scholarly journals Influence of Platen Temperature of Freeze-drying on the Quality of Lyophilized Alaska Pollack

1969 ◽  
Vol 35 (11) ◽  
pp. 1116-1120
Author(s):  
Yumiko MATSUDA
Keyword(s):  
Freeze Drying ◽  
Platen Temperature

Influence of Freeze-Drying Modes on the Quality of Live Plague Vaccine

2019 ◽  
Vol 35 (4) ◽  
pp. 73-78
Author(s):  
S.E. Gostischeva ◽  
D.V. Rostovtseva ◽  
G.F. Ivanova ◽  
A.V. Kostrominov ◽  
M.V. Pilipenko
Keyword(s):  
Heating Rate ◽  
Freeze Drying ◽  
Eutectic Point ◽  
Freezing Temperature ◽  
Freezing Time ◽  
Residual Moisture ◽  
High Viability ◽  
Plague Vaccine ◽  
Selection Of

The optimization of the drying schedule has been carried out to improve the quality indicators of the live plague vaccine. Based on the data obtained on the eutectic point of the vaccine suspension, the freezing temperature and freezing time were set to -50 °С and 6-7 h, respectively. A pressure of 40 mTorr over the surface of the drying suspension and 20 mTorr during the desorption were shown to be the best conditions for sublimation. The drying tests with different options for the shelf heating rate, vacuum depth and duration of intermediate temperature indicators were carried out to develop the improved freeze-drying mode providing the selection of the most adapted bacteria. A vaccine lyophilized under the developed conditions has low residual moisture (up to 2%) and high viability index that persists over the whole shelf life. lyophilization, sublimation, eutectic, live plague vaccine, residual moisture, viability

scholarly journals The Quality of Red Bell Pepper Subjected to Freeze-Drying Preceded by Traditional and Novel Pretreatment

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 226
Author(s):  
Katarzyna Rybak ◽  
Artur Wiktor ◽  
Dorota Witrowa-Rajchert ◽  
Oleksii Parniakov ◽  
Małgorzata Nowacka
Keyword(s):  
Freeze Drying ◽  
Bell Pepper ◽  
Total Phenolic ◽  
Thermal Methods ◽  
Drying Time ◽  
Freeze Dried ◽  
Dehydration Processes ◽  
Vacuum Freezing ◽  
Better Than

It has been demonstrated previously in the literature that utilization of PEF or a combination of a pulsed electric field (PEF) and ultrasounds (US) can facilitate dehydration processes and improve the quality of dried products even better than the application of thermal methods such as blanching. The aim of the study was to evaluate the quality of red bell pepper subjected to freeze-drying preceded by blanching or PEF or US treatment applied in a single and combined mode. Furthermore, the freeze-drying was preceded by shock freezing or vacuum freezing performed inside the freeze-dryer as a result of pressure drop during the first stage of freeze-drying. All of the analyzed technological variants enhanced the drying kinetics when compared to the intact material. Freeze-dried bell pepper subjected to non-thermal pretreatment exhibited higher vitamin C, total phenolic and carotenoids content than blanched material despite the fact that blanching reduced drying time the most compared to all other analyzed methods.

scholarly journals Freeze-drying microscopy in mathematical modeling of a biomaterial freeze-drying

2012 ◽  
Vol 48 (2) ◽  
pp. 203-209 ◽  
Author(s):  
Camila Figueiredo Borgognoni ◽  
Joyce da Silva Bevilacqua ◽  
Ronaldo Nogueira de Moraes Pitombo
Keyword(s):  
Mathematical Modeling ◽  
Freeze Drying ◽  
Drying Process ◽  
Critical Temperatures ◽  
Fundamental Properties ◽  
Moving Interface ◽  
Energy Consuming ◽  
Sublimation Rates ◽  
Time And Energy

Transplantation brings hope for many patients. A multidisciplinary approach on this field aims at creating biologically functional tissues to be used as implants and prostheses. The freeze-drying process allows the fundamental properties of these materials to be preserved, making future manipulation and storage easier. Optimizing a freeze-drying cycle is of great importance since it aims at reducing process costs while increasing product quality of this time-and-energy-consuming process. Mathematical modeling comes as a tool to help a better understanding of the process variables behavior and consequently it helps optimization studies. Freeze-drying microscopy is a technique usually applied to determine critical temperatures of liquid formulations. It has been used in this work to determine the sublimation rates of a biological tissue freeze-drying. The sublimation rates were measured from the speed of the moving interface between the dried and the frozen layer under 21.33, 42.66 and 63.99 Pa. The studied variables were used in a theoretical model to simulate various temperature profiles of the freeze-drying process. Good agreement between the experimental and the simulated results was found.

scholarly journals Effect of Supplementation of Dried Bioflocs Produced by Freeze-Drying and Oven-Drying Methods on Water Quality, Growth Performance and Proximate Composition of Red Hybrid Tilapia

2022 ◽  
Vol 10 (1) ◽  
pp. 61
Author(s):  
Tarq Binalshikh-Abubkr ◽  
Marlia Mohd Hanafiah
Keyword(s):  
Water Quality ◽  
Body Composition ◽  
Growth Performance ◽  
Freeze Drying ◽  
Energy Levels ◽  
Fish Growth ◽  
Drying Methods ◽  
Oven Drying ◽  
Freeze Dried

Supplementation of dried bioflocs for red hybrid tilapia (Oreochromis sp.) was examined during 57 days of feeding trials. Five experimental treatments; T1 (the control; without bioflocs), T2 (4% freeze-dried bioflocs), T3 (16% freeze-dried bioflocs), T4 (4% oven-dried bioflocs), and T5 (16% oven-dried bioflocs) were prepared to examine the water quality, growth performance and body composition of red hybrid tilapia. T2 and T4 treatments resulted in a higher growth rate and survival similar to the control, while T3 and T5 treatments showed the lowest values of growth performance among all treatments. T1 treatment showed the best quality of culture water followed by T2 and T4 treatments, while T3 treatment resulted in poor water quality followed by T5 treatment. Based on these results, the ratios of bioflocs (4% and 16%) had more effect on fish growth and water quality than the drying methods (freeze-drying and oven-drying). The ratio of 4% freeze-dried or oven-dried bioflocs provided higher growth rates and better water quality parameters similar to the control, while the ratio of 16% showed the worst growth performance and water quality in the present study. In addition, body compositions of tilapia fed 4% dried bioflocs showed better nutritional value than tilapia fed 16% dried bioflocs. Protein and energy levels showed an increasing trend with decreasing supplement levels of bioflocs. Moisture content was significantly higher when supplementation of 16% bioflocs was used. Overall, supplementation of 4% freeze-dried or oven-dried bioflocs can be successively included in red hybrid tilapia diets without any effects on growth or body composition and can result in a good quality of culture water for red hybrid tilapia.

scholarly journals Effect of lacto-fermentation and freeze-drying on the quality of beetroot evaluated using machine vision and sensory analysis

2021 ◽  
Author(s):  
Ewa Ropelewska ◽  
Anna Wrzodak ◽  
Kadir Sabanci ◽  
Muhammet Fatih Aslan
Keyword(s):  
Freeze Drying ◽  
Sensory Quality ◽  
Bitter Taste ◽  
Sensory Attributes ◽  
Discrimination Accuracy ◽  
Flatbed Scanner ◽  
Color Channel ◽  
Texture Parameters ◽  
Freeze Dried

AbstractThis study was aimed at evaluating the effect of freeze-drying and lacto-fermentation on the texture parameters of images and sensory attributes of beetroots. The samples were imaged using a flatbed scanner, and textures from images converted to color channels L, a, b, R, G, B, X, Y, Z were computed. The discrimination of raw and processed beetroots was performed using models based on textures selected for each color channel. The sensory quality of processed samples was determined using the attributes related to smell, color, texture and taste. The highest discrimination accuracy of 97.25% was obtained for the model built for color channel b. The accuracies for other channels were equal to 96.25% for channel a, 95.25% for channel R, 95% for channel Y, 94.75% for channel B, 94.5% for channel X, 94% for channel L, 92.5% for channel G, 88.25% for channel Z. In the case of some models, the raw and lacto-fermented beetroots were discriminated with 100% correctness. The freeze-dried and freeze-dried lacto-fermented samples were also the most similar in terms of sensory attributes, such as off-odor, attractiveness color, beetroot color, crunchiness, hardness, bitter taste, overall quality. The results indicated that the image parameters and sensory attributes may be related.

Effects of vacuum and microwave freeze drying on microstructure and quality of potato slices

2010 ◽  
Vol 101 (2) ◽  
pp. 131-139 ◽  
Author(s):  
Rui Wang ◽  
Min Zhang ◽  
Arun S. Mujumdar
Keyword(s):  
Freeze Drying ◽  
Potato Slices

Effect of Freeze-Drying and Cooking on Shrimp Quality

1970 ◽  
Vol 53 (5) ◽  
pp. 899-902 ◽  
Author(s):  
Barbara R Moorhouse ◽  
Harold Salwin
Keyword(s):  
Freeze Drying ◽  
Starting Material ◽  
White Shrimp ◽  
Chemical Analyses ◽  
Decomposition Products ◽  
Organoleptic Quality ◽  
Freeze Dried ◽  
Plate Counts ◽  
Crushed Ice

Abstract Approximately 500 pounds of white shrimp were stored in crushed ice until they decomposed. Portions were withdrawn at intervals and processed. Based on judgments of odor, shrimp that reached a stage of incipient decomposition before processing were rated as passable after they were freeze-dried or cooked. The organoleptic quality of samples that reached a stage of advanced decomposition was also improved by processing, but not to the extent of their being classified as passable. Aerobic plate counts increased during storage but they were reduced significantly by freezedrying or cooking. Although there were changes in composition during storage, the classical chemical tests used were of limited value for assessing the degree of decomposition. Also, many volatile decomposition products were lost during processing. Computing the results of chemical analyses on a moisturefree basis offered distinct advantages. Inasmuch as organoleptic, bacteriological, and chemical tests on the finished products failed to reveal the decomposed condition of the starting material, there is need for additional investigation of methods for that purpose.

Expression of clpL1 and clpL2 genes in Lactobacillus rhamnosus VTT E-97800 after exposure to acid and heat stress treatments or to freeze-drying

2010 ◽  
Vol 1 (3) ◽  
pp. 253-257 ◽  
Author(s):  
C. Simões ◽  
H. Alakomi ◽  
J. Maukonen ◽  
M. Saarela
Keyword(s):  
Freeze Drying ◽  
Lactobacillus Rhamnosus ◽  
Rna Isolation ◽  
Laboratory Scale ◽  
Quality Analysis ◽  
Stress Genes ◽  
Freeze Dried ◽  
Related Stress ◽  
Harsh Conditions

The aim of the study was to evaluate the potential of utilising the information on expression levels of selected stress genes in assessing the quality of probiotic products. For this purpose RT-qPCR methods were developed to study the expression of clpL1 and clpL2 stress genes in Lactobacillus rhamnosus VTT E-97800 (E800) cells after exposure to processing-related stress conditions or to freeze-drying. Heat treatments in laboratory scale were performed with E800 cells incubated at 47 °C or 50 °C for 60 min. Acid treatments were performed both at laboratory and fermenter scale. At laboratory scale E800 cells were inoculated into General Edible Medium (GEM) adjusted to pH 4.0 and pH 3.5 and incubated at 37 °C for 180 min, whereas fermenter-grown cells were exposed to pH 4.0 for 60 min at the end of the fermentation. RNA from fresh cells and freeze-dried powders was reverse transcribed after isolation, quantification and standardisation. clpL1 and clpL2 transcripts were analysed by RT-qPCR with SYBR Green I. clpL1 was induced in L. rhamnosus E800 cells exposed to 50 °C and to a much lesser extent to 47 °C. No induction was observed for clpL2 in E800 cells during either acid or heat treatment, in any of the conditions applied. RNA isolation from freeze-dried powders was unsuccessful although several attempts were made with high quality products. In conclusion, our results suggest that developing quality indicators for probiotic products based on differences in the expression of stress genes is a challenging task for several reasons: at least with some genes (like in the present study with clpL) quite harsh conditions are needed to detect differences in the gene expression; mRNA isolation from freeze-dried powders was unsuccessful which hampers the quality analysis of large proportion of probiotic products; and furthermore RT-qPCR proved to be a too laborious procedure for routine use.

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