**2.4. Combined effects of pH, cinnamic, and vanillic acids on the viable count of the strain 13M**

The strain 13M was used as target; it was inoculated into MSM broth to 6–7 log cfu/ml. The amounts of cinnamic and vanillic acids and pH varied according to a 2k experimental (Table 1). The samples were stored at 30°C and periodically analyzed to evaluate the viable count and phenol content (up to 12 days).


**Table 1.** Combinations of 2k design.

The analyses were performed in duplicate and the results of viable count analyzed through a multiple regression approach by using the option DoE/2k design of the software Statistica for Windows.
