DNA barcoding after cloning identifies taxonomically diverse botanical adulterants in the market samples of saffron

Saffron (Crocus sativus L.), commonly used all over the world for culinary purposes is said to have many medicinal properties including antioxidant, anticancer, antidepressant, analgesic, diuretic and memory enhancing activities. Saffron is also consumed by pregnant women in many places. It is the world's most expensive spice. Its high cost is due to the low production and the highly intensive labor required for its harvest. As a result, saffron is highly prone to adulteration. In our initial screening of commercial saffron samples by DNA barcoding, six samples were found to have been adulterated by mixing plant parts from more than one species. To identify the constituent adulterant plant species, we employed the DNA barcoding after cloning (DBAC) method using rbcL DNA barcode and TA cloning. The results showed the presence of at least four and up to ten taxonomically diverse plant species in each adulterated sample. Twenty nine adulterant species belonging to 18 genera and 10 families were identified. Some of the adulterant species were reported to be toxic to humans if consumed. Therefore, it is essential to identify the botanical adulterants in saffron to prevent fraudulent business practices as well as to enhance the safety of consumers.