The effect of UV-C in combination with H_2O_2 treatments on microbial response and quality parameters of fresh cut pear discs

摘要

The response of Escherichia coli ATCC 11229, Listeria innocua ATCC 33090 and Zygosaccharomyces bailii NRRL 7256 in fresh-cut pear to simultaneous and serial combined treatments involving H_2O_2 immersion (3% w/v; pH 3.0; 25 ℃; 2.0 or 5.0 min) and UV-C exposure (7.5 min; 3.7 kJ m~(-2)) was investigated. For selected treatments, native flora, sensory and colour changes were also evaluated. E. coli and L. innocua were more sensitive than Z. bailii. Serial H_2O_2/UV-C treatments were more effective than the simultaneous arrangement. The single effect of UV-C was enhanced by the combination with 5 min H_2O_2, hence avoiding the recovery of the surviving population. The combined treatment kept optimal microbial stability and exhibited more luminosity than the single UV-C treatment. Texture profile analysis conducted using a trained panel showed that H_2O_2/UV-C processed pear discs were perceived with significantly less hardness and fracturability but as juicy as untreated discs. Consumers found them pleasant.