## 3 Results and Discussion
### Fatty-Acid Profile  
Brown seaweed such as as _Durvillaea antarctica_ has a low lipid content compared to marine fish [48]. However, the lipid fraction may contain higher levels of polyunsaturated essential fatty acids compared to vegetables [9; 49]. In this study, the impact of the inclusion of four levels of \(D\). _antarctica_ as a functional ingredient on the fatty-acid profile (%) and cholesterol levels (mg/100 g) of beef burgers was investigated. The fatty-acid profile, nutritional indices, and cholesterol are shown in Table 4. In order, the main groups of FAs found were saturated fatty acids (SFA), 44-52%; monounsaturated fatty acids (MUFA), 33-42%; and polyunsaturated fatty acids (PUFA), 12-15%, approximately. The inclusion of \(D\). _antarctica_ significantly modified the content of SFA, MUFA, and PUFA in beef burgers. A  
\begin{table} \begin{tabular}{l c c c c c} \hline \hline
**Color** & **Control** & **Da0.5\%** & **Da1.0\%** & **Da1.5\%** & **Da3.0\%** & \(p\)**Value** \\ \hline a* & 28.4 \(\pm\) 0.82 a & 22.3 \(\pm\) 0.82 b & 21.6 \(\pm\) 0.82 b & 21.1 \(\pm\) 0.824 b & 16.7 \(\pm\) 0.824 c & 0.001 \\ b* & 18.6 \(\pm\) 0.55 a & 18.0 \(\pm\) 0.55 a & 18.3 \(\pm\) 0.55 a & 18.6 \(\pm\) 0.552 a & 17.8 \(\pm\) 0.552 a & 0.744 \\ c* & 34.0 \(\pm\) 0.86 a & 28.7 \(\pm\) 0.86 b & 28.3 \(\pm\) 0.86 b & 28.2 \(\pm\) 0.862 b & 24.4 \(\pm\) 0.862 c & 0.001 \\ L* & 43.0 \(\pm\) 1.24 a & 43.6 \(\pm\) 1.24 a & 44.4 \(\pm\) 1.24 a & 42.0 \(\pm\) 1.245 a & 42.8 \(\pm\) 1.245 a & 0.718 \\ h* & 34.5 \(\pm\) 1.17 c & 39.0 \(\pm\) 1.17 b & 40.9 \(\pm\) 1.17 b & 41.4 \(\pm\) 1.17 b & 46.9 \(\pm\) 1.17 a & 0.001 \\ \hline \hline \end{tabular}  a  
decrease in SFA was observed in the Da1.0% treatment, and the MUFA content increased proportionally by 1.0, 6.0, and 7.0% for the Da1.0%, Da1.5%, and Da3.0% treatments, respectively. This improvement in the MUFA content of the burgers was mainly determined by the increase in oleic acid content (C18:In9), a major component of biological membranes. Recently, these types of lipids have been associated with the prevention of cardiovascular and metabolic diseases [50]. Oleic acid is the most abundant fatty acid in \(D\). _antarctica_, constituting 25.83% of the total number of fatty acids found in stems [9]. In addition, it has been reported that \(D\). _antarctica_ contains other nutritionally important fatty acids, such as C18:2n6 (linoleic acid) and C18:3n3 (linolenic acid) and the eicosanoid precursors C20:4n6 (arachidonic acid) and C20:5n3 (eicosapentaenoic acid, or EPA) [9]. However, in general, the C18:2n6 and C18:3n3 concentrations were not related to the inclusion of \(D\). _antarctica_ in any of the beef burger groups, as well as DHA (C22:6n3). Regarding the overall PUFA content, only the Da1.0% treatment was significantly higher than the control (by approximately 0.70%). Although there is no consensus on this, it has long been said that fatty acids can reduce human health because they are involved in mechanisms that favor the development of cardiovascular diseases, which even makes some countries incorporate a distinctive seal on food labels (e.g., traffic lights, black octagons, etc.) which indicates that foods such as meat products have high levels of saturated fats (>4.0%). The inclusion of 1.0, 1.5, and 3.0% \(D\). _antarctica_ meal produced a slight but statistically significant decrease (\(p<0.05\)) in lauric acid (C12:0), myristic acid (C14:0), palmitic acid (C16:0), and stearic acid (C18:0). On the other hand, the statistical analysis also showed significant differences in the total levels of omega 3 (n3) and the n3/n6 ratio, observing that the levels of n3 differences were manifested with a lower index in the treatments with 1.0 and 1.5% meal compared to the control. Additionally, the cholesterol concentration of the burgers was approximately 109-113 mg/100 g. A significant reduction (\(p<0.05\)) in cholesterol was observed for beef burgers with 3.0% D. antarctica meal, which could be related to the fact that unstudied components of \(D\).