Conference Agenda

Stable isotope ratio analysis has become a pivotal analytical technique, providing unique insights into the composition, origin, and processing of products across various disciplines. At the intersection of food and pharmaceuticals, its applications offer innovative solutions for authenticity verification, quality control, and process monitoring.

In the food industry, stable isotope analysis is indispensable for assessing product authenticity, detecting adulteration, and ensuring traceability. Similarly, these techniques are gaining traction in the pharmaceutical sector, particularly for verifying the origin and purity of bioactive compounds in supplements that blur the lines between food and medicine. By analyzing isotopic signatures of elements such as carbon, hydrogen, and oxygen, stable isotope ratio analysis can characterize raw materials, detect exogenous additives or active ingredients, and assess production process consistency.

This approach not only guarantees the integrity of products but also addresses growing concerns over consumer safety and regulatory compliance. Additionally, stable isotope data supports sustainability initiatives by tracing the geographic and biological origins of materials, ensuring ethical sourcing practices.

By bridging the realms of food science and pharmaceutical research, stable isotope ratio analysis provides a transformative tool at the food-pharma interface. It underpins innovation in product development, enhances consumer trust, and reinforces global efforts toward safer and more transparent supply chains. Stable isotope analysis contributes to the evolution of these interconnected fields, opening new possibilities for addressing challenges and ensuring product excellence.

The determination of serum concentrations of testosterone (T) and 4-androstendione (A4) was implemented into the Steroidal Module of the Athlete Biological Passport in 2023 to complement current approaches relying solely on steroids excreted into urine. Monitoring T and A4 individually in a longitudinal manner enables to detect the misuse of low-dose T administrations especially in female athletes while urinary markers of the steroid profile may not be influenced significantly. In contrast to the urinary steroid profile, knowledge on confounding factors to serum concentrations of T and A4 is scarce. This may complicate the interpretation of measured values in the context of sports drug testing. Furthermore, no isotope ratio mass spectrometry-based confirmation method for serum steroids has been established so far which would enable to further investigate serum samples showing abnormal concentrations or concentration ratios in parallel to the approach already applied to urine samples for more than two decades.

In parallel to well established methods employed for urinary steroids, high performance liquid chromatography clean-up was tested and validated for serum steroids. Cholesterol and pregnenolone-sulfate were employed as endogenous reference compounds. As target analytes dehydroepiandrosterone-sulfate, 5-androstene-3β,17β-diol-sulfate, androsterone-sulfate, and epiandrosterone-sulfate were included into the test menu. The method was fully validated in line with current regulations issued by the World Anti-Doping Agency including linear mixing models, measurement uncertainty, and detection limits. Finally, a reference population encompassing 124 male and female athlete samples was investigated to enable the calculation of population-based thresholds as a basis to differentiate between endogenous and exogenous sources of serum derived steroids.

Keywords: endogenous steroids, doping controls, testosterone doping, GC/C/IRMS, reference population

Vanillin, the primary component of vanilla flavour, is predominantly artificially manufactured due to the high cost and time-intensive nature of cultivating natural vanilla pods. Isotope ratio mass spectrometry (IRMS) is the standard method, this approach has several limitations: it requires 1 g of sample, our research use Fourier Transform-Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS). This ultra-high mass resolution technique can achieve the precision of isotope ratio measurements needed to discern naturally occurring variability on intact molecular ions in complex natural mixtures. Our novel method for analyzing the ¹³C/¹²C and ¹⁸O/¹⁶O isotopic ratios of vanillin using FT-ICR-MS, focuses on a characteristic vanillin fragment that provides site-specific ¹⁸O/¹⁶O isotopic ratio data, we achieved superior clustering and discrimination of samples based on their botanical source and geographical origin. This innovative approach holds significant potential for vanillin authentication, requiring a mere 20 μg of pure vanillin and just 10 minutes of analysis time.

The isotopic ratio analyses carried out in the C₆H₄O vanillin fragment provided better clustering and discrimination of the samples based on botanical source (Vanilla planifolia, Vanilla tahitensis) and geographical location, including the separation between biosynthetic and synthetic samples compared to the vanillin-averaged isotopic ratio analyses. Thus far, our method can discriminate natural, authentic vanillin samples from their biosynthetic or synthetic counterparts, contrary to the analysis of δ¹³C and δ²H of vanillin methoxyl groups from vanilla pods, such as between vanillin derived from ex-eugenol or guaiacol and vanillin ex-glucose.

As proof of concept, our direct infusion FT-ICR-MS method demonstrates its ability to distinguish natural, authentic vanillin samples from biosynthetic or synthetic sources with superior separation. Ongoing work includes gathering samples from diverse geographical, botanical, and synthesis origins. Furthermore, the method's applicability in finished products such as ice cream and yoghurts is being explored, and we anticipate using fewer samples for analysis.

Wheat is a globally important trade commodity, valued for its durability, longevity, and use in producing wheat-derived foods. The authentication of wheat and its processed products is critical to ensure quality and traceability. While stable isotope analysis (SIA) has been widely employed for authenticating wheat grains, the application of δ²H and δ¹⁸O isotopes to processed wheat-derived foods, such as noodles, presents additional challenges. This study investigates the influence of processing, specifically boiling and high-temperature heating (100℃, 180℃ and 260℃), on the stable isotopic composition (δ²H, δ¹⁸O ) of wheat-derived noodles produced with varying gluten-to-starch ratios. The results reveal that the gluten-to-starch ratio significantly impacts δ²H and δ¹⁸O values, with a more pronounced effect on δ²H. Gluten exhibits greater temperature sensitivity, while starch demonstrates higher isotopic exchangeability. Heating induces temperature-dependent isotopic changes through organic substance denaturation, leading to notable δ²H depletion. Boiling, in contrast, exerts a stronger influence on hydrogen isotope fractionation due to water uptake and exchange, with δ²H values in noodles closely reflecting the isotopic composition of the cooking water. This study provides novel insights into the isotopic behaviour of food components in wheat-derived products and establishes a theoretical foundation for developing robust analytical methods in the future.