Authentication of saffron (Crocus sativus L.) in different processed, retail products by means of SCAR markers

•A SCAR-based method was set up to detect seven bulking agents in saffron-containing foods.•The method was applied to 24 products containing saffron.•A good performance was obtained also in processed foods with mixed ingredients.•The 21% of the samples contained one or more bulking agents.

A method based on Sequence-Characterized Amplified Regions (SCARs) was applied to 24 different food products composed by or containing different amounts of saffron (Crocus sativus L.), in order to detect adulteration/contamination with seven common bulking agents, namely Arnica montana L., Bixa orellana L., Calendula officinalis L., Carthamus tinctorius L., Crocus vernus L. (Hill), Curcuma longa L. and Hemerocallis sp. The food products screened included ground saffron, mixed seasonings and spices, ready-made dishes and herbal formulations. The method allowed a very good performance in both DNA extraction and amplification stages regardless of the presence of lipidic, sugary or polyphenolic substances and despite the presence of dried, stored and processed material. Two samples evidenced a contamination with C. vernus, four with Carthamus, one with Curcuma and one with Hemerocallis, while a product was found to contain no C. sativus. The recourse to SCAR markers may represent a fast, reliable and low-cost screening method for the authentication of a wide range of dried food products containing saffron. Despite the great attention paid by the food industry to the authentication of saffron, some common bulking agents can be present in retail foods, as the 21% of the screened samples was not composed by pure saffron.