Open AccessAssessing the supercooling of fresh-cut onions at −5°C using electrical impedance analysis
Author(s) -
Shoji Kido,
Ami Yoneyama,
Takahiro Orikasa,
Matsuo Uemura
Publication year - 2020
Publication title -
food quality and safety
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.955
H-Index - 14
eISSN - 2399-1402
pISSN - 2399-1399
DOI - 10.1093/fqsafe/fyz044
Subject(s) - supercooling , freezing point , chemistry , analytical chemistry (journal) , materials science , thermodynamics , chromatography , physics
We supercooled fresh-cut onion at −5°C for 12 h. After supercooling, the electric impedance properties of the samples were evaluated by electrical impedance spectroscopy over the frequency range of 42 Hz − 5 MHz. The time-temperature profiles of samples indicated that the freezing point and supercooling point were −2.3°C ± 0.7°C and −6.9°C ± 1.0°C, respectively. The results indicated that 34 of the 36 supercooled samples exhibited a definite circular arc in the Cole-Cole plot, which suggested that the cell membrane remained intact during supercooling. In the other two samples which did not exhibit a definite circular arc, the cell membrane had sustained serious damage during supercooling. Furthermore, there was large difference in drip loss percentage between supercooled samples exhibited a definite circular arc in the Cole-Cole plot and samples not exhibiting a definite circular arc. Our results suggest that fresh-cut onions can be supercooled at −5°C.