Kiwifruit cultivar 'Halla gold' functional component changes during preharvest fruit maturation and postharvest storage

There is an increasing interest in the use of immature fruit for its health benefits; however, little is known about changes in the molecular composition of functional compounds during the stages of fruit maturation and over their postharvest ripening process. This study investigates the changing content levels of key functional molecules in the golden kiwifruit cultivar harvested between 70 and 160 days after full blooming (DAFB) and stored at 4 °C for 9 weeks. We found that mature fruit contained higher levels of total phenolics, total flavonoids, and vitamin C, while having lower levels of pigments such as lutein, β-carotene, 9'-cis-neoxanthin, and pheophytins. Lutein and β-carotene content was maintained during postharvest storage regardless maturity at harvest, with the notable exception of β-carotene which increased dramatically between 3 and 6 weeks of storage in fruit harvested 160 DAFB. Other pigments tended to decrease during ripening and maturation. Overall these results suggest that less mature kiwifruits are likely to be a better source health-beneficial pigment molecules like lutein and β-carotene.