scholarly journals Coaxial treatment chamber for liquid food treatment through pulsed electric field

Author(s):  
Rai Naveed Arshad ◽  
Zulkurnain Abdul Malek ◽  
Mohd. Hafizi Ahmad ◽  
Zolkafle Buntat ◽  
C L G Pavan Kumara ◽  
...  

<div style="text-align: justify;"><span style="font-family: 'Times New Roman', serif; font-size: 9pt;">Over the last couple of decades, pulsed electric field (PEF) attained substantial consideration in the food industry with an effort to generate replacements to conventional thermal treatment. It is recognised to produce secure and chill-stable liquid food samples with fresh and nutritional qualities. The uniform electric field in the treatment zone has been recognised as the main handling parameter. The design of the treatment chamber shows an essential impact on the effectiveness of the procedure by controlling homogenous treatment. This study revealed the homogeneity of the electric field strength of the different existing treatment chambers through COMSOL Multiphysics. It adopted a study to design a co-axial treatment chamber for continuous treatment of liquid samples. This research helps to take some fundamental designing steps for a new treatment chamber with a uniform distribution of the electric field.</span></div>

2014 ◽  
Vol 554 ◽  
pp. 588-592 ◽  
Author(s):  
Ali Mohammad Dastgheib ◽  
Zolkafle Buntat ◽  
Muhammad Abu Bakar Sidik

The application of high voltage electric field for preservation of fruit juices has a promising scope in the food industry. The pulsed electric field (PEF) is an innovative non- thermal technique and free from bio-toxic effects. The technique has a viable solution of the problem yet faced in the food industry to prolong life and preserve and maintain quality with natural properties of the liquid food and beverages. In this study, we have treated the pineapples juice samples by different strengths of pulsed electric field such as 10, 20 and 30kV/cm for 5 minutes in each test. This study used new design of helix treatment chamber with three different lengths of 20, 30and 50cm. In these experiments, all samples were kept in same and normal condition with a temperature around 25-26 andthe humidity was between 55 and 65%. Then the observation based on chemical tests such as pH, conductivity, salinity and total dissolved solids (TDS) was recorded for all samples before and after the test. Based on results obtained by chemical parameters suggest that the injection on pulsed electric field of 30 kV/cm by the 50 cm treatment chamber has the best effect on pineapple juices characteristic as compared to the other value. The result of this experiment is encouraging and supportive of the better way for pasteurization the pineapple juices and increasing longevity of pineapple juices.


Electroporation is an effective phenomenon of inactivating viable pathogens present in the liquid food for pulsed electric field (PEF) applications. It is a technique which depends on applied electric field strength for causing pores on cell plasma membrane. The various parameters which affect the electroporation efficacy are, the electric field intensity, pulse width, number of pulses, pulse interval and the electrode. The electrode provides a contact between the high voltage pulse generator and the liquid food, and it plays an important role in getting the required inactivation outcome. The electric field distribution varies based on electrode designs. Parallel plate electrodes are generally used due to the uniform electric field it delivers in the inactivation area, where high possibility of microbial inactivation will occur. This paper analyses the effectiveness of round edged parallel plate electrodes immersed in water which provides uniform electric field distribution in the inactivation area. Analyses have been performed on electric field distribution through four kinds of materials such as glass, alumina, quartz and plexiglass, which contains these electrodes in the center filled with sterile water. The electrodes are circular, and edge smoothened and hence the field distribution is also analyzed on electrode edges. The distance between the electrodes including the surface material is kept at 5 mm. The diameter of the electrodes are 40 mm and the electric field simulations are implemented in ANSYS MAXWELL v 15.0. Based on results it is reported that alumina required less peak voltage for generating 20 kV/cm field strength (nominal field required for bacterial inactivation) when compared with other materials. Also alumina exhibited less reduction of field travelling through it, and resulted in 82% of field application in the inactivation area which is comparatively higher than other materials. The results indicate that alumina is highly recommended for future noninvasive pulsed electric field applications.


Author(s):  
V. M. (Bala) Balasubramaniam

Consumers demand healthier fresh tasting foods without chemical preservatives. To address the need, food industry is exploring alternative preservation methods such as high pressure processing (HPP) and pulsed electric field processing. During HPP, the food material is subjected to elevated pressures (up to 900 MPa) with or without the addition of heat to achieve microbial inactivation with minimal damage to the food. One of the unique advantages of the technology is the ability to increase the temperature of the food samples instantaneously; this is attributed to the heat of compression, resulting from the rapid pressurization of the sample. Pulsed electric field (PEF) processing uses short bursts of electricity for microbial inactivation and causes minimal or no detrimental effect on food quality attributes. The process involves treating foods placed between electrodes by high voltage pulses in the order of 20–80 kV (usually for a couple of microseconds). PEF processing offers high quality fresh-like liquid foods with excellent flavor, nutritional value, and shelf life. Pressure in combination with other antimicrobial agents, including CO2, has been investigated for juice processing. Both HPP and PEF are quite effective in inactivating harmful pathogens and vegetative bacteria at ambient temperatures. Both HPP and PEF do not present any unique issues for food processors concerning regulatory matters or labeling. The requirements are similar to traditional thermal pasteurization such as development of a Hazard Analysis Critical Control Point (HACCP) plan for juices and beverages. Examples of high pressure, pasteurized, value added products commercially available in the United States include smoothies, fruit juices, guacamole, ready meal components, oysters, ham, poultry products, and salsa. PEF technology is not yet widely utilized for commercial processing of food products in the United States. The presentation will provide a brief overview of HPP and PEF technology fundamentals, equipment choices for food processors, process economics, and commercialization status in the food industry, with emphasis on juice processing. Paper published with permission.


2020 ◽  
Vol 8 (11) ◽  
pp. 1684
Author(s):  
Efrat Emanuel ◽  
Irina Dubrovin ◽  
Ester Hanya ◽  
Gad A. Pinhasi ◽  
Roman Pogreb ◽  
...  

One of the promising technologies that can inactivate microorganisms without heat is pulsed electric field (PEF) treatment. The aim of this study was to examine the influence of PEF treatment (2.9 kV cm−1, 100 Hz, 5000 pulses in trains mode of 500 pulses with a pulse duration of 10 µs) on Saccharomyces cerevisiae eradication and resealing in different conditions, such as current density (which is influenced by the medium conductivity), the sort of medium (phosphate buffered saline (PBS) vs. yeast malt broth (YMB) and a combined treatment of PEF with the addition of preservatives. When the S. cerevisiae were suspended in PBS, increasing the current density from 0.02 to 3.3 A cm−2 (corresponding to a total specific energy of 22.04 to 614.59 kJ kg−1) led to an increase of S. cerevisiae eradication. At 3.3 A cm−2, a total S. cerevisiae eradication was observed. However, when the S. cerevisiae in PBS was treated with the highest current density of 3.3 A cm−2, followed by dilution in a rich YMB medium, a phenomenon of cell membrane resealing was observed by flow cytometry (FCM) and CFU analysis. The viability of S. cerevisiae was also examined when the culture was exposed to repeating PEF treatments (up to four cycles) with and without the addition of preservatives. This experiment was performed when the S. cerevisiae were suspended in YMB containing tartaric acid (pH 3.4) and ethanol to a final concentration of 10% (v/v), which mimics wine. It was shown that one PEF treatment cycle led to a reduction of 1.35 log10, compared to 2.24 log10 when four cycles were applied. However, no synergic effect was observed when the preservatives, free SO2, and sorbic acid were added. This study shows the important and necessary knowledge about yeast eradication and membrane recovery processes after PEF treatment, in particular for application in the liquid food industry.


2002 ◽  
Vol 65 (9) ◽  
pp. 1441-1446 ◽  
Author(s):  
M. A. KHADRE ◽  
A. E. YOUSEF

The rotavirus causes a food-transmitted gastroenteritis that affects mainly children. Currently, the food industry is interested in alternative food-processing technologies, but research on the control of food-transmitted viruses by these technologies is limited. In this study, the human rotavirus was cultured on MA104 cells, and suspensions of the virus were prepared and treated with ozone, high pressure, and pulsed electric field (PEF). Virus viability was quantified as 50% tissue culture infectious doses (TCID50) per milliliter. Ozone at 25 μg/ml decreased rotavirus infectivity by 8 to 9 log10 TCID50/ml. High pressure was extremely effective against the rotavirus; treatment with 300 MPa for 2 min at 25°C inactivated ~8 log10 TCID50/ml. A small fraction of the virus population, however, remained resistant to pressure treatments of up to 800 MPa for 10 min. Viruses surviving these extreme pressures showed a cytopathic effect different from that of the untreated viruses. The rotavirus was found to be resistant to PEF treatment at 20 to 29 kV/cm, for which no appreciable reductions in virus titer were observed.


1998 ◽  
Vol 34 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Bai-Lin Qin ◽  
G.V. Barbosa-Canovas ◽  
B.G. Swanson ◽  
P.D. Pedrow ◽  
R.G. Olsen

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