Food Authentication: Species and Origin Determination of Truffles (Tuber spp.) by Inductively Coupled Plasma Mass Spectrometry and Chemometrics

Abstract

The aim of this study was to develop a protocol for the authentication of truffles using inductively coupled plasma mass spectrometry. The price of the different truffle species varies significantly, and because the visual differentiation is difficult within the white truffles and within the black truffles, food fraud is likely to occur. Thus, in the context of this work, the elemental profiles of 59 truffle samples of five commercially relevant species were analyzed and the resulting element profiles were evaluated with chemometrics. Classification models targeting the species and the origins were validated using nested cross validation and were able to differentiate the most expensive Tuber magnatum from any other examined truffle. For the black truffles, an overall classification accuracy of 90.4% was achieved, and, most importantly, a falsification of the expensive Tuber melanosporum by Tuber indicum could be ruled out. With regard to the geographical origin, for Italy and Spain, one-versus-all classification models were calculated each to differentiate truffle samples from any other origins by 75.0 and 86.7%, respectively. The prediction was still possible according to an internal mathematical normalization scheme using only the element ratios instead of the absolute element concentrations. The established authentication protocol was successfully tested with an external sample set of five fresh truffles. Our results show the high potential of the element profile for the parallel species and origin authentication of truffles.

Differentiation of European and Chinese Truffle (Tuber sp.) Species by Means of Sterol Fingerprints

“…Moreover, the sterol fingerprints could be combined with further biomarkers to better discover environmental influences and postharvest food adulterations. Sulfur-containing volatile compounds − and the identification of polymerase chain reaction (PCR) primers − as well as (compound-specific) stable isotope , and elemental analysis , were also found to be suitable for truffle authentication. Big data fusion of these biomarkers may achieve forgery-proof profiles of true Tuber species from different geographical origins and qualities.…”

“…Hence, the availability of robust authentication methods for truffles is an important task in food control. For this purpose, several strategies have already been suggested, including flavor analysis, ,− element analysis combined with chemometry, and stable isotope analysis . However, several marker values may be artificially mimicked by fraudsters, which are solely not suitable for the controlling of food fraud without a broad data fusion .…”

Food authentication: truffle species classification by non-targeted lipidomics analyses using mass spectrometry assisted by ion mobility separation

“…For this reason, research efforts at various cellular levels have been massively advanced in recent years. For example, there are approaches to detect truffle species using genomics-, [7][8][9][10][11] proteomics- [12][13][14] or isotopolomics-based [15][16][17][18] methods. However, all of these approaches are quite time-consuming or require special laboratory infrastructure.…”

Portable vs. Benchtop NIR-Sensor Technology for Classification and Quality Evaluation of Black Truffle

“…Due to the strong organoleptic similarity of highly prized T. melanosporum and much cheaper T. indicum, food adulteration is difficult to observe by the naked eye for unexperienced consumers. Due to the above-mentioned cases of food adulteration, many analytical methods for identification and confirmation of black truffle have been applied, including matrix assisted time of flight mass spectrometry (MALDI-TOF-MS) [21], stable isotope ratio analysis [22], headspace solid-phase microextraction followed by gas chromatographymass spectrometry (HS-SPME/GC-MS) [23], capillary gel electrophoresis and real-time PCR [24], inductively coupled plasma mass spectrometry [25], and FT-NIR spectroscopy and chemometrics with freeze-dried samples [26]. Destructive and cost-intensive sample preparation, expensive equipment and highly trained personnel, and a huge time effort are required for the presented methods.…”