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

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.

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Screening of the freeze‐drying protective agent for high quality milk beer yeast ( Kluyveromyces marxianus) and optimization of freeze‐drying process conditions

Journal of Food Processing and Preservation ◽

10.1111/jfpp.16016 ◽

2021 ◽

Author(s):

Liang Wang ◽

Mingying He ◽

Tao Wu ◽

Kangye Yang ◽

Yulian Wang ◽

...

Keyword(s):

Kluyveromyces Marxianus ◽

Freeze Drying ◽

Process Conditions ◽

Protective Agent ◽

Drying Process ◽

High Quality ◽

Beer Yeast

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Impact of the Freeze-Drying Conditions Applied to Obtain an Orange Snack on Energy Consumption

Foods ◽

10.3390/foods10112756 ◽

2021 ◽

Vol 10 (11) ◽

pp. 2756

Author(s):

Marilú Andrea Silva-Espinoza ◽

María del Mar Camacho ◽

Javier Martínez-Monzó ◽

Nuria Martínez-Navarrete

Keyword(s):

Energy Consumption ◽

Freeze Drying ◽

Gum Arabic ◽

Economic Cost ◽

Added Value ◽

Process Conditions ◽

Drying Time ◽

Freeze Dried ◽

Secondary Drying ◽

The Impact

Nowadays, the consumer is looking for healthier, more attractive, ready-to-eat, and safer foodstuffs than fresh products. Despite freeze drying being known for providing high added value products, it is a slow process which is conducted at low pressures, so, in terms of energy consumption, it turns out to be quite costly for the food industry. With the purpose of obtaining a freeze-dried orange puree, previously formulated with gum Arabic and bamboo fiber, which can be offered to consumers as a snack at a low economic cost, the impact of the process conditions on energy consumption has been considered. The product temperature evolution and the energy consumption were registered during the drying of frozen samples at different combinations of chamber pressures (5 and 100 Pa) and shelf temperatures (30, 40 and 50 °C). In each case, the time processing was adapted in order to obtain a product with a water content under 5 g water/100 g product. In this study, the secondary drying stage was considered to start when the product reached the shelf temperature and both the pressure and the temperature affected the duration of primary and secondary drying stages. The results obtained led to the conclusion that the shorter duration of the process when working at 50 °C results in significant energy saving. Working at a lower pressure also contributes to a shortening of the drying time, thus reducing the energy consumption: the lower the temperature, the more marked the effect of the pressure.

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Studies on the Catalytic Properties of Crude Freeze-Dried Preparations of Yarrowia lipolytica Extracellular Lipases for Geranyl Ester Derivative Synthesis

Biomolecules ◽

10.3390/biom11060839 ◽

2021 ◽

Vol 11 (6) ◽

pp. 839

Author(s):

Karina Jasińska ◽

Bartłomiej Zieniuk ◽

Dorota Nowak ◽

Agata Fabiszewska

Keyword(s):

Freeze Drying ◽

Antioxidant Properties ◽

Antibacterial Properties ◽

Synthetic Activity ◽

Drying Process ◽

Enzyme Preparations ◽

Ester Derivative ◽

Freeze Dried ◽

The Impact ◽

Geranyl Ester

The study aimed to evaluate the impact of selected factors of the freeze-drying process on the hydrolytic and synthetic activity of the extracellular lipases of Y. lipolytica KKP 379 and to attempt the use of the crude enzyme preparation as a biocatalyst in the synthesis of geranyl 4-hydroxyphenylpropanoate. Antioxidant and antibacterial properties of the geranyl ester derivative were also investigated in order to evaluate their usefulness as a novel food additive. The studies confirmed that freeze-drying was an effective method of dehydrating yeast supernatant and allowed for obtaining lyophilizates with low water activity from 0.055 to 0.160. The type and concentration of the additive (2–6% whey protein hydrolyzate, 0.5% and 1% ammonium sulphate) had a significant effect on the hydrolytic activity of enzyme preparations, while the selected variants of drying temperature during the freeze-drying process were not significant (10 °C and 50 °C). Low yield of geranyl 4-hydroxyphenylopropionate was shown when the lyophilized supernatant was used (5.3%), but the yield of ester synthesis increased when the freeze-dried Y. lipolytica yeast biomass was applied (47.9%). The study confirmed the antioxidant properties of the synthesized ester by the DPPH• and CUPRAC methods, as well as higher antibacterial activity against tested bacteria than its precursor with 0.125 mM MIC (minimal inhibitory concentration) against L. monocytogenes.

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

Drying Technology ◽

10.1080/07373937.2020.1739065 ◽

2020 ◽

pp. 1-15 ◽

Cited By ~ 1

Author(s):

Getachew Assegehegn ◽

Edmundo Brito-de la Fuente ◽

José M. Franco ◽

Críspulo Gallegos

Keyword(s):

Freeze Drying ◽

Drying Process ◽

Secondary Drying

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Effect of addition an amino acid or its combination with EDTA on DNA integrity and morphometry sperm heads of freeze-dried bovine spermatozoa

Journal of the Indonesian Tropical Animal Agriculture ◽

10.14710/jitaa.45.3.189-196 ◽

2020 ◽

Vol 45 (3) ◽

pp. 189-196

Author(s):

S. Said ◽

T. Maulana ◽

S. Setiorini ◽

G.E. Ibrahim ◽

M.N. Ramadhan ◽

...

Keyword(s):

Plasma Membrane ◽

Amino Acid ◽

Freeze Drying ◽

Sperm Head ◽

Test Method ◽

Dna Integrity ◽

Drying Process ◽

Freeze Dried ◽

Bovine Spermatozoa ◽

Amino Acid Glycine

The objective of the current study was to investigate the effect of addition an amino acid or its combination with EDTA on DNA integrity and morphometry sperm heads of freeze-dried bovine spermatozoa. Spermatozoa were freeze-dried in medium with the addition of an amino acid glycine, cysteine, glutamine, or its combination with EDTA. Sperm head morphometry was identified at 400X magnification using Axio Vision(Zeiss Company, Germany), while for membrane plasma integrity (MPI) determined by calculation of the percentage of spermatozoa having intact plasma membrane by osmotic resistance test method and DNA integrity analysis using acridine orange staining. Sperm head had declined in size after the freeze-drying process, MPI of FD spermatozoa gradually increased significantly when FD solution was added with an amino acid solution (glycine, cysteine) and its combination with EDTA. DNA integrity of all freeze-dried spermatozoa treatments was remaining intact, no significantly different (P>0.01) among treatments. The present study concluded that the addition of an amino acid (glycine, cysteine) or its combination with EDTA could be reduced morphometric sperm heads and plasma membrane damage of freeze-dried bovine spermatozoa, however, DNA integrity of bovine sperm nucleus remaining intact after the freeze-drying process without addition both amino acids and EDTA.

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Solubilization of ibuprofen for freeze dried parenteral dosage forms

Acta Pharmaceutica ◽

10.2478/acph-2019-0009 ◽

2019 ◽

Vol 69 (1) ◽

pp. 17-32

Author(s):

Maja Preskar ◽

Tomislav Vrbanec ◽

Franc Vrečer ◽

Primož Šket ◽

Janez Plavec ◽

...

Keyword(s):

Freeze Drying ◽

Aqueous Solubility ◽

Pharmaceutical Formulations ◽

Dosage Forms ◽

Drying Process ◽

Solid Dosage Forms ◽

Solid Dosage ◽

Combined Use ◽

Freeze Dried

Abstract Ibuprofen, a weakly acidic non-steroidal anti-inflammatory drug having poor aqueous solubility, is a challenging drug for the development of pharmaceutical formulations, resulting in numerous research attempts focusing on improvement of its solubility and consequently bioavailability. Most studies have been done for solid dosage forms, with very little attention paid to parenterals. Hence, the main purpose of the present study was to enhance ibuprofen solubility as a result of formulation composition and the freeze drying process. Moreover, the purpose was to prepare a freeze dried dosage form with improved ibuprofen solubility that could, after simple reconstitution with water for injection, result in an isotonic parenteral solution. Solubility of ibuprofen was modified by various excipients suitable for parenteral application. Drug interactions with selected excipients in the final product/lyophilisate were studied by a combined use of XRPD, DSC, Raman and ss-NMR. Analyses of lyophilized samples showed solubility enhancement of ibuprofen and in situ formation of an ibuprofen salt with the alkaline excipients used.

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Optimised Extraction of Trypsin Inhibitors from Defatted Gac (Momordica cochinchinensis Spreng) Seeds for Production of a Trypsin Inhibitor‐Enriched Freeze Dried Powder

Separations ◽

10.3390/separations6010008 ◽

2019 ◽

Vol 6 (1) ◽

pp. 8 ◽

Cited By ~ 1

Author(s):

Anh V. Le ◽

Sophie E. Parks ◽

Minh H. Nguyen ◽

Paul D. Roach

Keyword(s):

Moisture Content ◽

Freeze Drying ◽

Trypsin Inhibitors ◽

Seed Kernel ◽

Solvent Ratio ◽

Optimal Conditions ◽

High Solubility ◽

High Quality ◽

Freeze Dried ◽

Momordica Cochinchinensis

The seeds of the Gac fruit, Momordica cochinchinensis Spreng, are rich in trypsin inhibitors (TIs) but their optimal extraction and the effects of freeze drying are not established. This study aims to (1) compare aqueous solvents (DI water, 0.1 M NaCl, 0.02 M NaOH and ACN)/water/FA, 25:24:1) for extracting TIs from defatted Gac seed kernel powder, (2) to optimise the extraction in terms of solvent, time and material to solvent ratio and (3) to produce a TI-enriched freeze-dried powder (FD-TIP) with good characteristics. Based on the specific TI activity (TIA), the optimal extraction was 1 h using a ratio of 2.0 g of defatted powder in 30 mL of 0.05 M NaCl. The optimisation improved the TIA and specific TIA by 8% and 13%, respectively. The FD-TIP had a high specific TIA (1.57 ± 0.17 mg trypsin/mg protein), although it also contained saponins (43.6 ± 2.3 mg AE/g) and phenolics (10.5 ± 0.3 mg GAE/g). The FD-TIP was likely stable during storage due to its very low moisture content (0.43 ± 0.08%) and water activity (0.18 ± 0.07) and its ability to be easily reconstituted in water due to its high solubility index (92.4 ± 1.5%). Therefore, the optimal conditions for the extraction of TIs from defatted Gac seed kernel powder followed by freeze drying gave a high quality powder in terms of its highly specific TIA and physical properties.

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Freeze-Drying Investigations of Antlers

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.195-196.441 ◽

2012 ◽

Vol 195-196 ◽

pp. 441-446

Author(s):

Jun Liu ◽

Shi Wei Zhang ◽

Zhi Jun Zhang

Keyword(s):

Freeze Drying ◽

Eutectic Temperature ◽

Tissue Structure ◽

Chemical Compositions ◽

Drying Method ◽

Drying Process ◽

Hot Air Drying ◽

Air Drying ◽

Hot Air ◽

Freeze Dried

In this paper, the vacuum freeze-drying experiments of both antler slices and whole antlers are reported in details. The moisture content and the eutectic temperature of antler were measured. A 22 h process curve of antler slice freeze drying was obtained. The freeze drying process of whole antler was also investigated. The microscopic tissue structure was observed and chemical compositions were analyzed for those freeze-dried whole antlers in comparison with the traditional water boiling and hot air drying method. More nutrients were retained for freeze drying in addition to the better physical properties than traditional drying.

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