Is there really truffle in truffle oil? Are preserved truffles any good?
Recently we were asked to help investigate a possible case of food fraud for BBC 1 Rip Off Britain. Aired on the 5th of June 2017, the programme revolves around a jar of truffles preserved with oil that had a surprisingly odd aroma. The Rip Off Britain team sought Dr Paul Thomas’ help to test for truffle spores and truffle DNA.
Recently we were asked to help investigate a possible case of food fraud for BBC 1 Rip Off Britain. Aired on the 5th of June 2017, the programme revolves around a jar of preserved truffles with a surprisingly odd aroma. The Rip Off Britain team sought Mycorrhizal Systems’ help.
Dr Paul Thomas attempted to extract DNA from the preserved truffles but the high-temperature processing had made the DNA difficult to recover and it’s this same temperature processing that damages the aroma! The truffles had lost all of their natural marble patterning, although some details such as small and common larvae had remained.
Although Dr Thomas wasn’t able to extract truffle DNA, we did manage to extract well preserved truffle spores and from this we were able to discern that the truffle was probably a Summer truffle (Tuber aestivum syn. uncinatum) and not the Chinese truffle (Tuber indium complex), which is a common contaminant in truffle products as well as in truffle trees (see article on tree contaminants, here).
Although heat treatment does damage the truffle flavour and causes some alteration to the truffle, in this case the main issue seemed to be possible contamination by yeasts and/or bacteria which had caused a sour flavour and some degree of fermentation (we’re not just cultivation experts…) -Not good to eat!
If you’ve bought truffles or a truffle product and are concerned that there is something wrong, potentially mislabelling, we can certainly help with DNA testing or other diagnostic services (contact us, here). However, if your truffles smell fresh, are firm and without surface mould or vinegar and rotting aromas, then your product is probably fine. If you have a jarred product and it fizzes upon opening, like in the case above, certainly don't consume (unless you’re lucky enough to have truffle champagne…)!
If you're in the UK you can watch the 10 minute segment on truffle products via BBC iplayer here from around 14 minutes into the programme.