Abstract:

The quality changes of plum fruit (Prunus salicina cv. Black amber) during storage at 20 ℃ and 2 ℃ were evaluated and the antioxidant capacity of different parts of plum pulp were determined. Plum fruits stored at 20 ℃ showed a significant decline in firmness, along with the scavenging activity of superoxide, DPPH radical and hydroxyl radical, whereas fruit pH value, along with total antioxidant activity, total phenol and total flavonoid concentration increased with time. In contrast, the low temperature alleviated these trends of fruit quality and antioxidant activity parameters simultaneously, Correlation analysis revealed that both total phenolic and flavonoid content were highly correlated (P ＜ 0.01) with total antioxidant capacity of plum fruit. In addition, the significant difference between outer and inner part of plum fruit was observed in terms of total antioxidant activity, hydroxyl radical scavenging activity, total phenol and total flavonoid contents, as well as the correlation between their antioxidant capacity and fruit quality attributes, expressed as the antioxidant activity of outer part of plum showed stronger correlation with SSC, whereas the inner part correlated more highly with pH value. The results indicated that postharvest quality deterioration of plum fruit may be attributed to the decrease of superoxide, DPPH radical, and hydroxyl radical scavenging activity.

Key words: ‘Black Amber&rsquo, plum, quality, antioxidant capacity, different parts