Chitosan postharvest treatment suppresses the pulp breakdown development of longan fruit through regulating ROS metabolism.

The influences of Kadozan, a novel chitosan formulation, on the pulp breakdown and ROS metabolism in postharvest 'Fuyan' longans were studied. Compared with control longans, the longans treated with 1:500 Kadozan dilution (VKadozan: VKadozan + Water) exhibited the suppressed development of pulp breakdown, higher AsA and GSH amounts, higher activities of ROS-scavenging enzymes like SOD, CAT, APX and POD, higher reducing power, and higher scavenging ability for DPPH radical, but a lower MDA amount, lower levels of ROS including O2- and H2O2. These findings indicated that the application of 1:500 Kadozan dilution (VKadozan: VKadozan + Water) for harvested longans could enhance the ROS-scavenging capacity to decrease the generation and accumulation of ROS, and a lower level of ROS could slow down the peroxidation progress of membrane lipids, alleviate the damage of longan pulp cellular membrane structure, and ultimately suppress pulp breakdown occurrence of harvested longans.