S17 - Session O4 - Influence of rootstock, fruit development stage and ploidy level on the peel essential oil yield, composition and aromatic properties of sweet orange (Citrus sinensis).

Authors: Vincent Ferrer *, Noémie Paymal, Carole Quiton, Mathieu Paoli, Gilles Costantino, Yann Froelicher, Patrick Ollitrault, Félix Tomi, François Luro

The peel essential oils (PEO) of citrus fruits have aromatic properties widely exploited by the industry of the transformation as for example that of the preparation of parfums or aromatized drinks and spirits. The stability of the aromatic properties is one of the main problems encountered by the manufacturers because the raw material comes from several countries with non-standardized cultivation and harvesting processes of the fruits. The objectives of this work are to identify the factors, which can influence the chemical composition and the organoleptic properties of the PEO of sweet orange ( Citrus sinensis ). Among them we tested the effect of rootstock, the fruit development stage and the ploidy level of the scion and the rootstock. The PEO was extracted by water distillation on a Clevenger apparatus and its composition was analyzed by gas chromatography coupled with mass spectrometry. The PEO aromatic profiles has been described by sensorial analysis conducted by Remy-Cointreau panelists using (i) descriptors intensity to study the stage of development of the fruit, (ii) triangle test method to determine the influence of rootstocks and (iii) the A not A method to compare the different ploidy combinations. The yield, composition and aromatic properties of sweet orange PEO varied during the fruit development. At the early phase of fruit growth, the oxygenated compounds represented 15% of the PEO and decreased to reach 1% after 6 months of development. The rootstock has a low influence on the PEO composition and aromatic profile but a significant influence on the PEO yield. The panelists detected difference on the aromatic profile related to the ploidy level (tetraploid vs. diploid) of scion and not of the rootstock. These results will allow to improve the production of essential oil and to better control its organoleptic quality.