Eur Food Res Technol

This study provides cultivar-specific metabolic fingerprints of volatile organic compounds in the headspace of cloudy apple juices. Cloudy juices from 47 « true to type » apple cultivars grown under identical agricultural and climatic conditions in South Tyrol, Italy, have been analysed through headspace solid-phase microextraction gas chromatography coupled with high-resolution time-of-flight mass spectrometry (HS-SPME/GC--HRTO-–MS), yielding cultivar-specific volatile organic compound (VOC) profiles. Apple cultivars included 10 old cultivars with local relevance, 18 commercial cultivars, dominating the current international market, 10 scab-resistant and 9 red-fleshed ones. The 28 most abundant VOCs were found in the whole dataset, indicating a remarkable chemodiversity within juices. The main discriminant metabolites were butyl acetate; pentyl acetate; 2-methylbutyl acetate; pentan-1-ol; hexan-1-ol; n-hexanal and (E)-2-hexenal. A principal component analysis (PCA) and a hierarchical cluster analysis (HCA) have not identified a clear separation of the analysed cultivar classes. Nevertheless, a series of scab-resistant and red-fleshed cultivars with VOC profiles similar to established commercial cultivars were identified; these data could help substituting current cultivars with more sustainable ones. On a more general basis, our study supports a knowledge-driven selection of apple cultivars for specific consumer preferences and helps appreciating the biodiversity of apples across old local and more recent (scab-resistant and red-fleshed) cultivars

Régimes hydrologiques : des concepts et modèles adaptés au développement des connaissances

The development of the knowledges in hydrology, and of the accuracy in its analysises, together with the remaining huge complexity of the hydrological processes, leads to a necessity for scientifically based synthesises of such knowledges, including modelization and not only display. Such models, beyond their internal utility, can allow interfacing with neibourghing sciences, and render more easy to use this knowledges for water managers. But for success, some basic adapted concepts of such models or displays have to be defined, understandable for non-hydrologists, and this is not obvious without specific research. When such conditions are satisfied, fructuous things appear, like emerging properties, always too rare in hydrology. Attention must be given to maintain sufficient links betwwen analytical and synthetical approaches, so as to ensure the internal coherency of hydrology.Le développement des connaissances en hydrologie et de la finesse de ses analyses, associé à l'incontournable complexité des processus hydrologiques, rend nécessaire une approche scientifique rigoureuse des aspects de synthèse vis à vis de ces connaissances, et y compris à un niveau de modélisation et pas seulement d'affichage. De tels modèles, outre leur usage en interne à la discipline, permettent les interfaçages avec les disciplines connexes, et facilitent l'usage des connaissances hydrologiques pour la gestion des eaux et de leurs milieux. Mais il faut que les modes de représentations et de modélisation choisis soient articulables sur ceux de ces autres displines et usagers, ce qui n'est pas accessible a priori, sans concepts adaptés, voire créés, pour cela. Sous ces conditions, ces pistes de recherches de synthèses apparaissent fructueuses, et révèlent des propriétés émergentes fort appréciables, car rares, en hydrologie. Mais il faut veiller à bien interfacer les niveaux d'analyse et de synthèse, pour assurer la cohérence interne en hydrologie