Influence of harvesting date on some physicochemical properties of nectarine leaf and fruit

Abstract

The influence of harvesting date were studied on antioxidant activity and some physicochemical properties of nectarine (cultivar, red gold) leaf and fruit including weight, pigments, carbohydrate and total phenolic and flavonoids contents. Leaves and fruit were harvested in four different stages; two weeks after fruit set (AFS), five weeks AFS or pit hardening (PH), three and six weeks after PH. The results showed that the content of carbohydrates increased gradually as harvesting date delayed. The content of sucrose decreased gradually in the next harvests. The highest carbohydrate contents were observed at the last harvest time. It is suggested that the observed changes may be due to the replacement of sucrose by other kind of carbohydrate like glucose during late stage of ripening. The results showed that although the content of total phenol and flavonoid in fruit were reduced significantly by delaying in harvest time, no significant reduction was observed in antioxidant activity. It is concluded that the other compounds such as anthocyanin, carotenoids and vitamin C have more role in the antioxidant activity of ripened nectarine fruit. Key words: Antioxidant activity, chlorophyll, flavonoids, harvesting time, nectarine, sugar, total phenols, DPPH