*3.4. Antioxidant Test*

Antioxidant properties of tissues sprayed with polyphenols were evaluated by using the DPPH method. The antioxidant activity was expressed in radical scavenging activity RSA (%) values that were calculated as reported in Equation (1) and represent the capacity of the active molecules to reduce the free-radical activity. From the results shown in Figure 8, a clear antioxidant activity of the active tissues was observed, which significantly grew with the concentration of polyphenols. In addition, it was shown that the lowest concentration of polyphenols needed more than 30 minutes to reveal antioxidant properties, while the other concentrations used showed a significant antioxidant effect in less than 30 minutes.

**Figure 8.** RSA (%) values of DPPH for polyphenol solutions at different concentrations after 0, 30, and 60 minutes.
