# Processing Fresh-Cut Potatoes Using Non-Thermal Technologies and Edible Coatings
## 5 Emerging Processing Technologies: Operating Principles and Examined Parameters
### Miscellaneous Technologies
#### 5.5.1 Ultrasound  
The operating principle of ultrasound treatment in food preservation involves the application of high-frequency ultrasound waves, typically exceeding 20 kHz, with high-intensity (10-1000 W/cm\({}^{2}\)) and low-frequency (18-100 kHz) characteristics. Ultrasound \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Materials** & **Processing Conditions** & **Storage Conditions** & **Reference** \\ \hline OH & 20 and 40 V/cm, exposure: 2 and 4 min, final temperature after 4 min at 40 V/cm: 65 \({}^{\circ}\)C, electrode distance: 10 cm, electrode size: & - & [159] \\ \hline OH & 15 and 30 V/cm, time: 5 and 10 min at 30, 60 and 90 \({}^{\circ}\)C, anthocyanin and extraction & - & [161] \\ \hline OH with convective drying & Applied voltage: 112 V, needle-shape electrodes: 3 mm in diameter, air velocity: & - & [160] \\ \hline Ultrasound & 20 kHz frequency, 500 W/cm\({}^{-2}\) power intensity & 2 and 4 min, final temperature = 23 \({}^{\circ}\)C & - & [159] \\ \hline Ultrasound & 40 kHz, 200 W, immersion: 1, 5 and 10 min, 20 g/L citric acid & 12 d, \(3\pm 1\) \({}^{\circ}\)C & [116] \\ \hline Ultrasound & 40 kHz, 5 min, 20 g/L citric acid & 12 d, \(3\pm 1\) \({}^{\circ}\)C & [98] \\ \hline Ultrasound & 40 kHz, 480 W, 10 min & 8 d, 4 \({}^{\circ}\)C & [162] \\ \hline Ultrasound & Acoustic intensity 0.75 W/m\({}^{2}\) for 5 min, frequency: 40 kHz, potato slices packed in PE bags & 8 d, 4 \({}^{\circ}\)C & [163] \\ \hline Ultrasound-assisted OD & Osmotic solution: NaCl + maltodextrin (30\% & & \\ Ultrasound-assisted OD & \(w/w\)), 60 min immersion at 45 \({}^{\circ}\)C\({}_{p}\) potato cubes/solution = 1:40 (20 g/L), electrical power: 130 W, frequency: 20 kHz & - & [6] \\ \hline Ultrasound + catus & 40 kHz, 480 W, 10 min, 1% \(w/w\)CP, potato slices to solution = 1:4 & 8 d, 4 \({}^{\circ}\)C & [162] \\ \hline Ultrasound + _Portulaca oleran_ (purslane) extract & Ultrasound: 40 kHz, 630 W, 10 min, purslane extract 0.02 \(w/w\), packaged in PE self-sealing bags & 8 d, 4 \({}^{\circ}\)C & [164] \\ \hline UV-C irradiation & Immersion of slices in sodium ascorbate (2\% \(m/v\)) for 3 min, vacuum-packed in PA/PE bags, UV-C irradiation: 2.70 kJ/m\({}^{2}\) for 5 min & 15 d, 6 \({}^{\circ}\)C & [11] \\ \hline UV-C irradiation & 2-5 min irradiation time, packed in PE bags & 5 d, 4 \({}^{\circ}\)C & [165] \\ \hline UV-C irradiation & Irradiation dose: 13.68 kJ/m\({}^{2}\), packed in closed plastic boxes & 10 d, 4 \({}^{\circ}\)C & [166] \\ \hline UV-C irradiation +ascorbic acid + CaCl\({}_{2}\) & 1\% \(w/v\) ascorbic acid and 0.1\% \(w/v\) CaCl\({}_{2}\), dipping for 5 min at 4 \({}^{\circ}\)C, irradiation dose: 6.84 kJ/m\({}^{2}\), packed in closed plastic boxes & 10 d, 4 \({}^{\circ}\)C & [166] \\ \hline PPA & 10 min, vacuum-packed & \(-80\) \({}^{\circ}\)C & [94] \\ \hline CP & Power = 900 W, treatment time = 40 min & - & [110] \\ \hline PAW process & 200 Hz-PAW, optimized discharge time = 10 min & 5 d, 4 \({}^{\circ}\)C & [167] \\ \hline \hline \end{tabular}  
* PE: polyethylene.  
\end{table} 
Table 6: Other technologies for processing fresh-cut potatoes *. treatment is based on the phenomenon of cavitation, which refers to the formation, oscillation, and collapse of microbubbles in a liquid [168]. The output power (W) divided by the beam area (cm\({}^{2}\)) defines the power intensity of the ultrasonic probe. This process generates localized extreme conditions, including high temperatures and pressures, which have various effects on the food matrix. This process facilitates the inactivation of enzymes by inducing the leakage of cell membranes, making ultrasound technology integral in mitigating the effect of browning on fresh-cut potatoes [98]. Notably, ultrasonication plays a dual role in facilitating wound healing and maintaining the membrane integrity of fresh-cut produce [163]. The versatility of sonication in the food industry holds immense potential for enhancing sustainability in production.