The FUSION PTR-TOF 10k was recently used as part of a real-time nosespace study to investigate the cause of bad aftertaste in ten soups, each seasoned with a distinct commercial truffle product, alongside genuine black and white truffles.
Image Credit: Pop Samatcha/Shutterstock.com
The truffle soup example showcases groundbreaking possibilities in flavor science and analysis, made possible by the FUSION PTR-TOF 10k. Setting the standard for PTR-MS instruments, it offers an impressive mass resolution of approximately 15,000 m/Δm and unparalleled sensitivities of up to 80,000 cps/ppbv.
It is common knowledge that the majority of truffle-flavored products, including oils and pastes, get their signature aroma from a somewhat complex combination of food chemicals as opposed to real truffles.
The literature states that the compounds dimethyl sulfoxide (C2H6OS) and dimethyl sulfone (C2H6O2S) are not present in natural truffles meaning that their presence in truffle oil may be indicative of artificial flavors.
Upon analysis (Fig. 1), neither compound was detected in pure white truffles (sample K) nor pure black truffles (sample I). However, both were present in varying concentrations in seven out of eight truffle products, with one exception: a white truffle oil (sample B).
Nevertheless, sample B exhibited an unnaturally high concentration of 2,4-dithiapentane and lacked 2-acetyl-5-methylfuran—a compound naturally found in white truffles—strongly suggesting it, too, is artificially flavored (Fig. 1).
When eating foods containing artificial truffle aroma, many report a pleasant flavor sensation that soon degenerates into a disagreeable experience.
To understand more about how such bad aftertastes arise, Ionicon Analytik carried out an online Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) analysis with the FUSION PTR-TOF 10k. A test subject’s nosespace was analyzed in real-time during the consumption of a series of homemade truffle soups.
Figure 1. Dimethyl sulfoxide and dimethyl sulfone can be found in many truffle products. Image Credit: IONICON Analytik
Persistence of Flavors
Ten truffle soups were prepared and repeatedly tasted during nosespace sampling. Following an initial sip, nuanced flavor mixtures were identified by the FUSION PTR-TOF; however, the majority of compounds disappeared in seconds.
Interestingly, certain compounds seemed to be more persistent than others, such as C9H18O (tentatively identified as nonanal).
For example, in black truffle flavor samples E (in olive oil) and F (in rapeseed oil) C9H18O persisted through over 20 exhalations (sip of truffled soup at 6). In contrast, no traceable amounts of C9H18O were observed in sample C (black truffle flavor in olive oil from a different manufacturer) or pure black truffle soup I. (Fig. 2)
Figure 2. Example of nosespace persistence of one compound. Image Credit: IONICON Analytik
Compare and Contrast
Ionicon Analytik further compared two black truffle oils (samples C and E) to understand whether different manufacturers utilize the same flavor mix
Both samples shared a truffle-like taste and aroma. C tasted fresh, spicy, garlicky, and pleasant, while E had an earthy, dull, flat and increasingly unpleasant aftertaste.
The headspace mass spectra of soups prepared with samples C and E found that sample E contained elevated concentrations of a wider range of compounds. C9H18O.H+ was especially prevalent in sample E, whereas dimethyl sulfide (C2H6S.H+; “sharp green cabbage” taste) was predominant in sample C. (Fig. 3)
Figure 3. The comparison of two black truffle oil headspace mass spectra reveals different flavor mixes to mimic the truffle aroma. Image Credit: IONICON Analytik
Conclusions for Food Analysis Utilizing Nosespace Research
Following the study, Ionicon Analytik concluded that all of the tested truffle products contained artificial flavoring as opposed to natural truffle aroma.
Different manufacturers use different compound mixtures to imitate different kinds of truffles. Such compounds are easy to identify from mass spectra. Moreover, many of these compounds are extremely persistent in the nosespace and are detectable at higher concentrations for minutes following ingestion of a single sip of truffled soup.
The FUSION PTR-TOF 10k that was used as part of this study proved effective in delivering high mass resolution which is critical for nosespace research. The tool is well-suited for both separation of complex mixtures and real-time analysis and can thus provide valuable insights into food and flavor analysis alike.
This information has been sourced, reviewed and adapted from materials provided by IONICON Analytik.
For more information on this source, please visit IONICON Analytik.
