Saffron is a true spice or false species?

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…
~ 170’000 flowers
~ 108 kg
~ 510’000 fresh stigmas
~ 5 kg
1 KG OF DRY
SAFFRON
~ 14’000 CHF
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
Carthamus tinctorius
Crocus vernus
Bixa orellana
Calendula officinalis
Arnica montana
Hemerocallis sp.
Curcuma longa
Fig. 1: Seven potential contaminants species used as saffron adulterants.
DNA analysis to detect fraud
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method ,
According to Marieschi et al. (2012)
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).
Crocus sativus
Carthamus tinctorius
bp
bp
400
300
200
400
300
200
B.
100
100
L
1 2
3
4
5
6
7 8 9
C+ O1 Z
Crocus sativus
Carthamus tinctorius
Optical
microscopy
DNA
markers
A.
L
1 2
3 4 5 6
7
8 9 C+ O1 Z
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).
CONCLUSION
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.
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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.