In this study, we investigated the effects and mechanisms involved in high pressure argon and xenon (HP Ar + Xe) mixed treatment on wound healing in fresh-cut apples and pineapples. Fresh-cut apples and pineapples treated by HP (1.8 MPa absolute) Ar and Xe (Ar:Xe = 2:9 partial pressure) were stored at 4 degrees C for 96 h. H2O2 production, the activities of related enzyme, the accumulation of phenolics and lignin were compared amongst those untreated and treated by HP air, normal atmosphere pressure (NAP Ar + Xe). The apple and pineapple samples subjected to the above treatments were inoculated with Escherichia coli and Saccharomyces cerevisiae, respectively, and incubated at 10 degrees C for one week. The growth of E. coli or S. cerevisiae was monitored to evaluate the wound-induced response to defense or the resistance against infection. Results showed that the HP (Ar + Xe) mixed treatment promoted the wound-healing response and enhanced resistance against the infection of E. coli or S. cerevisiae in fresh-cut apples and pineapples. The enhanced wound healing ability in fruit pieces subjected to HP (Ar + Xe) mixed treatment is found to be associated with the increase in H2O2 production and the accumulation of phenolics and lignin during storage after treatment. (C) 2012 Elsevier Ltd. All rights reserved.