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

• DOI: 10.1007/s00217-001-0458-x
• Publication Date: 2003-03-05T19:14:55Z
• Authors: Moor D.; Brodmann P.; Nicholas G.; Eugster A.
• Keywords: 0106 biological sciences; 01 natural sciences; 3. Good health

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 identify- ing mushroom species. The ITS region of several Boletus edulis and several closely related mushroom species (e.g. Suillus luteus) was sequenced. Using these results specif- ic 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 mar- ket survey showed that in highly processed food products with labelling identifying king bolete in fact always con- tained these Chinese bolete species. Many tons of mushrooms per year were imported into Switzerland mainly from China, the Balkan States, Germany and Italy. Among imported forest mushrooms the amount of slippery jack (Suillus luteus) and Suillus collinitus has been considerable. From the genus Suillus in 1999 more than 12 tons of dried and often granulated mushrooms were imported. When the method was first developed for the detec- tion of mushrooms of the genus Suillus, Suillus was nev- er mentioned in food labelling. This, together with the fact that 12 tons per year were being imported, made us developing a method for the detection of fraudulent addi- tion of the cheaper slippery jack to the more expensive king bolete. The genera Boletus and Suillus both belong within the class Basidiomycetes of the order Boletales.