected from camels after field culling in central Australia) camel meat samples were quantitated using a validated ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The quantitation results showed 46.7% of the in situ- and 20.0% of the ex situ-collected camel meat samples were contaminated by indospicine (more than the limit of detection (LOD) of 0.05 mg kg^–1 fresh weight). The overall indospicine concentration was higher (p < 0.05) in the in situ-collected samples. Indospicine levels detected in the present study are considered to be low; however, a degree of caution must still be exercised, since the tolerable daily intake for indospicine is currently not available for risk estimation.

Graphical Abstract

KEYWORDS:

• Indospicine
• Indigofera
• camel meat
• ultra−performance liquid chromatography−tandem mass spectrometry

Acknowledgements

The authors are grateful for the support of the Australian Feral Camel Management Project, administered by NintiOne; Jordan Hampton and Corissa Miller (Ecotone Wildlife Veterinary Services), who collected in situ camel tissue samples; and Mike Eathorne and Meramist Pty Ltd for providing ex situ camel meat samples. UPLC-MS/MS technical advice was provided by Cindy Giles and Dennis Webber (Department of Agriculture and Fisheries, Queensland, Australia). Greg George and Tom Joyce (The University of Queensland) provided assistance and advice in map plotting.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This present study was partly funded by an Academic Training Scheme for Institutions of Higher Education (SLAI) Scholarship sponsored by the Malaysian Government and Universiti Teknologi MARA, and a Top-up Assistance Program Scholarship (TUAP) sponsored by The University of Queensland.