Vol.:(0123456789) 1 3 European Food Research and Technology https://doi.org/10.1007/s00217-019-03352-7 ORIGINAL PAPER Geographical classifcation of Iranian and Italian safron sources based on HPLC analysis and UV–Vis spectra of aqueous extracts Solmaz Tabtabaei 1  · Angelo Antonio D’Archivio 2  · Maria Anna Maggi 3  · Marlon Brutus 1  · Diwash H. Bajracharya 1  · Dinara Konakbayeva 1  · Akbar Soleimani 4  · Hassan Brim 4  · Hassan Ashktorab 4 Received: 11 April 2019 / Revised: 19 July 2019 / Accepted: 3 August 2019 © Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract Twenty-nine diferent Iranian and Italian safron samples have been characterized using high-performance liquid chromatog- raphy (HPLC) equipped with UV–Vis detection as well as ultraviolet–visible (UV–Vis) spectroscopy methods by preparing aqueous extracts according to the ISO 3632 standard. UV–Vis spectral data in the wavelength range of 200–600 nm and the intensities of the chromatographic peaks attributed to picrocrocin, safranal and crocetin esters were considered as vari- ables in principal component analysis (PCA) and linear discriminant analysis (LDA) methods to classify Iranian and Italian safron samples based on their geographical origin. The geographical classifcation results based on HPLC data indicated safranal, cis-crocetin (β-D-gentiobiosyl)(β-D-glucosyl) ester (C3Gg), trans-crocetin (β-D-neapolitanosyl)(β-D-glucosyl) ester (T4ng), and trans-crocetin (β-D-gentiobiosyl)(β-D-glucosyl) ester (T3Gg) as the most discriminant. The best classifcation performance was achieved by the UV–Vis spectra where the most discriminant regions can be associated with both cis- and trans-crocins (326–327 and 260–264 nm), safranal (310 nm), picrocrocin (240–250 nm), and kaempferol derivatives (265 and 340–350 nm). Keywords Iranian and Italian safron · Crocetin esters · Picrocrocin · Safranal · Linear discriminant analysis · Principal component analysis Introduction Safron is obtained from dry stigmas of Crocus sativus L., a member of the Iridaceae family. It is the most expensive culinary condiment in the world as it provides the combina- tion of taste, aroma and color to foods and beverages [1]. Due to safron’s therapeutic properties, its medicinal appli- cation has been also the focus of several scientifc research studies [2–6]. The compounds responsible for the qual- ity of safron are a group of biologically active secondary metabolites. The major biologically active compounds are crocetin esters, picrocrocin, and safranal. Crocetin esters (also called crocins, which are glycosylated carotenoids derived from crocetin) are responsible for safron color, and they exist in safron as both cis- and trans-isomers. The well- known bitter taste of safron originates from picrocrocin, a monoterpene glycoside. The aroma of safron comes from safranal, a monoterpene aldehyde, which is the major vola- tile compound of this spice [7–9]. The quality of safron in the international trade market is certifed according to the specifcation standard ISO 3632-2 [10]. This specifcation classifes safron into three diferent categories, taking into account a large number of physical and chemical parameters. Three major parameters that con- tribute to safron quality are determined by UV–Vis spec- trophotometry and expressed as coloring strength ( E 1% 1cm at 440 nm, the wavelength of crocin maximum absorbance), aroma ( E 1% 1cm at 330 nm, the wavelength of safranal maxi- mum absorbance) and taste ( E 1% 1cm at 257 nm, the wave- length of picrocrocin maximum absorbance). However, this UV–Vis procedure does not provide a detailed composition * Solmaz Tabtabaei solmaz.tabtabaei@howard.edu 1 Department of Chemical Engineering, Howard University, 2300 6th Street, NW, Washington, DC 20059, USA 2 Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, Via Vetoio, Coppito, 67100 L’Aquila, Italy 3 Hortus Novus, Via Aldo Moro 28 D, 67100 L’Aquila, Italy 4 Department of Medicine, Department of Pathology and Cancer Center, Howard University College of Medicine, Washington, DC 20059, USA