The efficacy of combined application of edible coatings and essential oil in mango preservation

Abstract

The aim of this study was to examine the effect of lemongrass oil (Cymbopogon citratus), citronella oil (Cymbopogon winterianus) and cajeput oil (Melaleuca leucadendron) against Aspergillus niger by the agar diffusion method. The selected oil was combined with the edible film (chitosan 1 % w/v or alginate 1 % w/v) and applied to preserve Cat Chu mango (infected by A. niger at 105 spores /ml) in 14 days at 30 °C. The result showed that the essential oils inhibited against Aspergillus niger significantly among which lemongrass oil was the most effective inhibitor with a minimum inhibitory concentration (MIC) of 10 µ1/ mL while those of citronella oil and cajeput oil were of 20 LI/ ml. The result of the mango preservation showed that all of the control samples were completely rotten after 10 days of storage, whereas the shelf life of the coated samples was longer than 10 days. The essential oils at high concentrations (10-20 µI/ml) have a negative impact on mango preservation, as they made the fruits bruised on the surface and rapidly decay. The results also indicated that alginate (1% w/v) combines with lemongrass oil (5 µI/ml) maintained the antifungal effect after 14 days of preservation.