Ohmic heating of Japanese white radish <i>Rhaphanus sativus</i> L.

Imai, Tetsuya; Uemura, Kunihiko; Ishida, Noriko; Yoshizaki, Shigeru; Noguchi, Akinori

doi:10.1111/j.1365-2621.1995.tb01393.x

Cited by 99 publications

(64 citation statements)

References 17 publications

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“…This effect becomes more important with E increase from 40 to 100 V/cm. Imai et al [47] have found that OH behavior and impedance values of Japanese white radish depended from the frequency of electric field varied from 50 Hz to 10 kHz. At the constant voltage of 40 V/cm, the time necessary for heating the sample to the desired temperature was longer for higher frequencies of electric field.…”

Section: Principles Of Oh Treatmentmentioning

confidence: 99%

Enhanced Extraction from Solid Foods and Biosuspensions by Pulsed Electrical Energy

2010

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The purpose of this article is to review matters dealing with application of electrical pulsed energy (pulsed electric field, pulsed ohmic heating and high voltage electrical discharges) for enhancing the solid-liquid extraction in the food industry. The quality of products (e.g., purity, color, texture, flavor and nutritients) extracted from solid foods (sugar beets, apples, grapes, etc.) and quality of proteins and polysaccharides extracted from biosuspensions (aqueous suspensions of yeast, e.coli cells, etc.) may be degraded by conventional mechanical, thermal or chemical pretreatment. The traditional treatments are restricted by temperature elevation and require high energy consumptions; moreover, chemical methods are based on application of unsafe organic solvents, enzymes and detergents. Physical treatments assisted by electrical pulsed energy are shown to be very remarkable for enhancing the solvent and pressure extraction and dehydration processes and of high interest for the food industry. This article provides an overview of the pulsed energy extraction technologies showing promise for commercial food processing.

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Section: Principles Of Oh Treatmentmentioning

confidence: 99%

Enhanced Extraction from Solid Foods and Biosuspensions by Pulsed Electrical Energy

2010

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“…Ohmic heating (also referred to as Joule heating, electroheating and electro conductive heating) is defined as a process wherein an electrical current (usually alternating) is passed through materials (Goullieux & Pain, 2005;Vicente, Castro, & Teixeira, 2006) and can be used to generate heat within the product (Imai, Uemura, Ishida, Yoshizaki, & Noguchi, 1995). The heating occurs in the form of internal energy transformation (from electric to thermal which is due to Joule effect) within the material (Sastry & Barach, 2000).…”

Section: Introductionmentioning

confidence: 99%

Comparison of ohmic-assisted hydrodistillation with traditional hydrodistillation for the extraction of essential oils from Thymus vulgaris L.

Gavahian

Farahnaky

Javidnia

et al. 2012

Innovative Food Science & Emerging Technologies

155

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“…To prevent undesirable electrochemical reactions between electrodes and solid or viscous liquid products, increasing the frequency or changing the waveform of alternating current has been suggested (10). There have been some efforts to clarify the impact of frequency and waveform of alternating current on ohmic heating rates of solid or semisolid foods (11)(12)(13)(14)(15). However, there has been no comprehensive research on the effects of frequency on electrode corrosion, electrical conductivity and microbial inactivation in solid-liquid food mixtures.…”

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confidence: 99%

Effect of Frequency and Waveform on Inactivation of Escherichia coli O157:H7 and Salmonella enterica Serovar Typhimurium in Salsa by Ohmic Heating

Lee

Ryu

Kang

2013

Appl Environ Microbiol

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The effect of frequency of alternating current during ohmic heating on electrode corrosion, heating rate, inactivation of foodborne pathogens, and quality of salsa was investigated. The impact of waveform on heating rate was also investigated. Salsa was treated with various frequencies (60 Hz to 20 kHz) and waveforms (sine, square, and sawtooth) at a constant electric field strength of 12.5 V/cm. Electrode corrosion did not occur when the frequency exceeded 1 kHz. The heating rate of the sample was dependent on frequency up to 500 Hz, but there was no significant difference (P > 0.05) in the heating rate when the frequency was increased above 1 kHz. The electrical conductivity of the sample increased with a rise in the frequency. At a frequency of 60 Hz, the square wave produced a lower heating rate than that of sine and sawtooth waves. The heating rate between waveforms was not significantly (P > 0.05) different when the frequency was >500 Hz. As the frequency increased, the treatment time required to reduce Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium to below the detection limit (1 log CFU/g) decreased without affecting product quality. These results suggest that ohmic heating can be effectively used to pasteurize salsa and that the effect of inactivation is dependent on frequency and electrical conductivity rather than waveform.O hmic heating is a highly attractive technology by which internal heating as a result of electrical resistance is rapidly induced when passing an alternating current through a food product (1). This technology can provide a uniform temperature distribution with the absence of a cold spot in the product, because both liquid and solid phases can be heated simultaneously (2). Therefore, it is ideally suited to thermal processing of solid-liquid food mixtures with little structural, nutritional, or organoleptic changes and as well as those that are microbiologically safe and can be successfully treated using a short processing times (3). Commercial ohmic sterilization has been developed for particulate and multiphase foods based on applied research of ohmic heating (4-6), and it has been widely used in blanching, evaporation, dehydration, fermentation, extraction, and pasteurization (7).Although viewed as a promising food processing technology, ohmic heating has some technical limitations. Most ohmic heating systems have been used at an alternating current frequency of 50 to 60 Hz. One constraint of low alternating current frequency in ohmic heating is that electrolytic reactions can take place at the electrode surface, leading to product burning and corrosion of electrodes (8, 9). To prevent undesirable electrochemical reactions between electrodes and solid or viscous liquid products, increasing the frequency or changing the waveform of alternating current has been suggested (10). There have been some efforts to clarify the impact of frequency and waveform of alternating current on ohmic heating rates of solid or semisolid foods (11-15). However, there has been n...

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Ohmic heating of Japanese white radish Rhaphanus sativus L.

Cited by 99 publications

References 17 publications

Enhanced Extraction from Solid Foods and Biosuspensions by Pulsed Electrical Energy

Enhanced Extraction from Solid Foods and Biosuspensions by Pulsed Electrical Energy

Comparison of ohmic-assisted hydrodistillation with traditional hydrodistillation for the extraction of essential oils from Thymus vulgaris L.

Effect of Frequency and Waveform on Inactivation of Escherichia coli O157:H7 and Salmonella enterica Serovar Typhimurium in Salsa by Ohmic Heating

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