# Changes in Quality Features of Pork Burgers Prepared with Chokeberry Pomace During Storage
## 3 Results and Discussion  
### Culinary Quality Characteristics and Chemical Properties of Pork Burgers  
Thermal loss in burgers after baking ranged from 23.5% in the BC product to 30.8% in the B5 product and varied significantly (\(p\) < 0.05) depending on changes in the raw material composition of the burgers (Table 1). Compared to the control product (BC), burgers with a lower concentration of chokeberry pomace, i.e., B2 and B3.5, exhibited a greater (\(p\) < 0.05) weight loss. Burgers with the highest amount of chokeberry pomace (B5) showed the highest (\(p\) < 0.05) thermal loss among all meat product treatments. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Feature** & **BC*** & **B2*** & **B3.5*** & **B5*** \\ \hline Thermal loss [\%] & 23.5 \({}^{\text{a}}\)\(\pm\) 1.58 & 27.4 \({}^{\text{b}}\)\(\pm\) 0.85 & 27.7 \({}^{\text{b}}\)\(\pm\) 1.52 & 30.8 \({}^{\text{c}}\)\(\pm\) 0.80 \\ \hline Shrinkage [\%] & 16.9 \({}^{\text{a}}\)\(\pm\) 1.92 & 17.5 \({}^{\text{a}}\)\(\pm\) 2.07 & 18.7 \({}^{\text{a}}\)\(\pm\) 1.68 & 21.1 \({}^{\text{a}}\)\(\pm\) 0.90 \\ \hline Water content [\%] & 59.3 \({}^{\text{d}}\)\(\pm\) 0.06 & 57.74 \({}^{\text{c}}\)\(\pm\) 0.03 & 57.08 \({}^{\text{b}}\)\(\pm\) 0.11 & 55.97 \({}^{\text{a}}\)\(\pm\) 0.11 \\ \hline Protein content [\%] & 26.68 \({}^{\text{a}}\)\(\pm\) 0.08 & 27.89 \({}^{\text{b}}\)\(\pm\) 0.10 & 27.71 \({}^{\text{b}}\)\(\pm\) 0.11 & 28.47 \({}^{\text{c}}\)\(\pm\) 0.06 \\ \hline Fat content [\%] & 12.47 \({}^{\text{a}}\)\(\pm\) 0.01 & 12.84 \({}^{\text{b}}\)\(\pm\) 0.00 & 13.77 \({}^{\text{c}}\)\(\pm\) 0.12 & 13.96 \({}^{\text{c}}\)\(\pm\) 0.06 \\ \hline Sodium chloride content [\%] & 1.94 \({}^{\text{b}}\)\(\pm\) 0.03 & 1.71 \({}^{\text{a}}\)\(\pm\) 0.04 & 1.64 \({}^{\text{a}}\)\(\pm\) 0.03 & 1.63 \({}^{\text{a}}\)\(\pm\) 0.02 \\ \hline \hline \end{tabular}  
* Treatments: BC—pork burgers without chokeberry pomace; B2—pork burgers with 2.0% chokeberry pomace; B3—pork burgers with 3.5% chokeberry pomace; B5—pork burgers with 5.0% chokeberry pomace; a–d—mean values in the same row marked with different letters are significantly different at \(p\) < 0.05.  
\end{table} 
Table 1: Thermal loss (\(n\) = 6), shrinkage (\(n\) = 6), and the content of selected chemical components (\(n\) = 4) in pork burgers with added black chokeberry pomace (mean value \(\pm\) standard deviation). The change in the diameter of burgers after baking referred to as \"shrinkage\", ranged on average from 16.9% in the BC product to 21.1% in the B5 product and increased with the proportion of pomace in the raw material composition (Table 1). However, the differences between the burger treatments were insignificant (\(p>0.05\)). The results of this study indicate that incorporating a plant-based ingredient into the raw material composition of a minced meat product can affect some aspects of its culinary quality. Similarly, other researchers [40; 41] found that the production yield of burgers after heat treatment--measured as the ratio of the finished product weight to meat batter weight--may depend on the inclusion of a plant-based ingredient. However, the results are not conclusive. For example, the production yield of grilled mixed beef and pork burgers significantly decreased (\(p<0.05\)) when 6.0% oat fiber preparation was added to the meat batter [41]. Unlike the present study, [PERSON] et al. [42] demonstrated that the cooking characteristics of pork burgers improved (\(p<0.05\)) with the addition of passion fruit albedo at concentrations of 2.5% and 5%. The authors attributed the increased cooking yield to the dietary fiber in the fruit albedo, which has a high capacity for retaining moisture and fat. Additionally, burgers containing passion fruit albedo exhibited a smaller reduction in diameter after cooking than control burgers. In beef burgers, adding 5% dried Sicilian sumac fruit resulted in reduced cooking loss compared to the control product, though the differences were not statistically significant [43].