Ripening and Ethylene Production in Kiwifruit (A. deliciosa)on the Market

Abstract

Recent studies revealed that kiwifruit does not evolve no ethylene virtually and not ripen without any help of some exogenous factors. In order to know how to improve commercial ripening of kiwifruit, the fruits purchased from retail shops were studied on ripening, ethylene production, occurrence of soft rot and fruit quality.
1. Domestic kiwifruits hardly evolved ethylene even 10 days after purchase, except soft rotted fruit which comprised about 40% of the total fruit.
2. The greater part of kiwifruit imported from New Zealand also did not evolve ethylene 10 days after purchase. Four percent of the fruit, however, evolved ethylene with occurence of soft rot and 14% of the one did without soft rot. The ones purchased from wholesales did not produce ethylene and ripen with a few exception.
3. Ethylene of zero to over 50ppm was detected in small plastic boxes in which kiwifruits were enclosed for retail. Ethylene of 0.5 to 5ppm accumulated in the box enclosing one ethylene producing and 4 non-producing fruits.
4. Only about 40% of the purchased kiwifruit became eatable through 10 days after purchase in terms of flesh firmness and acid contents even though soft rot fruit was taken into account.
These results suggest that it is necessary to make up a system to ship and retail kiwifruit compulsorily ripened by exogenous ethylene.