基于冷冻干燥前处理的半干型果蔬微波真空干燥的孔道行为及机理

项目名称： 基于冷冻干燥前处理的半干型果蔬微波真空干燥的孔道行为及机理

项目编号： No.31201399

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 水果、蔬菜

项目作者： 黄略略

作者单位： 深圳职业技术学院

项目金额： 23万元

中文摘要： 高能耗、高成本限制了冷冻干燥（FD）食品规模在我国的扩大，冷冻干燥作为前处理与微波真空干燥（MVD）进行串联联合能够使能耗大幅度降低，但其产品质量仍与传统冻干产品存在较大差异。针对这一问题，本项目以荔枝和怀山药为试材，研究半干型果蔬微波真空干燥的孔道行为及干燥机理。通过对半干型果蔬低压放电机制的研究，结合微波真空干燥过程中微孔道中水分迁移规律，探明果蔬微波真空干燥的收缩变形机理和微波加载策略；再结合果蔬预冻及冻干过程中各因素对孔道形成的影响，寻找半干型果蔬后续真空微波干燥水分转换的机理；在此基础上，运用数学模拟计算及红外热成像技术，获得果蔬物料在微波真空干燥过程中的热电耦合传热传质模型。该研究可为进一步推动冻干-微波真空联合干燥在高品质脱水果蔬加工中的实际应用提供基础数据和理论依据，具有重要的理论及应用价值。

中文关键词： 微波真空；干燥；介电性质；孔道结构；传热传质

英文摘要： High energy consumption and high cost limit the scale of freeze dried (FD) food. Tandem combined FD as pretreatment and microwave vacuum drying (MVD) can drastically reduce the energy consumption of FD. However, there exists significant difference in quality between combined dried products and traditional FD products. In order to resolve this problem, lychee and Rhizoma dioscoreae are served as test materials to study the pore character and drying mechanism of semi- moist fruits and vegetables during MVD. This program aims to make clear the shrinkage mechanism of fruits and vegetables as well as the strategy of microwave loading during MVD by investigating the low pressure discharge mechanism for semi-moist fruits and vegetables as well as the moving law of moisture in micro pore during MVD. It is also expected to find out the mechanism for moisture conversion of semi-moist fruits and vegetables during MVD by studying the effect of various factors during prefrozen and FD on the formation of pores. On that basis, the mathematic analogous computation and infrared thermal imaging technique are adopted to obtain thermoelectric coupling heat and mass transfer models for semi-moist fruits and vegetables during MVD. This research can provide the basic data and theoretical principles for the application of tandem combin

英文关键词： microwave vacuum；drying；dielectric property；pore structure；heat and mass transfer