Cold shock treatment increases chilling injuries in ‘Douradão’ peaches

Abstract

This study was carried out to evaluate the cold shock, before cold storage, influence on quality of cold stored ‘Douradão’ peaches, with the objective to reduce the chilling injuries. For this, the fruits were exposed at -2 or -4 °C for 1, 2, or 3 hours. After treatments the fruits were stored at 0.5 ± 1 °C and 85-90% RH for 30 days. The variables evaluated suggests that the treatment with cold shock does not influence the physical and chemical fruit characteristics but intensifies and accelerates the onset of symptoms characteristic of chilling injuries. This may be associated with changes in enzymes of endo-PG, PME, PL and ?-Gal amount and activity that affect the dynamics of cell wall degradation, in the case of woolliness and changes in enzymes PAL, POD and PPO activity and the increased membrane permeability in the case of internal browning. The anticipation of the chilling injuries and decay in fruits subjected to cold shock suggests that this practice should not be used in order to maintain the fruit quality.