Comparative Analysis of the Characteristics of Two Hardy Kiwifruit Cultivars (Actinidia arguta cv. Cheongsan and Daebo) Stored at Low Temperatures

TL;DR

This study compares how two types of hardy kiwifruit respond to cold storage, showing that storage conditions and cultivar type affect fruit quality and antioxidants.

Contribution

The study provides cultivar-specific insights into how low-temperature storage affects hardy kiwifruit quality and antioxidant properties.

Findings

Cold storage at 3°C increased browning and pitting in 'Cheongsan' fruits more than in 'Daebo' fruits.

Antioxidant activity and ascorbic acid content in 'Cheongsan' fruits were lower at 3°C compared to 5°C storage.

Both cultivars showed significant differences in quality and antioxidant levels between the two storage temperatures.

Abstract

A cold storage system is useful for maintaining the quality of hardy kiwifruit. However, extended cold storage periods inevitably result in cold stress, leading to lower fruit marketability; the severity of chilling injury depends on fruit types and cultivars. In this study, the impact of cold storage conditions on the physicochemical properties and antioxidant capacity of two phenotypically different hardy kiwifruit cultivars—‘Cheongsan’ (large type) and ‘Daebo’ (small type)—stored at low (L; 3 °C, relative humidity [RH]; 85–90%) and moderate-low (ML; 5 °C, RH; 85–90%) temperatures was determined. Significant differences in fruit firmness and titratable acidity between treatments L and ML were observed in both cultivars during the experimental storage period. Meanwhile, the browning and pitting rates of the ‘Cheongsan’ fruits in treatment L increased for 8 weeks compared with those of the ‘Daebo’ fruits in treatments L and ML; nonetheless, fruit decay was observed in the ‘Daebo’ fruits in treatment ML after 6 weeks. The total chlorophyll, carotenoid, flavonoid, and ascorbic acid concentrations as well as the antioxidant activities of both the cultivars significantly differed between treatments L and ML. After 2 weeks of storage, the ‘Cheongsan’ fruits in treatment L had lower antioxidant activities and ascorbic acid content than those in treatment ML. These results demonstrate that the quality attributes and antioxidant activity of hardy kiwifruit are influenced by the low-temperature storage conditions and the specific kiwifruit cultivars. Our findings suggest that optimal cold storage conditions, specific to each hardy kiwifruit cultivar, promise to maintain fruit quality, including their health-promoting compounds, during long-term storage.

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