Effect of peppermint oil on the shelf-life of dragon fruit during storage

Dragon fruit (Hylocereus undatus) is a short shelf-life, non-climacteric fruit which can be easily destroyed by mold growth during storage time. This study investigated the use of peppermint oil as an alternative method to inhibit surface mould and prolong the shelf-life of dragon fruit during storage. Peppermint oil adsorbed activated carbon at different concentrations (100-1000 μL L−1) was placed with the dragon fruit in the storage box (1 L) at 25 ± 2 °C and 75 ± 5%RH for 21 days. The effect of peppermint oil adsorbed activated carbon on antifungal activity and quality of dragon fruit were evaluated. It was found that peppermint oil adsorbed activated carbon at 700 μL L−1 could provide 100% inhibition of surface mould and decay fungi for more than 14 days of storage (control start decayed at day 7). In addition, essential oil vapour maintained a more firm fruit, greenness of the bract, titratable acid value and total phenolic content after 21 days in comparison to the control. The possible mode of action was demonstrated by gas chromatography-mass spectrometry (GC-MS) analysis to involve the release of menthol from peppermint oil activated carbon, which then interacts with other compounds to exhibit antifungal activity.