## 3 Results  
### Color  
The effect of high hydrostatic pressure treatment on perceptual lightness (L*) is shown in Figure 2.  
The statistical analysis showed that only samples treated at 300 MPa differed significantly (\(p<0.05\)) from the control, untreated means in terms of their perceptual lightness (L*). The same trend was observed in both Large White swine and wild boar means. The significant difference first appeared just after the preservative process and lasted until the end of the experiment. The length of storage did not have a significant impact (\(p=0.141\)) on  
Figure 2: The effect of high hydrostatic pressure treatment on perceptual lightness (L*). Different superscript letters on the bars indicate significant differences. (**A**) Large White swine. (**B**) Wild boar. the L* parameter of the pork samples, nor did it significantly (\(p\) = 0.175) influence the same color component of wild boar meat. The interaction effect between the independent factors was not significant in either case (Large White swine: \(p\) = 0.217, wild boar: \(p\) = 0.249). The effect of high hydrostatic pressure treatment on the red/green opponent color (a*) is shown in Figure 3.  
High hydrostatic pressure treatment proved to have a significant effect on the red/green component, but only above a certain pressure. In the case of Large White swine, samples treated at 250 and 300 MPa were found to differ significantly (\(p\) < 0.05) from the not treated ones. In the case of wild boar meat, a significant difference (\(p\) < 0.05) was only experienced at 300 MPa. The results showed that the storage time did not affect significantly the a* values (Large White swine: \(p\) = 0.237, wild boar: \(p\) = 0.194). The interaction effect between the treatment and time was also not significant in either the case of pork (\(p\) = 0.174) or in the case of wild boar (\(p\) = 0.152). The effect of high hydrostatic pressure treatment on the yellow/blue component (b*) is shown in Figure 4.  
According to the results, the high hydrostatic pressure had a significant effect on the yellow/blue component (b*). A significant difference (\(p\) < 0.05) was detected when applying hydrostatic pressures of 250 and 300 MPa in the case of pork. The length of storage also had a significant impact. On Day 7 and Day 14, the b* color parameter of Large White swine  
Figure 3: The effect of high hydrostatic pressure treatment on red/green opponent colors (a*). Different superscript letters on the bars indicate significant differences. (**A**) Large White swine. (**B**) Wild boar. samples treated at 200 MPa was significantly different (\(p<0.05\)) from the control samples. The interaction effect between the independent factors was also found to be significant (\(p<0.05\)). In the case of wild boar meat, the treatments performed at 250 and 300 MPa were proven to cause a significant difference (\(p<0.05\)) compared to the control samples. However, unlike the pork samples the time factor did not have a significant influence (\(p=0.219\)) on the b\({}^{\star}\) color coordinate. The interaction between the preservative treatment and the period of time was not significant either (\(p=0.162\)). The color difference (\(\Delta\)E*) between the untreated and treated samples calculated at each measurement time is shown in Table 6.  
The color difference (\(\Delta\)E*) between the untreated and treated samples was only visible to experienced observers in the case of pressures of 150 and 200 MPa. However, the application of 250 and 300 MPa pressures resulted in a color difference (\(\Delta\)E*) which could be noticed by even unexperienced evaluators. Studies have shown that after HHP treatment, the lightness (L*) value increases while the redness (a*) value decreases. For instance, the treated pork exhibited a higher L* value and a lower a* value over time compared to untreated samples [23,44]  
The color changes can also be influenced by the storage conditions post-treatment.