Kim Si-Yeon, Lee Byung-Min, Hong Seok-Young, Yeo Hyun-Ho, Jeong Se-Ho, Lee Dong-Un
Department of Food Science and Technology, Chung-Ang University, Anseong 17546, Republic of Korea.
Foods. 2023 Jan 30;12(3):589. doi: 10.3390/foods12030589.
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 () 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.
脉冲电场（PEF）是一种非热食品加工技术，它能诱导细胞膜发生电穿孔，从而改善物质通过细胞膜的传递。在本研究中，对胡萝卜（）在50℃对流干燥过程中经脉冲电场预处理后的干燥和复水动力学、微观结构及类胡萝卜素含量进行了研究。脉冲电场处理采用固定脉冲宽度20µs、脉冲频率50Hz，不同场强（1.0 - 2.5 kV/cm）。2.5 kV/cm的脉冲电场干燥时间最短，为180分钟，而对照组达到相同含水率需要330分钟，干燥时间缩短了45%。复水能力也随脉冲电场强度的增加而提高。复水（1小时）后，2.5 kV/cm脉冲电场处理组的含水率相比对照组提高了27.58%。将三个数学模型应用于干燥和复水数据；分别选择Page模型和Peleg模型作为描述干燥和复水动力学最合适的模型。随着脉冲电场强度的增加，样品的切割力降低，在脉冲电场预处理组观察到更均匀的细胞结构。脉冲电场缩短干燥时间对类胡萝卜素含量有益，2.5 kV/cm脉冲电场处理组的类胡萝卜素保存量最高。总体而言，这些结果表明脉冲电场预处理以及干燥和复水速率会影响产品质量、功能成分和细胞结构。
