Absolutes isolated from Viola odorata leaves, valuable materials for the flavor and fragrance industry, were studied. Violets are mainly cultivated in France and Egypt and extracted locally. The absolutes of the two origins showed different olfactory profiles both in top and heart notes, as evidenced by sensory analysis. The aims of this study were i) to characterize the volatile compounds, ii) to determine the odorant-active ones, and iii) to identify some markers of the plant origin. Two complementary analytical methods were used for these purposes, i.e., headspace solid-phase microextraction (HS-SPME) using different fiber coatings followed by GC/MS analysis and gas chromatography - olfactometry/mass spectrometry (GC-O/MS) applied to violet leaf extracts. From a total of 70 identified compounds, 61 have never been reported so far for this species, 17 compounds were characterized by both techniques (with seven among them known from the literature), 23 compounds were solely identified by HS-SPME GC/MS (among them only two being already mentioned as components of violet absolutes in the literature), and, finally, 30 compounds were only identified by GC-O/MS. According to the HS-SPME GC/MS analyses, ethyl hexanoate and (2E,6Z)-nona-2,6-dienol were specific volatile compounds of the sample with French origin, while (E,E)-hepta-2,4-dienal, hexanoic acid, limonene, tridecane, and eugenol were specific of the samples with Egyptian origin. Additional compounds that were not detected by HS-SPME GC/MS analysis were revealed by GC-O analyses, some of them being markers of origin. Pent-1-en-3-ol, 3-methylbut-2-enal, 2-methoxy-3-(1-methylethyl)pyrazine, 4-ethylbenzaldehyde, β-phenethyl formate, and 2-methoxy-3-(2-methylpropyl)pyrazine revealed to be odorant markers of the French sample, whereas cis-rose oxide, trans-rose oxide, and 3,5,5-trimethylcyclohex-2-enone were odorant markers of the Egyptian samples.

International audienceNatural extracts used in flavour and fragrances are exposed to authentication issues. Companies working in this industrial market acquire the raw materials locally but also abroad, sourcing exotic plants with specific olfactive features or lower costs of production. The geographical origin, the botanical variety, environmental conditions, extraction processes and storage conditions represent some parameters affecting the natural extract quality. All these factors are likely to affect the sensorial properties and especially the organoleptic characteristics of the extract. In addition, fraudulent practices known as adulterations have also an impact on the quality. Sensitive and precise analytical techniques are required to identify adulterations among other sources of variability. In this context, the highly valuable rose absolute was selected as a model study for its importance in perfumery. The existence of two botanical species and several production countries are additional reasons that make this extract an interesting case study. Because the usual GC-MS metabolomic approach is not able to cover the broad range of nonvolatile compounds, complementary approaches are required. An UHPLC-ToFMS fingerprinting approach was therefore developed to allow the identification of nonvolatile markers of the two closely related species of the genus Rosa. Thus, 12-oxophytodienoic acid was identified as a biomarker (level 2 according to MSI guideline) enabling the distinction between R. centifolia and R. damascena. Our results finally underline the efficiency of the UHPLC-ToFMS metabolomic approach for the qualification of odorant extracts

OBJECTIVE: Zein is known to have filmogen properties. We wanted to show if a zein film containing eugenol (eugenol as model) would retain the fragrances, slow their evaporation and therefore produce a long-lasting perception of perfume. METHODS: We added corn zein to eugenol in a hydro-alcoholic solution to form a film in vitro and at the surface of the human skin. We have studied the trapping and release of eugenol from zein film by GC/MS. Also we labelled eugenol with deuterium to image specifically its distribution in the zein film using Secondary Ion Mass Spectrometry technique (NanoSIMS 50). Finally, we applied the zein/D-eugenol formulation onto skin to image the eugenol location on and in skin by SIMS (Secondary Ion Mass Spectrometry). RESULTS: We showed that eugenol evaporation from zein film can be divided in three periods. The first period (≤2 h) corresponds to the simultaneous solvent and eugenol evaporation occurring during film formation. The second period corresponds to the continuous and slow eugenol evaporation during a few hours (about 10 h) but not to its completion. The third period (at least up to 48 h) results from the trapping of eugenol in zein film. After 24 or 48 h, trapped eugenol can be released and evaporated under mechanical deformations of the film. Moreover we showed that zein addition does not favour the eugenol penetration into viable epidermis which may cause allergenic cutaneous reaction. CONCLUSION: The zein additive is safe to use, does not impact the olfactory perception, allows a better perception of the fragrance (long-lasting effect) in a more protective way and can be used in perfume. eug enol qui peutêtre lib er e et evapor e sous l'effet de d eformations m ecaniques du film. De plus, nous montrons que l'ajout de z eine ne favorise pas la p en etration de l'eug enol dans l' epiderme viable, ce qui aurait pu augmenter le risque de r eaction cutan ee ind esirable. CONCLUSION: L'utilisation de z eine comme additif n'alt ere pas la perception du parfum, permet une perception prolong ee du parfum (effet long lasting) sans risque pour la sant e. La z eine peut donĉ etre utilis ee dans une formulation cosm etique.

Natural extracts used in fine fragrances (alcoholic perfumes) are rare and precious. As such, they represent an interesting target for fraudulent practices called adulterations. Absolutes, important materials used in the creation of perfumes, are obtained by organic solvent extraction of raw plant materials. Because the nonvolatile part of these natural extracts is not normalized and scarcely reported, highlighting potential adulterations present in this fraction appears highly challenging. For the first time, we investigated the use of nontargeted UHPLC-ToFMS metabolomics for this purpose, considering Viola odorata l., a plant largely used in the perfume industry, as a model. Significant differences in the metabolic fingerprints of the violet leaf absolutes were evidenced according to geographical locations, and/or adulterations. Additionally, markers of the geographical origin were detected through their molecular weight/most probable molecular formula and retention time, while adulterations were statistically validated. In this study, we thus clearly demonstrated the efficiency of UHPLC-ToFMS-based metabolomics in accelerating both the identification of the origin of raw materials as well as the search for potential adulterations in absolutes, natural products of high added value.