Fig 4.

Inactivation of stationary-phase cells of Salmonella Typhimurium STCC 878 by UV light (black bars) (19.94 J ml⁻¹/2.23 min), heat at different temperatures (white bars) (2.23 min), and the combined process (gray bars) (19.94 J ml⁻¹/2.23 min) in McIlvaine buffer adjusted to a pH of 7.0, with an absorption coefficient of 23.66 cm⁻¹. The sum of the heat and UV inactivation was lower than that reached by the simultaneous application of both technologies. The log₁₀ cycles of the synergistic effect, calculated by subtracting UV and heat inactivation cycles from those obtained during UV-H treatment, were 0.44, 0.88, 1.38, and 0.96 log₁₀ cycles at 50.0, 52.5, 55.0, and 57.5°C, respectively.