The Rapid Detection of Sage Adulteration Using Fourier Transform Infra-Red (FTIR) Spectroscopy and Chemometrics

Abstract

Background: Sage, a common term for the various species of the genus Salvia L., is an herb that is mainly used as a seasoning, or for medicinal purposes. Valuable herbs such as sage, are under constant threat from criminalsdealing in economically motivated adulteration. Objective: In this study, the development of a rapid screening technique to detect adulteration in sage was developed using FTIR and chemometrics. Method: A range of sage sampleswere collected, along with possible known adulterants, olive leaves, myrtle leaves, sumac, hazelnut leaves, cistus and phlomis, strawberry tree leaves and sandalwood. The samples were analyzed on the Thermo Nicolet iS5 FTIR with iD7 attenuated total reflectance accessory and diamond crystal. Chemometric techniques were applied to convert this raw spectral data obtained from the instrument into qualitative models.The qualitative chemometricmodels for adulteration detection were obtained using principal component analysis and orthogonal partial least squares-discriminant analysis following preprocessing of the spectra.Results: The orthogonal partial least squares-discriminant analysis models had a measurement of fit of 0.978 and 0.952 and a measurement ofprediction of 0.975 and 0.936 for binary and multiclass models, respectively. The receiver operating curves following external validation had an area under the curve of 1, indicating excellent method performance. Conclusions: The use of FTIR and chemometrics can potentially screen unknown sage samples for adulteration and can be used in the fight against fraud in the herb and spice industry.

Rapid Evaporative Ionization Mass Spectrometry: A Review on Its Application to the Red Meat Industry with an Australian Context

“…The study confirmed the presence of antioxidant molecules such as flavonoids and iridoids, and provided insights into the native lipid composition which may contribute to the biological activity of the fruit [60]. Numerous examples of economically motivated fraud have been documented in a wide range of botanicals, particularly herbs and spices [61]. In the near-term, further application areas for REIMS are expected in verifying provenance of botanicals in addition to extensions of models in animal protein sectors with resulting improvements in the associated supply chains.…”

Challenges in Medicinal and Aromatic Plants DNA Barcoding—Lessons from the Lamiaceae

“…Like other species of the Lamiaceae, species of Salvia are under constant threat of economically motivated adulteration. For instance: (i) the roots of S. miltiorrhizaare adulterated with roots of S. przewalskii , S. yunnanensis , and S. trijug, (ii) sage leaves are adulterated witholive leaves, myrtle leaves, sumac, hazelnut leaves, Cistus and Phlomis , strawberry tree leaves and sandalwood [ 293 ], (iii) chia oil is expensive to produce and can therefore be easily adulterated with cheaper oils such as corn oil, peanut, soybean and sunflower [ 294 ]. Analytical techniques, such as gas chromatography mass spectroscopy (GC-MS) and FTIR, have been used to detect adulterants in Salvia species [ 293 , 295 ], however these techniques require expertise and can be time consuming as described earlier.…”

A sense of ginger fraud: prevalence and deconstruction of the China-European union supply chain

“…The search results from the Web of Science, Scopus and Google Scholar (as shown in Table 4) indicates that most of the literature mentioned ginger adulteration, while some articles also gave examples of adulterants [27][28][29] , however, only a few articles directly focussed on the description or the detection of ginger fraud and the type of ginger products was also not described in detail in the articles 30,31 . In most cases, ginger adulteration is only used as an example in other food fraud studies 12,27 . In addition, misrepresentation/ mislabelling of ginger and unapproved/undeclared processing of ginger were less common in the literature, only three out of 31 studies indicated these fraud issues [31][32][33] .…”

“…In addition, low-priced and high trade volume spices receive limited attention compared with expensive spices such as saffron and vanilla. In 2018, a review by Galvin-King et al 12 gave a general insight into the spice supply chain and looked at the type and effect of fraud in spices and herbs. This review created a need for further research on the topic; especially focused on specific spices.…”