A robust set of qPCR methods to evaluate adulteration in major spices and herbs

Abstract

Spices and herbs are used in multiple forms by consumers and companies related to food or pharmaceuticals. Their intricate supply chains, high prices and limited productions make them susceptible to deceptive practises. However, robust methodology to detect multiple adulterants is still rarely available, preventing national control laboratories from enforcing European and national regulations. This article presents qPCR methods developed to identify adulterants in six commonly consumed spices and herbs, namely paprika, turmeric, saffron, cumin, oregano and black pepper. Each genuine sample was blended with the top five adulterants identified in the European Union-wide coordinated control plan on herbs and spices and existing literature. These SYBR Green qPCR methods enable specific detection of adulterants, and their sensitivities allow to differentiate inadvertent contamination from deliberate adulteration. Methods performances were evaluated both in binary mixtures and with complex adulteration pattern, validating their effectiveness in safeguarding the authenticity of these high values commodities. HighlightsO_LIAuthenticity of spices and herbs is at high risk of fraudulent malpractices. C_LIO_LIWe provide specific qPCR methods to detect prevalent adulterants. C_LIO_LITrueness of each method was systematically assessed. C_LIO_LISensitivity of methods meet ISO requirements for purity assessment. C_LIO_LIMethods versatility is evaluated with multi-adulterated samples. C_LI