Identification of adulteration in the market samples of saffron using morphology, HPLC, HPTLC, and DNA barcoding methods

Saffron, the stigma of Crocus sativus L., is the most expensive spice used for culinary, medicinal, dye, and cosmetics purposes. It is highly adulterated because of its limited production and high commercial value. In this study, 104 saffron market samples collected from 16 countries were tested using morphology, high-performance liquid chromatography (HPLC), high-performance thin-layer chromatography (HPTLC), and deoxyribonucleic acid (DNA) barcoding. Overall, 45 samples (43%) were adulterated. DNA barcoding identified the highest number of adulterated saffron (44 samples), followed by HPTLC (39 samples), HPLC (38 samples), and morphology (32 samples). Only DNA barcoding identified the adulterated samples containing saffron and other plants' parts as bulking agents. In addition, DNA barcoding identified 20 adulterant plant species, which will help develop quality control methods and market surveillance. Some of the adulterant plants are unsafe for human consumption. The HPLC method helped identify the saffron samples adulterated with synthetic safranal. HPLC and HPTLC methods will help identify the samples adulterated with other parts of the saffron plant (auto-adulteration).