Effect of Harvesting Time on Some Flavonoids in Different Fruit Tissues of Matured Commercial Varieties of Sweet Orange

The aim of present research was to study the effect of harvesting time and fruit tissue on the content of some flavonoids of different varieties of orange. The experiment was done based on the split plot design with completely randomized design in three replications. In this research the main factor was texture of the fruit (epicarp, mesocarp and endocarp) and secondary factors were matured fruits of four different varieties (Thomson navel, Washington navel, Sanguine and lebani) and seven different harvesting times. Results showed that harvesting time had significant effect on all measured parameters. In which, the highest dry weight as well as total soluble solid (11.81 percent) were observed in the samples harvested in the sixth harvest time. In this stage, the highest hesperidin content (219.1 mg/ml) was observed in endocarp section. In contrast to that, the highest amount of naringin (435.3 mg/l) was observed in third stage in epicarp section without significant difference with fifth (endocarp) and sixth (mesocarp) harvest time. Among used varieties, the highest amount of both hesperidin and naringin was observed in Thomson navel fruit in sixth stage.