The postharvest performance of kiwi fruit after long cold storage

Conventionally (CG), semi-organically (low chemical, LCG) and organically grown (OG) kiwi fruit was stored at 0° C for 24 weeks. Firmness gradually decreased with storage time regardless of cultivation type, and the rate of softening was slightly higher in OG fruits than those of CG or LCG fruits. Soluble solids content increased with storage time, while acidity decreased in all fruits. Reducing sugar content considerably increased until 12 weeks after storage, while starch content significantly decreased. Rate of fruit decay abruptly increased at middle stage of storage in OG fruits. In 24 weeks after storage, the rate reached 35 %. Most fruits decayed with infection of Botritis cineria regardless of cultivation type. Respiration and ethylene contents have peaked at middle stage of storage, and those contents were slightly higher in OG than in CG and LCG fruits. Shelf life of kiwi fruit considerably decreased in OG fruits by increasing fruit decay and softening during storage. Fluorescence measurements showed a difference between the investigated samples, especially in their antioxidant status. The used statistical evaluation confirmed the obtained results. The quenching properties of these samples are correlated with their antioxidant properties and the amount of polyphenols and the decrease in fluorescence intensity.