Do Sun- versus Shade-Grown Kiwifruits Perform Differently upon Storage? An Overview of Fruit Maturity and Nutraceutical Properties of Whole and Fresh-Cut Produce

Fresh-cut produce represents a good method to save about 25% of the kiwifruit not useful to meet the fresh fruit-marketing standard due to improper size and shape. For that reason, fresh-cut kiwifruit has been extensively studied. However, the comprehension of the influence of some aspects of cultivation might further increase the shelf life as well as the nutritional values of that fruit. This study explored the hypothesis that kiwifruits grown fully exposed to sunlight or partially shaded differently perform upon storage as whole fruit and as minimally processed produce. Flesh firmness (FF), total solids soluble (SSC), ascorbate (AAT), flavonoids (TFO), and phenols (TF) contents were evaluated in sliced and whole fruit upon 3 days of storage at 4 °C after 75 days of cold chamber storage at 0 °C. The activities of two enzymes related to the softening process, polygalacturonase (PG) and pectinmethylesterase (PME), were evaluated as well. FF and SSC were constitutively higher in sun-exposed fruit, and those characteristics remained higher during the storage as whole fruit. Greater constitutive content of AAT, TFO, and TP was found in sun-exposed whole fruit, although after cutting the reduction in their content was significantly lower in shaded fruits. PME and PG activities were higher only in whole shaded fruits, whereas no relevant differences occurred after cutting. In summary, sun-exposed fruits were more suitable for the fresh-fruit market, whereas the shaded counterpart displayed a good predisposition for use as fresh-cut produce, maintaining similar fruit maturity properties but higher nutraceutical values when sliced than fruit grown under full sun