Effects of postharvest silicon application on phenolics, antioxidant system and phenylalanine ammonia-lyase activity in plum (Prunus salicina Shablon) fruits

Aims and In this study, the efficacy of silicon (Si) was determined in order to increase the pool of phenols and antioxidant activity in plum (Prunus salicina Shablon) fruits and, thereby, enhance postharvest plum fruit quality. The fruits were randomly divided in two groups so that Si-treated group immersed for thirty minutes in solutions of 5 g/l Si and were air-dried at room temperature. The activities of catalase (CAT) and superoxide dismutase (SOD) were determined. Postharvest silicon application had no effect on CAT activity; in contrast, weight loss, total phenolics concentration, lipid peroxidation as well as phenylalanine ammonia-lyase (PAL) and SOD activity responded positively to the Si treatment. Silicon application raised phenylalanine ammonia-lyase activity and total phenol concentrations led to increase the fruit’s ability to better withstand stressful cold impacts. In addition, Si considerably reduced the rise in malondialdehyde (MDA) content during storage, obviously because of an efficient scavenging following significant enhancement of SOD activity. Postharvest Si application raised antioxodant activity and total phenolic, reduced malondialdehyde content and lipid peroxidation, and led to increase the fruit’s ability to better withstand stressful cold impacts. These results suggest that Si application may be recommended for increasing storage life and maintaining their quality.