Analytical methods for cinnamon authentication

Abstract

Cinnamon is a widely marketed spice used in worldwide cuisines and medicinal applications. Although Cinnamomum verum is considered as “true cinnamon”, other cinnamon species (particularly Cinnamomum cassia) are also commercialized. The higher price of Cinnamomum verum makes it vulnerable to adulteration mainly by the addition of products of the same class, which also results in a health issue as Cinnamomum cassia presents a higher content of the hepatoxic compound coumarin. Scope and approach This review discusses the most important aspects of cinnamon authentication from an analytical perspective, focusing on analytical techniques and chemometric methods, and emphasizing the differences between targeted and non-targeted approaches. Additionally, the most common analytical markers employed in the authentication of cinnamon are summarized. Key findings and conclusions Targeted analysis is mainly based on either liquid or gas chromatography, as they allow the quantification of a large number of compounds, particularly when coupled to mass spectrometry. The most common analytical markers in cinnamon authentication are cinnamaldehyde, coumarin, eugenol, and cinnamyl alcohol. In contrast, more straightforward techniques like nuclear magnetic resonance or infrared spectroscopy, which can directly analyse solid samples, are usually preferred for non-targeted analysis. Regarding chemometrics, most studies are limited to exploratory analysis and the ones employing classification chemometric methods are mostly devoted to the differentiation among cinnamon species. The quantification of partial adulterations is still an on-going research field, although this is a likely case of adulteration in the current market.