Development of a comprehensive analytical platform for the detection and quantitation of food fraud using a biomarker approach. The oregano adulteration case study

- An efficient platform for herb adulteration detection has been developed.
- An LC-MS/MS method, based on biomarker discovery, has been successfully validated.
- Good correlation between LC-MS/MS and FTIR methods has been demonstrated.
- A survey of suspected samples revealed high incident and levels of adulteration.

Due to increasing number of food fraud incidents, there is an inherent need for the development and implementation of analytical platforms enabling detection and quantitation of adulteration. In this study a set of unique biomarkers of commonly found oregano adulterants became the targets in the development of a LC-MS/MS method which underwent a rigorous in-house validation. The method presented very high selectivity and specificity, excellent linearity (R2 > 0.988) low decision limits and detection capabilities (<2%), acceptable accuracy (intra-assay 92-113%, inter-assay 69-138%) and precision (CV < 20%). The method was compared with an established FTIR screening assay and revealed a good correlation of quali- and quantitative results (R2 > 0.81). An assessment of 54 suspected adulterated oregano samples revealed that almost 90% of them contained at least one bulking agent, with a median level of adulteration of 50%. Such innovative methodologies need to be established as routine testing procedures to detect and ultimately deter food fraud.