Nowak Dorota, Jakubczyk Ewa
Department of Food Engineering and Process Management, Warsaw University of Life Sciences, Nowoursynowska 159C, 02-776 Warsaw, Poland.
Foods. 2020 Oct 18;9(10):1488. doi: 10.3390/foods9101488.
Freeze-drying, also known as lyophilization, is a process in which water in the form of ice under low pressure is removed from a material by sublimation. This process has found many applications for the production of high quality food and pharmaceuticals. The main steps of the freeze-drying process, such as the freezing of the product and primary and secondary drying, are described in this paper. The problems and mechanisms of each step of the freeze-drying process are also analyzed. The methods necessary for the selection of the primary and secondary end processes are characterized. The review contains a description of the effects of process conditions and the selected physical properties of freeze-dried materials, such as structural properties (shrinkage and density porosity), color, and texture. The study shows that little attention is given to the mechanical properties and texture of freeze-dried materials obtained from different conditions of the lyophilization process.
冷冻干燥，也称为冻干，是一种在低压下通过升华从材料中去除冰态水的过程。该过程在高品质食品和药品生产中有着诸多应用。本文描述了冷冻干燥过程的主要步骤，如产品的冷冻以及一次干燥和二次干燥。还分析了冷冻干燥过程各步骤的问题及机理。阐述了选择一次和二次结束过程所需的方法。该综述包含了工艺条件的影响以及冻干材料所选物理性质的描述，如结构性质（收缩率和密度孔隙率）、颜色和质地。研究表明，对于从不同冻干工艺条件获得的冻干材料的机械性能和质地关注较少。
