## 2 Results and Discussion  
### Physicochemical Characterization  
Table 1 presents the results obtained for the physicochemical parameters of the tropical fruit pulps and the elaborated blend. The water contents of the pulps and blend ranged from 85.50 to 92.39%, with higher percentages in acerola and pitanga, not statistically different (\(p>0.05\)) between them. [PERSON] et al. [9], when evaluating the water content of acerola pulps, identified an average value of 90.75 g/100 g, close to that identified in this work. Studying this same parameter in guava pulp, [PERSON] et al. [10] found a value of 85.60 g/100 g, while [PERSON] et al. [11] and [PERSON] et al. [12] reported mean values of 83.5 and 89.78 g/100 g, respectively, also close to those shown in Table 1. [PERSON] et al. [13] found values of 90.06, 83.44 and 88.18 g/100 g in yellow, purple, and orange passion fruit pulp, respectively, levels close to those found in this work. Blends of pitaya with acerola combined in different proportions presented water contents ranging from 87.96 to 89.86 g/100 g [14] in the same range of value obtained in this study. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Parameters** & **acerola** & **Guava** & **Pitanga** & **Blend** \\ \hline Water content (g/100 g) & 92.07 \(\pm\) 0.01 A & 85.50 \(\pm\) 0.38 C & 92.39 \(\pm\) 0.23 A & 89.52 \(\pm\) 0.28 B \\ Water activity & 0.992 \(\pm\) 0.00 C & 0.996 \(\pm\) 0.00 AB & 0,997 \(\pm\) 0 A & 0.994 \(\pm\) 0.00 BC \\ Total titratable acidity (g citric acid/100 g) & 2.57 \(\pm\) 0.05 C & 1.29 \(\pm\) 0.03 D & 3.42 \(\pm\) 0.06 A & 2.81 \(\pm\) 0.05 B \\ pH & 3.52 \(\pm\) 0.02 B & 4.11 \(\pm\) 0.06 A & 3.18 \(\pm\) 0.08 D & 3.39 \(\pm\) 0.03 C \\ Ashes (g/100 g) & 0.36 \(\pm\) 0.01 B & 0.49 \(\pm\) 0.02 A & 0.30 \(\pm\) 0.01 C & 0.37 \(\pm\) 0.02 B \\ Total soluble solids (\({}^{\circ}\)Brix) & 9.73 \(\pm\) 0.05 A & 10.08 \(\pm\) 0.05 A & 3.60 \(\pm\) 0.08 B & 9.88 \(\pm\) 0.48 A \\ Total sugars (g glucose/100 g) & 1.25 \(\pm\) 0.02 C & 9.55 \(\pm\) 0.00 A & 0.48 \(\pm\) 0.00 D & 6.09 \(\pm\) 0.00 B \\ Reducing sugars (g glucose/100 g) & 1.03 \(\pm\) 0.00 C & 9.13 \(\pm\) 0.01 A & 0.44 \(\pm\) 0.00 D & 5.68 \(\pm\) 0.38 B \\ Non-reducing sugars (g sucrose/100 g) & 0.22 \(\pm\) 0.02 AB & 0.42 \(\pm\) 0.01 A & 0.03 \(\pm\) 0.00 B & 0.41 \(\pm\) 0.38 A \\ \hline \hline \end{tabular}  
* Means followed by the same letters in the lines do not differ statistically according to [PERSON]’s test at 5% probability (\(p\geq 0.05\)).  
\end{table} 
Table 1: Physicochemical characterization of acerola, guava and pitanga pulp and the blend prepared. All pulps showed high water activity (a\({}_{w}\) > 0.98), indicating a favorable substrate for the growth of microorganisms, biochemical reactions and, consequently, rapid deterioration. Close results were identified by [PERSON] et al. [15] both for acerola pulp (0.988) and for acerola and jabuticaba blends, which ranged from 0.988 to 0.993, and by [PERSON] et al. [14] in acerola and pitaya blends, ranging from 0.989 to 0.992. Pitanga had the highest total titratable acidity (TTA) (3.42 g citric acid/100 g) and guava had the lowest (1.29 g citric acid/100 g), with the blend remaining close to the value determined in acerola (2.57 g citric acid /100 g). The pH determined in the acerola pulp is similar to that reported by [PERSON] et al. [9] in the acerola variety 'Flor Branca', whose average value corresponded to 3.47, and by [PERSON] et al. [16] when evaluating fruits of 20 accessions of acerola trees, in which they found an average value of 3.72, with variation in total acidity between 0.72 and 1.17 g/100 g. Both parameters meet the values recommended in Brazilian legislation, which indicates a minimum of 2.8 for pH and 0.8 g/100 g for total titratable acidity in acerola pulps [17]. For the other pulps, there is no prescription. [PERSON] et al. [18], when evaluating Golden pitaya pulp, determined a pH of 4.79. Products with low pH have reduced enzymatic activity and microbial growth, meeting the preference of agroindustries [14].