Use of 1-MCP to Extend Postharvest Life of Hardy Kiwi Fruit and Anticancer Effect of the Fruit Extract

The hardy kiwifruit (Actinidia arguta cv ‘Cheongsan’), which was bred in Korea in 2005, has recently become popular in the market as demands for new tastes and healthy food increase. However, fruit distribution to the market is limited by rapid fruit ripening after harvest. To delay fruit ripening, hardy kiwifruits were treated with 20 mL/L 1-MCP for 16 h at 10 ^oC and subsequently stored at 1 ± 0.5 ^oC. Physicochemical changes and expressions of fruit ripening-related genes (AcACO, AcACS, and AcLOX) were analyzed. The anticancer properties of the fruit extracts were tested against five types of human cancer cells. The hardy kiwifruits without 1-MCP treatment showed increases in both respiration and ethylene production rates during fruit storage at 1 ± 0.5 ^oC. The 1-MCP treatment remarkably inhibited fruit ripening by reducing respiration and ethylene production rates. Transcript levels of AcACO, AcACS, and AcLOX were down-regulated by the 1-MCP treatment. Fruits with the 1-MCP treatment could be stored for up to five weeks by maintaining higher fruit firmness, ascorbic acid levels, and total phenolic contents compared to the control, which lost marketability completely due to over-ripening. The hardy kiwifruit extracts showed proliferative inhibitory effects to Hep3B and HeLa cells but not to HT29, HepG2, and LoVo cells. These results suggest that the application of 1-MCP at harvest effectively delayed the ripening process of the hardy kiwifruits, and the fruit extract had beneficial effects for the prevention of human cancer cell growth.