Effects Of Enlargement Treatments On The Phyto-chemicals And Antioxidant Activity Of Table Grape Berries

Using Red Globe, Thompson Seedless, Victoria and August as the test material, experiments were conducted to study the effects of enlargement treatment on the physiochemical indexes, enzyme activities, phenols and antioxidant activities, dietary fiber during the berry growth and maturation. And the differences between the treatment and control were analysed based on DPS. The main results are as follows:(1) After the enlargement treatment, the berry weight of Red Globe increased by 18%. Compared with the control, the fruit shape index and titrable acid content increased, while the fruit compression tolerence, the content of reducing sugar and acid-sugar ratio decreased. No significant influences of enlargement treatments were found on SOD, POD and PPO activities. The positive effects of the enlargement treatments on the total phenolic content and antioxidant activities of Red Globe was detected. The enlargement treatments could increase TDF and IDF content, decreased the TP and HC content, and had no influence on SDF content.(2) After the enlargement treatment, the berry weight of Thompson Seedless increased by 37%. Compared with the control, the fruit compression tolerence and titrable acid content increased, while the fruit shape index, the reducing sugar content and acid-sugar ratio decreased. The enlargement treatments could increase the activities of POD and PPO, but decreased the activity of SOD. The positive effects of the enlargement treatments on dietary fiber content was detected, while the negative effects of the enlargement treatments on the phenolic content and antioxidant activities of Thompson Seedless was detected.(3) After the enlargement treatment, the berry weight of Victoria increased by 9%. Compared with the control, the fruit shape index, the fruit compression tolerence and titrable acid content increased, while the reducing sugar content and acid-sugar ratio decreased. The enlargement treatments could increase the activity of POD, but decreased the activities of SOD and PPO. After the enlargement treatment, the phenolic content and cupric reducing antioxidant power, potassium ferricyanide reducing power, DPPH·radical scavenging capacity of Victoria were lower than control, while the ferrous ions chelating capacity and hydroxyl radical scavenging activity were higher than control. The positive effects of the enlargement treatments on the dietary fiber content of Victoria was detected.(4) After the enlargement treatment, the berry weight of August increased by 18%. Compared with the control, fruit shape index, the reducing sugar content and titrable acid content increased, while the fruit compression tolerence and acid-sugar ratio decreased. The enlargement treatment could increase the PPO activity, but had no significant influences on SOD and POD activities. The positive effects of the enlargement treatments on the phenolic content and antioxidant activities of August was detected, while the negative effects of the enlargement treatments on the dietary fiber content of August was detected.