Sensory and instrumental profiling of 18 apple cultivars to investigate the relation between perceived quality and odour and flavour

A large number of apple cultivars (18) have been evaluated both by sensory and instrumental methods with the aim to characterise their perceived quality and its relation with odour and flavour. Quantitative descriptive analysis of odours and flavours was performed by a trained panel. Seventy-two volatile compounds were identified in the apple headspace by solid-phase microextraction gas chromatography/mass spectrometry (SPME-GC-MS). Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied to both datasets allowing the identification and characterisation of 5 main groups of similar cultivars. Partial Least Square (PLS) regression models were able to predict 9 odours (apple, banana, cucumber, honey, kiwi, melon, pear, pumpkins and quince) and allowed elucidating the role played by volatile compounds in the formation of odour sensations. In particular, we highlight that the interaction of the same volatile compounds at different concentration can produce an alternative perceived odour/flavour. For example, mixing a different ratio of acetate esters contributes to the development of "apple", "banana" or "pear" odours. (C) 2012 Elsevier Ltd. All rights reserved.