Volatile compounds in ripe fig receptacle are influenced by environment in the vicinity of the fruit

Emission of volatile compounds is highly influenced by environment surrounding the fruit in the tree. Little is known about aroma constituents in ripe, fresh figs (Ficus carica L.). Ou hypothesis is that the training of the tree and pruning practice can improve light penetration inside the canopy, and consequently further enhance the aroma released by the fruit. Materials and methods – Fig volatile compounds were extracted and identified using Accelerated solvent extraction-Gas chromatography-Mass spectrometry (ASE-GC-MS) in the fruit from cultivar ‘Bouhouli’ growing in Northwest Tunisia. Results and discussion – Fifty-one volatiles were identified in the fruit. Fig volatile range is composed by three major groups (esters, ketones and alcohols) with butyl, isoamyl and hexyl acetate and acetoin (3-hydroxy-2-butanone) being the four major compounds. Of these four compounds, the isoamyl acetate (with a strong fruity, banana-like smell) and acetoin (described as giving a milk-like note) had the highest aroma potential. Analysis of the volatile blend released by the fruit from two different positions in the tree has shown quantitative as well as qualitative changes between outside and inside the canopy. Sun-exposed figs developed a total of 3,539 μg kg-1 fresh weight (FW) versus 2,657 μg kg-1 FW for shaded figs. Acetoin, the major volatile compound, represented 48% of total concentrations in sun-exposed fruit, and 44% in shaded figs. Principal component analysis (PCA) showed that volatile profile of figs ripened outside the canopy was closely associated to sesquiterpenes and alcohols. Other volatiles found to make difference between fruits from the two position in the tree were: linalool, (E)-2-heptenal and 2,4-decadienal (P≤0.05). Conclusion – Changes in volatiles released by figs from both periphery and underneath the canopy were rather quantitative and concern some compounds having little impac on aroma of the ripe fruit. A proper orchard management will contribute to improve the aromatic fruit quality in figs.