Effect of DC Magnetic Field on Freezing Process of Onion Cells

In order to explore the effect of DC electromagnetic field of different field strengths on the shape and size of cells and ice crystals during the freezing phase transformation process of plant tissue cells, the third layers of onion cut into squares of 0.5 cm×0.5 cm were studied. Put the onion slic...

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Bibliographic Details
Main Authors: Song Jianfei, Liu Bin, Guan Wenqiang, Zhang Dequan
Format: Article
Language:zho
Published: Journal of Refrigeration Magazines Agency Co., Ltd. 2016-01-01
Series:Zhileng xuebao
Subjects:
Online Access:http://www.zhilengxuebao.com/thesisDetails#10.3969/j.issn.0253-4339.2016.02.107
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Summary:In order to explore the effect of DC electromagnetic field of different field strengths on the shape and size of cells and ice crystals during the freezing phase transformation process of plant tissue cells, the third layers of onion cut into squares of 0.5 cm×0.5 cm were studied. Put the onion slices on the cold platform and the cooling rate of the experiment was: 10 ℃/min before 0 ℃, 3 ℃/min after 0 ℃, and the final temperature was﹣25 ℃, the DC magnetic field strengths were 0Gs (the control group) , 4.6 Gs, 18 Gs, 36 Gs, 72 Gs respectively. In the experiment, the changes of morphology of the cells and ice crystals under different strengths were observed, and the index of "two-dimensional cell retention rate ζ" was put forward to evaluate fruit and vegetable cells’ freezing effect. AutoCAD software was used to calculate the micrograph and the value of ζ. The results show that the magnetic field assisted freezing of the onion cells can make the formation of ice crystals tend to atomization and sand grains, which can inhibit the growth of ice crystals, thus reduce the size of the ice crystals, and it will also be more conducive to maintain the original cell morphology and decrease the cell damage rate. With the increasing of the magnetic field strength, phase transformation time of the onion cells decreases, supercooling degree decreases gradually, but it is always higher than that of non magnetic field.
ISSN:0253-4339