Identification of synthetic dyes magenta III (new fuchsin) and rhodamine B as common adulterants in commercial saffron

Saffron is a highly adulterated spice due to its limited production and high costs. Non-saffron plant material is coloured with synthetic dyes to produce counterfeit saffron. Continuous monitoring of the synthetic dyes used in counterfeit saffron is essential because some dyes are not safe for human consumption. In the present study, 104 commercial saffron samples from 16 countries were screened, and 20 samples were found to contain dyes. Thin-Layer Chromatography (TLC) analysis showed adulteration with magenta- and pink-coloured dyes (18 and 2 samples, respectively), which did not correspond to any of the dyes reported earlier. Mass spectrometry analysis identified the magenta-coloured dye as magenta III or new fuchsin and the pink-coloured dye as rhodamine B. Magenta III is regarded as possibly carcinogenic, and rhodamine B was reported to cause local sarcomas. Both of these synthetic dyes are reported as adulterants in saffron for the first time.