Exploratory analysis of avocado extracts by GC-MS: new insights into the avocado fruit ripening process

Abstract

Herewith the usefulness of a gas chromatography-electron ionization-quadrupole mass spectrometry (GC-EI-Q MS) methodology has been evaluated for the identification of potential ripening or variety markers of the avocado fruit. A selection of 13 avocado varieties at two diverse ripening degrees was made and their derivatized extracts were analyzed by GC-MS. Even though the method was able to identify about 60 metabolites within a single run, the approach used was more exploratory, and data processing and analysis steps were carried out, implying filtering, normalization, principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA). 17 compounds were selected as the most influential to be considered in PCA and clustering analysis by the k-means method. To corroborate further on the metabolic changes associated with ripening, a two class PLS-DA model was built, identifying abscisic acid, linoleic acid, aspartic acid and mannoheptulose as the compounds with the highest influence in the model.