Effect of Chlorine Dioxide and Ascorbic Acid on Enzymatic Browning and Shelf Life of Fresh-Cut Red Delicious and Granny Smith Apples

In this work, we tested the hypothesis that ascorbic acid (AA) reduces browning of fresh-cut apples (Red Delicious, RD, and Granny Smith, GS), and we investigated the impact of AA on phenylpropanoid metabolism of RD and GS. Apple slices were dipped in a solution of 100mg/L of chlorine dioxide (ClO2) and ClO2+3% AA and stored at 4C for 96h. Flesh firmness, solid soluble content and browning index, total phenols and flavonoids, and the activity of peroxidase and polyphenol oxidase were monitored upon storage (0, 48 and 96h). Our results demonstrated that GS is less sensitive to browning and thus more suitable for minimally processed produce. Ascorbate reduces the browning index also in RD, a cultivar largely appreciated by consumers but more prone to browning. AA likely contrasts browning appearance by interacting with peroxidase and polyphenol oxidase and/or promoting the regeneration of phenols and flavonoids. Practical Applications: Browning of fresh-cut apple is one of the main problems that limit the shelf life of this type of produce. Given that this produce is highly appreciated by consumers, different antibrowning treatments have been tested to extend the shelf life of fresh-cut apple. We found that treatment with 100mg/L of ClO2+3% of ascorbic acid significantly reduces the browning appearance in apple slices. Browning was also reduced in Red Delicious cultivar that is more prone than Granny Smith to this phenomenon, but that is highly appreciated by consumers.