Evaluation of Fruit Positions on Tree, Chilling Injury Sensitivity, and Antioxidant Enzyme Activities of (Mangifera indica L. 'Ewas’) Mangos during Cold Storage

Mango fruits have a high commercial income to being viewed as susceptible to chilling injury for the long storage duration. Fruits are stored at low temperatures many physiological changes that will demonstrate the side impacts of cold storage on fruits. The results are losing fruits and lower profits. The study aimed to find correlation between three fruit positions on the tree, i.e. sunny side (SUN; fruit exposed to the sun most of the day), shadow side (SHA; fruit grows on the shady side of trees), and inside the canopy (INS; fruit grows inside tree canopy), and cold storage stress (4 ± 1 °C and RH% 96%) for 35-days during two growing seasons (2015-2016). Obviously: the harvested fruit from INS presented more tolerance to chilled temperature compared to other fruit locations for 35 days. Through the results obtained the harvested fruit from INS showed significantly the highest activities of ascorbate peroxidase (APX), peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) than other fruit locations.  Reflecting the lack of chilling injury symptoms on fruits, unlike other fruit positions. In addition, contents of O₂^•- and H₂O₂ decreased in INS fruit throughout storage duration. Consequently, the cell membrane compositions were maintained, especially, low quantity in both malondialdehyde (MDA) and protein carbonyl group (PCG) throughout storage duration in days. These results pointed out that the fruit positions can be considered at harvesting for classifying of fruits before cold storage.