# 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
Limited literature is available on using raw fruit pomace in minced meat products. Most research has focused on the possible applications of dried fruit or vegetable pomace and fruit pomace extracts in meat processing [13; 15; 16; 44; 45]. [PERSON] et al. [13] found that adding 1% or 2% dried berry pomace resulted in a relatively small, insignificant (\(p>0.05\)) increase in pork patty yield after heat treatment. According to the authors, dried fruit pomace is rich in dietary fiber, which helps retain moisture and fat within the product matrix, preventing weight loss. However, in contrast to the present study, there was a tendency to decrease \"shrinkage\" in meat products containing fruit pomace, which was seen as a positive aspect of culinary quality. The authors concluded that dimensional changes occurring in pork patties during baking were primarily due to the denaturation of meat proteins, the predominant ingredient in the product. [PERSON] et al. [16] investigated the impact of berry pomace (from raspberries and blackberries) at levels of 1%, 3%, and 5% on the quality of beef patties during 9 days of storage at 4 \({}^{\circ}\)C. The highest weight loss was observed in the control patties (without added pomace) while adding pomace from both raspberries and blackberries resulted in a slight reduction in weight loss. In this study, the observed tendency of increasing thermal loss in burgers with higher amounts of chokeberry pomace may have been due to introducing a low-acid ingredient. This observation aligns with findings by [PERSON] et al. [46], who added prunes to pork burgers. The use of chokeberry pomace in pork burgers resulted in relatively small but significant (\(p<0.05\)) differences in the content of chemical components (Table 1). The water content ranged from 55.97% in the B5 product to 59.31% in the BC product, with a decrease (\(p<0.05\)) noted as the concentration of chokeberry pomace increased. This reduction in water content in burgers containing chokeberry pomace can most likely be attributed to higher thermal loss (Table 1). In contrast to the water content, both protein and fat levels in the burgers increased with higher amounts of pomace. The B5 product had significantly (\(p<0.05\)) the highest protein content (28.47%), while the BC product had the lowest (26.68%). The B2 and B3.5 products formed a homogeneous group, exhibiting lower (\(p<0.05\)) protein levels than those in the B5 product but higher (\(p<0.05\)) than in the BC product. Regardingfat content, the most significant difference (\(p<0.05\)) was observed between the BC product (12.47%) and both the B5 and B3.5 products (19.96% and 13.77%, respectively). The sodium chloride content in pork burgers ranged from 1.63% in the B5 product to 1.94% in the BC product, being significantly higher (\(p<0.05\)) in the burgers without chokeberry pomace (BC) compared to those containing added pomace (B2-B5). The difference in the sodium chloride content between the control product (BC) and products containing chokeberry pomace (B2-B5) could be because the amount of this ingredient added was calculated with the total pork ham and pork jowl without taking into account the relatively small weight of pomace. Therefore, the initial concentration of sodium chloride in the B2-B5 products was slightly lower than in the product without pomace. Moreover, the reduction in the sodium chloride content in burgers containing chokeberry pomace was most likely caused by differences in the amount of thermal loss between BC-B5 burgers. The greater the thermal loss, the higher the amount of pomace added. The quantitatively dominant component of thermal loss from a meat product is water [42], but it also contains sodium chloride [47]. To sum up, the differences in the chemical composition of pork burgers can be attributed to the different proportions of raw materials used for production: meat, fat, and chokeberry pomace. The dry matter content of fresh chokeberry pomace used in this study was 26.5%, which indicates a high water content in this raw material.