College of Engineering, China Agricultural University, P.O. Box 194, 17 Qinghua Donglu, Beijing 100083, China.
Department of Engineering, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada.
Food Chem. 2023 Dec 15;429:136832. doi: 10.1016/j.foodchem.2023.136832. Epub 2023 Jul 10.
Based on the concept of circular economy, citrus peel was considered a valuable source of bioactive compounds for high-value foods. Electrohydrodynamic (EHD) drying is a novel technology appropriated for the dehydration of heat-sensitive products such as citrus peel. In current work, EHD drying of citrus peel was performed based on alternating current (AC) or direct current (DC) sources at various voltage levels (9, 18, 27, 36, and 45 kV). The effect of EHD on drying characteristics, water retention capacity, enzyme inactivation, phytochemical contents (phenolic compounds and carotenoids), and volatile compounds of citrus peel were evaluated and compared. Results showed that the drying time in the AC electric field was shorter compared to DC electric field at the same applied voltages due to the polarization layer formed by unipolar charges. The applied voltage determined electric field strength as well as the degree of tissue collapse and cell membrane rupture. EHD elucidated the transformation and degradation of phytochemicals including phenolic compounds, carotenoids, and volatile composition in proportion to the applied voltage. The findings indicate that EHD drying with AC improves drying behaviors, inactivates enzymes, and retains the phytochemical properties of citrus peel.
基于循环经济理念，柑橘皮被认为是具有生物活性化合物的有价值资源，可用于高附加值食品。电动力学（EHD）干燥是一种适用于热敏产品（如柑橘皮）脱水的新技术。在当前的工作中，基于交流（AC）或直流（DC）电源在不同的电压水平（9、18、27、36 和 45 kV）下对柑橘皮进行了 EHD 干燥。评估并比较了 EHD 对柑橘皮干燥特性、保水能力、酶失活、植物化学物质（酚类化合物和类胡萝卜素）和挥发性化合物的影响。结果表明，由于单极电荷形成的极化层，在相同施加电压下，AC 电场中的干燥时间比 DC 电场短。所施加的电压决定了电场强度以及组织塌陷和细胞膜破裂的程度。EHD 阐明了与施加电压成比例的植物化学物质（包括酚类化合物、类胡萝卜素和挥发性成分）的转化和降解。研究结果表明，AC 驱动的 EHD 干燥可改善柑橘皮的干燥特性、使酶失活并保留其植物化学特性。
