scholarly journals Application of Ultrasound and Curing Agent during Osmotic Dehydration to Improve the Quality Properties of Freeze-Dried Yellow Peach (Amygdalus persica) Slices

Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1069
Author(s):  
Yuanming Chu ◽  
Saichao Wei ◽  
Zhaoyang Ding ◽  
Jun Mei ◽  
Jing Xie
Keyword(s):  
Freeze Drying ◽  
Osmotic Dehydration ◽  
Average Pore Size ◽  
Nutrient Loss ◽  
Ultrasonic Power ◽  
Curing Agent ◽  
Average Pore ◽  
Quality Properties ◽  
Freeze Dried

This study aimed to improve the quality of freeze-dried yellow peaches (Amygdalus persica). Yellow peaches were pretreated with osmotic dehydration for 15 min prior to vacuum-freeze drying and supplemented with different ultrasonic power levels (180 W, 240 W, 300 W) and a curing agent (calcium lactobionate, CaLa) to investigate the effects on the quality of freeze-dried yellow peach slices. After vacuum freeze-drying the yellow peach slices for 48 h, their moisture, color, texture, microstructure, total phenol (TP) content and oligomeric proantho-cyanidin (OPC) content were determined. It was found that the auxiliary ultrasonic power with various levels, especially powered at 240 W, produced very favorable effects on the quality characteristics of freeze-dried yellow peaches. The average pore size of USOD-240 W samples was reduced by 57.07% compared with that of the FD samples. In terms of nutrient maintenance, USOD-240 W can also prevent nutrient loss to the greatest extent. The TP content (5.40 mg/g) and OPC content (14.42 mg/g) were always highest in each pretreatment. The addition of CaLa can further improve the quality of yellow peach slices. Overall, the application of ultrasound and CaLa to improve the quality of freeze-dried yellow peach slices along with osmotic dehydration before freeze-drying is a method worth considering.

Preparation and Characterization of Chitosan-Based Scaffolds for Biomedical Applications

2006 ◽  
Vol 514-516 ◽  
pp. 1005-1009 ◽  
Author(s):  
José V. Araújo ◽  
J.A. Lopes da Silva ◽  
Margarida M. Almeida ◽  
Maria Elisabete V. Costa
Keyword(s):  
Biomedical Applications ◽  
Freeze Drying ◽  
Average Pore Size ◽  
Composite Scaffolds ◽  
Average Pore ◽  
Chitosan Matrix ◽  
Freeze Dried ◽  
Porous Chitosan ◽  
Interconnected Structure

Porous chitosan/brushite composite scaffolds were prepared by a freeze-drying technique, starting from brushite suspensions in chitosan solutions. The obtained scaffolds showed a regular macroporous and interconnected structure with brushite particles uniformly distributed in the chitosan matrix. The variation of the brushite concentration affected the microstructure of the final freeze-dried scaffold, in particular, its porosity and its average pore size. The yield strengths of the composite scaffolds could also be improved by the increase of the brushite content.

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 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 Microclimate Modification and Insect Pest Exclusion Using Agronet Improve Pod Yield and Quality of French Bean

HortScience ◽  
2014 ◽  
Vol 49 (10) ◽  
pp. 1298-1304 ◽  
Author(s):  
Elisha Otieno Gogo ◽  
Mwanarusi Saidi ◽  
Jacob Mugwa Ochieng ◽  
Thibaud Martin ◽  
Vance Baird ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Average Pore Size ◽  
Seedling Emergence ◽  
French Bean ◽  
Export Market ◽  
Average Pore ◽  
Black Bean ◽  
Pod Yield ◽  
Yield And Quality

French bean [Phaseolus vulgaris (L.)] is among the leading export vegetable in Africa, mostly produced by small-scale farmers. Unfavorable environmental conditions and heavy infestations by insect pests are among the major constraints limiting production of the crop. Most French bean producers grow their crop in open fields outdoors subject to harsh environmental conditions and repeatedly spray insecticides in a bid to realize high yield. This has led to rejection of some of the produce at the export market as a result of stringent limits on maximum residue levels. Two trials were conducted at the Horticulture Research and Teaching Field, Egerton University, Kenya, to evaluate the potential of using agricultural nets (herein referred to as agronets) to improve the microclimate, reduce pest infestation, and increase the yield and quality of French bean. A randomized complete block design with five replications was used. French bean seeds were direct-seeded, sprayed with an alpha-cypermethrin-based insecticide (control), covered with a treated agronet (0.9 mm × 0.7 mm average pore size made of 100 denier yarn knitted into a mesh impregnated with alpha-cypermethrin), or covered with an untreated-agronet (0.9 mm × 0.7 mm average pore size made of 100 denier yarn knitted into a mesh not impregnated with insecticide). Alpha-cypermethrin and agronets were manufactured by Tagros Chemicals (India) and A to Z Textile Mills (Tanzania), respectively. Covering French bean with the agronets modified the microclimate of the growing crop with air temperature increased by ≈10%, relative humidity by 4%, and soil moisture by 20%, whereas photosynthetic active radiation (PAR) and daily light integral (DLI) were decreased by ≈1% and 11.5%, respectively. Populations of silverleaf whitefly [Bemisia tabaci (Gennadius)] and black bean aphids [Aphis fabae (Scopoli)] were reduced under agronet covers as contrasted with control plots. Furthermore, populations of both pests were reduced on French bean grown under impregnated agronets compared with untreated agronets, but only on three of the five sampling dates [30, 44, and 72 days after planting (DAP)] for silver leaf whitefly or at only one of the five sampling dates (30 DAP) for black bean aphid. Covering French bean with agronets advanced seedling emergence by 2 days and increased seedling emergence over 90% compared with control plots. French bean plants covered with both agronet treatments had faster development, better pod yield, and quality compared with the uncovered plants. These findings demonstrate the potential of agronets in improving French bean performance while minimizing the number of insecticide sprays within the crop cycle, which could lead to less rejection of produce in the export market and improved environmental quality.

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.

Polymer Embedded Nanocrystalline Titania Sorbent for 99Mo-99mTc Generator

2008 ◽  
Vol 8 (9) ◽  
pp. 4447-4452 ◽  
Author(s):  
Rubel Chakravarty ◽  
Rakesh Shukla ◽  
Shyamla Gandhi ◽  
Ramu Ram ◽  
Ashutosh Dash ◽  
...  
Keyword(s):  
Saline Solution ◽  
Average Pore Size ◽  
Average Crystallite Size ◽  
Activity Level ◽  
X Ray Diffraction ◽  
Average Pore ◽  
X Ray ◽  
Nano Crystalline ◽  
99Mtc Generator

A new sorbent material, polymer embedded nano crystalline titania (Titanium Polymer-TiP) has been developed, from titanium (IV) chloride and isopropyl alcohol, for the adsorption of 99Mo, which is a precursor to 99mTc, a workhorse in radio-pharmaceuticals. The infrared absorption spectra of the TiP showed peaks corresponding to Ti-O groups. X-ray diffraction pattern of the adsorbent corresponded to rutile TiO2. The surface area of this polymer was 30 m2/g with an average pore size of 40 nm. The average crystallite size of TiO2, embedded in polymer, was found to be 5 nm. TEM micrograph of the adsorbent revealed the networkof polymer with dispersed titania phase. Potential of this adsorbent for the preparation of 99Mo-99mTc generator has been explored. 99Mo could be adsorbed on to the adsorbent column containing TiP at pH 1 from which 99mTc could be eluted with normal (0.9%) saline solution with an elution yield of ∼80%. The quality of the 99mTcO−4 obtained was in accordance with the international specifications applicable for radiopharmaceutical use. A process demonstration run was carried out with 1.1 GBq (30 mCi) 99Mo activity level making use of the above adsorbent and consistent results were obtained over a period of one week, which is generally the shelf life of 99Mo-99mTc generator.

scholarly journals Alginate/Gelatin Hydrogels Reinforced with TiO2 and β-TCP Fabricated by Microextrusion-based Printing for Tissue Regeneration

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 457 ◽  
Author(s):  
Rodrigo Urruela-Barrios ◽  
Erick Ramírez-Cedillo ◽  
A. Díaz de León ◽  
Alejandro Alvarez ◽  
Wendy Ortega-Lara
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Tissue Regeneration ◽  
Average Pore Size ◽  
Three Dimensional ◽  
Engineering Applications ◽  
Average Pore ◽  
Viscous Deformation ◽  
Freeze Dried ◽  
3D Printed

Three-dimensional (3D) printing technologies have become an attractive manufacturing process to fabricate scaffolds in tissue engineering. Recent research has focused on the fabrication of alginate complex shaped structures that closely mimic biological organs or tissues. Alginates can be effectively manufactured into porous three-dimensional networks for tissue engineering applications. However, the structure, mechanical properties, and shape fidelity of 3D-printed alginate hydrogels used for preparing tissue-engineered scaffolds is difficult to control. In this work, the use of alginate/gelatin hydrogels reinforced with TiO2 and β-tricalcium phosphate was studied to tailor the mechanical properties of 3D-printed hydrogels. The hydrogels reinforced with TiO2 and β-TCP showed enhanced mechanical properties up to 20 MPa of elastic modulus. Furthermore, the pores of the crosslinked printed structures were measured with an average pore size of 200 μm. Additionally, it was found that as more layers of the design were printed, there was an increase of the line width of the bottom layers due to its viscous deformation. Shrinkage of the design when the hydrogel is crosslinked and freeze dried was also measured and found to be up to 27% from the printed design. Overall, the proposed approach enabled fabrication of 3D-printed alginate scaffolds with adequate physical properties for tissue engineering applications.

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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