Production Practices and Quality Assessment of Food Crops. Vol. 1

Saffron Quality 233
sium were the qualitative tests used to detect fraud. Quantification was achieved
through the application of Devarda method and colorimetric methods used for nitrate.
The water and alcohol insoluble matter weight was also useful in this case. Numerous
saffron adulteration cases were reported by Stahl and Wagner (1968), who experimented
on the combination of microanalytical methods to indicate the characteristic
saffron components. Oberdieck (1991) and Alonso et al. (1998a) summarised the
most frequent adulteration practices:
(1) Misbranding or falsification of origin
(2) Admixture with old saffron or with style material
(3) Admixture with stamens previously cut and dyed
(4) Impregnation with substances to increase weight (syrups, honey, glycerin, oils,
potassium hydroxide, saltpetre, Glauber’s salt, Seignette’s salt, borax, lactose,
starch or glucose)
(5) Parts of other plants with or without colouring power
(6) Animal substances (fibers of salted and dried meat)
(7) Threads of coloured gelatin; organic colourings and colouring materials derived
from tar.
Among plant materials adulteration with dried petals of Carthamus tinctorius, L
seems to be common even in recent times (Seidemann, 2001). Other plant materials
reported are Calendula officinalis L., stigmas from other crocuses (C. vernus
L., C. esperiosus L) that are generally shorter and without colouring properties, strips
of petals from Papaver rhoeas L., Punicam granatum L., Arnica montana L., and
Scolymus hispanicus L., stamens from carnations, ground red pepper, sandlewood
dust and longwood particles and also curcuma. Molecular genetic methodology indicated
that the nucleotide sequence may differentiate C. sativus from three typical
adulterants used in the South East Asia, namely, C. tinctorius, Hemerocallis
fulva, L. and Hemerocallis citrina Baroni (Ma et al., 2001). Two phenylpropanoid
glucosides, verbascoside and poliumoside, determined by HPLC, have been used
to identify Buddleja officinallis Maxim. yellow natural colorants in foods containing
crocetin derivatives in the Chinese market (Aoki et al., 2001). Many other crocuses
may be used as potential adulterants (e.g., C. haussknechtii Boiss) (Radjabian et
al., 2001). Frequent seems to be the adulteration of saffron in the Italian (Corradi,
and Micheli, 1979a, b; Corradi, 1981) and Spanish market. The main reason is
that the product is imported in small amounts of 1 kg or even less so that analysis
of all batches becomes difficult. Adulteration with mixtures of synthetic dyes such
as tartrazine, Ponceau 4R, azorubine, sunset yellow and erythrosine were detectable
even with TLC procedures (e.g. Corradi et al., 1981; Alonso et al., 1999a; Carmona
et al., 2002). Many HPLC procedures have been also reported for the detection of
synthetic dyes (Lozano et al., 1999; Saltron et al., 1999). Authentication of saffron
aroma through the establishment of a fingerprint of the volatiles has been attempted
by Alonso et al. (1998a) or by safranal analysis by isotopic 13 C (Semiond et al.,
1996). The latter gives a clear discrimination between the synthetic and the natural
counterpart but no definite conclusion about the geographical origin. Even the
presence of mangicrocin, a xanthone-carotenoid glycosidic conjugate from saffron
has been discussed as a biomarker for the control of authenticity (Ghosal et al.,