## 3 Results and Discussion  
### Physicochemical Analyses  
Table 1 shows the physicochemical parameters of the extracts obtained for the natural sources used. The sterilization of the extracts caused an increase in the pH, the S\({}_{\text{B}}\) value was 16.9% higher than the S\({}_{\text{A}}\) values, while X\({}_{\text{B}}\) presented an increase of 21.87% with respect to X\({}_{\text{A}}\). This was related to the reduction of organic acids, such as ascorbic acid. Additionally, in the autoclave-sterilized extracts, the concentration of ascorbic acid due was reduced, due to the thermolabile character of the molecule, which could explain the increase of the pH in the sterilized samples. [29]. The contents of the total sugars during the sterilization process in sample S\({}_{\text{B}}\) increased by 13.4% with respect to S\({}_{\text{A}}\), and the reducing sugars content increased by 33.1%; however, they were not statistically different according to the Tukey test (_p_ < 0.05). Meanwhile, in the X\({}_{\text{B}}\) samples, the content of total sugars increased by 13.0%, and the reducing sugars by 10.98%; their increase may have been due to thermal hydrolysis processes from heating during the autoclave sterilization, generating a break in the bonds of the glycosylated compounds, and increasing the concentration the concentrations of simpler sugars [30]. Regarding the color of the extracts, it was observed that sterilized extracts of dragon's blood became darker with an amber hue with respect to the non-sterilized extracts; this was due to the reduction of luminosity and the increase of the b\({}^{*}\)-value, which tended to the color yellow (Table 2). The color change in the dragon's blood rhizome extracts could be linked to caramelization or Maillard reactions, due to the presence of sugars and the conditions of elevated temperature during the process of autoclave-sterilization [15]. The non-sterilized xoconostle extracts had a reddish coloration (greater \(a^{\star}\) value and lower luminosity), compared to the sterilized extracts. In the latter case, this may be due to the loss of betalains that are responsible for attributing a red coloration to the fruits of xoconostle, as also occurs in other Cactaceae fruits [8; 31]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Samples** & **pH** & **TSC (mgGluE/g DW)** & **RS (mgGluE/g DW)** & **ASC (mgASCE/100 g DW)** \\ \hline S\({}_{\text{A}}\) & 5.60 \(\pm\) 0.17b & 158.20 \(\pm\) 6.40c & 87.10 \(\pm\) 1.28c & 267.30 \(\pm\) 30.07b \\ S\({}_{\text{B}}\) & 6.55 \(\pm\) 0.50a & 179.44 \(\pm\) 7.02c & 116.01 \(\pm\) 6.40c & 99.53 \(\pm\) 24.73d \\ X\({}_{\text{A}}\) & 3.20 \(\pm\) 0.35d & 503.00 \(\pm\) 26.19b & 466.60 \(\pm\) 16.81b & 443.70 \(\pm\) 20.84a \\ X\({}_{\text{B}}\) & 3.90 \(\pm\) 0.25c & 568.46 \(\pm\) 19.20a & 517.84 \(\pm\) 9.30a & 280.02 \(\pm\) 16.18b \\ \hline \hline \end{tabular}  
* Letters in each column indicate statistically significant differences; pH was measured at extract concentrations of 10 mg/mL at 25.5 \({}^{\circ}\)C; TSC: total sugar content; RS: reducing sugars; ASC: ascorbic acid; S\({}_{\text{A}}\): unsterilized dragon’s blood rhizome extract; S\({}_{\text{B}}\): autoclave-sterilized dragon’s blood rhizome extract; X\({}_{\text{A}}\): unsterilized xoconostle fruit extract; X\({}_{\text{B}}\): autoclave-sterilized xoconostle fruit extract; GluE: Glucose equivalents; DW: dry weight of the sample; ASCE: ascorbic acid equivalents.  
\end{table} 
Table 1: Physical–chemical analysis of non-sterilized or autoclave-sterilized dragon’s blood rhizome and xoconostle fruit extracts.