Liu Haijun, Zhao Wei, Li Shikang, Zhang Lan, Chen Tingting, Wang Hui, Zhang Jian
School of Intelligent Manufacturing, Huzhou College, Huzhou, 313000, China.
Jiyang college of Zhejiang Agriculture & Forestry University, Zhuji, 311800, China.
Sci Rep. 2025 Jul 1;15(1):20543. doi: 10.1038/s41598-025-06253-w.
The objective of this study was to study the effect of microwave vacuum puffing (MVP) conditions on dielectric properties of berries. A central composite response surface experiment, with four factors and five levels, was carried out to assess the effect of puffing conditions on the dielectric properties. The microwave volumetric heat, dielectric constant and dielectric loss factor were, accordingly, evaluated based on the dynamic dielectric property index model of berries. As a result, the initial moisture content had significant effects on the dielectric constant and dielectric loss factor of the berry crisps. Specifically, in the early stage of puffing, the dielectric constant decreases with increasing initial moisture content. However, in the later stage of puffing, the dielectric constant first decreases and then increases as the initial moisture content rises. Meanwhile, the dielectric loss factor increases consistently with increasing initial moisture content throughout the puffing process. The MVP conditions exert a complex effect on dielectric properties of berries. Based on these findings, a theoretical for the dynamic processing mode and equipment design for MVP of berries can be provided.
本研究的目的是研究微波真空膨化（MVP）条件对浆果介电特性的影响。进行了一个四因素五水平的中心复合响应面实验，以评估膨化条件对介电特性的影响。相应地，基于浆果的动态介电特性指标模型，对微波体积热、介电常数和介电损耗因子进行了评估。结果表明，初始水分含量对浆果脆片的介电常数和介电损耗因子有显著影响。具体而言，在膨化初期，介电常数随初始水分含量的增加而降低。然而，在膨化后期，随着初始水分含量的升高，介电常数先降低后升高。同时，在整个膨化过程中，介电损耗因子随初始水分含量的增加而持续增加。MVP条件对浆果的介电特性有复杂的影响。基于这些发现，可以为浆果的MVP动态加工模式和设备设计提供理论依据。
