Use of Molecular Methods to Authenticate Animal Species and Tissue in Bovine Liver Dietary Supplements
Dietary supplements containing bovine (subfamily Bovinae) liver are susceptible to fraud due to the lack of modern detection methods available for processed animal tissues and premium pricing for dietary supplements. Therefore, the objective of this research was to use molecular methods to authenticate dietary supplements claiming to contain “bovine liver” or “beef liver” through the verification of species and animal tissue. A total of 53 bovine/beef liver dietary supplements were purchased from online sources. The presence of liver was verified with reverse transcription and real-time PCR testing for microRNA-122 (miR-122), which is highly expressed in liver tissue. Multiplex real-time PCR targeting domestic cattle (Bos taurus), horse (Equus caballus), sheep (Ovis aries), and pork (Sus scrofa) was used to verify species. Samples that failed species identification with multiplex real-time PCR underwent DNA mini-barcoding. Overall, bovine species were detected in 48/53 liver supplements: 35 samples were confirmed as B. taurus with multiplex real-time PCR and an additional 13 samples were confirmed as B. taurus or Bos spp. with DNA mini-barcoding. One sample was positive for domestic cattle and sheep/lamb, both of which were declared on the label. One product was mislabeled due to the detection of undeclared pork in addition to beef. MiR-122 was detected in 51 out of 53 supplements, suggesting the presence of liver. Tissue-specific microRNAs can be reliable in identifying tissue and may be useful in detecting mislabeling in supplements. However, this was the first study to utilize microRNA for authentication of liver in dietary supplements and more research is needed to evaluate the specificity of these markers.
MicroRNAs, Mini-Barcoding, PCR, miR-122, Mislabeling, AllHorse, Food Studies
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