A Pulsed Electric Field Accelerates the Mass Transfer during the Convective Drying of Carrots: Drying and Rehydration Kinetics, Texture, and Carotenoid Content

Abstract

The pulsed electric field (PEF) is a non-thermal food processing technology that induces electroporation of the cell membrane thus improving mass transfer through the cell membrane. In this study, the drying and rehydration kinetics, microstructure, and carotenoid content of carrot (Daucus carota) pretreated by PEF during convective drying at 50 °C were investigated. The PEF treatment was conducted with different field strengths (1.0–2.5 kV/cm) using a fixed pulse width of 20 µs and at a pulse frequency of 50 Hz. The PEF 2.5 kV/cm showed the shortest drying time, taking 180 min, whereas the control required 330 min for the same moisture ratio, indicating a 45% reduction in drying time. The rehydration ability also increased as the strengths of PEF increased. PEF 2.5 kV/cm resulted in 27.58% increase in moisture content compared to the control after rehydration (1 h). Three mathematical models were applied to the drying and rehydration data; the Page and Peleg models were selected as the most appropriate models to describe the drying and rehydration kinetics, respectively. The cutting force of the sample was decreased as the strength of PEF increased, and a more homogeneous cellular structure was observed in the PEF pretreatment group. The reduction in drying time by PEF was beneficial to the carotenoid content, and PEF 2.5 kV/cm showed the highest preservation content of carotenoid. Overall, these results suggested that the pretreatment of PEF and the drying and rehydration rate influence the quality of products, functional components, and cellular structure.

Impact of pre-meal immersion on multi-scale structural changes and starch digestibility of cooked dried noodles

“…35 The Peleg model is widely used to analyze the dynamics of water absorption during the rehydration process of dry materials. 36 It can be found in Fig. 2A that all samples were well fitted by the Peleg model ( R 2 > 0.99, RMSD < 0.05).…”

Kinetic and artificial neural network modeling of dried black beauty eggplant (Solanum melongenaL.) slices during rehydration

“…For instance, Demirhan and Özbek (2010) selected Weibull model ( R 2 = 0.9925–0.9987) as best for describing the rehydration kinetics (at 30°C) of microwave‐dried basil (at 180, 360, 540, 720, and 900 W), considering 25 g of sample. Moreover, Kim et al (2023) tested the effect of pulsed electric field (PEF) treatment on the mass transfer of convective dried carrots and checked the suitability of first‐order kinetic, Peleg, and two‐term models during their rehydration. Peleg model was superior, and calculated R 2 and RMSE values were as follows: 0.9854–0.9927 and 0.1282–0.1615, respectively.…”

“…Moreover, Kim et al (2023) tested the effect of pulsed electric field (PEF) treatment on the mass transfer of convective dried carrots and checked the suitability of first-order kinetic, Peleg, and two-term models during their rehydration. Peleg model was superior, and calculated R 2 and RMSE values were as follows: 0.9854-0.9927 and 0.1282-0.1615, respectively.…”

Analysis of the changes in quality and characteristics of hot air drying of Xinjiang jujube (Zizyphus jujuba Mill. cv. Junzao) following a delayed harvest

“…The jujube harvested at the S4–S6 stage rehydrated the fastest after drying, while that picked at the S1–S2 stage rehydrated the slowest. It is considered that the rapid thermal expansion and water-loss shrinkage during the hot air drying of jujube with a high initial moisture content caused more irreversible damage to the tissue structure of fruit and a poor intercellular water storage capacity 52 . The five indicators described above were combined with the drying time and the crack rate to assess jujube quality after hot air drying.…”