Volatilomic profile of the tree tomato (Solanum betaceum Cav.) pulp during ripening and senescence using HS–SPME with GC–MS

Abstract

The volatilomic profile of the tree tomato (Solanum betaceum Cav.) pulp during ripening stages and senescence times was determined by headspace solid-phase microextraction in combination with gas chromatography-mass spectrometry. The HS-SPME-GC-MS analysis allowed the identification of 46 metabolites that produce the metabolic fingerprint of this fruit, the major compounds at all ripening stages and senescence times were ethyl butanoate, methyl butanoate, β-myrcene and eucalyptol. The composition in the different stages was subjected to principal component analysis (PCA), which explained 77.3% of the total variance in the principal components. It allowed to classify the samples by ripening stages and senescence times and it was corroborated with K-means clustering and dendrogram analyses. Through multivariate analyses PCA, partial least squares-discriminant analysis (PLS-DA), and heatmap it was possible to determine volatiles methyl (E)-2-hexenoate, 4-tert-butylcyclohexyl acetate, methyl benzoate, methyl (Z)-3-hexenoate, 3-methylbutyl acetate, β-thujene, cis-3-hexenol, hexanal and trans-2-hexenal as potential markers in the ripening stages, while volatiles propyl butanoate, ethyl octanoate, ethyl acetate, ethyl butanoate, β-myrcene and estragol predominated in the senescence times. HS-SPME-GC-MS analysis of volatiles in combination with the chemometric approach used in this research allowed to make a clear distinction between ripening stages and senescence times in common red variety of tree tomato pulp.