The effects of lemon, lime and lemongrass essential oils on quality attributes of apples after controlled atmosphere storage

This study was conducted to evaluate the effect of citrus and lemongrass essential oils on antioxidant, phytochemical and physicochemical properties of apple (Malus domestica) cultivars ‘Granny Smith’ and ‘Pink Lady’. Fruit were evaluated after thermal fogging with lemongrass and citrus essential oils and storage at controlled atmosphere (-0.5°C; 1.5% O₂ + 1% CO₂) for 28 days followed by 7 days at 20°C. The titratible acidity of ‘Granny Smith’ apples treated with essential oils was significantly lower (ranging from 0.77 to 1.04) compared to untreated controls (ranging from 1.10 to 1.18). However, the titratible acidity of ‘Pink Lady’ apples treated with essential oils were significantly higher (ranging from 0.49 to 0.62) compared to those from the control treatments (ranging from 0.47 to 0.89). The total soluble solid content of both cultivars treated with essential oils was significantly lower compared to fruit from the control treatments. The total phenolic content of both apple cultivars was higher for all essential oil treatments. Radical scavenging activity of ‘Granny Smith’ apples treated with lime oil alone, lemon+lemongrass and lime+lemongrass oils was significantly high compared to other essential oils and control treatment but low for ‘Pink Lady’ apples. Radical ferric ion reducing antioxidant power of ‘Granny Smith’ apples was not significantly different from control treatment, while lemon+lemongrass treated ‘Pink Lady apples showed no significant difference. The results suggest that essential oils may maintain fruit quality related attributes during storage and transit.