scholarly journals Freeze-drying and its application to some Finnish agricultural products

1985 ◽  
Vol 57 (2) ◽  
pp. 125-131 ◽  
Author(s):  
Yrjö Roos ◽  
Jorma J. Laine
Keyword(s):  
Moisture Content ◽  
Freeze Drying ◽  
Nitrogen Atmosphere ◽  
Agricultural Products ◽  
Drying Process ◽  
Sublimation Rate ◽  
Freeze Dried ◽  
Being There ◽  
Drying Chamber ◽  
Maximum Surface Temperature

This study deals with the freeze-drying of berries, vegetables, roots and pork produced in Finland. The products were freeze dried whole, in slices or cubes. The pressure in the drying chamber was 10—20 Pa and the maximum surface temperature +23—+ 40°C. The products were packed after freeze-drying into glass jars under air and in polyester-aluminium-polyethene foil under vacuum or nitrogen atmosphere. The drying temperatures and drying times were measured. During storage for 4 months, the differences in quality were evaluated. The drying times ranged from 8 to 25 hours. The moisture content of the dry products was 1—3 %. The sublimation rate at the beginning of the drying process was very rapid, being there after constant. Bilberries, carrots and radishes collapsed during drying. Most of the products dried moistened and underwent aroma changes during storage in glass jars under air. The products packed under vacuum or nitrogen atmosphere proved stable.

scholarly journals Improvement of dill freeze-drying technology

2020 ◽  
Vol 222 ◽  
pp. 03002
Author(s):  
Ulugbek Kadirov ◽  
Ulug’bek Mannanov ◽  
Mirolim Aripov ◽  
Mirazam Meliboyev ◽  
Sherzod Mamatov
Keyword(s):  
Moisture Content ◽  
Freeze Drying ◽  
Drying Process ◽  
Freeze Dried ◽  
Sublimation Method ◽  
Pre Treatment ◽  
Drying Technology

In this work, we studied the use of IR pretreatments before freeze drying of dill. The indicators of the drying period, the process of rehydration of different samples dried by the sublimation method with and without pretreatment are compared. Experimentally, data have been obtained that when using IR pretreatment, the drying process is reduced by about 4-5 hours. The main reasons for the shortening of the freeze drying period is to reduce the moisture content to 25-30% during pre-treatment. The data confirms a reduction in the drying period for freeze-dried dill, and also provides data on the dehydration of dried samples.

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

Biomolecules ◽  
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.

scholarly journals Fortified and freeze-dried kiwi fruit (Actinidia deliciosa): quality and sensory assessment

2020 ◽  
Vol 23 ◽  
Author(s):  
Niladri Chakraborty ◽  
Rajat Chakraborty ◽  
Asit Kumar Saha
Keyword(s):  
Moisture Content ◽  
Freeze Drying ◽  
Raw Materials ◽  
Food Product ◽  
Rice Flour ◽  
Actinidia Deliciosa ◽  
Crude Fibre ◽  
Kiwi Fruit ◽  
Drying Time ◽  
Freeze Dried

Abstract Kiwi fruit (Actinidia deliciosa) (KF) is one of the best fruits available due to its large amount of nutrients. Despite its many health benefits, there are no previous reports on its preparation in other readily ingestible forms. The objective of the present study was to make a new food product from KF. The KF pulp was fortified and blended with several raw materials (such as rice flour and oat flour) using a stepwise short time addition and mixing methodology since this avoids unwanted biochemical and chemical reactions. The blended and reduced moisture KF paste was freeze-dried on a round silver coated steel plate (RSCSP), supplying the heat of sublimation using a newly designed cubic heater. The freeze-drying (FD) time was 4.5 h and the drying kinetics were studied using four established models. The effective moisture diffusivity (Deff) during FD (at 50 °C) was 1.532 x 10-6 m2/s and the activation energy (E) estimated for the FD was 28.35 kJ/mol. The freeze-dried sample was ground and placed under vacuum to reduce the weathering effects. The quality of the stored product was evaluated using the proximate analysis, physicochemical analysis and a sensory evaluation using a hedonic scale. The raw, fresh KF had a moisture content of 85.07% and the final freeze-dried product one of 3%. The carbohydrate, total sugar, protein, fat, total ash, crude fibre and vitamin C contents of the final product increased by 563%, 400%, 355%, 386%, 672%, 106%, and 117% respectively. Of the 66 panelists, the % consumer acceptances for the different attributes were: sweetness (68.18%), sourness (90.91%), saltiness (100%), bitterness (100%), flavour (95.45%), texture (77.27%) and overall acceptability (81.82%). Using conventional freeze-drying (CFD) for blended KF pulp without fortification, with the same RSCSP and the same cubic heater for sublimation, the drying time was found to be 7 h to reach the same final moisture content of 3%.

scholarly journals Effect of Size and Drying Time on the Rehydration and Sensory Properties of Freeze-Dried Snails (Achatina achatina)

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Matthew A. Achaglinkame ◽  
Eric Owusu-Mensah ◽  
Abena A. Boakye ◽  
Ibok Oduro
Keyword(s):  
Moisture Content ◽  
Nutritional Value ◽  
Freeze Drying ◽  
Consumer Preference ◽  
Sensory Properties ◽  
Temperature Dependent ◽  
Drying Time ◽  
Standard Methods ◽  
Freeze Dried ◽  
Hedonic Scale

Snails, a delicacy in most tropical communities, are highly perishable and seasonal. Employed preservative methods are highly temperature dependent, adversely affecting their nutritional value and sensory properties. This study was aimed at determining the effect of size and drying time on the rehydration and sensory properties of freeze-dried snails. Snails were sized into three categories with average weights: 7.59 g (quarter-sized), 14.41 g (half-sized), and 30.71 g (whole), and freeze-dried for 15, 20, and 25 h. The moisture content and percent rehydration of the dried samples were determined by standard methods and sensory properties assessed by an in-house panel of 30 using a 5-point hedonic scale. The moisture content of the fresh and freeze-dried samples ranged from 65.80 to 75.20% and 3.25 to 10.24%, respectively. Freeze-dried samples had higher percent rehydration (27 to 102%) than the control; smoked snails (21 to 32%). Size had a significant (P<0.05) effect on the rehydration ability of the samples with the half-sized and freeze-dried for 15 h samples having the highest. The freeze-dried samples generally had higher consumer preference than the control in all attributes assessed. The findings show that freeze-drying snails (approximate weight of 14.4 g) for 15 h could be a consumer-preferred alternative preservative method for extending the shelf life of snails.

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

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. 

scholarly journals Solubilization of ibuprofen for freeze dried parenteral dosage forms

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.

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

Separations ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 8 ◽  
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.

scholarly journals Effect of the Freeze-Drying Process on the Physicochemical and Microbiological Properties of Mexican Kefir Grains

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 127 ◽  
Author(s):  
Alicia Conde-Islas ◽  
Maribel Jiménez-Fernández ◽  
Denis Cantú-Lozano ◽  
Galo Urrea-García ◽  
Guadalupe Luna-Solano
Keyword(s):  
Moisture Content ◽  
Water Activity ◽  
Freeze Drying ◽  
Survival Rates ◽  
Freezing Temperature ◽  
Freezing Time ◽  
Residual Moisture Content ◽  
Drying Process ◽  
Residual Moisture ◽  
Kefir Grains

The purpose of this study was to investigate how the properties of Mexican kefir grains (MKG) are affected by the operating parameters used in the freeze-drying process. The factors investigated were the freezing time (3–9 h), freezing temperature (−20 to −80 °C), pressure (0.2–0.8 mbar), and lyophilization time (5–20 h). The maximum range of change and one-way analysis of variance showed that lyophilization time and freezing time significant affects (p < 0.05) the response variables, residual moisture content and water activity, and pressure had a significant effect on the color difference and survival rate of probiotic microorganisms. The best drying conditions were a freezing time of 3 h, a freezing temperature of −20 °C, a pressure of 0.6 mbar, and a lyophilization time of 15 h. Under these conditions, we obtained a product with residual moisture content below 6%, water activity below 0.2, and survival rates above 8.5 log cfu per gram of lactic acid bacteria and above 8.6 log for yeast.

Freeze-Drying Investigations of Antlers

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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