## 3 Results and Discussion
A—control sample; B, C, D samples produced with 0.05, 0.1, 0.15 g/100 g of GRFP, respectively. in anthocyanins, a strong pigment that adds an intense red color to meat and makes it highly desired by consumers. This effect was noticed in the conducted sensory evaluation. The samples with a higher level of addition of the GRFP are characterized by greater color acceptability [24]. Yellowness index (b* values) indicated crucial changes in quality, e.g., bacterial deterioration or oxidation, which disqualifies the meat for usage. The higher the b* values, the greater the \"oxidized/reductive form\" ratio. Desired meat products are characterized by a b* value near zero and, there, the yellow and blue colors were not dominated [18; 19]. In our study, the b* values of samples A and D did not differ statistically. This trend was also maintained after the storage period and the b* values of all samples on day 14 were lower than the values recorded on day 0. The amount of MDA gives precious information about lipid oxidation, as well as indicating the quality of meat products. In the TBARS test, MDA is a substance that reacts with thiobarbituric acid. Figure 3 shows average values of mg MDA/kg in meat products measured after production (day 0) and after the storage period (day 14). In the first experimental period (after production), samples A differed significantly from samples B, C and D (formulation prepared with GRFP added). In the formulation with no GRFP, a higher amount of MDA than in the group with GRFP was mentioned. Moreover, sample D contained the highest amount of GRFP (0.15 g/100 g), was characterized by the lowest amount of MDA and displayed the highest resistance to lipid peroxidation. However, a different relationship was observed in studies conducted by [PERSON] et al. [25]. The lower addition (0.5%) of grape skin and seed pomace (GRS) decreased the levels of TBARS more efficiently than the higher addition (1%) of GRS. During the storage period (4 \({}^{\circ}\)C, 14 days), higher values of MDA in comparison to the values measured on day 0 in all samples were observed, an effect of lipid peroxidation. Based on the average TBARS values of experimental samples, it is demonstrated that the samples C and D (0.05 and 0.1 g/100 g of GRFP, respectively) had a similar antioxidative effect. Sample A had a significantly higher amount of MDA than other samples during the entire storage period, whereas sample D was more efficient in terms of the antioxidant level than in other groups. In the conducted study, the levels of TBARS in all samples increased during the storage period. The same relation has also been shown in many studies [22; 24; 26]. In our study, the levels of MDA are between 1.017-2.711 and it is possible to detect racidness in meat products. Lipid peroxidation becomes detectable by senses when the  
Figure 3: TBARS levels (average mg MDA/kg value) of fresh and stored meat products prepared with different levels of GRFP, A—control sample; B, C, D samples produced with 0.05, 0.1, 0.15 g/100 g of GRFP, respectively. mg MDA/kg value is equal to or higher than 2 mg/kg. The study needs to be repeated, since the change in the MDA value (to a higher one) is not entirely transparent. No pathogenic microorganisms of _Bacillus cereus_ and _Salmonella_ species were detected in the tested samples. It was observed that the HMP produced with GRFP addition were characterized by the lower number of microorganisms: the microbial inhibition grew with increasing the content of GRFP in the recipe of HMP (Figures 4-11, results were averaged for two biological replicates: part 1 and part 2). Moreover, it was observed that, in the samples with the highest amount of the extract, the amount of microorganisms responsible for food spoilage decreased after 14 days of cold storage. This level of addition has a positive effect on increasing shelf life. According to the study by [PERSON] et al. [27] some red fruit extracts indicate antimicrobial properties, especially against the pathogens _B. cereus_, _S. aureus_ and _E. coli_.