Oxidative behaviour of fresh‐cut ‘Fuji’ apples treated with stabilising substances

BACKGROUND: Although changes in the quality of fresh‐cut products treated with chemical stabilisers have been extensively described in the literature, very little is known about the physiology of these products. This work aims to describe the physiological aspect and particularly the effects of chemical preservatives on the oxidative behaviour of fresh‐cut apples. RESULTS: Immediately after treatment, the samples treated with the anti‐browning agents (ascorbic acid + cysteine) exhibited a sharp increase in H₂O₂ levels (a five‐fold increase when compared to the other samples) and peroxidative damage, especially at the beginning of the storage period (two‐fold increase after 1 day). In line with this result, peroxidase (POX) activity decreased by 50% during the first day of storage, but no significant changes in superoxide dismutase (SOD) and catalase (CAT) activities were found between the different samples. H₂O₂ accumulation was not attributed to the action of cysteine but to a specific action of ascorbic acid, which mainly acted as a pro‐oxidant under these conditions. CONCLUSION: The results presented in this work showed that ascorbic acid cause important oxidative damage in fresh‐cut Fuji apples. Alternatives are required to prevent detrimental loss of quality resulting from this oxidative action. Copyright © 2008 Society of Chemical Industry