Enhancing decay resistance and maintaining quality of stored apples (Malus domestica ‘Golden Delicious’) through essential oil-enriched edible coatings

Purpose: Apples are susceptible to several diseases, which makes marketing and storage challenging. Therefore, it is critical to develop strategies that minimize weight loss while maintaining quality. Research method: Golden Delicious apples were coated with an edible mixture of Aloe vera gel (ALV) with or without Zataria multiflora essential oil (ZMO). Subsequently, the effects of these coatings on disease severity and incidence of Botrytis cinerea and Penicillium expansum, as well as storage quality features, were assessed. Inoculated apples with B. cinerea or P. expansum, the causative agents of apple postharvest gray and blue molds, were covered and stored at 25°C for 10 days and 2°C for 120 days. Findings: The antifungal ALV gel coatings significantly reduced the severity of gray and blue molds on inoculated apples, with the 150 μL L-1 of ZMO-based coating showing the highest effectiveness. The ALV+ZMO coatings had the best results, exhibiting a lower decay index, and increased firmness, total phenol content, and antioxidant activity in the coated apples. The highest ripening index was observed in the control samples, which ranged from the initial value of 37.0 to 54.7 by the end of the storage period. Meanwhile, ALV alone was the most effective at decreasing weight loss. Research limitations: Thyme essential oil (EO) has limitations when used directly, inculding its strong odor and flavor, low stability, low water solubility, and high volatility. Originality/Value: Overall, ALV and ZMO edible coatings appear to be a viable solution for suppressing fungal infections while maintaining apple quality under both situations.