Effect of harvesting time on antioxidant capacity and keeping quality of Actinidia deliciosa cv. Hayward fruit

Harvesting time of kiwifruit can influence quality characteristics. The current research was carried out according to a completely randomized design with three replications at Faculty of Agricultural Sciences, University of Guilan in 2009. Weight loss, flesh firmness, total soluble solid (TSS), titritable acidity (TA), ascorbic acid, total phenol content and antioxidant capacity of harvested fruit at different times was measured after four months storage at 0.5ºC. The results showed that fruit weight loss was significantly increased at the end of storage time when fruits harvested with higher ºbrix (more than 6.5). Furthermore, flesh firmness of these fruits was significantly reduced during storage. Delay in harvest was resulted to increase of TSS and TSS/TA. Data showed that total phenols and ascorbic acid increased significantly with delay in harvesting time up to 8.5 and nine °brix, respectively after four months storage at 0.5ºC and thereafter declined, however antioxidant capacity was higher when fruits harvested with 6.5 and nine ºbrix as compared with other harvesting times. Overall, although delay in harvest might increase antioxidant compounds in kiwifruit but reduced storage quality of fruits.