A Novel Approach to Improving the Rehydration of Freeze-Dried Potatoes through Electrical Treatment

Abstract

Rehydration significantly impacts the quality of dehydrated foods, especially vegetables. Factors like porosity are key in this process. Our study introduces a novel method for enhancing the rehydration of freeze-dried potatoes using electrical treatment. By applying a DC voltage across electrodes with the sample between them, at an electrical field strength of up to 30 V/cm for 1 min, we observed improved rehydration ratios compared to untreated samples. Electrically treated specimens reached a rehydration ratio of 4.1 in 1.5 min, whereas untreated specimens reached only 2.1 in the same timeframe. SEM micrograph evaluation of freeze-dried potato specimens, pre-and post-electric treatment, revealed a significant increase in pore count and surface area in the treated samples compared to untreated ones. This heightened porosity likely contributes to the observed higher rehydration ratio in the treated specimens. Furthermore, the treated samples presented a softer texture, which is advantageous for applications such as potato flakes used in puree production. Additionally, electrically treated specimens exhibited higher L * values, indicating increased lightness relative to untreated specimens.