Bacterial inactivation and quality changes of fresh-cut avocados as affected by intense light pulses of specific spectra

Abstract

Intense light pulses (ILP) treatments have good prospects for becoming an alternative to traditional thermal methods for decontamination of food surfaces. The aim of this work was to evaluate which ranges of the light spectrum are responsible for bacterial inactivation and their effect on the quality of fresh-cut avocado. Results show that the effectiveness of ILP treatment decreases when the ultraviolet (UV) spectral region is blocked (particularly UV-C). ILP treatments without UV-C light (305-1100nm) and an overall fluence of 10.68Jcm(-2) caused reductions of 2.47 and 1.35 log CFUg(-1) in the initial counts of inoculated Escherichia coli and Listeria innocua, respectively, in comparison with those treated using only VIS-NIR light (0.83 and 0.68 log CFUg(-1), respectively). Treatments applying light of a wavelength between 305 and 1100nm had a more pronounced impact on colour, texture and headspace gas composition than treatments that did not contain UV light (400-1100nm)