Bio-electrical impedance analysis of “silk sweet” sweet potato tissues under low-temperature storage using a novel indicator, LTO

• Published in: Biosystems engineering 2021-06, Vol.206, p.1-5
• Main Authors: Watanabe, Takashi, Nakamura, Nobutaka, Sakamoto, Kohei, Nagata, Masayasu
• Format: Article
• Language: English
• Subjects: Cole–Cole plot; Electrical impedance; Low-temperature storage; LTO; Sweet potato
• ISSN: 1537-5110; 1537-5129
• DOI: 10.1016/j.biosystemseng.2021.03.009

In this study, the specific changes in the electrical impedance properties of sweet potato tissues under low-temperature storage are reported. The tissue status was monitored by using an electrical indicator, LTO (which refers to the distance from the origin of the coordinate at the top of the circular arc of the corresponding Cole–Cole plot), and its variation was investigated at storage temperatures of 0, 5, and 13 °C for 20 d. Our results show that the LTO values increased gradually during storage for up to10 d. Moreover, the change kinetics constant increased linearly with decrease in the storage temperature. Furthermore, by 20 d, the LTO values of samples stored at 0 °C had significantly decreased. We speculate that these changes are influenced by changes in the sugar concentration or by the occurrence of chilling injury. These findings indicate that the LTO has applicability as a tool to rapidly monitor changes in the status of sweet potato tissues during low-temperature storage. •Electrochemical property of sweet potato tissues during storage was discussed.•LTO values increased linearly with a decrease in storage temperature.•LTO values decreased significantly during storage at 0 °C for 20 d.•LTO had applicability for a tool to monitor the status of the tissues.