# Influence of Tomato Pomace on the Quality of Canned Pork Meat with Reduced Nitrogen Compounds
## 4 Discussion  
Recently, there has been growing interest among scientists in the topic of by-products of the fruit and vegetable industry. This phenomenon is associated with the development of innovative food products, including meat products. The meat industry is seeking new  
Figure 4: Krona chart: isolated species, genera and family from samples with addition of 1.5% TTSP (DFS 1.5%). Figure 5: Krona chart: isolated species, genera and family from samples with addition of 2.5% TTSP (DFS 2.5%). solutions to increase the nutritional value of products while at the same time striving to reduce the use of synthetic additives, such as nitrogen compounds [31]. Therefore, the use of tomato peels and seeds powder, which is rich in valuable bioactive compounds, in meat preserves with reduced nitrogen compound content may contribute to the development of functional meat products that have positive effects on human health. When developing new products enriched with plant raw materials, it is essential to consider their impact on the physicochemical properties of the finished product. The addition of tomato peels and seeds' powder in the amounts of 0.5%, 1.5% and 2.5% contributed to the lowering of the pH of the tested cannot pork compared to the control sample. It was also observed that an increase in the concentration of the plant additive caused a decrease in the pH of the finished product. Similar observations were demonstrated by other researchers [16; 27]. The trends observed may be due to the high acidity of tomato peels and seeds' powder, as tomatoes are a good source of ascorbic acid [22]. They are also generally grouped as acidic foods (pH < 4.6), which is confirmed by the research of [PERSON] et al. [28], which showed that the pH of tomato powder from different tomato varieties was in the range of 4.19 to 4.29. Another important physicochemical indicator is water activity, which is important for the development of microorganisms in meat products. The additive used did not affect the value of this parameter in the tested products. The results ranged from 0.988 to 0.994. Due to the content of natural pigment (carotenoid and polyphenolic) in tomatoes, especially in their peel, the main effect of using tomato pomace in meat products is its impact on color parameters. It was indicated that the addition of tomato pomace to food products causes a decrease in the L* parameter as well as an increase in the a* and b* parameters [32; 33]. This phenomenon is also confirmed in the current study. The findings of other authors [34; 35; 36; 37; 38], who studied different types of meat products enriched with tomato processing by-products, were also in accordance with the indicated relationship. The reason for the increase in the a* value in the meat preserves can be attributed to the high content of lycopene in the chemical composition of tomato pomace [39]. Although lycopene is generally a red pigment, which additionally contributes to the increase in the b* parameter, its addition to meat can also cause a color change to more orange [37]. When analyzing the color differences (\(\Delta\)E) between the samples of the preserves, it should be noted that the greatest color changes occurred in the preserves with the highest content of tomato peels and seeds' powder. Therefore, as soon as color is concerned, tomato peels and seeds' powder can be used as a natural ingredient that can improve the overall appearance of canned pork. By-products of vegetable processing, including tomato peels and seeds, can be used to obtain valuable bioactive ingredients and as a source of antioxidants in the food industry, including meat products [40]. The most popular methods used to study various relationships between the mechanisms of antioxidant properties are based on the mechanism of inhibition of free radicals [41; 42]. In contrast to the DPPH method, ABTS-+ is soluble in both organic and aqueous environments, and therefore enables the detection of both lipophilic and hydrophilic compounds [43].