Influence of Hydrocolloid Concentration, Salinity and Citric Acid Addition on Heat Transfer in the Ohmic Heating Process

In this article, the effects of Ohmic heating process conditions on electrical conductivity and heat transfer were investigated. In order to study the Ohmic heating process, various hydrocolloid solutions containing starch in water with concentrations of 4–8% in the static cells were used. Temperature increments increased electrical conductivity of the solution, linearly. The concentration of dispersed solid particles in the solution caused a progressive trend in time-temperature curve for hydrocolloid solutions (with concentrations of 4, 5.5 and 8%) without electrolytes. The electrical conductivity was raised by increasing temperatures. In order to consider the salinity impact on electrical conductivity and the heating rate, sodium chloride (with concentrations of 1–0.25%) was added to the solution. It was observed that the salt addition to the system had a major effect on electrical conductivity and time-temperature curves. The pH level was modified with Citric acid addition, and the influence of pH level on the time-temperature curves and heating rates were investigated. The Citric acid addition had no on significant effect on the time-temperature curves.

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Correlation of Electrical Conductivity and Thermal Properties of Native Starch during Ohmic Heating

International Journal of Food Engineering ◽

10.2202/1556-3758.2228 ◽

2011 ◽

Vol 7 (5) ◽

Cited By ~ 3

Author(s):

Lam-Lam Wong ◽

Yong-Wei Xu ◽

Zhan-Hui Lu ◽

Li-Te Li

Keyword(s):

Electrical Conductivity ◽

Room Temperature ◽

Ohmic Heating ◽

Heating Process ◽

Rapid Evaluation ◽

Scanning Calorimetry ◽

Heating Method ◽

Starch Gelatinization ◽

On Line ◽

Water Ratio

Electrical conductivity of starch suspension during ohmic heating was applied to analyze the starch gelatinization process. Native starches from wheat, corn, rice, potato, sweet potato, and pea were prepared on a starch to water ratio of 1:3 (w/w) with adding 0.05 M potassium chloride. A laboratory scale ohmic heating setup was designed to heat the starch suspension from room temperature to 90°C at a controlled heating rate of 10°C/min operating at 50 Hz and 110 V. The results show that starch gelatinization temperatures could be precisely calculated from electrical conductivity of starch suspension during ohmic heating process. The starch gelatinization temperatures based on ohmic heating were comparable to those measured by differential scanning calorimetry (DSC). Highly significant correlation of onset temperature (R=0.9972) and peak temperature (R=0.9950) were observed. The ohmic heating method could provide an alternative way to DSC with a promising potential for on-line and rapid evaluation of starch gelatinization temperatures.

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The effect of heating factors on the properties of heat-induced surimi gel under ohmic heating

Can Tho University Journal of Science ◽

10.22144/ctu.jen.2021.028 ◽

2021 ◽

Vol 13 (2) ◽

pp. 32-42

Author(s):

Van Nguyen

Keyword(s):

Electrical Conductivity ◽

Heating Rate ◽

Salt Concentration ◽

Ohmic Heating ◽

Heating Time ◽

Holding Time ◽

Water Bath ◽

Heating Rates ◽

Fast Heating ◽

Water Bath Heating

Ohmic heating (OH) is a method that heat is generated within the food due to its electrical resistance, resulting in a relatively linear heating rate and uniform temperature distribution. Because surimi-based paste contains water and salts, the conductivity is sufficiently good for the ohmic effect. Gelation induced by OH greatly depends on heating conditions such as heating speed, heating time, or electrical conductivity. However, the detailed information obtained is quite limited. Therefore, in order to clarify how ohmic heating affects the physical properties of surimi gel under OH, gels from croaker surimi (SA grade) were obtained using different heating conditions (heating speed, heating time, or salt concentration - electrical conductivity). Furthermore, the gels heated by ohmic heating were compared with the gel obtained by conventional water-bath heating. The results showed that, at the same heating rates, higher salt concentration generated better surimi gels for croaker surimi. Gels cooked ohmically at a slow heating rate performed significantly better than those cooked at a fast heating rate or heated conventionally in a water bath. There was little discernible difference in protein pattern between gels heated by OH and conventional water bath heating at fast heating rates with two different salt concentrations. The results also indicated that holding time at target temperature showed no effect on the gel. These results suggested that the properties of heat-induced surimi gels by OH are affected by not only heating speed but also holding time at maximum temperature and salt content.

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Operability of the ohmic heating process: Electrical conductivity effects

Journal of Food Engineering ◽

10.1016/0260-8774(92)90038-8 ◽

1992 ◽

Vol 15 (1) ◽

pp. 21-48 ◽

Cited By ~ 65

Author(s):

A.A.P. de Alwis ◽

P.J. Fryer

Keyword(s):

Electrical Conductivity ◽

Ohmic Heating ◽

Heating Process

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The effect of transglutaminase on gluten-free soy bread baked using ohmic heating

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/924/1/012041 ◽

2021 ◽

Vol 924 (1) ◽

pp. 012041

Author(s):

J P Hutasoit ◽

Aji Sutrisno ◽

E S Murtini ◽

A Lastriyanto

Keyword(s):

Electrical Conductivity ◽

Moisture Content ◽

Process Parameters ◽

Profile Analysis ◽

Ohmic Heating ◽

Test Method ◽

Heating Process ◽

Gluten Free ◽

Rate Of Increase ◽

Conductivity Current

Abstract This study aims to compare the quality of gluten-free bread made from black soybean flour using and without transglutaminase (TGase) baked using ohmic heating technology. Parameters of bread quality observed were specific volume, moisture content, texture profile analysis, porosity, and color. To understand the changes in the ohmic heating process parameters during baking, an evaluation of temperature, electrical conductivity, current intensity, electrical power parameters was carried out. To analyze the data, the independent sample t-test method was used. The results obtained indicate that the addition of TGase affects the characteristics of the bread and process parameters during baking with ohmic heating. Bread with the addition of TGase has an increase in volume, texture, moisture content, and porosity of the bread that is better than without the addition of TGase. Based on the parameter process, the rate of increase in temperature, electrical conductivity, current, and power intensity is highly affected by the addition TGase. Electrical conductivity increases linearly with increasing temperature.

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Conductometric Study of the Effect of Citric Acid on Phase Evolution of Calcium Phosphate in Solutions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.306-307.11 ◽

2011 ◽

Vol 306-307 ◽

pp. 11-15

Author(s):

Cheng Feng Li ◽

Xiao Lu Ge ◽

Jia Hai Bai ◽

Guo Chang Li

Keyword(s):

Electrical Conductivity ◽

Grain Size ◽

Citric Acid ◽

Calcium Phosphate ◽

Amorphous Calcium Phosphate ◽

Phase Evolution ◽

Acid Addition ◽

Region I ◽

Conductometric Study ◽

Region Ii

The influence of citric acid on phase evolution of calcium phosphate is studied by the electrical conductivity of reaction solutions. The conductance curves are divided into three distinct regions and assigned to the formation of amorphous calcium phosphate (ACP), hydroxyapatite (HA) and the solubility of HA, respectively. When more citric acid is added, the width of region I decreases because more Ca2+ ions would prefer to foster the nucleation of HA from ACP. Decreasing rate of conductivity in region II becomes smaller with more addition of citric acid because the supersaturation of HA decreases in solutions. And thus, HA powders with larger grain size are synthesized with more citric acid addition.

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Effective Parameters Consideration in Ohmic Heating Process in Two Phase Static System of Bio-Particle-Liquid

International Journal of Food Engineering ◽

10.2202/1556-3758.2165 ◽

2011 ◽

Vol 7 (1) ◽

Author(s):

Mostafa Keshavarz Moraveji ◽

Reza Davarnejad ◽

Emad Ghaderi

Keyword(s):

Electrical Conductivity ◽

Ohmic Heating ◽

Three Dimensional ◽

Liquid System ◽

Heat Diffusion ◽

Heating Process ◽

Static System ◽

Effective Parameters ◽

Distribution Profile ◽

Two Phase

In this research, the effective parameters on Ohmic heating in aseptic and heating applications were studied. For this purpose, two- and three-dimensional Ohmic heating models in a two phase bio-solid-liquid system were developed. In these models, effects of particles distribution, particles size, effect of electrical conductivity on heating, overall heating of mixture and effect of salt concentration on heating rate were investigated. Temperature distribution profile, effects of intensity and distribution of electrical field on total temperature, and type of salt on phase electrical conductivity was also investigated. The modeling equation was solved with Finite Elements Method. The results showed that in Ohmic heating, heat diffusion in entire products was faster than the conventional methods, and it was accomplished with almost an equal rate in both phases.

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Simulation of the Transport Phenomena during Food Drying with Ohmic Heating in a Static System

International Journal of Food Engineering ◽

10.2202/1556-3758.1668 ◽

2010 ◽

Vol 6 (5) ◽

Cited By ~ 1

Author(s):

Mostafa Keshavarz Moraveji ◽

Emad Ghaderi ◽

Reza Davarnejad

Keyword(s):

Heat Transfer ◽

Ohmic Heating ◽

Heating Process ◽

Static System ◽

The Finite Element Method ◽

Electrical Field ◽

Drying Time ◽

Temperature Changes ◽

Electrical Field Intensity ◽

Computational Fluid Dynamics Cfd

In this article, the computational fluid dynamics (CFD) technique was used to simulate mass and heat transfer during the food drying via ohmic heating process. The effects of electrical field intensity, electrical conductivity, solid heating, liquid-solid conductivity and some parameters such as drying rate, moisture content and temperature changes on drying process of potato were investigated. The partial differential equations for the unsteady-state system were solved by the finite element method. In this modeling, simultaneous solution of the equations of heat transfer, moisture and electrical field was achieved. The results showed that ohmic heating process reduced drying time and accelerate the diffusion in the entire product in comparison with the other conventional methods. Therefore, heat and mass transfer were simultaneously and approximately conducted with the same rate in both phases of solid and liquid.

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