Characterization of the volatile profile of feijoa (Acca sellowiana) fruit at different ripening stages by HS-SPME-GC/MS

Abstract

This study investigated the changes of volatile organic compounds (VOCs) in feijoa fruits during ripening. The VOCs were determined by head space solid phase microextraction and gas chromatography coupled to mass spectrometry (HS-SPME-GC/MS). Results showed that 78 VOCs were identified, mainly containing esters, terpenoids, aldehydes and alcohols. Only the minority of VOCs had relatively higher contents in unripe feijoa fruits, while most VOCs were highly accumulated in mid-ripe and ripe feijoa fruits. In the early stage, aldehydes and alcohols were the main flavor compounds which provided fruity and green aroma. The contribution of esters and terpenoids increased during the ripening process, leading to strong fruity and flower fragrance. Hexanal was the main volatile component of unripe feijoa fruits, while methyl benzoate, ethyl benzoate and 3-carene were the main volatile components of mid-ripe and ripe feijoa fruits. According to partial least square-discriminant analysis (PLS-DA), 17 VOCs with variable importance in the projection (VIP) > 1 could be used as significant markers to distinguish feijoa fruits during ripening. This study provided a theoretical support for the further study of the formation mechanism of VOCs in feijoa fruits during the ripening process.