Fatemeh Eini Tari; Abdollah Ehtesham Nia; Hasan Mumivand; Mohamad Reza Raji
Abstract
IntroductionThe global demand for a healthy lifestyle has increased significantly in recent years. This growing awareness has highlighted the need for better preservation and storage ...
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IntroductionThe global demand for a healthy lifestyle has increased significantly in recent years. This growing awareness has highlighted the need for better preservation and storage of fresh produce, particularly fruits, due to their rich vitamin and mineral content. Additionally, the increase in post-harvest waste has underscored the importance of using natural, eco-friendly compounds to extend shelf life, minimize waste, and maintain high nutritional value without introducing harmful substances. Materials and MethodsThis study was conducted as a factorial experiment using a completely randomized design with four replications. The first factor included pre- and post-harvest foliar treatments, with control treatments (spraying with distilled water), chitosan (50 mg l-1), Nano-chitosan (50 and 100 mg l-1) and the post-harvest immersion (Calcium chloride solution (0 and 2 %)). The second factor was storage duration (0, 60, 90 and 120 days). The study was carried out on Golden Delicious apples grafted onto MM 111 (Malling Merton 111) rootstock. Pre-harvest foliar spraying was carried out in an 18-year-old apple orchard in Abestan region of Khorramabad, while post-harvest immersion treatments were carried out at Lorestan University. After harvesting, the apples were initially washed with distilled water, dried, and immersed in a calcium chloride solution at room temperature for 8 minutes. To remove excess surface moisture, the treated fruits were placed in plastic fruit boxes and stored in a refrigerator at 4 °C with 80-90% relative humidity until the evaluation period. The study examined physiological and biochemical characteristics such as weight loss, acidity, titratable acids, soluble solids, ripening index, vitamin C content, and malondialdehyde levels. Results and DiscussionThe results of this study indicated that the applied treatments significantly affected the physicochemical characteristics of Golden Delicious apples. Treated fruits exhibited lower weight loss compared to the control group. Biochemical analyses further confirmed the beneficial effects of all treatments on the evaluated parameters. The highest level of titratable acids, vitamin C, along with the lowest acidity and malondialdehyde content, were observed in apples subjected to the combined treatment of nano chitosan and calcium chloride. Additionally, the treatments led to a reduction in soluble solids content and the fruit ripening index. Coatings such as chitosan function as barriers with selective permeability to oxygen and carbon dioxide, modifying the surrounding atmosphere by increasing carbon dioxide levels and reducing oxygen concentration. This altered gaseous composition helps slow the respiration rate and ethylene production, thereby delaying the aging process and extending the fruit’s shelf life. Calcium also helps strengthen and maintain the integrity of the cell wall, ultimately preventing membrane deterioration and the increase in malondialdehyde in the fruit. Also, using calcium chloride plays a key role in strengthening cell walls, preserving the structure and function of membranes, and increasing the ability of cells to retain water. ConclusionOverall, the findings suggest that pre-harvest application of 100 mg/L chitosan nanoparticle, combined with post-harvest immersion in a 2% calcium chloride solution, yielded the most favorable results across most measured parameters. This combined treatment effectively preserved fruit quality and extended storage life, making it a promising approach for reducing post-harvest losses in Golden Delicious apples.
