FIG. 1.

(A, C, E, G) Survival curves of Salmonella Typhimurium CECT 443 after acid (pH 2.5 [A]), alkaline (pH 11.0) (C), heat (55°C) (E), and oxidative (H₂O₂, 40 mM) (G) treatment. The symbols represent the experimental data obtained, while the lines were the result of the adjustment of the data through the mathematical model log N_t/N₀ = −(t/δ)^p. (B, D, H) Untransformed representative FT-IR spectra (1,450 to 800 cm⁻¹) of nonacid-treated cells (black line) and (B) acid-, (D) alkaline-, and (H) oxidative stress-treated cells for 5, 10, 20, 30, and 40 min (all with gray lines). (F) Untransformed representative FT-IR spectra (1,450 to 800 cm⁻¹) of non-heat-treated cells (black line) and heat-treated cells at 55°C for 3, 6, 9, 12, and 15 min (all with gray lines). A, absorbance.