Rapid metabolites fingerprinting by ion mobility spectrometry: A novel evaluation method for bio-adulteration of saffron (Crocus sativus L.)

This research presents an application of ion mobility spectrometry (IMS) for investigating adulteration of saffron (SA) with five specific bio-adulterants of plant source i.e., safflower (SAF), calendula (CAL), curcumin (CUR), sumac (SUM), and SA-stamens (SST). For this purpose, 10 SA spices were adulterated with different proportions (ranging from 0% to 50%) of these bio-adulterants. Each sample type had unique metabolites, and the fingerprints of SA metabolites significantly changed with increasing the bio-adulteration ratio, particularly at drift zones ranging from 6.51 to 14.34 ms. Principal component analysis and hieratical clustering provided excellent grouping patterns for discriminating pure SA and its bio-adulterants. In addition, promising results were obtained for predicting the adulteration ratio of SAF, CAL, CUR, SUM, and SST by partial least square regression (PLSR). The values of root-mean-square error (RMSE) and correlation of multiple determination (R-2) were in the ranges of 4.82-10.23%, and 0.644-0.920 for the test set samples, respectively.