Influence of the stage of ripeness on the phytochemical profiles, antioxidant and antiproliferative activities in different parts of Citrus reticulata Blanco cv. Chachiensis

Abstract

Abstract Citrus is a rich source of nutritive and bioactive compounds. Impact of fruit tissues and ripening stage on phytochemical profile, antioxidant capacity and antiproliferative activity was investigated in Citrus reticulata Blanco cv. Chachiensis (Chachi). Regardless of different ripening stage, peel had the highest contents of phenolics and flavonoids, strongest antioxidant activities resolved by PSC, ORAC and CAA assay and antiproliferative activities against MCF-7, HepG2 and SiHa cancer cell. Increased level of total phenolics, hesperidin and naringin, and elevated antioxidant capacities were detected in peel during maturity, whereas highest amount of nobiletin and strongest antiproliferative activities were explored in immature peel. In flesh the vitamin C content increased during ripening, while lower phenolic content, smallest ORAC value and weakest antiproliferative activity were resolved in mature flesh. The flavonoid content and antioxidant capacity in seed were comparable with flesh and relatively constant during ripening, suggesting seeds as a valuable source of flavonoid extraction for further utilization. The characteristic flavonoids, nobiletin, tangeretin, hesperetin and naringenin inhibited proliferation of SiHa, HepG2 and MCF-7 cell dose-dependently, thus suggesting their contribution and potential application. Results presented here provide the foundation for comprehensive utilization of phytochemicals in different parts of this medicinal and edible citrus fruit.