Quality assessment of the saffron samples using second-order spectrophotometric data assisted by three-way chemometric methods via quantitative analysis of synthetic colorants in adulterated saffron

•Quality assessment of saffron using multivariate processing of second-order data.•Non separative methods for determination of synthetic colorants in saffron.•Modeling the system through the unique decomposition of the three way data array.

Saffron is a valuable culinary spice that can be used not only for dyes and cooking, but also for many medical purposes. Due to its high price and restriction of its production, various fraud manners in its production have been growing. Addition of synthetic colorants to saffron is the most common way for adulteration. In this work, chemometric methods are proposed to resolve the three-dimensional absorbance spectra–pH data for simultaneous determination of the two colorants Tartrazin and Sunset yellow, in adulterated saffron. The rank deficiency in the concentration mode impaired the system. Therefore, to extirpate the ambiguity, which results from rank deficiency, three-way variation array V was generated by subtracting the first pH spectrum from each spectrum at each pH. This allows the extraction of extent reaction profile and mixture reaction spectral profiles, as well as the relative concentrations of the analytes.

Graphical abstractQuality assessment of the saffron with spectrophotometric method using multivariate processing of pH–spectra matrices in the presence of unexpected interference.Figure optionsDownload full-size imageDownload as PowerPoint slide