Electrical and Rheological Analysis of Freezing Injury of Agricultural Products

Ohnishi, Shigehiko; Fujii, Tomoyuki; Miyawaki, Osato

doi:10.1081/jfp-120005788

Cited by 19 publications

(17 citation statements)

References 19 publications

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“…The impedance after freezing-thawing decreased with an increase in freezing period, showing an increase in the plasma membrane injury by ice crystal formation (Ohnishi et al, 2002). The impedance decreased rapidly after ca.…”

Section: Resultsmentioning

confidence: 92%

“…Measurement of impedance Integrity of the plasma membrane was analyzed by an electrical measurement (Ishikawa et al, 1997;Ohnishi et al, 2002). The electrical properties of agricultural products were measured by a LCR meter (3523-50; Hio-ki, Japan) with a test fixture (16047C; Hewlett-Packard Japan).…”

Section: Methodsmentioning

confidence: 99%

“…Measurement of rheological properties Rheological properties of agricultural products were determined by the vibrating reed method (Dejmek & Miyawaki, 2002;Ohnishi et al, 2002;Drake, 1962;Miyawaki & Yano, 1980). The experimental apparatus for measurement by this method is shown in Fig.…”

Section: Methodsmentioning

confidence: 99%

“…This reflects the difference in the crude fiber contents between carrot and potato (Kagawa, 1998) as shown in Table 1. In our previous paper (Ohnishi et al, 2002), it was reported that crude fiber contents reflect the physical strength of cell wall and intercellular structure, and this strength determines the viscoelasticity of cell tissues after freezing-thawing. Thus, potato, in which the concentration of crude fiber is lower than carrot, was thought to be more influenced by the loss of turgor pressure by the chloroform treatment.…”

Section: Figmentioning

confidence: 99%

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Freezing Injury and Rheological Properties of Agricultural Products

Ohnishi¹,

Fujii

Miyawaki

2003

FSTR

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Time changes in electrical and rheological properties of carrot and potato cell tissues after freezing-thawing or chloroform-vapor treatment were compared to clarify the mechanism of cell tissue softening by freezing injury. Integrity of cell plasma membrane was analyzed by the electrical measurement and rheological properties of cell tissues were determined by the vibrating reed method. Changes in the rheological properties by the chloroform-vapor treatment were assumed to be caused only by the loss of turgor pressure, while those by the freezing-thawing were caused by loss of this pressure and injuries to the cell wall and intercellular structure. The change in the rheological properties of carrot and potato tissue by the freezing-thawing and chloroform-vapor treatment were compared to determine the contribution ratio of the loss of turgor pressure and injuries to the cell wall and intercellular structure, which are known as major causes of softening by freezing injury. Findings showed that the loss of turgor pressure due to plasma membrane injury is the main reason for cell tissue softening by freezing injury while injuries to the cell wall and intercellular structure have an auxiliary role.

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Section: Resultsmentioning

confidence: 92%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Figmentioning

confidence: 99%

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Freezing Injury and Rheological Properties of Agricultural Products

Ohnishi¹,

Fujii

Miyawaki

2003

FSTR

Self Cite

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“…Numerous investigations have been carried out by electrical measurement to assess conditions of agricultural products such as variety (White et al, 1971), quality and freshness (Sugiyama et al , 1987;Kato, 1988), ripeness and maturity (Bauchot et al, 2000;Desai et al, 1977;Weaver et al, 1966), infection of virus (Greenham et al , 1952) and injury of tissues (Greenham, 1966;Zhang et al , 1993;Jiang et al , 2001). Effectiveness of impedance measurement has been shown in freezing and cold injury of agricultural products (Zhang et al , 1992(Zhang et al , , 1992Dejmek et al , 2002;Ohnishi et al , 2002). Nonetheless, impedance and rheological change of food materials involving agricultural products, meat and gel foods such as tofu, konnyaku and kamaboko by freezing have not been thoroughly investigated.…”

Section: Introductionmentioning

confidence: 99%

Effect of Freezing on Electrical and Rheological Properties of Food Materials

Ohnishi

Shimiya

Kumagai

et al. 2004

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Changes in electrical and rheological properties in freezing-thawing were measured and compared for various food materials, which could be classified into three groups. In the first group, plant tissue (vegetables and fruits) showed large and frequency-dependent impedance and clear characteristic Cole-Cole arc in their fresh state. These electrical properties drastically changed after freezing-thawing: impedance greatly decreased and the Cole-Cole arc disappeared, suggesting the serious change in the cell structure. Correspondingly, the dynamic elasticity and viscosity substantially decreased. In the second group, animal and fish meats showed the lower impedance and unclear Cole-Cole arc as compared with plant tissue, but these properties scarcely changed after freezing-thawing. Rheological properties were also unchanged reflecting the large freezing-tolerance for food materials in this group. In the third group, konnyaku (alimentary yam paste) and tofu (soyprotein curd) showed increase both in impedance and viscoelasticity after freezing-thawing reflecting the freezedenaturation of the major components.

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Cellular Changes in “Hass” Avocado Mesocarp During Cold‐Pressed Oil Extraction

Yang

Hallett

Rebstock

et al. 2018

J Americ Oil Chem Soc

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The aim of this study was to understand factors affecting oil release from "Hass" avocado cells during the cold-pressed oil extraction process. Early-season "Hass" avocado fruit and pulp were sampled from a commercial extraction process. Light microscopy and electrical impedance spectroscopy were used to examine avocado flesh structure at defined steps during the extraction process (destoning, grinding, malaxing, and decanting). Most parenchyma cells were ruptured during destoning, grinding, and mixing before malaxing. In contrast, the other oil bearing cells, idioblast cells, appeared to remain unruptured and intact during the extraction process. The greatest reduction in electrical resistance was observed after the destoning step. There were also significant differences between the resistances of flesh after destoning, grinding, and prior to malaxing samples. Malaxing for two hours assisted the process of oil aggregation, which led to a greater oil yield. These findings will help to develop methods to enhance oil extraction from early-season "Hass" avocado fruit.

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Electrical and Rheological Analysis of Freezing Injury of Agricultural Products

Cited by 19 publications

References 19 publications

Freezing Injury and Rheological Properties of Agricultural Products

Freezing Injury and Rheological Properties of Agricultural Products

Effect of Freezing on Electrical and Rheological Properties of Food Materials

Cellular Changes in “Hass” Avocado Mesocarp During Cold‐Pressed Oil Extraction

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