## 3 Results and Discussion  
### Physicochemical Parameters  
Beef burgers made by hand with a formulation based on fresh meat (pork or beef), salt, water, and pork bacon, along with other natural seasonings, have a pH that ranges between 5.5 and 5.8 [23; 27; 28; 29; 30]. In this research, the analysis of variance showed that the inclusion of _Durvillaea antarctica_ modified the pH of the burgers from day one (Table 2). Differences were observed between the control, treatments with 0.5 and 1.0% _D. antarctica_ meal, and treatments with 1.5 and 3.0% _D. antarctica_ meal. Controls and treatments with lower concentrations of _D. antarctica_ (0.5 and 1.0%) had a lower pH (_p_ < 0.05) than those with higher concentrations (1.5% and 3.0%). In a study reported by [PERSON] et al. [28], they noted that low-fat pork patties made with 3.0% and 5.0% _Laminaria digitata_ significantly reduced the pH compared to the control, which is contrary to our results. The authors of other similar studies with Laminaria suggest that this could be related to the components of brown algae, such as fucoidan and alginic acid, which would act as acidifying agents [28; 31; 32]. The pH of meat and meat products can vary due to microbial contamination, but in this study, during the manufacturing and storage process, all sanitary and handling measures were carefully considered, which prevented the presence of bad odors and undesirable aspects that could be caused by contaminating microorganisms [33]. However, during storage (7 days), a considerable decrease in pH was observed for all treatments. The inter-subject effects test showed a significant interaction between _D. antarctica_ levels and storage time on pH (_p_ < 0.001). At the end storage, the control treatments had a lower pH (_5.29) than the treatments with _D. antarctica_ concentrations of 0.5, 1.0, 1.5, and 3.0% (5.35; 5.34; 5.32, and 5.36, respectively). In other words, the pH of the beef burgers decreased slightly less in those treatments with _D. antarctica_ meal. These results are consistent with those reported by other authors. For example, [PERSON] et al. [34] reported a proportional relationship between increasing concentrations of _Kappaphycus alvarezii_ meal (2-4%) and pH in chicken burgers. Likewise, [PERSON] et al. [35] reported similar results in beef burgers formulated with 0.025%, 0.05%, and 0.1% _Fucus vesiculosus_ extract. According to the authors, by day seven of storage, the pH had decreased less in the treatments with the three algae levels than in the control treatment. Possibly, the levels of alpha-tocopherol present in _Durvillaea antarctica_ could act as modulators of amino acid and lipid oxidation, limiting them [9]. This should be reviewed in upcoming studies. The effect of including _Durvillaea antarctica_ meal on the water-holding capacity (WHC) of beef burgers is presented in Figure 2. The literature indicates that WHC is strongly correlated with pH [36]. This is evident in the pH values observed in this study. The WHC of meat, or an experimental meat product such as beef burgers, is of the utmost importance for evaluating scaling processes, yield, and the profitability of commercialization. The greater the amount of water retained, the greater the product's weight and, consequently, its value. Conversely, a low water-holding capacity can also affect the product's appearance and therefore the consumer's desire to purchase it [37; 38]. In this study, we observed that the WHC of the beef burgers varied in relation to the amount of _Durvillaea antarctica_ meal incorporated into the meat matrices. Beef burgers made with 3.0% _D. antarctica_ meal showed the highest WHC (_p_ < 0.05), which was equal to but not better than the control (Figure 2). In this sense, several authors have pointed out that the physicochemical and absorbent properties of algae favor water retention and swelling capacity [39]. Other