Ozone for post-harvest treatment of apple fruits

Different biotic contaminations can affect apple production. Among these, infections by Penicillium expansum, the causal agent of blue-green post-harvest rot and patulin production, is particularly important. Fruit of the apple varieties: 'Royal Gala', 'Golden Delicious' and 'Fuji' were challenged with a patulin-producing P. expansum strain and stored at 1 +/- 1 degrees C in presence of gaseous ozone at 0.5 mu L L-1 for 2 months. During the storage period, fungal populations, the biosynthesis of patulin and the activity of some Pathogenesis Related Proteins (glucanase, peroxidase and phenylalanine ammonia-lyase) were evaluated. Ozone treatment reduced fungal populations and patulin production. The activity of the assayed enzymes was not directly or clearly correlated with the inhibiting effect of ozone. These results indicate that ozone could be used to increase storage duration of apple varieties to maintain their quality.