Polymerase chain reaction (PCR) for the detection of king bolete (Boletus edulis) and slippery jack (Suillus luteus) in food samples

. Expensive food is always a possible target for fraudulent labelling. King bolete (Boletus edulis) belongs to the most popular and expensive mushrooms in Europe. Polymerase chain reaction (PCR) analysis on the internal transcribed spacer (ITS) is a suitable method of identifying mushroom species. The ITS region of several Boletus edulis and several closely related mushroom species (e.g. Suillus luteus) was sequenced. Using these results specific PCR methods could be established. Furthermore it was shown that a mushroom sold as king bolete originated in China, and is actually another mushroom species. A market survey showed that in highly processed food products with labelling identifying king bolete in fact always contained these Chinese bolete species.