Understanding and optimization of the secondary drying step of a freeze-drying process: a case study

2020 ◽  
pp. 1-15 ◽  
Author(s):  
Getachew Assegehegn ◽  
Edmundo Brito-de la Fuente ◽  
José M. Franco ◽  
Críspulo Gallegos
Keyword(s):  
Freeze Drying ◽  
Drying Process ◽  
Secondary Drying

scholarly journals The Freeze-Drying of Foods—The Characteristic of the Process Course and the Effect of Its Parameters on the Physical Properties of Food Materials

Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1488 ◽  
Author(s):  
Dorota Nowak ◽  
Ewa Jakubczyk
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Structural Properties ◽  
Freeze Drying ◽  
Process Conditions ◽  
Drying Process ◽  
High Quality ◽  
Freeze Dried ◽  
Secondary Drying ◽  
Selection Of

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.

scholarly journals Quality by Design in the Secondary Drying Step of a Freeze-Drying Process

2012 ◽  
Vol 30 (11-12) ◽  
pp. 1307-1316 ◽  
Author(s):  
Roberto Pisano ◽  
Davide Fissore ◽  
Antonello A. Barresi
Keyword(s):  
Freeze Drying ◽  
Quality By Design ◽  
Drying Process ◽  
Secondary Drying

scholarly journals Mathematical model of vacuum freeze-drying in the secondary drying

2007 ◽  
Vol 3 (2) ◽  
pp. 192-196
Author(s):  
Hua Li ◽  
Lihua Li ◽  
Xingli Jiao ◽  
Xueli Qin
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Transfer Process ◽  
Present Status ◽  
Freeze Drying ◽  
Mass Transfer Process ◽  
Drying Process ◽  
Secondary Drying ◽  
At Home

The freeze-drying process is a complex heat and mass transfer process virtually. The drying process of freeze-drying is not only the key stage which decides the success of freeze-drying, but also the most difficult stage to control. There are lots of papers about heat and mass transfer in vacuum freeze drying at home and abroad. The present status of research on heat and mass transfer during vacuum freeze drying in the secondary drying is summed up and analyzed, and the trend of research in this field is discussed in this paper.

Using mathematical modeling to optimize secondary drying stage of lyophilization technology

2020 ◽  
pp. 33-42
Author(s):  
Konstantin Alekseyev ◽  
Evgeniya Blynskaya ◽  
Sergey Tishkov
Keyword(s):  
Mathematical Modeling ◽  
Heat Transfer ◽  
Mathematical Model ◽  
Freeze Drying ◽  
Design Space ◽  
Heat Transfer Fluid ◽  
Drying Process ◽  
Residual Moisture ◽  
Secondary Drying ◽  
Temperature And Pressure

During lyophilization frozen water and moisture associated with dissolved substances are removed, desorption occurs in the process of secondary drying. This stage is one of the main stages of the technological process in terms of duration comparable with primary freeze drying and is of paramount importance for the further storage of lyophilisates. Mathematical modeling of secondary drying and the use of these methods in calculating design space of the process are described in the presented article. The equations for calculating the rate of secondary drying, residual moisture, and other conditions on the basis of values of the temperature of the heat-transfer fluid and pressure in the freezedrying chamber are shown. Possibilities for determining design space boundaries on the basis of the composition of lyophilisate, required values of residual moisture and drying kinetics are demonstrated. The proposed mathematical model makes it possible to estimate the duration of the secondary drying process for various values of temperature and pressure in the chamber within the design space.

Video real-time imaging of artificial membranes during freeze-drying by cryo-electron microscopy

1988 ◽  
Vol 46 ◽  
pp. 16-17
Author(s):  
Alan S. Rudolph ◽  
Ronald R. Price
Keyword(s):  
Real Time ◽  
Self Assembly ◽  
Freeze Drying ◽  
Video Capture ◽  
Drying Process ◽  
Artificial Membranes ◽  
The Past ◽  
Cryo Electron Microscopy ◽  
Spherical Structures ◽  
Capture Techniques

We have employed cryoelectron microscopy to visualize events that occur during the freeze-drying of artificial membranes by employing real time video capture techniques. Artificial membranes or liposomes which are spherical structures within internal aqueous space are stabilized by water which provides the driving force for spontaneous self-assembly of these structures. Previous assays of damage to these structures which are induced by freeze drying reveal that the two principal deleterious events that occur are 1) fusion of liposomes and 2) leakage of contents trapped within the liposome [1]. In the past the only way to access these events was to examine the liposomes following the dehydration event. This technique allows the event to be monitored in real time as the liposomes destabilize and as water is sublimed at cryo temperatures in the vacuum of the microscope. The method by which liposomes are compromised by freeze-drying are largely unknown. This technique has shown that cryo-protectants such as glycerol and carbohydrates are able to maintain liposomal structure throughout the drying process.

scholarly journals Strengthening of Porcine Plasma Protein Superabsorbent Materials through a Solubilization-Freeze-Drying Process

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 772
Author(s):  
Estefanía Álvarez-Castillo ◽  
Carlos Bengoechea ◽  
Antonio Guerrero
Keyword(s):  
Water Uptake ◽  
Plasma Protein ◽  
Freeze Drying ◽  
Meat Industry ◽  
Drying Process ◽  
Uptake Capacity ◽  
Water Uptake Capacity ◽  
Protein Flour ◽  
Hydrophilic Materials ◽  
By Products

The replacement of common acrylic derivatives by biodegradable materials in the formulation of superabsorbent materials would lessen the associated environmental impact. Moreover, the use of by-products or biowastes from the food industry that are usually discarded would promote a desired circular economy. The present study deals with the development of superabsorbent materials based on a by-product from the meat industry, namely plasma protein, focusing on the effects of a freeze-drying stage before blending with glycerol and eventual injection molding. More specifically, this freeze-drying stage is carried out either directly on the protein flour or after its solubilization in deionized water (10% w/w). Superabsorbent materials obtained after this solubilization-freeze-drying process display higher Young’s modulus and tensile strength values, without affecting their water uptake capacity. As greater water uptake is commonly related to poorer mechanical properties, the proposed solubilization-freeze-drying process is a useful strategy for producing strengthened hydrophilic materials.

Sign in / Sign up

Export Citation Format

Share Document