Changes in strawberry volatile constituents after pre‐harvest treatment with natural hormonal compounds

Abstract

ABSTRACTThe effect of the pre‐harvest treatment with ethanol (EtOH), methyl jasmonate (MJ) and both of them in combination on volatile compounds in strawberry was investigated by applying different concentrations of the hormonal compounds to strawberry plants. In general terms, all treated strawberries exhibited higher total volatile content than untreated control strawberries. Surprisingly, the level of total volatiles dropped significantly by exposing the berries to the highest MJ concentration. This is probably owing to a delay in the strawberry ripening process. The effect of the pre‐harvest treatments on specific volatile compounds varied with the chemical structure of the studied compounds. Some of the most important contributors to strawberry aroma (i.e. ethyl butanoate, butyl acetate, hexyl acetate and 2,5‐dimethyl‐4‐hydroxy‐2H‐furan‐3‐one) were not significantly affected by MJ/EtOH treatments whereas others (i.e. ethyl hexanoate and methyl hexanoate) were significantly modified. Similarly, some minor compounds, such as styrene, 2‐hexenal, 2‐heptanone, exhibited insignificant changes with the pre‐harvest exposition of strawberry to natural hormonal compounds whilst the levels of linalool, nonanol and nerolidol were significantly distinct between controls and treated samples. No significant variations of the enantiomeric composition of chiral volatile compounds with the treatments were observed, however. The results suggest that the pre‐harvest treatment of strawberry plants with natural hormonal compounds is able to slow ripening process by affecting the biochemical pathways implicated in the formation of their components. Copyright © 2012 John Wiley & Sons, Ltd.