scholarly journals Cell Permeabilisation, Microstructure and Quality of Dehydrated Apple Slices Treated with Pulsed Electric Field During Blanching

2018 ◽  
Vol 4 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Om Prakash Chauhan ◽  
Shima Shayanfar ◽  
Stefan Topefl

ABSTRACTEffect of pulsed electric field as a blanching pretreatment on cell permeabilization, microstructure and quality of dehydrated apple slices was studied. Apple slices were pulsed electric field pretreated (1.0, 1.5 and 2.0 kV/cm using 25 and 75 pulses) at a temperature of 60 and 80°C in water followed by dehydration at 60°C in a cabinet dryer. Cell disintegration index was found to increase significantly (p<0.05) with increase in the electric field strength, number of pulses and blanching temperature and thereby reducing the drying time. The dehydrated slices showed lower hardness and higher lightness (L*) values for the samples treated at higher electric field strength for longer durations. Scanning electron microscopic studies of samples revealed better retention of cellular integrity when pre-treated at a low level of PEF (1.0 kV/cm using 25 pulses) and blanched at low temperature (60°C). However, the samples treated to a level of 1.5 kV/cm and 75 pulses of PEF with subsequent blanching temperature 80°C was found to yield optimum cell permeabilization. The study suggests that PEF can be used as an effective blanching pretreatment for achieve good quality dehydrated apple slices in less drying time. 

Author(s):  
I. A. Shorstkii ◽  
D. A. Khudyakov

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.


2002 ◽  
Vol 65 (10) ◽  
pp. 1623-1627 ◽  
Author(s):  
Z. AYHAN ◽  
Q. H. ZHANG ◽  
D. B. MIN

The effects of pulsed electric field (PEF) processing on microorganisms in orange juice and on the flavor and color of the juice during storage for 112 days at 4 and 22°C were investigated. Single-strength orange juice was PEF processed at an electric field strength of 35 kV/cm for 59 μs and placed into sterilized glass bottles in a sanitary glove box. PEF-processed orange juice was microbiologically stable at 4 and 22°C for 112 days. PEF processing resulted in significant increases in the hydrocarbons d-limonene, α-pinene, myrecene, and valencene (P ≤ 0.05) but did not have any effect on octanal, decanal, ethyl butyrate, and linalool. The levels of hydrocarbon compounds did not change at 4 and 22°C in 112 days. Octanal, decanal, ethyl butyrate, and linalool levels significantly decreased in 14 days at 4°C and in 2 days at 22°C. The decrease in these compounds did not have a significant effect on the sensory quality of the orange juice (P ≥ 0.05). The microorganisms in PEF-processed orange juice, along with the flavor and color of the juice, remained stable at 4°C for 112 days.


2014 ◽  
Vol 10 (4) ◽  
pp. 857-862 ◽  
Author(s):  
Yali Wu ◽  
Dongguang Zhang

Abstract The influence of pulsed electric field (PEF) on the drying behavior of potato was investigated, and the optimal parameters were determined. Drying experiments were conducted with different PEF pre-treatments. The effects of process parameters of PEF pre-treatment were examined with respect to drying rate, drying time, productivity per unit area, and energy consumption. Results showed that the three parameters investigated were significant in the following sequence: pulse number, electric field strength, and pulse width. The optimal electric field strength, pulse width, and pulse number were 1,500 V cm−1, 120 μs, and 45 pulses, respectively. Under these optimal conditions, productivity per unit area increased by 32.28%, specific energy consumption decreased by 16.59%, drying time was shortened by 31.47%, and drying rate improved by 14.31% compared with the control group.


2021 ◽  
Vol 11 (4) ◽  
pp. 503-514
Author(s):  
Margaret Messiah Singh ◽  
Priyanka Chandel ◽  
Atanu Kumar Pati ◽  
Arti Parganiha

Occupational exposure to microwave radiation (MWR) has become an inevi-table part of life. Therefore, it is essential to assess the MWR effect on hu-man health. In this study, we examined the non-thermal effect of MWR from base transceiver station (BTS) on humans' sleep quality. Total 1150 partici-pants of different zones based on distance from BTS (145 from inter-tower/zone A; 256 from 0-150m/zone B; 241 from 150-300m/zone C, 381 from 300-500m/zone D), and 127 controls from the area without BTS installations were included. We recorded the electric field strength at the subject’s resi-dence using NBM-550 equipped with probe EF0-391. We assessed the sub-jects' sleep quality by administering the Pittsburgh Sleep Quality Index Ques-tionnaire. ANOVA revealed statistically significantly higher electric-field strength in zone B and zone A. Participants of all the groups exhibited a glob-al PSQI score less than the accepted median score of <5. This implies that subjects of all groups had good sleep quality. However, a more detailed anal-ysis using the Kruskal-Wallis and Mann-Whitney U tests revealed that the participants of exposed zones (except zone D), females, and residents of the 1-5y group had decreased sleep quality compared to control, males, and subjects of >5y group, respectively. From the above findings, it can be con-cluded that the MWR had little effect on the sleep quality, but it does modu-late sleep parameters within the accepted range of good sleep quality as a function of the zone, gender, and year of residence. However, extensive studies involving more BTS are desirable to validate the above conclusion.


Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1554
Author(s):  
Vasileios M. Pappas ◽  
Achillia Lakka ◽  
Dimitrios Palaiogiannis ◽  
Vassilis Athanasiadis ◽  
Eleni Bozinou ◽  
...  

Olive leaves (OLL) are reported as a source of valuable antioxidants and as an agricultural by-product/waste. Thus, a twofold objective with multi-level cost and environmental benefits arises for a “green” standalone extraction technology. This study evaluates the OLL waste valorization through maximizing OLL extracts polyphenol concentration utilizing an emerging “green” non-thermal technology, Pulsed Electric Field (PEF). It also provides further insight into the PEF assistance span for static solid-liquid extraction of OLL by choosing and fine-tuning important PEF parameters such as the extraction chamber geometry, electric field strength, pulse duration, pulse period (and frequency), and extraction duration. The produced extracts were evaluated via comparison amongst them and against extracts obtained without the application of PEF. The Folin-Ciocalteu method, high-performance liquid chromatography, and differential scanning calorimetry were used to determine the extraction efficiency. The optimal PEF contribution on the total polyphenols extractability (38% increase with a 117% increase for specific metabolites) was presented for rectangular extraction chamber, 25% v/v ethanol:water solvent, pulse duration (tpulse) 2 μs, electric field strength (E) 0.85 kV cm−1, 100 μs period (Τ), and 15 min extraction duration (textraction), ascertaining a significant dependence of PEF assisting extraction performance to the parameters chosen.


2017 ◽  
Vol 48 (1) ◽  
pp. 119-145 ◽  
Author(s):  
Apostolos Baklavaridis ◽  
Ioannis Zuburtikudis ◽  
Costas Panayiotou

Chitosan nanofibers reinforced with tungsten disulfide inorganic nanotubes (INT-WS2) were fabricated in this study. The aim was to investigate the effect of the material parameters and the electrospinning process parameters on the obtained nanofibrous morphology of the mats. The INT-WS2 content, the polymer solution concentration, the electric field strength, and the solution's flow rate were the investigated factors within the framework of response surface methodology. Scanning electron microscopic and image analysis were used for the dimensional characterization of the nanofibrous morphology and the estimation of three selected responses. Two responses were related to the quality of the nanofibrous morphology: the number surface density of the beads ( Nbead) and the average bead-to-fiber diameter ( Dbead/ Dfiber). The third response was indicative of the fiber thickness ( Dfiber). The developed models as well as the coupling and the individual effects of the four investigated factors are given. The results indicate that the electrospun nanofibrous morphology is mostly affected by the polymer solution concentration, the electric field strength and the INT-WS2 loading. Furthermore, the response-surface results reveal possible experimental pathways that may be followed in order to obtain specified nanofibrous chitosan/INT-WS2 morphologies.


Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1552 ◽  
Author(s):  
Shunsuke Kato ◽  
Fitri Adila Amat Yusof ◽  
Toyohiro Harimoto ◽  
Kenji Takada ◽  
Tatsuo Kaneko ◽  
...  

Biopolyimides poly(ATA-CBDA), made from of 4,4′-diamino-α-truxillic acid dimethyl ester (ATA) and 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), is synthesized and measured its electric volume resistivity at various experimental conditions. The effects of film size, thickness, drying time, and the electric field strength on electric resistivity are investigated and compared with polyimide (Kapton). The electric resistivity for all polyimide and biopolyimide are distributed in the range of 1015–1016 Ωcm, which shows that biopolyimide has high electrical insulation as well as polyimide. The electric resistivity strongly depends on film thickness, which suggests that electric resistivity is a function of electric field strength. The critical electric field for polyimide and biopolyimide films are determined to be 5.8 × 107 V/m and 3.2 × 107 V/m, respectively. Humidity was found to strongly affect the electric resistivity; ~1016 Ωcm at 34% RH and ~1013 Ωcm at 60% RH for both polyimide and biopolyimide films.


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