Propyl gallate, belonging to the polyphenolic compound family, is one of the most widely used phenolic antioxidants in food that contains dehydrated foodstuffs, edible fats and oils (Lin et al., 2013). The application of propyl gallate has been shown to reduce the accumulation of peroxides and lessen enzymatic browning in the pericarp of cold-stored banana fruit (Jiang, Chen, Lin, & Chen,1991). In addition, propyl gallate has the potential to control membrane lipid peroxidation and retard the pericarp browning of harvested litchi fruit (Lin, Xi, & Chen, 2002). However, there is very little information
on the effectiveness of propyl gallate as an exogenous active oxygen scavenger and its relationship to active oxygen metabolism and browning in pericarp of harvested longan fruit. To better understand this relationship, the effects of an exogenous supply of propyl gallate on browning, the activities of active oxygen-scavenging enzymes, the contents of endogenous antioxidant substances, the rate of O$ 2 production, and the content of malondialdehyde (MDA) (a product of membrane lipid peroxidation) were investigated. The objective of the present study was to develop a viable postharvest treatment to retard or inhibit pericarp browning and extend the storage life of harvested longan fruit.