Saffron is a true spice or false species? Eugeni Piller Lucia, Scheffel Laurence, Sester Cindy, Fridez Françoise

Service de la consommation et des affaires vétérinaires (SCAV), CH-2001 Neuchâtel, Switzerland

INTRODUCTION Saffron is derived from dried stigmas of Crocus sativus Linnaeus (Iridaceae) which originally came from Asia Minor. This species is a triploid plant that is propagated vegetatively by corms. Saffron blooms only once a year and flowers, with a deep auburn colour and sweet flavour, provide only three stigmas, which are harvested manually then subjected to desiccation. This spice is well known as Red Gold in producer countries. Currently, the largest saffron spice producer and exporter is Iran, followed by India, Greece, Spain, Morocco, and Italy. The world's annual saffron production is estimated around 300 tons per year (Iran produces 76% of world production).

The world’s most expensive spice…

All these parameters make saffron the world's most expensive spice. Especially because of its cost, saffron is frequently adulterated with cheaper substitutes with similar colour and morphology to increase the volume and weight of commercial lots. Saffron is used for cooking, staining, medicine, cosmetics, perfumery and some other purposes.

Plant adulterants used as a bulking agents DNA analysis to detect fraud

According to Marieschi et al. (2012) method1, the identification and authentication of aromatic plants is based on Random Amplified Polymorphic DNA markers (RAPDs). RAPDs allow to obtain more reliable, robust and specific markers named SCARs (Sequence-Characterized Amplified Regions). This method was developed for seven adulterant plants commonly spotted in the saffron trade (Fig. 1) and it enables the unequivocal detection of low amounts (up to 1%) of each adulterant, allowing the identification of suspect samples.

APPLICATIONS Screening of commercial dried or powdered saffron samples were done in the French part of Switzerland. Results show a non compliance rate of 10%. This percentage included labelling issues and species substitution, C. tinctorius (Ct) was found instead of C. sativus (Cs) (Fig. 2).

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y Crocus sativus Carthamus tinctorius A.

The aim of this work is to apply SCAR markers method to verify authenticity of commercial saffron (dried or powder) in Switzerland and prevent malicious practices to protect consumers against fraudulency. We would thank Botanical Garden of Neuchâtel to have supplied C. tinctorius, C. officinalis, Hemerocallis sp., C. longa and the University of Parma (IT) for Bixa orellana seeds. Bulbs of C. sativus and C. vernus were bought to Sativa AG, Rheinau. 1 Matteo Marieschi, Anna Torelli, and Renato Bruni, Quality Control of Saffron (Crocus sativus L.): Development of SCAR Markers for the Detection of Plant Adulterants Used as Bulking Agents, J. Agric. Food Chem. 2012, 60, 10998−11004.

CONCLUSION

Fig. 2: A. DNA results. PCR was performed with ScCs263 primer pair specific for C. sativus showing a band at 263bp (left) and with ScCt131 primer pair specific for C. tinctorius, detected at 131 bp (right). L: 100 bp DNA ladder; 1-9: commercial samples labelled “saffron”; C+: positive control (left for Cs and right for Ct); O1: negative extraction control; Z: negative amplification control. B. Microscopy observation. Images of pollen granules obtained by optical microscopy (100x) from C. sativus stigmas (left) and C. tinctorius stigmas (right).

B. Carthamus tinctorius Crocus sativus

Fig. 1: Seven potential contaminants species used as saffron adulterants.

Carthamus tinctorius Crocus vernus Calendula officinalis Hemerocallis sp.

Bixa orellana Arnica montana Curcuma longa

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bp bp

~ 170’000 flowers ~ 108 kg

~ 510’000 fresh stigmas ~ 5 kg

1 KG OF DRY SAFFRON

~ 14’000 CHF

L 1 2 3 4 5 6 7 8 9 C+ O1 Z L 1 2 3 4 5 6 7 8 9 C+ O1 Z