TY - JOUR AB - A rapid shot-gun method by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) is proposed for the characterization of fennel proteins. After enzymatic digestion with trypsin, few microliters of extract were analyzed by direct infusion in positive ion mode. A custom-made non-redundant fennel-specific proteome database was derived from the well-known NCBI database; additional proteins belonging to recognized allergenic sources (celery, carrot, parsley, birch, and mugwort) were also included in our database, since patients hypersensitive to these plants could also suffer from fennel allergy. The peptide sequence of each protein from that derived list was theoretically sequenced to produce calculated m/z lists of possible m/z ions after tryptic digestions. Then, by using a home-made Matlab algorithm, those lists were matched with the experimental FT-ICR mass spectrum of the fennel peptide mixture. Finally, Peptide Mass Fingerprint searches confirmed the presence of the matched proteins inside the fennel extract with a total of 70 proteins (61 fennel specific and 9 allergenic proteins). AU - Melfi, M.T.* AU - Kanawati, B. AU - Schmitt-Kopplin, P. AU - Macchia, L.* AU - Centonze, D.* AU - Nardiello, D.* C1 - 60825 C2 - 49606 CY - Radarweg 29, 1043 Nx Amsterdam, Netherlands TI - Investigation of fennel protein extracts by shot-gun Fourier transform ion cyclotron resonance mass spectrometry. JO - Food Res. Int. VL - 139 PB - Elsevier PY - 2021 SN - 0963-9969 ER - TY - JOUR AB - Glutathione-rich inactivated dry yeasts (GSH-IDY) are purported to accumulate glutathione intracellularly and then released into the must. Glutathione is beneficial for wine quality, but research has highlighted that GSH-IDYs have a synergic antioxidant effect similar to that of molecular GSH. Combination of negative mode ultrahigh-resolution Fourrier-Transform Ion-Cyclotron-Resonance Mass Spectrometry ((-)FT-ICR-MS), ultra-high-performance liquid chromatography coupled to a Quadrupole-Time of Flight mass spectrometer (UHPLC-Q-ToF-MS) and HPLC/Diode Detector Array (DAD)-Fluorescence spectroscopy was applied to three inactivated dry yeasts soluble fractions, with increasing intracellular glutathione concentration, in order to explore the chemical diversity released in different synthetic media.Using the mean of size exclusion chromatography/DAD and fluorescence detection we report than most of the signals detected were below the 5-75 kDa-calibrated region of the chromatogram, indicating that most of the soluble protein fraction is composed of low molecular weight soluble peptides. In light of these results, high resolution mass spectrometry was used to scan and annotate the low molecular weight compounds from 50 to 1500 Da and showed that GSH level of enrichment in IDYs was correlated to a discriminant chemical diversity of the corresponding soluble fractions. Our results clearly show an impact of the GSH accumulation process not only visible on the glutathione itself, but also on the global diversity of compounds. Within the 1674 ions detected by (-)FT-ICR-MS, the ratio of annotated elemental formulas containing carbon, hydrogen, oxygen, nitrogen and sulfur (CHONS) to annotated elemental formulas containing carbon, hydrogen, oxygen (CHO) increased from 0.2 to 2.1 with the increasing levels of IDYs GSH content and 36 unique CHONS annotated formulas were unique to the IDY with the highest concentration of GSH. Amongst the 1674 detected ions 193 were annotated as potential peptides (from 2 to 5 residues), 61 ions were annotated as unique amino acid combinations and 46% of which being significantly more intense in GSH-rich IDY. Thus, the process leading to the accumulation of glutathione also involves other metabolic pathways which contribute to an increase in CHONS containing compounds potentially released in wine, notably peptides. AU - Bahut, F.* AU - Liu, Y.* AU - Romanet, R.* AU - Coelho, C.* AU - Sieczkowski, N.* AU - Alexandre, H.* AU - Schmitt-Kopplin, P. AU - Nikolantonaki, M.* AU - Gougeon, R.D.* C1 - 56348 C2 - 47018 CY - Radarweg 29, 1043 Nx Amsterdam, Netherlands SP - 762-770 TI - Metabolic diversity conveyed by the process leading to glutathione accumulation in inactivated dry yeast: A synthetic media study. JO - Food Res. Int. VL - 123 PB - Elsevier PY - 2019 SN - 0963-9969 ER - TY - JOUR AB - The gaseous species evolving during the roasting of cocoa beans were analyzed by a newly developed technique, a micro-probe-photo-ionization-time-of-flight mass spectrometer system. A lot of volatile roasting products and typical aroma compounds, such as methylbutanal, phenylacetaldehyde and pyrazines, could be online detected. The differences between the roast gas composition inside and outside the bean were pointed out. Two additional signals at m/z 266 and 294 with resonance-enhanced multi-photon ionization (REMPI), which argues for an aromatic character, and a higher methanethiol signal with single photon ionization (SPI) could have been identified at first glance for the measurements inside the bean. Principal component analysis (PCA) and difference spectra revealed and confirmed these findings. Higher concentrations of theobromine and fatty acids are present outside and more caffeine inside the bean. With both ionization techniques, the changes in the PCA are more prominent at the beginning of the roast courses, which are mostly explained by caffeine and theobromine. Following the courses of these characteristic compounds showed the same results as obtained with the PCA and revealed that caffeine is always released before theobromine. The new analytical technique proved to be a fast, reliable and non-labor intensive method, which could therefore be a practical technique for the online analysis and monitoring of the cocoa roasting process. AU - Diab, J.* AU - Hertz-Schünemann, R.* AU - Streibel, T. AU - Zimmermann, R. C1 - 31683 C2 - 34652 SP - 344-352 TI - Online measurement of volatile organic compounds released during roasting of cocoa beans. JO - Food Res. Int. VL - 63 PY - 2014 SN - 0963-9969 ER -