## 3 Results
### GOS Application in a Dairy Product  
GOS syrup production for the application in a baby porridge was performed following the protocol mentioned in the section before, with a reaction time of 0.5 h to guarantee a maximum GOS concentration in solution. The syrup was concentrated to 75% (\(w/w\)) soluble solids and was applied as is in the product (Figure 3). Composition of the GOS syrup is presented in Table 3.  
Figure 3: GOS syrup at 75% \(w/w\) of soluble solids. Figure 2: Distribution of carbohydrates in solution during the enzymatic production of GOS. Carbohydrates identified include galactose, glucose, lactose and GOS with degrees of polymerization 2 (DP2), 3 (DP3) and 4 (DP4). No larger oligomers were found in the samples. For the formulation of the GOS-added porridge, a content of 3 g GOS per portion of 100 g of porridge was stablished. Formulation of the original porridge (control) and the GOS-added porridge is presented in Table 1.  
Physicochemical characteristics, including pH, soluble solids, and color (Lab coordinates) of the control and GOS-added porridge is presented in Table 4.  
The pH of the control was slightly higher than the GOS-added porridge due to the lower pH of the GOS syrup (5.8) compared to the porridge matrix (5.9-6); however, this change did not significantly modify the organoleptic characteristics of the porridge with GOS. The color also remains very similar between the control and the test, with a small variation on the Lab coordinates that were not perceived by the human eyes. Concentration of soluble solids was the major difference between the samples, increasing by 50% when the GOS syrup is added. This is an expected result since the amount of syrup added, at a soluble solids concentration of 75%, was balanced by removing water (0% soluble solids) from the formulation, which resulted in a higher concentration of soluble solids in the GOS-added porridge. To evaluate the effect of the changes in pH, color, and soluble solids concentration on the organoleptic characteristics of the control and GOS-added porridge, a blind paired comparison test was performed with ten panelists. Statistically, no perceived difference was noticed in color and odor between the two samples presented (Figure 4). However, with a 0.05 significance level, differences in flavor and texture were noticed by the panelists. Some comments on the flavor of the GOS-added porridge included: \"fruit notes are more intense;\" \"better balance in flavor;\" \"sweeter, more flavor.\" On the other hand, for the texture test, the only comment said \"_thicker_\". This outcome was expected given the sweetener capacity of the syrup, as it contains a significant amount of lactose, glucose, and GOS, all of them with a relative sweetness between 0.3 to 0.7 (when compared to sucrose, 1). Additionally, the higher concentration of soluble solids in the GOS-added porridge, necessarily affects the texture and mouthfeel of the product, which was perceived as an improvement by the panelists. These results are similar to those reported by [PERSON] and others [29], where a sygohurt was supplemented with 6% db of a GOS syrup. The sensory characteristics of a regular yoghurt and GOS-added yoghurt were analyzed by a trained panel through a quantitative descriptive analysis (QDA), resulting in a statistically higher qualification of creaminess, sweetness, and mouth feel for the GOS-added product. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & & & **Color** & \\ \hline  & **pH** & **\% SS * & **L** & **a** & **b** \\ \hline Control & 5.97 & 10.7 & 63.05 & 6.29 & 15.31 \\ GOS-added & 5.87 & 16 & 66.55 & 5.12 & 16.72 \\ \hline \hline \end{tabular}
* Percentage of soluble solids.  
\end{table} 
Table 4: Physicochemical characteristics of original porridge (control) and GOS-added porridge.