Metabolic Profiling and Outer Pericarp Water State in Zespri, CI.GI, and Hayward Kiwifruits

The metabolic profiling of aqueous extracts of Zespri Gold (Actinidia chinensis) and CI.GI (a controlled crossbreed from different species of Actinidia deliciosa) kiwifruits and the water state of the outer pericarp of entire fruits were monitored over the season by means of high-field NMR spectroscopy and T-2 relaxation time measurements, respectively, and compared with the corresponding ones of Hayward kiwifruits previously investigated. A more complete assignment of the H-1 spectrum with respect to that obtained previously was reported: histidine, phenylalanine, quercetin 3-rhamnoside, and epicatechin were identified. Metabolic profiling confirmed Zespri's earlier maturation compared with the two other varieties. The water state of entire kiwifruits was measured nondestructively on fruits attached to the plants or detached from the plants. T-2 relaxation times were found to be sensitive to the kiwifruit developmental stage.