Detection of saffron adulteration by other plant species using SPME-GC-HRMS

Saffron, a spice obtained by drying the scars of saffron flowers ( Crocus sativus L.), is by far the most valuable spice in the world, and, not surprisingly, it often becomes an object of adulteration. In this study, non-target screening of volatile compounds in 38 authentic saffron samples and 25 samples of plant materials, potential saffron adulterants (safflower, calendula, capsicum and turmeric) was performed using headspace solid-phase microextraction for sample extraction followed by gas chromatography coupled to high-resolution mass spectrometry (HS-SPME-GC-HRMS) for non-target volatiles screening. The chemometric analysis of generated data by principal component analysis (PCA) and partial least squares discriminative analysis (PLS-DA) showed good separation of authentic saffron from potential plant adulterants. Significant compounds (‘markers’) for each group of these plants, as well as for saffron were tentatively identified. The target screening of selected ‘markers’ in model admixtures enabled simple and reliable detection levels as low as 2% w/w of safflower, calendula, capsicum or turmeric present in saffron.