Development of real-time PCR methods for cocoa authentication in processed cocoa-derived products

The applicability of real-time PCR to highly processed cocoa-derived products for authentication purposes depends on the possibility of extracting high quality DNA and developing efficient PCR tests. This study compares three methods for DNA extraction from cocoa-derived products and chocolate. The best method providing suitable DNA for PCR amplification was the classical CTAB method. Seven real-time PCR tests for cocoa detection were designed based on low (nuclear) and high-copy (ribosomal and chloroplast) DNA targets. Two methods, one based on a nuclear target (vicilin-li PCR test) and a second one based on chloroplast DNA (lipids PCR test), successfully passed the performance criteria considering the specificity, sensitivity, efficiency of amplification, robustness and applicability in processed cocoa-derived products and chocolate. Therefore, this methodology is useful for cocoa authentication purposes and constitutes a first step in the direction of a future distinction between fine and bulk genotypes with an easy, fast and cost-effective methodology.

Automated summary

The study compared three methods for DNA extraction from cocoa-derived products and chocolate, with the classical CTAB method proving to provide suitable DNA for PCR amplification. Seven real-time PCR tests for cocoa detection were designed, with two methods successfully meeting the performance criteria for specificity, sensitivity, and applicability in processed cocoa-derived products and chocolate. This methodology is useful for cocoa authentication and may lead to a future distinction between fine and bulk genotypes using a cost-effective and efficient approach.