الفهرس 
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Abstract
This study was carried out during 2018 and 2019 seasons on ripe mandarin (Citrus reticulate L.Osbeck) fruits cv. Murcott. Fruits were harvested in first March of the two seasons and subjected to three separated experiments: The first; the effect of coating with different concentrations of nano-chitosan and wax. The second; the effect of coating with different concentrations of nano silver and wax and the third; the effect of coating with different concentration of nano chitosan, nano silver and wax. Fruits of all treatments were packaged in 0.005 % perforated Polyethylene (PPE) and stored for four months at 5±1˚C and 90-95 % relative humidity (RH). Thereafter fruits were stored for six days at 20˚C and 60-70 % RH (simulated to super market conditions, SMP) to detect the effect of treatments on fruit quality during shelf life. Samples of each treatment were randomly taken at monthly intervals to evaluate the effect of cold storage and shelf life periods as well as the tested treatments. The data of the nano chitosan experiment proved that the combination of wax plus 100 ppm nano chitosan packaged in 0.005% perforated polyethylene (PPE) was the most effective treatment for reducing discarded fruits, fresh weight loss, and catalase enzyme activity, as well as maintaining pulp firmness and vitamin C content and keeping a better taste panel index. Packaging in 50 ppm nano chitosan maintained the activity of catalase and radical scavenging acidity higher than other treatments. Therefore, these coatings could be promising alternative materials for extending mandarin fruits, postharvest life and marketing period. The data of the nano silver experiment proved that the combination of wax plus 100 ppm nano silver packaged in 0.005% (PPE) was the most effective treatment for reducing discarded fruits and fresh weight loss as well as maintaining high pulp firmness and vitamin C content, total antioxidants and keeping a better taste panel index. While, coating with wax only maintained high catalase activity. Consequently, using nano silver coating could prolong postharvest life and increase the marketing period of “Murcott” mandarin fruits. The data of the combination between nano silver and nano chitosan experiment proved that the combination of wax plus 100 ppm nano chitosn and 100 ppm nano silver then packaged in 0.005% (PPE) was the most effective treatment for reducing discarded fruits and fresh weight loss as well as maintaining pulp firmness and vitamin C content, high catalase activity and keeping a better taste panel index. While, the combination of 50 ppm nanochitosan + 50 ppm nano silver maintained higher radical scavenging activity. Generally, all coating treatments maintained fruit pulp firmness, vit.C, total acidity, and panel test index higher than control fruits during both cold storage and shelf life periods. On the contrary, coating treatments decreased fresh weight loss, discarded fruits, total soluble solids, pH value and peel firmness. The advance in storage period during four months caused progressive increments in fruit fermness, fresh weight loss, TSS, and PH value. On the contrary, advance in cold storage period depressed fruit pulp, total acidity and vitamin C in all tested treatments. The aim of this investigation was to enhance the storability and marketability of ˝Murcott ̏ mandarin fruits to export to different new markets by coating with nano chitosan and nano silver as eco-friendly materials.