‘Annurca’ apple fruit, a southern Italy apple cultivar: textural properties and aroma composition

‘Annurca’ apple fruit, which is commonly cultivated in southern Italy and undergoes a typical reddening treatment and, is notable for its high firmness and its characteristic flavour, was examined for its pectic and aroma composition. Pectin, extracted with a water solution of potassium oxalate and dimethylsulphoxide, was found to be quantitavely and qualitatively important for its contribution to the high tissue firmness. Pectin changes its composition during the reddening process and there is even a difference in the pectic composition of the two ‘Annurca’ clones examined in this paper, ‘Standard’ and ‘Rossa del Sud’. Volatile compounds were collected by headspace sampling of intact unreddened and reddened fruits. Thirty-one compounds of several chemical classes were identified, to establish their role in the characteristic flavor of this apple cv. Among these compounds, n-pentanol was unusually present in large amounts; also δ-octalactone, never found in apples, was present.