The golden kiwi is highly sensitive to ethylene
A scientific article (Influence of exogenous ethylene during refrigerated storage on storability and quality of Actinidia chinensis (cv. Hort16A), Pranamornkith et al; Postharvest Biology and Technology 64 (2012) 1-8) shows that the firmness and colour of the golden kiwi are seriously affected by the level of ethylene in the atmosphere of commercial cold stores.
“The kiwifruit industry was established on ‘green kiwifruit’ (Actinidia deliciosa, ‘Hayward’). In the recent years, however, the ‘golden kiwifruit’ (A. chinensis cv. Hort16A) has become increasingly popular and important for international trade. Golden kiwifruits are attractive because of their bright yellow flesh with fruity and tropical-like flavours and are regarded as sweeter and less sour than ‘green kiwifruit’.”
“‘Green kiwifruit’ is known as an ethylene responsive fruit, with very low concentrations (0.005–0.01 µl/l) leading to fruit softening and inducing advanced ripening which can limit long-term storage. Avoidance of ethylene exposure and elimination of ethylene present in the storage environment around kiwifruit are considered as crucial factors to ensure successful long-term storage of kiwifruit at refrigerated storage temperatures. However, there was limited information about the sensitivity of ‘golden kiwifruit’ to ethylene during refrigerated storage and hence current ethylene management practices for ‘Golden kiwifruit’ mimic those established for ‘Green kiwifruit’.”
“This research aimed to quantify the effect of ethylene during refrigerated storage on golden kiwi quality (firmness, colour and total soluble solids). Three grower lines were stored at 1.5ºC, 95% RH with ethylene in the range of 0.001–1 µl/l applied to the environment after 3 weeks of storage for the remainder of storage (17 weeks).”
- “Loss of firmness was found to be very sensitive to ethylene, with significant differences between fruit stored in 0.001 µl/l (as a control) and 0.1 µl/l occurring after 2 weeks of exposure.”
- “Fruit exposed to 1 µl/l ethylene not only rapidly softened, but also increased in hue angle (greenness) and reduced in lightness (darkened) further reducing the quality of the yellow coloured kiwifruit cultivar.”
- “Total soluble solids were not heavily influenced by ethylene exposure, with grower differences being maintained throughout the experiment.”
The results of this scientific study confirm that to ensure the successful conservation of the golden kiwi fruit it is crucial to eliminate ethylene in cold chambers used to store this fruit, applying appropriate technologies such as bioconservation based on the irreversible oxidation of ethylene with potassium permanganate (Bi-On granulate).