## 2 Materials and Methods
### Sample Preparation  
The ingredients for preparing the breaded chicken nuggets were wheat flour, breadcrumb, sparkling water, and skinless chicken breast, all purchased from a local market (Foggia, Italy). In the first step, three types of batter were prepared as described in Table 1. The control batter had no by-products (#A), one batter contained pomace powder (#B), and the other one contained both pomace powder and pomeranate extract (#C), in substitution of part of the wheat flour.  
The chicken breast was cut into bite-sized pieces, each about 2 cm thick and weighing approximately 10 g. Depending on the batter selected among (#A), (#B) and (#C), on the use of a previous dipping in lactic acid (4% solution, Greensistem, Foggia, Italia) and depending on the type of final coating to bread the samples (breadcrumb or GPP), a total of six samples were prepared: two controls and four active samples. The control samples (CTRL 1 and CTRL 2) were obtained by dipping the meat pieces into batter #A, followed by coating in traditional breadcrumb. For CTRL 2, these steps were preceded by an additional dipping in a 4% lactic acid solution. The active samples were prepared using the active batters (#B and #C). Specifically, the first sample (SAMP_1) was prepared by dipping the chicken into batter #B, followed by coating in the GPP. The second sample (SAMP_2) was dipped in 4% lactic acid, then in batter #B and finally coated with GPP. Another sample (SAMP_3) followed the same preparation procedure as SAMP_1, but using active batter #C instead of #B. The last sample (SAMP_4) was prepared in the same manner as SAMP_2 but adding a previous dipping in a 4% lactic acid solution. All of the formulations are summarized in Table 2.  
All of the concentrations adopted in the current study for each active ingredient (LA, GPP and PE) come from a proper preliminary screening carried out in the lab, based on both antimicrobial efficacy and sensory acceptance, whose data are not published.  
After the preparation, two nugget samples of each typology were placed on a food-grade pad and packaged in air using a multi-layer bag (nylon/polyethylene), provided by Myvac (Bolzano, Italy), and stored in the refrigerator (4 \(\pm\) 1 \({}^{\circ}\)C) for about two weeks. All samples were examined on days 0, 1, 2, 3, 6, 7, 8, 9, 10, and 13 to monitor microbiological quality, pH, and sensory properties.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Ingredients** & **\#A** & **\#B** & **\#C** \\
**(g)** & **(g)** & **(g)** & **(g)** \\ \hline Sparkling water & 95 & 95 & 95 \\ Wheat flour 00 & 55 & 25 & 25 \\ Pomace powder & - & 30 & 30 \\ Pomegranate extract & - & - & 12 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Formulation of the batter used for the different chicken nuggets samples.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sample** & **Dipping in Lactic Acid** & **Batter** & **Breaded Coating** \\ \hline CTRL 1 & no & \#A & Breadcrumb \\ CTRL 2 & yes & \#A & Breadcrumb \\ SAMP\_1 & no & \#B & GPP \\ SAMP\_2 & yes & \#B & GPP \\ SAMP\_3 & no & \#C & GPP \\ SAMP\_4 & yes & \#C & GPP \\ \hline \hline \end{tabular}
\end{table}
Table 2: Chicken nugget formulations for control and active samples.