Most fell shorteither packed with sugar, overloaded with sodium, made with questionable sweeteners, or just flat-out unpleasant to drink
These include botany, morphology, microscopy, high-performance thin-layer chromatography (HPTLC), high-performance liquid chromatography (HPLC), liquid chromatography with mass spectrometry (LC-MS), inductively coupled plasma mass spectrometry (ICP-MS) for heavy metals testing, spectrophotometric methods (UV-Vis, FTIR), testing for microbial contamination, and other standard scientific methods
My understanding is it has such smaller reference ranges and very difficult to detect, and so there's only one lab that has created a test for this
No unusual color changes from previous inspections
doi: 10.1016/j.ijbiomac.2015.05.035 26