Postharvest physiology
Sajjad Mostafayi; Mohammad Reza Asghari
Abstract
Introduction Apple (Malus domestica) is considered as one of the important members of the Rosaceae family and is among the most consumed fruits in the world. One of the biggest challenges for agricultural researchers is to increase the quantity and quality of food to feed the growing population, without ...
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Introduction Apple (Malus domestica) is considered as one of the important members of the Rosaceae family and is among the most consumed fruits in the world. One of the biggest challenges for agricultural researchers is to increase the quantity and quality of food to feed the growing population, without negatively affecting the health of the soil and agricultural ecosystems. Due to the adverse effects of chemicals on human health and environmental safety, the production of organic products has been considered as one of the most important issues in food production systems. It is utilized in various forms, including fresh fruit or processed as industrial products. Based on the respiratory and ethylene production pattern, apples are classified as climacteric fruits. Metabolic activities and ripening continue after harvest, so apples have the potential to transform into highly perishable products after harvest. Post-harvest treatments are certainly not the most suitable method for preserving the shelf life and quality of fruits during the post-harvest period. Therefore, employing new and effective methods to enhance quality, control decay, and consequently extend the post-harvest life of apples appears to be essential. Organic farming, as an agricultural system to protect human health and the environment, can improve product quality and shelf life. Materials and MethodsThis study was conducted on an apple orchard (Malus domestica) in Zarabad area of Khoy city located in the northwest of Iran (with the same management and growth conditions) in 2018-2019. The experiment was conducted as a factorial in the form of a completely randomized block design in 4 replications. The experimental factors included spraying fruit trees with nano-chitosan in 3 concentrations (zero, 5 and 10 ml) and ferulic acid in 3 concentrations (zero, 0.5 and 1 mM). Apple trees in three times, the first stage in the hazelnut time. Fruit drop, the second stage 20 days after the first stage and the third stage 20 days after the second stage spraying, were sprayed in the afternoon using a Cross mark PB20 manual sprayer. The harvested fruits were sprayed according to the treatments were packed and labeled and transferred to the central laboratory of horticultural sciences of Urmia University. After 24 hours of storage at the laboratory temperature, the measurement of the studied traits started on the fruits, the control treatment in this experiment was distilled water with Tween 80 (0.1/v/v). Results and DiscussionCompared to the control group, fruits treated with a combination of chitosan and ferulic acid exhibited a significant increase in firmness after harvest. Notably, the most effective treatment involved a combination of 10 milliliters of nano-chitosan and 1 millimolar ferulic acid, resulting in the highest level of firmness among all treatments.As a result, the combined treatment of chitosan and ferulic acid can delay the aging process by reducing the activity of enzymes involved in cell wall degradation and maintain firmness in apples, contributing to a positive effect. According to the obtained results, fruits treated with nano-chitosan and ferulic acid showed a higher soluble solid content compared to the control fruits, and this amount increased with the higher concentrations of nano-chitosan and ferulic acid. The minimum level of TA was observed in the control treatment, and the highest level was observed in the treatment with 10 milliliters of chitosan and 1 millimolar ferulic acid. The treatment with 1 millimolar ferulic acid and 10 milliliters of chitosan showed the highest percentage of TA content compared to the control. The combination of nano-chitosan and ferulic acid treatment led to a reduction in fruit juice pH, with the lowest pH observed in the treatment with 1 millimolar ferulic acid and 10 milliliters of chitosan, and the highest pH observed in the control treatment. Vitamin C is the primary water-soluble antioxidant that directly reduces damage caused by free radicals. According to the obtained results, the maximum content of vitamin C was observed in the treatment with 1 millimolar ferulic acid and 10 milliliters of chitosan. According to the obtained results, the maximum PAL enzyme activity was observed in the treatment with 1 millimolar ferulic acid and 10 milliliters of chitosan. Conclusion In general, the findings of the current study showed that pre-harvest treatment with nano-chitosan and ferulic acid had a positive effect on the post-harvest quality of apple fruits. The fruits treated with the highest concentration of nano-chitosan and ferulic acid exhibited the highest fruit firmness, titratable acidity, vitamin C content, PAL enzyme activity, and the lowest pH compared to the control fruits. These results indicate that nano-chitosan and ferulic acid treatment can be proposed as a promising and healthy method for improving the post-harvest quality of apple fruits.
