Avocado fruit growth
and development, unlike that of other fruits,
is characterized by the accumulation of oil and C7 sugars (in most
fruits, the carbohydrates that prevail are C6). There are five essential
carbohydrates which constitute 98% of the total content of soluble
sugars in this fruit; these are fructose, glucose, sucrose, d-mannoheptulose, and perseitol, which together with quinic acid and
chlorogenic acid have been the analytes under study in this work.
After applying an efficient extraction procedure, a novel methodology
based on hydrophilic interaction liquid chromatography coupled to
mass spectrometry was applied to determine the levels of these seven
substances in tissuesexocarp, seed, and mesocarpfrom
avocado fruits of two different varieties scarcely studied, Bacon and Fuerte, at three different ripening
stages. Quantitative characterization of the selected tissues was
performed, and the inter-tissue distribution of metabolites was described.
For both varieties, d-mannoheptulose was the major component
in the mesocarp and exocarp, whereas perseitol was predominant in
the seed, followed by sucrose and d-mannoheptulose. Sucrose
was found to be more abundant in seed tissues, with much lower concentrations
in avocado mesocarp and exocarp. Quinic acid showed a predominance
in the exocarp, and chlorogenic acid was exclusively determined in
exocarp samples.