**2. Materials and Methods**

### *2.1. Plant Materials and Treatments*

The present study was carried out during the 2020 and 2021 seasons on mature green stage mango fruits (*Mangifera indica* L. cv. "Kent"). The fruits were harvested from a private orchard at Alexandria–Cairo desert road and were immediately transported to the Horticulture Lab in the Faculty of Agriculture, Alexandria University, Egypt. The coating solution preparation was done as 1 g of chitosan (40 kDa in thickness, from crab shells) which was gently dissolved in 100 mL of 2 percent acetic acid solution (*v*/*v*) on a magnetic stirrer (350 rpm INTLLAB, New York, NY, USA) to get 1 percent chitosan solution (*w*/*v*), and Tween 20 (0.2 g) was added in the chitosan solution. The fruits were selected for uniformity of size, ripeness, and being free of defects, and were divided into four groups (50 fruit for each). The first group of fruits was washed with distilled water (control). The second group was dipped in hot water (HW) at 55 ◦C for 5 min. The third group was dipped in 1% chitosan solution for 1 min. The fourth group was dipped in hot water (HW) at 55 ◦C for 5 min, and then dipped in 1% chitosan solution for 1 min. After being air dried, all the fruits were stored at 13 ◦C, 85%–90% RH for 28 days. The initial physio-chemical properties were determined in ten mango fruits and the changes were followed up in 7 day intervals during the storage period.
