Maturity at harvest is the key factor influencing storage life and the final quality of fruit. This study examined how the firmness of ‘Sweet Gold’ kiwifruit at harvest affects its post-ripening characteristics to create a maturity chart. Throughout the storage period, firmness decreased in all categories of fruit: hard, medium, and soft. ‘Soft’ fruits lost 40% of their firmness within 2 days after harvest, whereas ‘hard’ fruits remained firmer than soft fruits throughout the storage period and had the least soluble solids content, indicating a slower ripening progression. The acidity of ‘soft’ kiwifruit was very low from the day of harvest, suggesting that it was utilized as a respiratory substrate during ripening. The a-values (indicating redness) for ‘soft’ fruits gradually increased until day 6, stabilizing thereafter. ‘Soft’ fruits exhibited the highest ethylene production rate throughout storage. They showed a climacteric rise in ethylene on day 13, compared to ‘medium’ and ‘hard’ fruits, which exhibited increases on days 19 and 21, respectively. This data can help determine the optimal ethylene treatment duration for ripening ‘Sweet Gold’ kiwifruit. The firmness of ‘Sweet Gold’ kiwifruit at harvest is a crucial factor in determining its marketability and can effectively serve as a maturity index to estimate its shelf life.

This study was conducted to determine CO2 treatment condition to extend the shelf-life of ‘Seolhyang' strawberry. Fresh strawberries with red color on 80% of the fruit surface were harvested. The samples at two different stages (on the 1st and 3rd day after harvest) were placed in a gas-tight chamber with 0, 5, 15, or 30% CO2 concentration for 3 hours at 4℃. Then, the strawberry samples were immediately packaged in a PET tray and stored at 4℃. The carbon dioxide treatment was effective in maintaining the quality of ‘Seolhyang’ strawberries treated on the 1st day after harvest. These samples had higher firmness, lower redness, softening index, and decay rate compared to samples treated on the 3rd day after harvest. Treatment with both 15 and 30% of CO2 concentration on the 1st day after harvest induced an increase of firmness of ‘Seolhyang’ strawberry after the treatment. Samples treated with 15 and 30% CO2 the 1st day after harvest maintained quality for 10 days. However, samples treated with CO2 on the 3rd day after harvest lost marketability at 10 days of storage. At the atmosphere containing 30% CO2 on the 1st day after harvest was most effective in reducing decay rate and fruit softening, and maintaining bright red color of strawberries among different CO2 concentrations. Therefore, a 30% CO2 treatment within one day after harvest can be a practical postharvest technology to extend shelf-life of ‘Seolhyang’ strawberry.