I would think this would be a very basic FDA test.

Demonstration of 60 MHz 1H NMR as a screening tool for distinguishing beef from horse meat. •A simple chloroform extraction combined with a 10 min spectral acquisition time. •A principal components-based authenticity model yielding a ‘beef’ or ‘not-beef’ outcome.

https://pmc.ncbi.nlm.nih.gov/articles/PMC4308633/

I would think that human meat, would be substantially different from Beef/Horse.