## 3 Results and Discussions
### Color Measurements
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Power (kHz)**} & \multirow{2}{*}{**Time (min)**} & \multirow{2}{*}{**Parameter**} & \multicolumn{6}{c}{**Days after Treatment**} \\ \cline{3-10}  & & & **0** & **4** & **8** & **12** & **16** & **20** \\ \hline \multirow{8}{*}{30} & Control & & 41 \(\pm\) 0 aA & 40 \(\pm\) 2 aA & 40 \(\pm\) 2 aA & 42 \(\pm\) 1 aB & 42 \(\pm\) 2 aA & 47 \(\pm\) 1 bC \\  & 10 & & 49 \(\pm\) 1 dC & 42 \(\pm\) 1 bB & 42 \(\pm\) 1 bB & 39 \(\pm\) 1 aA & 44 \(\pm\) 2 cB & 42 \(\pm\) 2 bA \\  & 20 & & 42 \(\pm\) 1 aA & 42 \(\pm\) 2 aB & 42 \(\pm\) 0 aB & 44 \(\pm\) 1 bC & 46 \(\pm\) 2 cC & 46 \(\pm\) 1 cB \\  & 30 & L\({}^{*}\) & 46 \(\pm\) 2 cB & 39 \(\pm\) 1 aA & 39 \(\pm\) 1 aA & 41 \(\pm\) 1 bB & 42 \(\pm\) 1 bA & 45 \(\pm\) 1 cB \\  & 10 & & 46 \(\pm\) 3 aB & 46 \(\pm\) 2 aC & 46 \(\pm\) 2 aC & 46 \(\pm\) 1 aC & 48 \(\pm\) 2 aC & 53 \(\pm\) 3 bD \\
40 & 20 & & 45 \(\pm\) 3 cB & 40 \(\pm\) 1 aA & 42 \(\pm\) 1 bB & 46 \(\pm\) 1 cD & 46 \(\pm\) 1 cC & 50 \(\pm\) 0 dD \\  & 30 & & 41 \(\pm\) 1 aA & 42 \(\pm\) 2 aB & 43 \(\pm\) 2 abB & 44 \(\pm\) 2 bC & 44 \(\pm\) 2 bB & 45 \(\pm\) 3 bB \\  & Control & & 6 \(\pm\) 1 aA & 8 \(\pm\) 1 cA & 7 \(\pm\) 0 bA & 5 \(\pm\) 1 aA & 5 \(\pm\) 1 aA & 8 \(\pm\) 1 cC \\  & 10 & & 11 \(\pm\) 1 cC & 9 \(\pm\) 1 bB & 8 \(\pm\) 1 bB & 7 \(\pm\) 1 aB & 6 \(\pm\) 1 aA & 6 \(\pm\) 0 aB \\
30 & 20 & & 7 \(\pm\) 1 aA & 8 \(\pm\) 1 bA & 9 \(\pm\) 1 bB & 9 \(\pm\) 1 bC & 6 \(\pm\) 1 aA & 7 \(\pm\) 1 aB \\  & 30 & a\({}^{*}\) & 8 \(\pm\) 1 bB & 8 \(\pm\) 0 bA & 8 \(\pm\) 1 bB & 7 \(\pm\) 1 aB & 6 \(\pm\) 1 aA & 7 \(\pm\) 1 aB \\  & 10 & & 11 \(\pm\) 2 bC & 10 \(\pm\) 2 bB & 10 \(\pm\) 1 bC & 8 \(\pm\) 2 aB & 6.9 \(\pm\) 0.3 aB & 10 \(\pm\) 1 bD \\
40 & 20 & & 9 \(\pm\) 2 bB & 9 \(\pm\) 0 bB & 9 \(\pm\) 1 bB & 7 \(\pm\) 3 abB & 7 \(\pm\) 1 abB & 8 \(\pm\) 1 bC \\  & 30 & & 7 \(\pm\) 1 bA & 7 \(\pm\) 1 bA & 7 \(\pm\) 1 bA & 7 \(\pm\) 0 bB & 6 \(\pm\) 1 aA & 5 \(\pm\) 1 aA \\  & Control & & 20 \(\pm\) 1 aA & 23 \(\pm\) 2 bB & 23 \(\pm\) 3 abA & 27 \(\pm\) 1 cB & 27 \(\pm\) 3 cC & 28 \(\pm\) 1 dB \\  & 10 & & 32 \(\pm\) 2 bD & 23 \(\pm\) 1 aB & 23 \(\pm\) 1 aA & 24 \(\pm\) 1 aA & 23 \(\pm\) 3 aAB & 23 \(\pm\) 1 aA \\
30 & 20 & & 24 \(\pm\) 1 bB & 22 \(\pm\) 1 aB & 24 \(\pm\) 2 abA & 31 \(\pm\) 3 cC & 25 \(\pm\) 1 bC & 26 \(\pm\) 3 bB \\  & 30 & b\({}^{*}\) &The increase in redness (a*) and yellowness (b*) may be related to the isomerization of carotenoids present in the _gulupa_ pulp [57], which can form compounds with brown color characteristics, similar to those that occur in the browning process. According to [PERSON] et al. [11], any change in the values of the parameters a* and b* is associated with a simultaneous change in luminosity value (L*) as observed in this experiment, mainly in shelf life. In addition, they increase with the application of ultrasound treatments but decrease with exposure time (day 0). The values found for \(\Delta\)E* (Table 5) showed that all treatments (day 0) had significant changes compared to the control and that these changes can be perceptible by the human eye (\(\Delta\)E > 2) [58]. The smallest global color difference (\(\Delta\)E) for the control was found in the 40 kHz treatment at 30 min through the entire shelf life (day 0 to 20), besides presenting minor variations, possibly related to the lower loss of ascorbic acid in this treatment caused by the rapid elimination of gases dissolved in the pulp. Most of the treatments with ultrasound showed a \(\Delta\)E* decreasing trend, presenting values lower than the control, especially on day 16. The trend continued until day 20 except for samples treated at 40 kHz at 10 and 20 min, which remained at values higher than the control. In the untreated pulp (control), there is a tendency to increase the color parameters L*, a*, and b*, which involves many aspects that can influence the \(\Delta\)E*, as was mentioned already. However, these changes can sometimes be desirable because they reinforce its natural color and increase pigment content.