Duplex real-time PCR for the determination of wasabi ( Eutrema wasabi) contents in horseradish ( Armoracia rusticana) products applying the ΔΔct-method.

Many products claim to contain wasabi. Due to its high price, original wasabi ( Eutrema wasabi) is often replaced by its cheaper close relative horseradish ( Armoracia rusticana). To analyze such products, we developed a duplex real-time PCR method determining the DNA content of wasabi and horseradish, applying the ΔΔct-method. The developed horseradish-specific system turned out to be highly specific within the plant family Brassicaceae. We validated this duplex real-time PCR system and present results from common commercial products. The system proved to be reliable for uncovering fraudulent practices in the wasabi product group. [ABSTRACT FROM AUTHOR]