# Current Applications of Ultrasound in Fruit and Vegetables Osmotic Dehydration Processes
## 5 Properties of the Product Treated with US before or during OD
### Functional Properties of the Product Treated with US before or during OD
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Product** & **Treatment Applied** & **Functional Properties after OD** & \
\begin{tabular}{c} **Functional Properties after** \\ **Drying** \\ \end{tabular} \\ \hline Apricot [119] & OD (55 \({}^{\circ}\)C, 30 and 45 min) + edible coating (P, P+CA, P+AA) & Decrease in TPC and vitamin C & The highest retention of TPC and vitamin C was noticed in OD \\ Apricot [119] & OD (55 \({}^{\circ}\)C, 30 and 45 min) + edible coating (P, P+AA) & Decrease in TPC and vitamin C &
\begin{tabular}{c} samples coated by P+AA \\ followed by UOD and P+AA \\ samples. Both treatments led to a \\ higher antioxidant activity. \\ UOD and P+CA coating \\ preserved better the \\ \(\beta\)-carotene content. \\ \end{tabular} \\ \hline Blueberries & UOD (25 kHz, amplitude of—20, 60 and 100\%; 61.5\% sucrose solution at \\
[106] & 30, 40 and 50 \(\circ\)C for 20, 40 and 60 min) &
\begin{tabular}{c} The optimal conditions for the \\ highest antioxidant activity and \\ total content of anthocyanins, \\ flavonoids and polyphenols were \\ obtained by using 30 \({}^{\circ}\)C for 40 min \\ at a 100\% amplitude. \\ \end{tabular} & - \\ \hline Sour cherries [120] & UOD (25 kHz, 60\% sucrose solution for 0–120 min, shaking 30 rpm for 0–120 min, 40 \({}^{\circ}\)C) & Total anthocyanins and TPC & After drying, a further decrease of each compound was observed, confirming the trend observed in OD samples. \\ \hline Sweet potatoes [118] & OD (10–20\% glucose, 10–45 min) & & Better preservation of TPC and TF was observed in OD samples, while antioxidant activities were improved by US alone or in combination with OD. \\
10-45 min & & & The vitamin C was retained better in UOD samples. \\ \hline
[117] & UOD (28 kHz, 300 W, 20–60 min) & \begin{tabular}{c} \textgreater{}70\% of vitamin C retention, \\ however higher loss of carotenoids \\ was noticed in UOD samples in \\ comparison to OD ones. \\ \end{tabular} & - \\ Sweet potatoes [117] & UOD (20 kHz, 10–45 min) & - & Higher retention in vitamin C content was reported in UOD samples (46.0\%), than in US (31.28\%) and OD ones (25.95\%). \\ \hline Apples [115] & OD (30 \({}^{\circ}\)C, 30 min); US (20 kHz, 300 W/L) & - & \begin{tabular}{c} Higher retention in vitamin C content was reported in UOD \\ samples (46.05\%), than in US \\ (31.28\%) and OD ones (25.95\%). \\ \end{tabular} \\ \hline Strawberry [114] & UOD (40 kHz, 21 min, 20–31 \({}^{\circ}\)C; 47.5 \({}^{\circ}\)Brix) & - & \
\begin{tabular}{c} TPC content decreased in the \\ dried samples in the similar range \\ for samples with UOD \\ pretreatment and those just dried. \\ \end{tabular} \\ \hline Kiwifruits [108] & US (35 kHz, 10–30 min) and/or OD (61.5 \({}^{\circ}\)Brix, 120 min, 25 \({}^{\circ}\)C) & US pretreatment for 20 and 30 min \\ \hline Kiwifruits [108] & US (35 kHz, 10–30 min) and/or OD (61.5 \({}^{\circ}\)Brix, 120 min, 25 \({}^{\circ}\)C) &
\begin{tabular}{c} US pretreatment for 20 and 30 min \\ significantly enhanced the \\ chlorophyll content in kiwifruit if \\ compared to OD samples. \\ \end{tabular} & - \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._Concerning the vitamin C, its content and behavior upon the application of different treatments strongly depended on the type of product and combination of different pre-treatments. In sweet potato, US application allowed better retention of vitamin C in the final osmo-dehydrated product [117] and hot air-dried product [118]. Similarly, in dried apple samples, [PERSON] et al. [115] observed a higher retention of vitamin C when apples were subjected to a pretreatment with UOD rather than to US and OD alone. In apricot, UOD-treated samples [119], instead, a higher decrease of vitamin C was observed if compared to the untreated samples or those treated just with OD. This decrease was proportional to the increase in the frequency and treatment duration. A similar relation was observed also after the hot-air drying of apricot cubes [119]. [PERSON] et al.