Aroma volatile compositions of high- and low-aromatic guava varieties

The traditional guava variety cultivated in Israel, 'Ben Dov', emits a very strong odour, whereas some newly bred varieties have a mild odour. In this study the aroma profile composition of the high-aromatic 'Ben Dov' variety was compared with those of four new low-aromatic varieties.

Overall, using gas chromatography/mass spectrometry, a total of 30 aroma volatiles were detected in fresh ripe guava fruit: 15 of them were specifically detected only in the high-aromatic 'Ben Dov' variety, 13 were detected in both the high- and low-aromatic varieties and two were detected only in the new low-aromatic varieties. Interestingly, 11 out of the 15 volatiles specifically detected in 'Ben Dov' were esters that contribute sweet, tropical and fruity notes. In contrast, ten out of 13 detected terpenes and two detected aldehydes, contributing green, spicy, herbal and woody notes, were common to both the high- and low-aromatic varieties.

Based on these findings, it is concluded that accumulation of esters is the main reason why the traditional 'Ben Dov' guava variety emits such a strong tropical fruity odour. In contrast, the newly bred low-aromatic guava varieties did not synthesise esters at all and thus lacked fruity aromatic notes. Overall, the results of this study point out the important role of esters in forming tropical fruity guava odours.