# Processing Fresh-Cut Potatoes Using Non-Thermal Technologies and Edible Coatings
## 5 Emerging Processing Technologies: Operating Principles and Examined Parameters
### Conventional and Novel Anti-Browning Agents  
Inorganic and organic compounds have been tested as anti-browning agents in order to slow down PPO activity and prolong the durability of fresh-cut potatoes. Typically, fresh-cut potatoes undergo immersion in anti-browning solutions, composed of either a single substance or a combination of compounds, to mitigate discoloration. This preventive action occurs through three main mechanisms: firstly, by lowering the pH to levels below 4; secondly, by chelating copper from PPO molecules, thereby disrupting their structure; and thirdly, by reducing o-quinones back to phenolics [187]. This reduction inhibits oxidation \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Technology** & **Pros** & **Cons** \\ \hline OD & Retains sensory qualities (texture, flavor); supports microbial stability with minimal heat application & Nutrient loss due to osmotic process; requires large volumes of osmotic solution, increasing costs \\ \hline HPP & Effective microbial inactivation without nutrient loss; preserves sensory qualities & High equipment and packaging costs; limited suitability for small facilities \\ \hline PEF & Enhances texture and reduces oil absorption in fried products; energy-efficient & Scalability challenges; requires optimization of parameters for consistent results \\ \hline OH & Rapid, uniform heating with lower energy consumption than conventional heating; environmentally friendly & Challenges with electrode corrosion; scalability issues in large industrial settings \\ \hline Ultrasound & Enhances mass transfer; can be combined with other treatments for increased effectiveness & Limited by high-power requirements; potential tissue damage in sensitive products \\ \hline Irradiation & Strong microbial inactivation; prolongs shelf life effectively & Consumer perception issues; regulatory restrictions in certain regions \\ \hline Plasma Treatment & Effective in reducing microbial load; no chemical residues left on products & Scalability issues; equipment costs and technical complexity \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Comparison of non-thermal technologies for fresh-cut potato shelf life extension: advantages and limitations. and the subsequent polymerization of phenolics into colored melanins. It is worth noting that the effectiveness of an anti-browning agent relies on factors such as its concentration and the pH of the solution [18]. Chemicals such as ascorbic acid, sodium bisulfite, potassium bisulfite, and sodium metabisulfite are considered low-cost products and are readily available on the market; they have been certified as safe food additives by the U.S. Food and Drug Administration [165; 188]. Their acidity differs since sodium bisulfite is a stronger acidic medium (\(pK_{a}=2.0\)) than citric acid (\(pK_{a}=3.1\)) and ascorbic acid (\(pK_{a}=4.1\)) [165]. Immersion of fresh-cut vegetables in acidic solutions leads to a pH decrease at the cut surface and a reduction in browning, since pH values below 4 mark the limit of PPO activity, thus inhibiting enzymatic browning. While acidic solutions reduce browning, citric acid is particularly effective, setting the limit for PPO activity around pH 3.5, thus offering a more potent browning inhibition. Other studies have investigated acidification and alkalization using sulfuric acid or sodium hydroxide for browning control, finding that citric acid is more efficient than these alternatives due to its ability to lower the pH more effectively without adversely affecting texture or flavor. Notably, citric acid does not significantly alter the sensory properties of the treated vegetables, making it an ideal choice for browning prevention in fresh-cut produce [189]. Other researchers found that the potato cultivar (Birgit and Laidy Claire) affected the durability and quality properties of fresh-cut potato slices that received the same treatment [190]. This finding suggests the need for further studies focusing on appropriate cultivars.