Efficacy of hydrogen peroxide + peracetic acid and trans-2-hexenal against apple rots during long-distance transport

Preserving apples in semi-hermetic tray-packs is essential for maintaining intrinsic quality during long-term storage and transport (45–60 days) due to favorable internal hygrometric conditions. However, prolonged storage and high humidity can promote rots, molds, and secondary pathogen development on the fruit epicarp. This study evaluated the effectiveness of two treatments: (1) a bath with a hydrogen peroxide (25%) and peracetic acid (15%) solution, and (2) a gaseous treatment with trans-2-hexenal on controlling fungal pathogens in 'Pinova' apples stored in tray-packs. Apples treated with the hydrogen peroxide + peracetic acid solution (1 ml/L) were submerged for 2 minutes and compared with untreated apples soaked in clean water. Trans-2-hexenal was applied by evaporating a 12.5 μl/ml solution. All apples were stored at 1.5°C and 85% relative humidity. The hydrogen peroxide + peracetic acid treatment slightly reduced rot incidence after 30 days (-1%) and 110 days (-2.6%) of storage, compared to untreated apples. The aldehyde treatment did not significantly affect rot incidence. However, it showed a 5% reduction in secondary pathogen incidence after 30 days, although this effect was not sustained during longer storage periods. Despite these initial observations, further studies are required to optimize treatment dosages and application protocols to enhance effectiveness against apple pathogens.