Effect of Essential Oils of Medicinal Plants on Post-harvest Stability of Fruits Quality and Decay Management of Kinnow Mandarin

To study the effect of essential oils of medicinal plants on post-harvest stability of fruits quality and decay management of Kinnow mandarin, this experiment was carried out as factorial in completely randomized design with four replications. Essential oils of Thyme, Mint, Fennel, Rosemary, Ajowan and Cummin at two levels; 500 and 750 ml/l were applied to wounded and non-wounded fruits, that had been sprayed by Botrytis cinerea spores, and then stored in common and cold stores and kept for four months. Fruit decay (%), fruit weight loss (%), TTS (%), total acid (mg/100ml) and changes in Vitamin C were measured and recorded. Store had significant effect on fruit decay. Decayed fruits in cold store (20.9%) was significantly less than in common store (32.7%). The lowest decayed fruits was observed in 750 ml/l Mint essential oil and the highest decayed fruits rate was in sprayed wounded treatment. This indicated that wounds are necessary for pathogen penetration. Fruits in cold store had significantly higher total acid content than common store. The highest total acid content was measured in 500 ml/l of Fennel essential oil and the lowest in 750 ml/l of Mint essential oil treatments. TSS (%) was significantly higher in cold store than in common store. This can be associated to higher respiration rate of fruits due to higher temperatures in common store. Non-wounded control fruits had the highest TSS (%) which could be due to low respiration rate of these fruits. Non-wounded control had no significant difference with 750 ml/l Mint essential oils. The lowest TSS (%) was measured in 500 ml/l essential oils of Ajowan. Vitamin C content was highest in 750 ml/l essential oil of thyme and lowest in 500 ml/l essential oil of Cummin. Fruits treatment with essential oils of Thyme, Fennel, Rosemary and Mint at either levels of 500 and 750 ml/l and Ajowan only at 750 ml/l level had significantly higher vitamin C content. This research showed that essential oils of medicinal plants were effective in controlling post-harvest stability of fruits quality and decay management. Essential oils of Mint and Ajowan had the highest effect at the 750ml/l level and can be recommended for post-harvest fruits decay management of Kinnow mandarin.