scholarly journals Pulsed electric field enhanced freeze-drying of apple tissue

2019 ◽  
Vol 37 (No. 6) ◽  
pp. 432-438 ◽  
Author(s):  
Yali Wu ◽  
Dongguang Zhang
Keyword(s):  
Electric Field ◽  
Freeze Drying ◽  
Effective Diffusion ◽  
Specific Energy Consumption ◽  
Pulsed Electric Field ◽  
Drying Process ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Effective Diffusion Coefficients ◽  
Apple Tissue

The influence of pulsed electric field (PEF) on freeze-drying of apple tissue was investigated. The freeze-drying was performed with different parameters of PEF treatment, and PEF treatment on the drying characters, microstructure, rehydration ratio, effective diffusion coefficient and hardness of apple tissue were discussed separately. The results indicated that PEF utilization as a pretreatment of apples enhances the drying process. The drying time was shortened by 17.73% at most, specific energy consumption decreased by 24.74% at most, and the rehydration ratio was improved by 65.22% at most for PEF treatment samples respectively, compared with the untreated samples. The effective diffusion coefficients varied from 2.60 × 10−8 m2/s to 4.20 × 10−8 m2/s for PEF pretreated samples, and was 2.40 × 10−8 m2/s for untreated samples drying at 75°C, the hardness of the untreated apple tissue was about 144.4 N which was decreased to 39.5–115.0 N after PEF treatment. 

scholarly journals Pulsed electric field pre-treatment efficiency analysis in processes of biomaterials drying

2019 ◽  
Vol 80 (4) ◽  
pp. 49-54 ◽  
Author(s):  
I. A. Shorstkii ◽  
D. A. Khudyakov
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Mathematical Models ◽  
Electric Field Strength ◽  
Pulsed Electric Field ◽  
Convective Drying ◽  
Efficient Production ◽  
Drying Process ◽  
Drying Time ◽  
Pre Treatment

The transition to an efficient economy and efficient production requires building the foundations for the development of energy efficient technologies and the drying of biomaterials to convert them into useful products. The purpose of this work is to analyze the effectiveness of pretreatment with a pulsed electric field (PEF) in the process of convective drying of biomaterials. The PEF was processed with electric field strength of 2, 4 and 6 kV/cm, the number of pulses 500, with a pulse duration of 50 ?s. Based on the electrical conductivity data of the biomaterial, the index of the disintegration 56% was determined before and after the PEF treatment, which confirms the existence of an electroporation mechanism of the material structure. The drying process is presented with a description of various mathematical models. PEF pre-treatment with the parameters of electric field strength 4 and 6 kV / cm and the number of impulses 500 allowed to reduce the drying time by 13.8% for the value E = 0.02. Total time spent on the drying process reduced by 20-25 minutes. It should be noted that the total energy spent on PEF pre-treatment (<150 W / kg) compared with the energy spent on the drying process is incommensurably small. Statistical analysis of the considered mathematical models showed good convergence of most models with experimental data. The considered technology of pretreatment of PEF can ensure the effective processing of biomaterials in the required amount to obtain high-quality and safe products. Obtained data of the kinetics process can be used to the mathematical model of the drying process design with the use of preliminary treatment processing.

scholarly journals Applicability of Pulsed Electric Field (PEF) Pre-Treatment for a Convective Two-Step Drying Process

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 512 ◽  
Author(s):  
Robin Ostermeier ◽  
Oleksii Parniakov ◽  
Stefan Töpfl ◽  
Henry Jäger
Keyword(s):  
Electric Field ◽  
Pyruvic Acid ◽  
Acid Content ◽  
Pulsed Electric Field ◽  
Convective Drying ◽  
Quality Analysis ◽  
Drying Process ◽  
Drying Time ◽  
Treated Sample ◽  
Pre Treatment

Available literature and previous studies focus on the Pulsed Electric Field (PEF) parameters influencing the drying process of fruit and vegetable tissue. This study investigates the applicability of PEF pre-treatment considering the industrial-scale drying conditions of onions and related quality parameters of the final product. First, the influence of the PEF treatment (W = 4.0 kJ/kg, E = 1.07 kV/cm) on the convective drying was investigated for samples dried at constant temperatures (65, 75, and 85 °C) and drying profiles (85/55, 85/65, and 85/75 °C). These trials were performed along with the determination of the breakpoint to assure an industrial drying profile with varying temperatures. A reduction in drying time of 32% was achieved by applying PEF prior to drying at profile 85/65 °C (target moisture ≤7%). The effective water diffusion coefficient for the last drying section has been increased from 1.99 × 10−10 m2/s to 3.48 × 10−10 m2/s in the PEF-treated tissue. In case of the 85/65 °C drying profile, the PEF-treated sample showed the highest benefits in terms of process efficiency and quality compared to the untreated sample. A quality analysis was performed considering the colour, amount of blisters, pyruvic acid content, and the rehydration behavior comparing the untreated and PEF-treated sample. The PEF-treated sample showed practically no blisters and a 14.5% higher pyruvic acid content. Moreover, the rehydration coefficient was 47% higher when applying PEF prior to drying.

Pulsed electric field assisted vacuum freeze-drying of apple tissue

2016 ◽  
Vol 35 ◽  
pp. 52-57 ◽  
Author(s):  
Oleksii Parniakov ◽  
Olivier Bals ◽  
Nikolai Lebovka ◽  
Eugene Vorobiev
Keyword(s):  
Electric Field ◽  
Freeze Drying ◽  
Pulsed Electric Field ◽  
Apple Tissue

scholarly journals Trade-Off between Operating Time and Energy Consumption in Pulsed Electric Field Electrodialysis: A Comprehensive Simulation Study

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 43
Author(s):  
Manuel César Martí-Calatayud ◽  
Mario Sancho-Cirer Poczatek ◽  
Valentín Pérez-Herranz
Keyword(s):  
Energy Consumption ◽  
Electric Field ◽  
Simulation Study ◽  
Specific Energy ◽  
Operating Time ◽  
Specific Energy Consumption ◽  
Threshold Value ◽  
Pulsed Electric Field ◽  
Pulse Frequency ◽  
Time And Energy

Electrodialysis (ED) has been recently introduced in a variety of processes where the recovery of valuable resources is needed; thus, enabling sustainable production routes for a circular economy. However, new applications of ED require optimized operating modes ensuring low energy consumptions. The application of pulsed electric field (PEF) electrodialysis has been demonstrated to be an effective option to modulate concentration polarization and reduce energy consumption in ED systems, but the savings in energy are usually attained by extending the operating time. In the present work, we conduct a comprehensive simulation study about the effects of PEF signal parameters on the time and energy consumption associated with ED processes. Ion transport of NaCl solutions through homogeneous cation-exchange membranes is simulated using a 1-D model solved by a finite-difference method. Increasing the pulse frequency up to a threshold value is effective in reducing the specific energy consumption, with threshold frequencies increasing with the applied current density. Varying the duty cycle causes opposed effects in the time and energy usage needed for a given ED operation. More interestingly, a new mode of PEF functions with the application of low values of current during the relaxation phases has been investigated. This novel PEF strategy has been demonstrated to simultaneously improve the time and the specific energy consumption of ED processes.

scholarly journals Effect of Hot-Water Blanching Pretreatment on Drying Characteristics and Product Qualities for the Novel Integrated Freeze-Drying of Apple Slices

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hai-ou Wang ◽  
Qing-quan Fu ◽  
Shou-jiang Chen ◽  
Zhi-chao Hu ◽  
Huan-xiong Xie
Keyword(s):  
Electron Microscopy ◽  
Freeze Drying ◽  
Hot Water ◽  
The Novel ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Drying Characteristics ◽  
Promising Alternative ◽  
Freeze Dried ◽  
Apple Slices

The effect of hot-water blanching (HWB) on drying characteristics and product qualities of dried apple slices with the novel integrated freeze-drying (NIFD) process was investigated by comparing with 3 different FD methods. Compared with the NIFD process without HWB pretreatment (VF-FD), the NIFD process with HWB pretreatment (HWB-VF-FD) resulted in a significantly higher mass loss and more sufficient freezing in vacuum-frozen samples, significantly higher rehydration ratio (RR), higher shrinkage ratio (SR), smaller Vitamin C (VC) content and lower hardness and better apparent shape in freeze-dried samples, and fewer change to the color of the dried or rehydrated samples (p<0.05). Compared with the conventional FD process with HWB pretreatment (HWB-PF-FD), HWB-VF-FD cost significantly less processing time and FD time and obtained significantly higher RR (p<0.05), almost the equivalent SR, VC content, and hardness, and similar appearance in dried samples. The microstructure of apple cell tissues was analyzed by transmission electron microscopy and scanning electron microscopy to interpret the above differences in drying characteristics and product qualities. The results suggested that the NIFD process of apple slices with HWB pretreatment was a promising alternative method to decrease drying time, achieve similar product quality, and simplify the process steps of the conventional FD technology.

Study on a Combination Drying Technique of Shrimp

2012 ◽  
Vol 260-261 ◽  
pp. 804-807
Author(s):  
Ya Xiang Bai ◽  
Yu Cai Hu ◽  
Qiang Huang
Keyword(s):  
Freeze Drying ◽  
Sensory Properties ◽  
Drying Rate ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Air Drying ◽  
Combined Process ◽  
Highly Efficient ◽  
Sensory Qualities

In order to develop a highly efficient drying technique for shrimp, a combination of air drying (AD) and vacuum freeze drying (FD) is examined. The drying rate of combination drying, the shrinkage, rehydration ratio, and sensory properties, such as the color and trimness, of the dried product in the AD–FD method are measured. Compared with FD, the combined process consumes less drying time, compared with AD drying alone. Also the product processed by combined drying displays lower shrinkage, higher rehydration rate and better sensory qualities.

scholarly journals Effect of Solar Radiation on the Drying Parameters of Mint (Mentha Spicata L.) Dried in Natural Convective Solar Dryer

2020 ◽  
Author(s):  
SEBIHA REHMAN ◽  
SEEMIN RUBAB
Keyword(s):  
Weather Conditions ◽  
Quality Parameter ◽  
Drying Process ◽  
Kashmir Valley ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Mentha Spicata ◽  
Solar Dryer ◽  
Pre Treatment ◽  
Kinetics Of

Abstract The paper presents a kinetic study of solar dried mint (Mentha spicata L.) without any pre-treatment. Mint grows effortlessly in Kashmir valley but is not obtainable throughout the year because of inconsiderate weather conditions. The genus belongs to the Labiatae family and includes large varieties with different properties. A significant quality parameter is its colour. The drying kinetics of mint leaves dried in Domestic Solar Dryer in terms of colour attributes, moisture content, drying time, non enzymatic browning, water activity, rehydration ratio was studied. This study is very useful for household scale drying of mint leaves to optimize drying process and to achieve superior quality dried product at home maintaining its colour and aroma.

scholarly journals Modeling and thermodynamic properties of ‘bacaba’ pulp drying

2019 ◽  
Vol 23 (9) ◽  
pp. 702-708 ◽  
Author(s):  
Maria F. de Morais ◽  
José R. O. dos Santos ◽  
Marisângela P. dos Santos ◽  
Dyego da C. Santos ◽  
Tiago N. da Costa ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermodynamic Properties ◽  
Diffusion Coefficients ◽  
Effective Diffusion ◽  
Thermal Conditions ◽  
Drying Process ◽  
Experimental Conditions ◽  
Effective Diffusion Coefficients ◽  
Drying Rates ◽  
Increasing Temperature

ABSTRACT This study aimed to dry ‘bacaba’ (Oenocarpus bacaba Mart.) pulp under different thermal conditions, fit different mathematical models to the dehydration curves, and calculate the diffusion coefficients, activation energy and thermodynamic properties of the process. ‘Bacaba’ fruits were meshed to obtain the pulp, which was dried at temperatures of 40, 50 and 60 °C and with thickness of 1.0 cm. Increase in drying temperature reduced the dehydration times, as well as the equilibrium moisture contents, and drying rates of 0.65, 1.04 and 1.25 kg kg min-1 were recorded at the beginning of the process for temperatures of 40, 50 and 60 °C, respectively. The Midilli’s equation was selected as the most appropriate to predict the drying phenomenon, showing the highest R2, lowest values of mean square deviation (MSD) and χ2 under most thermal conditions, and random distribution of residuals under all experimental conditions. The effective diffusion coefficients increased with increasing temperature, with magnitudes of the order of 10-9 m2 s-1, being satisfactorily described by the Arrhenius equation, which showed activation energy (Ea) of 37.01 kJ mol-1. The drying process was characterized as endergonic, in which enthalpy (ΔH) and entropy (ΔS) reduced with the increment of temperature, while Gibbs free energy (ΔG) was increased.

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