Integrated nutritional and functional components analyses reveal insights into the peel and pulp quality at different harvest times of ‘Dahongpao’ tangerine (Citrus reticulata Blanco)

The fruit of Citrus reticulata 'Dahongpao' (DHP) is typically harvested when fully ripe, exhibiting a dark red color, high sweetness, and pleasant taste. However, it remains uncertain whether the optimum harvesting time for its medicinal part (peel) aligns with that of the fruit. The findings of the study indicated that the peel exhibited the highest concentration of total flavonoids (4.018 mg/g) during the middle stage of maturity. Additionally, the total polysaccharide content increased progressively with ripening, reaching its peak (5.36 %) at full maturity. Furthermore, the DHP pulp demonstrated the highest concentration of total polyphenols (11.5 %) and the lowest titrable acid content (0.97 %) during the middle stage of maturity. Furthermore, the peel and pulp of DHP at the middle stage of ripening exhibited the highest antioxidant capacity. Considering the nutritional and functional components at various harvest times of DHP, it is recommended to harvest the peel at the intermediate stage of ripeness. Additionally, during this stage, the pulp also exhibited greater abundance of nutritional components. The findings of this study elucidate the process of accumulation and alteration of nutritional and functional constituents during the ripening of DHP fruit.