Authentication of prized white and black truffles in processed products using quantitative real-time PCR

Abstract

Truffles, such as Tuber magnatum and Tuber melanosporum, are greatly appreciated throughout the world, both as fresh fruiting bodies and as ingredients in processed products. Diagnostic methods are therefore required to check the identity of truffles in this kind of food. The present paper reports the application of microscopic and molecular techniques to authenticate truffle species in commercial products. Through the application of microscopic techniques, it has been possible to distinguish spores in a cream that could be ascribed to the truffle species (T. magnatum, the highest priced truffle) declared on the label and also spores of a less prized and aromatic truffle that was not indicated on the label. Good quality DNA was quickly obtained in a few hours using a kit generally employed for DNA extraction from soil. A new primer pair was developed to authenticate T. magnatum in commercial products and it was employed in a quantitative PCR assay (qPCR). T. melanosporum, which was neither indicated on the label nor recognized in the processed products containing truffles, was also detected in a cream and its amount was quantified by qPCR. This method can therefore be used to detect fraudulent practices and to protect the consumer of truffle delicacies.