Evaluating the Efficacy of Essential Oils and Chitosan in Reducing Post-Harvest Decay of Elmamora Winter Guava

Guava is a perishable fruit that peaks and spoils quickly after harvest. This study investigates the effects of post-harvest treatments using essential oils, chitosan, and nano-chitosan on guava fruits’ storage potential and quality. The experiment was conducted during the 2023 season using fruits from 14-year-old guava trees on a private farm in El-Qalubia Governorate, Egypt. The treatments included immersing the fruits for 5 minutes in solutions of distilled water (control), moringa oil, lemongrass oil, rosemary oil, marjoram oil, and chitosan at concentrations of 1%, 2%, and nano-chitosan at 100 & 200 ppm, respectively. The treated fruits were stored at 8±1°C and 90% relative humidity for 24 days. Results indicated that essential oils significantly reduced fruit rot and weight loss while improving fruit firmness, TSS%, acidity, TSS/acid ratio, and ascorbic acid content compared to the control. Moringa oil (1% & 2%) and nano-chitosan (100 ppm) were particularly effective in maintaining the firmness, acidity, vitamin C content, TSS%, and TSS/acid ratio of guava fruits during storage. The study concludes that moringa oil and nano-chitosan are highly effective in reducing weight loss, decay, and fruit quality while preserving the overall quality of winter guava fruits under cold storage conditions for 24 days.