Figure 3.

Correlation between the concentrations of the measured planktonic (Log₁₀ CFU/mL) and attached populations to the SS coupons (Log₁₀ CFU/cm²) of the four-strain L. monocytogenes cocktail. The solid line represents the linear regression equation, while the dashed parallel lines represent the prediction intervals (α = 0.95). The mathematical equation of the linear regression, together with its regression coefficient (R²), Pearson correlation coefficient (r_p), and p-value are also presented. Dots represent the mean values of all experiments included in the CCRD (n = 20; i.e., those shown in Table 1). For more clarity, the bars of standard deviations have been omitted. The horizontal dotted line illustrates the detection limit of the plate counting method of the sessile cells (i.e., −0.05 Log₁₀ CFU/cm²).