## Results and Discussion
### Proximate Composition and Physicochemical Parameters
Regarding the effect of the reformulation, we observed that the energy value decreased with decreasing the fat contents in the frankfurters among treatments. Thus, the lowest fat content and energy value during frankfurters analysis was observed in T0 samples (21.83% and 258.20 Kcal/100 g, respectively). The moisture presented the opposite trend in comparison with fat. The reformulated frankfurters (T2 and T3) had lower moisture content than the control (T0). Therefore, inverse and significant behavior were observed in the proximate (moisture and fat) composition according to the formulation. The higher moisture content in the control sausages determines that the rest of the parameters have a lower content in percentage terms, which explains the results obtained in our study. Moreover, murta addition also produced an increase in the total carbohydrate content of the frankfurters due to the high content on the fruit (75.4 % total carbohydrate; Table 1). However, although the murta contains about 7% of fiber, the reformulation did not influence ash (2.05-2.12%) nor crude fiber (0.41-0.44%). The low amounts of murta used in the reformulation (0.53%) could be the reason for this behavior. As a general conclusion, despite the significant differences that we have just mentioned, it should be noted that the proximate composition of the frankfurters of the different formulations was very similar, and the variations were minimal (<4% in moisture, <1.5% in fat, 0.3% in carbohydrates), while the rest of the parameters did not vary significantly. This agrees with the results previously observed by other researchers who found that the addition of fruit extract of strawberry tree (_Arbustus unted_ L.) and dog rose (_Rosa canina_ L.) or additives did not affect the chemical composition of frankfurters [1]. Another study also indicated that the chemical composition of the frankfurters was affected by the reduction/replacement of fat content more than the addition of fruits extracts or additives [40], which agree with the findings obtained in the present manuscript. On the other hand, taking into account that the fat is the main parameter that influences the energy content of foods (9 Kcal/100 g instead 4 Kcal/100 g in carbohydrates or proteins), it is expected that the fat content differences resulted also in differences in the energy content. In fact, a direct relation between fat and energy content was observed in our study, where the samples with the lowest fat values (T0) also presented the lowest energy values. This direct relation between the fat content and energy value was previously reported by other authors [5,40,42], who confirm our findings. Therefore, in the present research, the differences in energy values were due to the differences in fat content between samples. In the Chilean warning system implemented in June of 2019, the steps for discouraging food consumption with high content of unhealthy nutrients (sugar, saturated fat, sodium, and calories), consist into identifying the products that exceed pre-established thresholds and must include the octagonal signs with the expression \"High in... \" for each nutrient. Regarding the calories, the threshold is 275 kcal/100 g [43]. In this sense, in the present study, only the frankfurters formulated with chemical antioxidant (Plus Color; T1) need to include the octagonal sign for calories since the control and murta reformulated samples presented lower energy values than the threshold (258.2 and 271.4 Kcal/100 g for T0 and T2, respectively). Our findings show that murta addition only increased the sodium content by 2.29% and the chemical antioxidant increased by 49% of sodium compared with the control treatment. This result was expected since the sodium content of chemical antioxidant (20.7 g/100 g, Table 1) was extremely higher than those found in the murta (51.2 mg/100 g, Table 1).