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Relationship between moisture content and electrical impedance of carrot slices during drying

100%

Kertesz A., Hlavacova Z., Vozary E., Staronova L.

International Agrophysics

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2015

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tom 29

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nr 1

Electrical properties of food materials can give information about the inner structure and physiological state of biological tissues. Generally, the process of drying of fruits and vegetables is followed by weight loss. The aim of this study was to measure the impedance spectra of carrot slices during drying and to correlate impedance parameters to moisture content in different drying periods. Cylindrical slices were cut out from the carrot root along the axis. The slices were dried in a Venticell 111 air oven at 50°C. The weight of the slices was measured with a DenverSI-603 electronic analytical and precision balance. The weighing of the samples was performed every 30 min at the beginning of drying and every 60 min after the process. The moisture content of the samples was calculated on wet basis. The magnitude and phase angle of electrical impedance of the slices were mea-sured with HP 4284A and 4285A precision LCR meters in thefrequency range from 30 Hz to 1 MHz and from 75 kHz to 30 MHz,respectively, at voltage 1 V. The impedance measurement was per-formed after weighting. The change in the magnitude of impe-dance during drying showed a good correlation with the change in the moisture content.

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Role of phase angle measurement in electical impedance spetroscopy

100%

Cseresnyes I., Rajkai K., Vozary E.

International Agrophysics

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2013

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tom 27

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nr 4

Importance of phase angle measurement during the application of electrical impedance spectroscopy was studied by executing pot experiments with maize. Electrical impedance, phase angle (strength of capacitive character), and dissipation factor in the plant-soil system were scanned between 100 and 10 000 Hz current frequency. The frequency-dependent change in the phase angle could be described by optimum curves culminating within 920-3 650 Hz. Since the rate of energy dissipation is independent of root extent, the higher phase angle and lower energy dissipation were associated with the higher coefficient of determination achieved for the root electrical impedance – root system size (root dry mass and root surface area) regressions. The characteristic frequency selected on the basis of phase angle spectra provided a higher significance level at statistical comparison of plant groups subjected to stress conditions influencing root development. Due to the physicochemical changes observable in aging root tissue, the apex of phase angle spectra, thus the characteristic frequency, shifted continuously toward the higher frequencies over time. Consequently, the regularly repeated phase angle measurement is advisable in time-course studies for effective application of the electrical impedance method, and the systematic operation at the same frequency without determination of phase angle spectra should be avoided.

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Influence of substrate type and properties on root electrical capacitance

100%

Cseresnyes I., Vozary E., Kabos S., Rajkai K.

International Agrophysics

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2020

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tom 34

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nr 1

4

Does electrical capacitance represent roots in the soil?

100%

Cseresnyes I., Vozary E., Rajkai K.

Acta Physiologiae Plantarum

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2020

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tom 42

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nr 05

Ograniczanie wyników

3 International Agrophysics

1 Acta Physiologiae Plantarum

4 Vozary E.

3 Cseresnyes I.

3 Rajkai K.

1 Hlavacova Z.

1 Kabos S.

1 Kertesz A.

1 Staronova L.

2 2020

1 2015

1 2013

Relationship between moisture content and electrical impedance of carrot slices during drying

Role of phase angle measurement in electical impedance spetroscopy

Influence of substrate type and properties on root electrical capacitance

Does electrical capacitance represent roots in the soil?