Pulsed light treatment for the inactivation of selected pathogens and the shelf-life extension of beef and tuna carpaccio

The efficacy of pulsed light to improve the safety of carpaccio has been investigated. Beef and tuna slices were superficially inoculated with approximately 3 log cfu/cm(2) of Listeria monocytogenes, Escherichia coli, Salmonella Typhimurium and Vibrio parahaemolyticus. Fluences of 0.7, 2.1, 4.2, 8.4 and 11.9 J/cm(2) were assayed. Colour, sensory and shelf-life studies were carried out. Treatments at 8.4 and 11.9 J/cm(2) inactivated the selected pathogens approximately by 1 log cfu/cm(2), although they modified the colour parameters and had a negative effect on the sensory quality of the product. The raw attributes were not affected by fluences of 2.1 and 4.2 J/cm(2) immediately after the treatment, although changes were observed during storage. The inactivation obtained with these fluences was lower than 1 log cfu/cm(2), which may not be negligible in case of cross-contamination at a food plant or at a food service facility. Pulsed light showed a greater impact on the sensory quality of tuna carpaccio compared to beef. None of the fluences assayed extended the shelf-life of either product. (C) 2012 Elsevier B.V. All rights reserved.