Sometimes size matters! Fruit size in combination with 1-methylcyclopropene influence kiwifruit postharvest quality

Kiwifruit is an edible berry that is gaining relevance in the markets. Its nutritional qualities, that include high content of ascorbic acid (AsA), tocopherols and other antioxidants, make it attractive for consumers. Fruit size is an important issue for consumers and producers, because it defines the fruit price. The aim of this work was to evaluate the postharvest life of two different kiwi fruit sizes, small and large fruits, combined with the treatment of an ethylene signal inhibitor, 1-methylcyclopropene (1-MCP), under storage at 3 degrees C for up to six months. Large fruits showed an earlier respiration peak (two months) than small fruits. After four months from harvest, the amount of AsA in small fruits was higher than that of large fruits, independently from the 1-MCP treatment. On the other side, the application of 1-MCP delayed the loss of firmness in small and large fruits but did not affect quality parameters such as soluble solids or total titratable acidity. Small kiwifruits showed a greater weight loss while large fruits showed a decrease in the total sugars when they were treated with 1-MCP. Small fruits increased the AsA and malic acid content, presenting nutritional attributes that could improve the consumers' diet. This report provides evidence that different fruit sizes should be separated at harvest time and sold at different shelf-life stages.