Choked flow and importance of Mach I in freeze-drying process design

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.

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Effects of freeze drying process on the production of cashew apple powder: Determination of bioactive compounds and fruit powder properties

Journal of Food Processing and Preservation ◽

10.1111/jfpp.15466 ◽

2021 ◽

Author(s):

R Harin ◽

G Nandhini Devi

Keyword(s):

Bioactive Compounds ◽

Freeze Drying ◽

Drying Process ◽

Cashew Apple ◽

Powder Properties ◽

Fruit Powder

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

Polymers ◽

10.3390/polym13050772 ◽

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.

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